diff.con commit merge: remove drop_save() in favor of remove_merge_branch_state() (b643355)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26#include "help.h"
  27
  28#ifdef NO_FAST_WORKING_DIRECTORY
  29#define FAST_WORKING_DIRECTORY 0
  30#else
  31#define FAST_WORKING_DIRECTORY 1
  32#endif
  33
  34static int diff_detect_rename_default;
  35static int diff_indent_heuristic = 1;
  36static int diff_rename_limit_default = 400;
  37static int diff_suppress_blank_empty;
  38static int diff_use_color_default = -1;
  39static int diff_color_moved_default;
  40static int diff_color_moved_ws_default;
  41static int diff_context_default = 3;
  42static int diff_interhunk_context_default;
  43static const char *diff_word_regex_cfg;
  44static const char *external_diff_cmd_cfg;
  45static const char *diff_order_file_cfg;
  46int diff_auto_refresh_index = 1;
  47static int diff_mnemonic_prefix;
  48static int diff_no_prefix;
  49static int diff_stat_graph_width;
  50static int diff_dirstat_permille_default = 30;
  51static struct diff_options default_diff_options;
  52static long diff_algorithm;
  53static unsigned ws_error_highlight_default = WSEH_NEW;
  54
  55static char diff_colors[][COLOR_MAXLEN] = {
  56        GIT_COLOR_RESET,
  57        GIT_COLOR_NORMAL,       /* CONTEXT */
  58        GIT_COLOR_BOLD,         /* METAINFO */
  59        GIT_COLOR_CYAN,         /* FRAGINFO */
  60        GIT_COLOR_RED,          /* OLD */
  61        GIT_COLOR_GREEN,        /* NEW */
  62        GIT_COLOR_YELLOW,       /* COMMIT */
  63        GIT_COLOR_BG_RED,       /* WHITESPACE */
  64        GIT_COLOR_NORMAL,       /* FUNCINFO */
  65        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  66        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  67        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  68        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  69        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  70        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  71        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  72        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  73        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  74        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  75        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  76        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  77        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  78        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  79};
  80
  81static const char *color_diff_slots[] = {
  82        [DIFF_CONTEXT]                = "context",
  83        [DIFF_METAINFO]               = "meta",
  84        [DIFF_FRAGINFO]               = "frag",
  85        [DIFF_FILE_OLD]               = "old",
  86        [DIFF_FILE_NEW]               = "new",
  87        [DIFF_COMMIT]                 = "commit",
  88        [DIFF_WHITESPACE]             = "whitespace",
  89        [DIFF_FUNCINFO]               = "func",
  90        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  91        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  92        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  93        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  94        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  95        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  96        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  97        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  98        [DIFF_CONTEXT_DIM]            = "contextDimmed",
  99        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 100        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 101        [DIFF_CONTEXT_BOLD]           = "contextBold",
 102        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 103        [DIFF_FILE_NEW_BOLD]          = "newBold",
 104};
 105
 106static NORETURN void die_want_option(const char *option_name)
 107{
 108        die(_("option '%s' requires a value"), option_name);
 109}
 110
 111define_list_config_array_extra(color_diff_slots, {"plain"});
 112
 113static int parse_diff_color_slot(const char *var)
 114{
 115        if (!strcasecmp(var, "plain"))
 116                return DIFF_CONTEXT;
 117        return LOOKUP_CONFIG(color_diff_slots, var);
 118}
 119
 120static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 121                                struct strbuf *errmsg)
 122{
 123        char *params_copy = xstrdup(params_string);
 124        struct string_list params = STRING_LIST_INIT_NODUP;
 125        int ret = 0;
 126        int i;
 127
 128        if (*params_copy)
 129                string_list_split_in_place(&params, params_copy, ',', -1);
 130        for (i = 0; i < params.nr; i++) {
 131                const char *p = params.items[i].string;
 132                if (!strcmp(p, "changes")) {
 133                        options->flags.dirstat_by_line = 0;
 134                        options->flags.dirstat_by_file = 0;
 135                } else if (!strcmp(p, "lines")) {
 136                        options->flags.dirstat_by_line = 1;
 137                        options->flags.dirstat_by_file = 0;
 138                } else if (!strcmp(p, "files")) {
 139                        options->flags.dirstat_by_line = 0;
 140                        options->flags.dirstat_by_file = 1;
 141                } else if (!strcmp(p, "noncumulative")) {
 142                        options->flags.dirstat_cumulative = 0;
 143                } else if (!strcmp(p, "cumulative")) {
 144                        options->flags.dirstat_cumulative = 1;
 145                } else if (isdigit(*p)) {
 146                        char *end;
 147                        int permille = strtoul(p, &end, 10) * 10;
 148                        if (*end == '.' && isdigit(*++end)) {
 149                                /* only use first digit */
 150                                permille += *end - '0';
 151                                /* .. and ignore any further digits */
 152                                while (isdigit(*++end))
 153                                        ; /* nothing */
 154                        }
 155                        if (!*end)
 156                                options->dirstat_permille = permille;
 157                        else {
 158                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 159                                            p);
 160                                ret++;
 161                        }
 162                } else {
 163                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 164                        ret++;
 165                }
 166
 167        }
 168        string_list_clear(&params, 0);
 169        free(params_copy);
 170        return ret;
 171}
 172
 173static int parse_submodule_params(struct diff_options *options, const char *value)
 174{
 175        if (!strcmp(value, "log"))
 176                options->submodule_format = DIFF_SUBMODULE_LOG;
 177        else if (!strcmp(value, "short"))
 178                options->submodule_format = DIFF_SUBMODULE_SHORT;
 179        else if (!strcmp(value, "diff"))
 180                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 181        else
 182                return -1;
 183        return 0;
 184}
 185
 186int git_config_rename(const char *var, const char *value)
 187{
 188        if (!value)
 189                return DIFF_DETECT_RENAME;
 190        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 191                return  DIFF_DETECT_COPY;
 192        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 193}
 194
 195long parse_algorithm_value(const char *value)
 196{
 197        if (!value)
 198                return -1;
 199        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 200                return 0;
 201        else if (!strcasecmp(value, "minimal"))
 202                return XDF_NEED_MINIMAL;
 203        else if (!strcasecmp(value, "patience"))
 204                return XDF_PATIENCE_DIFF;
 205        else if (!strcasecmp(value, "histogram"))
 206                return XDF_HISTOGRAM_DIFF;
 207        return -1;
 208}
 209
 210static int parse_one_token(const char **arg, const char *token)
 211{
 212        const char *rest;
 213        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 214                *arg = rest;
 215                return 1;
 216        }
 217        return 0;
 218}
 219
 220static int parse_ws_error_highlight(const char *arg)
 221{
 222        const char *orig_arg = arg;
 223        unsigned val = 0;
 224
 225        while (*arg) {
 226                if (parse_one_token(&arg, "none"))
 227                        val = 0;
 228                else if (parse_one_token(&arg, "default"))
 229                        val = WSEH_NEW;
 230                else if (parse_one_token(&arg, "all"))
 231                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 232                else if (parse_one_token(&arg, "new"))
 233                        val |= WSEH_NEW;
 234                else if (parse_one_token(&arg, "old"))
 235                        val |= WSEH_OLD;
 236                else if (parse_one_token(&arg, "context"))
 237                        val |= WSEH_CONTEXT;
 238                else {
 239                        return -1 - (int)(arg - orig_arg);
 240                }
 241                if (*arg)
 242                        arg++;
 243        }
 244        return val;
 245}
 246
 247/*
 248 * These are to give UI layer defaults.
 249 * The core-level commands such as git-diff-files should
 250 * never be affected by the setting of diff.renames
 251 * the user happens to have in the configuration file.
 252 */
 253void init_diff_ui_defaults(void)
 254{
 255        diff_detect_rename_default = DIFF_DETECT_RENAME;
 256}
 257
 258int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 259{
 260        if (!strcmp(var, "diff.indentheuristic"))
 261                diff_indent_heuristic = git_config_bool(var, value);
 262        return 0;
 263}
 264
 265static int parse_color_moved(const char *arg)
 266{
 267        switch (git_parse_maybe_bool(arg)) {
 268        case 0:
 269                return COLOR_MOVED_NO;
 270        case 1:
 271                return COLOR_MOVED_DEFAULT;
 272        default:
 273                break;
 274        }
 275
 276        if (!strcmp(arg, "no"))
 277                return COLOR_MOVED_NO;
 278        else if (!strcmp(arg, "plain"))
 279                return COLOR_MOVED_PLAIN;
 280        else if (!strcmp(arg, "blocks"))
 281                return COLOR_MOVED_BLOCKS;
 282        else if (!strcmp(arg, "zebra"))
 283                return COLOR_MOVED_ZEBRA;
 284        else if (!strcmp(arg, "default"))
 285                return COLOR_MOVED_DEFAULT;
 286        else if (!strcmp(arg, "dimmed-zebra"))
 287                return COLOR_MOVED_ZEBRA_DIM;
 288        else if (!strcmp(arg, "dimmed_zebra"))
 289                return COLOR_MOVED_ZEBRA_DIM;
 290        else
 291                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 292}
 293
 294static unsigned parse_color_moved_ws(const char *arg)
 295{
 296        int ret = 0;
 297        struct string_list l = STRING_LIST_INIT_DUP;
 298        struct string_list_item *i;
 299
 300        string_list_split(&l, arg, ',', -1);
 301
 302        for_each_string_list_item(i, &l) {
 303                struct strbuf sb = STRBUF_INIT;
 304                strbuf_addstr(&sb, i->string);
 305                strbuf_trim(&sb);
 306
 307                if (!strcmp(sb.buf, "no"))
 308                        ret = 0;
 309                else if (!strcmp(sb.buf, "ignore-space-change"))
 310                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 311                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 312                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 313                else if (!strcmp(sb.buf, "ignore-all-space"))
 314                        ret |= XDF_IGNORE_WHITESPACE;
 315                else if (!strcmp(sb.buf, "allow-indentation-change"))
 316                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 317                else {
 318                        ret |= COLOR_MOVED_WS_ERROR;
 319                        error(_("unknown color-moved-ws mode '%s', possible values are 'ignore-space-change', 'ignore-space-at-eol', 'ignore-all-space', 'allow-indentation-change'"), sb.buf);
 320                }
 321
 322                strbuf_release(&sb);
 323        }
 324
 325        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 326            (ret & XDF_WHITESPACE_FLAGS)) {
 327                error(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
 328                ret |= COLOR_MOVED_WS_ERROR;
 329        }
 330
 331        string_list_clear(&l, 0);
 332
 333        return ret;
 334}
 335
 336int git_diff_ui_config(const char *var, const char *value, void *cb)
 337{
 338        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 339                diff_use_color_default = git_config_colorbool(var, value);
 340                return 0;
 341        }
 342        if (!strcmp(var, "diff.colormoved")) {
 343                int cm = parse_color_moved(value);
 344                if (cm < 0)
 345                        return -1;
 346                diff_color_moved_default = cm;
 347                return 0;
 348        }
 349        if (!strcmp(var, "diff.colormovedws")) {
 350                unsigned cm = parse_color_moved_ws(value);
 351                if (cm & COLOR_MOVED_WS_ERROR)
 352                        return -1;
 353                diff_color_moved_ws_default = cm;
 354                return 0;
 355        }
 356        if (!strcmp(var, "diff.context")) {
 357                diff_context_default = git_config_int(var, value);
 358                if (diff_context_default < 0)
 359                        return -1;
 360                return 0;
 361        }
 362        if (!strcmp(var, "diff.interhunkcontext")) {
 363                diff_interhunk_context_default = git_config_int(var, value);
 364                if (diff_interhunk_context_default < 0)
 365                        return -1;
 366                return 0;
 367        }
 368        if (!strcmp(var, "diff.renames")) {
 369                diff_detect_rename_default = git_config_rename(var, value);
 370                return 0;
 371        }
 372        if (!strcmp(var, "diff.autorefreshindex")) {
 373                diff_auto_refresh_index = git_config_bool(var, value);
 374                return 0;
 375        }
 376        if (!strcmp(var, "diff.mnemonicprefix")) {
 377                diff_mnemonic_prefix = git_config_bool(var, value);
 378                return 0;
 379        }
 380        if (!strcmp(var, "diff.noprefix")) {
 381                diff_no_prefix = git_config_bool(var, value);
 382                return 0;
 383        }
 384        if (!strcmp(var, "diff.statgraphwidth")) {
 385                diff_stat_graph_width = git_config_int(var, value);
 386                return 0;
 387        }
 388        if (!strcmp(var, "diff.external"))
 389                return git_config_string(&external_diff_cmd_cfg, var, value);
 390        if (!strcmp(var, "diff.wordregex"))
 391                return git_config_string(&diff_word_regex_cfg, var, value);
 392        if (!strcmp(var, "diff.orderfile"))
 393                return git_config_pathname(&diff_order_file_cfg, var, value);
 394
 395        if (!strcmp(var, "diff.ignoresubmodules"))
 396                handle_ignore_submodules_arg(&default_diff_options, value);
 397
 398        if (!strcmp(var, "diff.submodule")) {
 399                if (parse_submodule_params(&default_diff_options, value))
 400                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 401                                value);
 402                return 0;
 403        }
 404
 405        if (!strcmp(var, "diff.algorithm")) {
 406                diff_algorithm = parse_algorithm_value(value);
 407                if (diff_algorithm < 0)
 408                        return -1;
 409                return 0;
 410        }
 411
 412        if (!strcmp(var, "diff.wserrorhighlight")) {
 413                int val = parse_ws_error_highlight(value);
 414                if (val < 0)
 415                        return -1;
 416                ws_error_highlight_default = val;
 417                return 0;
 418        }
 419
 420        if (git_color_config(var, value, cb) < 0)
 421                return -1;
 422
 423        return git_diff_basic_config(var, value, cb);
 424}
 425
 426int git_diff_basic_config(const char *var, const char *value, void *cb)
 427{
 428        const char *name;
 429
 430        if (!strcmp(var, "diff.renamelimit")) {
 431                diff_rename_limit_default = git_config_int(var, value);
 432                return 0;
 433        }
 434
 435        if (userdiff_config(var, value) < 0)
 436                return -1;
 437
 438        if (skip_prefix(var, "diff.color.", &name) ||
 439            skip_prefix(var, "color.diff.", &name)) {
 440                int slot = parse_diff_color_slot(name);
 441                if (slot < 0)
 442                        return 0;
 443                if (!value)
 444                        return config_error_nonbool(var);
 445                return color_parse(value, diff_colors[slot]);
 446        }
 447
 448        /* like GNU diff's --suppress-blank-empty option  */
 449        if (!strcmp(var, "diff.suppressblankempty") ||
 450                        /* for backwards compatibility */
 451                        !strcmp(var, "diff.suppress-blank-empty")) {
 452                diff_suppress_blank_empty = git_config_bool(var, value);
 453                return 0;
 454        }
 455
 456        if (!strcmp(var, "diff.dirstat")) {
 457                struct strbuf errmsg = STRBUF_INIT;
 458                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 459                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 460                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 461                                errmsg.buf);
 462                strbuf_release(&errmsg);
 463                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 464                return 0;
 465        }
 466
 467        if (git_diff_heuristic_config(var, value, cb) < 0)
 468                return -1;
 469
 470        return git_default_config(var, value, cb);
 471}
 472
 473static char *quote_two(const char *one, const char *two)
 474{
 475        int need_one = quote_c_style(one, NULL, NULL, 1);
 476        int need_two = quote_c_style(two, NULL, NULL, 1);
 477        struct strbuf res = STRBUF_INIT;
 478
 479        if (need_one + need_two) {
 480                strbuf_addch(&res, '"');
 481                quote_c_style(one, &res, NULL, 1);
 482                quote_c_style(two, &res, NULL, 1);
 483                strbuf_addch(&res, '"');
 484        } else {
 485                strbuf_addstr(&res, one);
 486                strbuf_addstr(&res, two);
 487        }
 488        return strbuf_detach(&res, NULL);
 489}
 490
 491static const char *external_diff(void)
 492{
 493        static const char *external_diff_cmd = NULL;
 494        static int done_preparing = 0;
 495
 496        if (done_preparing)
 497                return external_diff_cmd;
 498        external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF"));
 499        if (!external_diff_cmd)
 500                external_diff_cmd = external_diff_cmd_cfg;
 501        done_preparing = 1;
 502        return external_diff_cmd;
 503}
 504
 505/*
 506 * Keep track of files used for diffing. Sometimes such an entry
 507 * refers to a temporary file, sometimes to an existing file, and
 508 * sometimes to "/dev/null".
 509 */
 510static struct diff_tempfile {
 511        /*
 512         * filename external diff should read from, or NULL if this
 513         * entry is currently not in use:
 514         */
 515        const char *name;
 516
 517        char hex[GIT_MAX_HEXSZ + 1];
 518        char mode[10];
 519
 520        /*
 521         * If this diff_tempfile instance refers to a temporary file,
 522         * this tempfile object is used to manage its lifetime.
 523         */
 524        struct tempfile *tempfile;
 525} diff_temp[2];
 526
 527struct emit_callback {
 528        int color_diff;
 529        unsigned ws_rule;
 530        int blank_at_eof_in_preimage;
 531        int blank_at_eof_in_postimage;
 532        int lno_in_preimage;
 533        int lno_in_postimage;
 534        const char **label_path;
 535        struct diff_words_data *diff_words;
 536        struct diff_options *opt;
 537        struct strbuf *header;
 538};
 539
 540static int count_lines(const char *data, int size)
 541{
 542        int count, ch, completely_empty = 1, nl_just_seen = 0;
 543        count = 0;
 544        while (0 < size--) {
 545                ch = *data++;
 546                if (ch == '\n') {
 547                        count++;
 548                        nl_just_seen = 1;
 549                        completely_empty = 0;
 550                }
 551                else {
 552                        nl_just_seen = 0;
 553                        completely_empty = 0;
 554                }
 555        }
 556        if (completely_empty)
 557                return 0;
 558        if (!nl_just_seen)
 559                count++; /* no trailing newline */
 560        return count;
 561}
 562
 563static int fill_mmfile(struct repository *r, mmfile_t *mf,
 564                       struct diff_filespec *one)
 565{
 566        if (!DIFF_FILE_VALID(one)) {
 567                mf->ptr = (char *)""; /* does not matter */
 568                mf->size = 0;
 569                return 0;
 570        }
 571        else if (diff_populate_filespec(r, one, 0))
 572                return -1;
 573
 574        mf->ptr = one->data;
 575        mf->size = one->size;
 576        return 0;
 577}
 578
 579/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 580static unsigned long diff_filespec_size(struct repository *r,
 581                                        struct diff_filespec *one)
 582{
 583        if (!DIFF_FILE_VALID(one))
 584                return 0;
 585        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 586        return one->size;
 587}
 588
 589static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 590{
 591        char *ptr = mf->ptr;
 592        long size = mf->size;
 593        int cnt = 0;
 594
 595        if (!size)
 596                return cnt;
 597        ptr += size - 1; /* pointing at the very end */
 598        if (*ptr != '\n')
 599                ; /* incomplete line */
 600        else
 601                ptr--; /* skip the last LF */
 602        while (mf->ptr < ptr) {
 603                char *prev_eol;
 604                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 605                        if (*prev_eol == '\n')
 606                                break;
 607                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 608                        break;
 609                cnt++;
 610                ptr = prev_eol - 1;
 611        }
 612        return cnt;
 613}
 614
 615static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 616                               struct emit_callback *ecbdata)
 617{
 618        int l1, l2, at;
 619        unsigned ws_rule = ecbdata->ws_rule;
 620        l1 = count_trailing_blank(mf1, ws_rule);
 621        l2 = count_trailing_blank(mf2, ws_rule);
 622        if (l2 <= l1) {
 623                ecbdata->blank_at_eof_in_preimage = 0;
 624                ecbdata->blank_at_eof_in_postimage = 0;
 625                return;
 626        }
 627        at = count_lines(mf1->ptr, mf1->size);
 628        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 629
 630        at = count_lines(mf2->ptr, mf2->size);
 631        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 632}
 633
 634static void emit_line_0(struct diff_options *o,
 635                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 636                        int first, const char *line, int len)
 637{
 638        int has_trailing_newline, has_trailing_carriage_return;
 639        int needs_reset = 0; /* at the end of the line */
 640        FILE *file = o->file;
 641
 642        fputs(diff_line_prefix(o), file);
 643
 644        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 645        if (has_trailing_newline)
 646                len--;
 647
 648        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 649        if (has_trailing_carriage_return)
 650                len--;
 651
 652        if (!len && !first)
 653                goto end_of_line;
 654
 655        if (reverse && want_color(o->use_color)) {
 656                fputs(GIT_COLOR_REVERSE, file);
 657                needs_reset = 1;
 658        }
 659
 660        if (set_sign) {
 661                fputs(set_sign, file);
 662                needs_reset = 1;
 663        }
 664
 665        if (first)
 666                fputc(first, file);
 667
 668        if (!len)
 669                goto end_of_line;
 670
 671        if (set) {
 672                if (set_sign && set != set_sign)
 673                        fputs(reset, file);
 674                fputs(set, file);
 675                needs_reset = 1;
 676        }
 677        fwrite(line, len, 1, file);
 678        needs_reset = 1; /* 'line' may contain color codes. */
 679
 680end_of_line:
 681        if (needs_reset)
 682                fputs(reset, file);
 683        if (has_trailing_carriage_return)
 684                fputc('\r', file);
 685        if (has_trailing_newline)
 686                fputc('\n', file);
 687}
 688
 689static void emit_line(struct diff_options *o, const char *set, const char *reset,
 690                      const char *line, int len)
 691{
 692        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 693}
 694
 695enum diff_symbol {
 696        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 697        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 698        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 699        DIFF_SYMBOL_BINARY_DIFF_BODY,
 700        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 701        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 702        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 703        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 704        DIFF_SYMBOL_STATS_LINE,
 705        DIFF_SYMBOL_WORD_DIFF,
 706        DIFF_SYMBOL_STAT_SEP,
 707        DIFF_SYMBOL_SUMMARY,
 708        DIFF_SYMBOL_SUBMODULE_ADD,
 709        DIFF_SYMBOL_SUBMODULE_DEL,
 710        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 711        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 712        DIFF_SYMBOL_SUBMODULE_HEADER,
 713        DIFF_SYMBOL_SUBMODULE_ERROR,
 714        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 715        DIFF_SYMBOL_REWRITE_DIFF,
 716        DIFF_SYMBOL_BINARY_FILES,
 717        DIFF_SYMBOL_HEADER,
 718        DIFF_SYMBOL_FILEPAIR_PLUS,
 719        DIFF_SYMBOL_FILEPAIR_MINUS,
 720        DIFF_SYMBOL_WORDS_PORCELAIN,
 721        DIFF_SYMBOL_WORDS,
 722        DIFF_SYMBOL_CONTEXT,
 723        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 724        DIFF_SYMBOL_PLUS,
 725        DIFF_SYMBOL_MINUS,
 726        DIFF_SYMBOL_NO_LF_EOF,
 727        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 728        DIFF_SYMBOL_CONTEXT_MARKER,
 729        DIFF_SYMBOL_SEPARATOR
 730};
 731/*
 732 * Flags for content lines:
 733 * 0..12 are whitespace rules
 734 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 735 * 16 is marking if the line is blank at EOF
 736 */
 737#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 738#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 739#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 740#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 741#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 742
 743/*
 744 * This struct is used when we need to buffer the output of the diff output.
 745 *
 746 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 747 * into the pre/post image file. This pointer could be a union with the
 748 * line pointer. By storing an offset into the file instead of the literal line,
 749 * we can decrease the memory footprint for the buffered output. At first we
 750 * may want to only have indirection for the content lines, but we could also
 751 * enhance the state for emitting prefabricated lines, e.g. the similarity
 752 * score line or hunk/file headers would only need to store a number or path
 753 * and then the output can be constructed later on depending on state.
 754 */
 755struct emitted_diff_symbol {
 756        const char *line;
 757        int len;
 758        int flags;
 759        int indent_off;   /* Offset to first non-whitespace character */
 760        int indent_width; /* The visual width of the indentation */
 761        enum diff_symbol s;
 762};
 763#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 764
 765struct emitted_diff_symbols {
 766        struct emitted_diff_symbol *buf;
 767        int nr, alloc;
 768};
 769#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 770
 771static void append_emitted_diff_symbol(struct diff_options *o,
 772                                       struct emitted_diff_symbol *e)
 773{
 774        struct emitted_diff_symbol *f;
 775
 776        ALLOC_GROW(o->emitted_symbols->buf,
 777                   o->emitted_symbols->nr + 1,
 778                   o->emitted_symbols->alloc);
 779        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 780
 781        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 782        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 783}
 784
 785struct moved_entry {
 786        struct hashmap_entry ent;
 787        const struct emitted_diff_symbol *es;
 788        struct moved_entry *next_line;
 789};
 790
 791struct moved_block {
 792        struct moved_entry *match;
 793        int wsd; /* The whitespace delta of this block */
 794};
 795
 796static void moved_block_clear(struct moved_block *b)
 797{
 798        memset(b, 0, sizeof(*b));
 799}
 800
 801#define INDENT_BLANKLINE INT_MIN
 802
 803static void fill_es_indent_data(struct emitted_diff_symbol *es)
 804{
 805        unsigned int off = 0, i;
 806        int width = 0, tab_width = es->flags & WS_TAB_WIDTH_MASK;
 807        const char *s = es->line;
 808        const int len = es->len;
 809
 810        /* skip any \v \f \r at start of indentation */
 811        while (s[off] == '\f' || s[off] == '\v' ||
 812               (s[off] == '\r' && off < len - 1))
 813                off++;
 814
 815        /* calculate the visual width of indentation */
 816        while(1) {
 817                if (s[off] == ' ') {
 818                        width++;
 819                        off++;
 820                } else if (s[off] == '\t') {
 821                        width += tab_width - (width % tab_width);
 822                        while (s[++off] == '\t')
 823                                width += tab_width;
 824                } else {
 825                        break;
 826                }
 827        }
 828
 829        /* check if this line is blank */
 830        for (i = off; i < len; i++)
 831                if (!isspace(s[i]))
 832                    break;
 833
 834        if (i == len) {
 835                es->indent_width = INDENT_BLANKLINE;
 836                es->indent_off = len;
 837        } else {
 838                es->indent_off = off;
 839                es->indent_width = width;
 840        }
 841}
 842
 843static int compute_ws_delta(const struct emitted_diff_symbol *a,
 844                            const struct emitted_diff_symbol *b,
 845                            int *out)
 846{
 847        int a_len = a->len,
 848            b_len = b->len,
 849            a_off = a->indent_off,
 850            a_width = a->indent_width,
 851            b_off = b->indent_off,
 852            b_width = b->indent_width;
 853        int delta;
 854
 855        if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 856                *out = INDENT_BLANKLINE;
 857                return 1;
 858        }
 859
 860        if (a->s == DIFF_SYMBOL_PLUS)
 861                delta = a_width - b_width;
 862        else
 863                delta = b_width - a_width;
 864
 865        if (a_len - a_off != b_len - b_off ||
 866            memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 867                return 0;
 868
 869        *out = delta;
 870
 871        return 1;
 872}
 873
 874static int cmp_in_block_with_wsd(const struct diff_options *o,
 875                                 const struct moved_entry *cur,
 876                                 const struct moved_entry *match,
 877                                 struct moved_block *pmb,
 878                                 int n)
 879{
 880        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 881        int al = cur->es->len, bl = match->es->len, cl = l->len;
 882        const char *a = cur->es->line,
 883                   *b = match->es->line,
 884                   *c = l->line;
 885        int a_off = cur->es->indent_off,
 886            a_width = cur->es->indent_width,
 887            c_off = l->indent_off,
 888            c_width = l->indent_width;
 889        int delta;
 890
 891        /*
 892         * We need to check if 'cur' is equal to 'match'.  As those
 893         * are from the same (+/-) side, we do not need to adjust for
 894         * indent changes. However these were found using fuzzy
 895         * matching so we do have to check if they are equal. Here we
 896         * just check the lengths. We delay calling memcmp() to check
 897         * the contents until later as if the length comparison for a
 898         * and c fails we can avoid the call all together.
 899         */
 900        if (al != bl)
 901                return 1;
 902
 903        /* If 'l' and 'cur' are both blank then they match. */
 904        if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
 905                return 0;
 906
 907        /*
 908         * The indent changes of the block are known and stored in pmb->wsd;
 909         * however we need to check if the indent changes of the current line
 910         * match those of the current block and that the text of 'l' and 'cur'
 911         * after the indentation match.
 912         */
 913        if (cur->es->s == DIFF_SYMBOL_PLUS)
 914                delta = a_width - c_width;
 915        else
 916                delta = c_width - a_width;
 917
 918        /*
 919         * If the previous lines of this block were all blank then set its
 920         * whitespace delta.
 921         */
 922        if (pmb->wsd == INDENT_BLANKLINE)
 923                pmb->wsd = delta;
 924
 925        return !(delta == pmb->wsd && al - a_off == cl - c_off &&
 926                 !memcmp(a, b, al) && !
 927                 memcmp(a + a_off, c + c_off, al - a_off));
 928}
 929
 930static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 931                           const void *entry,
 932                           const void *entry_or_key,
 933                           const void *keydata)
 934{
 935        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 936        const struct moved_entry *a = entry;
 937        const struct moved_entry *b = entry_or_key;
 938        unsigned flags = diffopt->color_moved_ws_handling
 939                         & XDF_WHITESPACE_FLAGS;
 940
 941        if (diffopt->color_moved_ws_handling &
 942            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 943                /*
 944                 * As there is not specific white space config given,
 945                 * we'd need to check for a new block, so ignore all
 946                 * white space. The setup of the white space
 947                 * configuration for the next block is done else where
 948                 */
 949                flags |= XDF_IGNORE_WHITESPACE;
 950
 951        return !xdiff_compare_lines(a->es->line, a->es->len,
 952                                    b->es->line, b->es->len,
 953                                    flags);
 954}
 955
 956static struct moved_entry *prepare_entry(struct diff_options *o,
 957                                         int line_no)
 958{
 959        struct moved_entry *ret = xmalloc(sizeof(*ret));
 960        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 961        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 962
 963        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 964        ret->es = l;
 965        ret->next_line = NULL;
 966
 967        return ret;
 968}
 969
 970static void add_lines_to_move_detection(struct diff_options *o,
 971                                        struct hashmap *add_lines,
 972                                        struct hashmap *del_lines)
 973{
 974        struct moved_entry *prev_line = NULL;
 975
 976        int n;
 977        for (n = 0; n < o->emitted_symbols->nr; n++) {
 978                struct hashmap *hm;
 979                struct moved_entry *key;
 980
 981                switch (o->emitted_symbols->buf[n].s) {
 982                case DIFF_SYMBOL_PLUS:
 983                        hm = add_lines;
 984                        break;
 985                case DIFF_SYMBOL_MINUS:
 986                        hm = del_lines;
 987                        break;
 988                default:
 989                        prev_line = NULL;
 990                        continue;
 991                }
 992
 993                if (o->color_moved_ws_handling &
 994                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 995                        fill_es_indent_data(&o->emitted_symbols->buf[n]);
 996                key = prepare_entry(o, n);
 997                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 998                        prev_line->next_line = key;
 999
1000                hashmap_add(hm, key);
1001                prev_line = key;
1002        }
1003}
1004
1005static void pmb_advance_or_null(struct diff_options *o,
1006                                struct moved_entry *match,
1007                                struct hashmap *hm,
1008                                struct moved_block *pmb,
1009                                int pmb_nr)
1010{
1011        int i;
1012        for (i = 0; i < pmb_nr; i++) {
1013                struct moved_entry *prev = pmb[i].match;
1014                struct moved_entry *cur = (prev && prev->next_line) ?
1015                                prev->next_line : NULL;
1016                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
1017                        pmb[i].match = cur;
1018                } else {
1019                        pmb[i].match = NULL;
1020                }
1021        }
1022}
1023
1024static void pmb_advance_or_null_multi_match(struct diff_options *o,
1025                                            struct moved_entry *match,
1026                                            struct hashmap *hm,
1027                                            struct moved_block *pmb,
1028                                            int pmb_nr, int n)
1029{
1030        int i;
1031        char *got_match = xcalloc(1, pmb_nr);
1032
1033        for (; match; match = hashmap_get_next(hm, match)) {
1034                for (i = 0; i < pmb_nr; i++) {
1035                        struct moved_entry *prev = pmb[i].match;
1036                        struct moved_entry *cur = (prev && prev->next_line) ?
1037                                        prev->next_line : NULL;
1038                        if (!cur)
1039                                continue;
1040                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
1041                                got_match[i] |= 1;
1042                }
1043        }
1044
1045        for (i = 0; i < pmb_nr; i++) {
1046                if (got_match[i]) {
1047                        /* Advance to the next line */
1048                        pmb[i].match = pmb[i].match->next_line;
1049                } else {
1050                        moved_block_clear(&pmb[i]);
1051                }
1052        }
1053
1054        free(got_match);
1055}
1056
1057static int shrink_potential_moved_blocks(struct moved_block *pmb,
1058                                         int pmb_nr)
1059{
1060        int lp, rp;
1061
1062        /* Shrink the set of potential block to the remaining running */
1063        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1064                while (lp < pmb_nr && pmb[lp].match)
1065                        lp++;
1066                /* lp points at the first NULL now */
1067
1068                while (rp > -1 && !pmb[rp].match)
1069                        rp--;
1070                /* rp points at the last non-NULL */
1071
1072                if (lp < pmb_nr && rp > -1 && lp < rp) {
1073                        pmb[lp] = pmb[rp];
1074                        memset(&pmb[rp], 0, sizeof(pmb[rp]));
1075                        rp--;
1076                        lp++;
1077                }
1078        }
1079
1080        /* Remember the number of running sets */
1081        return rp + 1;
1082}
1083
1084/*
1085 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1086 *
1087 * Otherwise, if the last block has fewer alphanumeric characters than
1088 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1089 * that block.
1090 *
1091 * The last block consists of the (n - block_length)'th line up to but not
1092 * including the nth line.
1093 *
1094 * Returns 0 if the last block is empty or is unset by this function, non zero
1095 * otherwise.
1096 *
1097 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1098 * Think of a way to unify them.
1099 */
1100static int adjust_last_block(struct diff_options *o, int n, int block_length)
1101{
1102        int i, alnum_count = 0;
1103        if (o->color_moved == COLOR_MOVED_PLAIN)
1104                return block_length;
1105        for (i = 1; i < block_length + 1; i++) {
1106                const char *c = o->emitted_symbols->buf[n - i].line;
1107                for (; *c; c++) {
1108                        if (!isalnum(*c))
1109                                continue;
1110                        alnum_count++;
1111                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1112                                return 1;
1113                }
1114        }
1115        for (i = 1; i < block_length + 1; i++)
1116                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1117        return 0;
1118}
1119
1120/* Find blocks of moved code, delegate actual coloring decision to helper */
1121static void mark_color_as_moved(struct diff_options *o,
1122                                struct hashmap *add_lines,
1123                                struct hashmap *del_lines)
1124{
1125        struct moved_block *pmb = NULL; /* potentially moved blocks */
1126        int pmb_nr = 0, pmb_alloc = 0;
1127        int n, flipped_block = 0, block_length = 0;
1128
1129
1130        for (n = 0; n < o->emitted_symbols->nr; n++) {
1131                struct hashmap *hm = NULL;
1132                struct moved_entry *key;
1133                struct moved_entry *match = NULL;
1134                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1135                enum diff_symbol last_symbol = 0;
1136
1137                switch (l->s) {
1138                case DIFF_SYMBOL_PLUS:
1139                        hm = del_lines;
1140                        key = prepare_entry(o, n);
1141                        match = hashmap_get(hm, key, NULL);
1142                        free(key);
1143                        break;
1144                case DIFF_SYMBOL_MINUS:
1145                        hm = add_lines;
1146                        key = prepare_entry(o, n);
1147                        match = hashmap_get(hm, key, NULL);
1148                        free(key);
1149                        break;
1150                default:
1151                        flipped_block = 0;
1152                }
1153
1154                if (!match) {
1155                        int i;
1156
1157                        adjust_last_block(o, n, block_length);
1158                        for(i = 0; i < pmb_nr; i++)
1159                                moved_block_clear(&pmb[i]);
1160                        pmb_nr = 0;
1161                        block_length = 0;
1162                        flipped_block = 0;
1163                        last_symbol = l->s;
1164                        continue;
1165                }
1166
1167                if (o->color_moved == COLOR_MOVED_PLAIN) {
1168                        last_symbol = l->s;
1169                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1170                        continue;
1171                }
1172
1173                if (o->color_moved_ws_handling &
1174                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1175                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1176                else
1177                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1178
1179                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1180
1181                if (pmb_nr == 0) {
1182                        /*
1183                         * The current line is the start of a new block.
1184                         * Setup the set of potential blocks.
1185                         */
1186                        for (; match; match = hashmap_get_next(hm, match)) {
1187                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1188                                if (o->color_moved_ws_handling &
1189                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1190                                        if (compute_ws_delta(l, match->es,
1191                                                             &pmb[pmb_nr].wsd))
1192                                                pmb[pmb_nr++].match = match;
1193                                } else {
1194                                        pmb[pmb_nr].wsd = 0;
1195                                        pmb[pmb_nr++].match = match;
1196                                }
1197                        }
1198
1199                        if (adjust_last_block(o, n, block_length) &&
1200                            pmb_nr && last_symbol != l->s)
1201                                flipped_block = (flipped_block + 1) % 2;
1202                        else
1203                                flipped_block = 0;
1204
1205                        block_length = 0;
1206                }
1207
1208                if (pmb_nr) {
1209                        block_length++;
1210                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1211                        if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1212                                l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1213                }
1214                last_symbol = l->s;
1215        }
1216        adjust_last_block(o, n, block_length);
1217
1218        for(n = 0; n < pmb_nr; n++)
1219                moved_block_clear(&pmb[n]);
1220        free(pmb);
1221}
1222
1223#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1224  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1225static void dim_moved_lines(struct diff_options *o)
1226{
1227        int n;
1228        for (n = 0; n < o->emitted_symbols->nr; n++) {
1229                struct emitted_diff_symbol *prev = (n != 0) ?
1230                                &o->emitted_symbols->buf[n - 1] : NULL;
1231                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1232                struct emitted_diff_symbol *next =
1233                                (n < o->emitted_symbols->nr - 1) ?
1234                                &o->emitted_symbols->buf[n + 1] : NULL;
1235
1236                /* Not a plus or minus line? */
1237                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1238                        continue;
1239
1240                /* Not a moved line? */
1241                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1242                        continue;
1243
1244                /*
1245                 * If prev or next are not a plus or minus line,
1246                 * pretend they don't exist
1247                 */
1248                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1249                            prev->s != DIFF_SYMBOL_MINUS)
1250                        prev = NULL;
1251                if (next && next->s != DIFF_SYMBOL_PLUS &&
1252                            next->s != DIFF_SYMBOL_MINUS)
1253                        next = NULL;
1254
1255                /* Inside a block? */
1256                if ((prev &&
1257                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1258                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1259                    (next &&
1260                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1261                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1262                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1263                        continue;
1264                }
1265
1266                /* Check if we are at an interesting bound: */
1267                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1268                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1269                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1270                        continue;
1271                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1272                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1273                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1274                        continue;
1275
1276                /*
1277                 * The boundary to prev and next are not interesting,
1278                 * so this line is not interesting as a whole
1279                 */
1280                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1281        }
1282}
1283
1284static void emit_line_ws_markup(struct diff_options *o,
1285                                const char *set_sign, const char *set,
1286                                const char *reset,
1287                                int sign_index, const char *line, int len,
1288                                unsigned ws_rule, int blank_at_eof)
1289{
1290        const char *ws = NULL;
1291        int sign = o->output_indicators[sign_index];
1292
1293        if (o->ws_error_highlight & ws_rule) {
1294                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1295                if (!*ws)
1296                        ws = NULL;
1297        }
1298
1299        if (!ws && !set_sign)
1300                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1301        else if (!ws) {
1302                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1303        } else if (blank_at_eof)
1304                /* Blank line at EOF - paint '+' as well */
1305                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1306        else {
1307                /* Emit just the prefix, then the rest. */
1308                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1309                            sign, "", 0);
1310                ws_check_emit(line, len, ws_rule,
1311                              o->file, set, reset, ws);
1312        }
1313}
1314
1315static void emit_diff_symbol_from_struct(struct diff_options *o,
1316                                         struct emitted_diff_symbol *eds)
1317{
1318        static const char *nneof = " No newline at end of file\n";
1319        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1320        struct strbuf sb = STRBUF_INIT;
1321
1322        enum diff_symbol s = eds->s;
1323        const char *line = eds->line;
1324        int len = eds->len;
1325        unsigned flags = eds->flags;
1326
1327        switch (s) {
1328        case DIFF_SYMBOL_NO_LF_EOF:
1329                context = diff_get_color_opt(o, DIFF_CONTEXT);
1330                reset = diff_get_color_opt(o, DIFF_RESET);
1331                putc('\n', o->file);
1332                emit_line_0(o, context, NULL, 0, reset, '\\',
1333                            nneof, strlen(nneof));
1334                break;
1335        case DIFF_SYMBOL_SUBMODULE_HEADER:
1336        case DIFF_SYMBOL_SUBMODULE_ERROR:
1337        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1338        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1339        case DIFF_SYMBOL_SUMMARY:
1340        case DIFF_SYMBOL_STATS_LINE:
1341        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1342        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1343                emit_line(o, "", "", line, len);
1344                break;
1345        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1346        case DIFF_SYMBOL_CONTEXT_MARKER:
1347                context = diff_get_color_opt(o, DIFF_CONTEXT);
1348                reset = diff_get_color_opt(o, DIFF_RESET);
1349                emit_line(o, context, reset, line, len);
1350                break;
1351        case DIFF_SYMBOL_SEPARATOR:
1352                fprintf(o->file, "%s%c",
1353                        diff_line_prefix(o),
1354                        o->line_termination);
1355                break;
1356        case DIFF_SYMBOL_CONTEXT:
1357                set = diff_get_color_opt(o, DIFF_CONTEXT);
1358                reset = diff_get_color_opt(o, DIFF_RESET);
1359                set_sign = NULL;
1360                if (o->flags.dual_color_diffed_diffs) {
1361                        char c = !len ? 0 : line[0];
1362
1363                        if (c == '+')
1364                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1365                        else if (c == '@')
1366                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1367                        else if (c == '-')
1368                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1369                }
1370                emit_line_ws_markup(o, set_sign, set, reset,
1371                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1372                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1373                break;
1374        case DIFF_SYMBOL_PLUS:
1375                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1376                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1377                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1378                case DIFF_SYMBOL_MOVED_LINE |
1379                     DIFF_SYMBOL_MOVED_LINE_ALT |
1380                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1381                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1382                        break;
1383                case DIFF_SYMBOL_MOVED_LINE |
1384                     DIFF_SYMBOL_MOVED_LINE_ALT:
1385                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1386                        break;
1387                case DIFF_SYMBOL_MOVED_LINE |
1388                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1389                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1390                        break;
1391                case DIFF_SYMBOL_MOVED_LINE:
1392                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1393                        break;
1394                default:
1395                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1396                }
1397                reset = diff_get_color_opt(o, DIFF_RESET);
1398                if (!o->flags.dual_color_diffed_diffs)
1399                        set_sign = NULL;
1400                else {
1401                        char c = !len ? 0 : line[0];
1402
1403                        set_sign = set;
1404                        if (c == '-')
1405                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1406                        else if (c == '@')
1407                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1408                        else if (c == '+')
1409                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1410                        else
1411                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1412                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1413                }
1414                emit_line_ws_markup(o, set_sign, set, reset,
1415                                    OUTPUT_INDICATOR_NEW, line, len,
1416                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1417                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1418                break;
1419        case DIFF_SYMBOL_MINUS:
1420                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1421                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1422                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1423                case DIFF_SYMBOL_MOVED_LINE |
1424                     DIFF_SYMBOL_MOVED_LINE_ALT |
1425                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1426                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1427                        break;
1428                case DIFF_SYMBOL_MOVED_LINE |
1429                     DIFF_SYMBOL_MOVED_LINE_ALT:
1430                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1431                        break;
1432                case DIFF_SYMBOL_MOVED_LINE |
1433                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1434                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1435                        break;
1436                case DIFF_SYMBOL_MOVED_LINE:
1437                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1438                        break;
1439                default:
1440                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1441                }
1442                reset = diff_get_color_opt(o, DIFF_RESET);
1443                if (!o->flags.dual_color_diffed_diffs)
1444                        set_sign = NULL;
1445                else {
1446                        char c = !len ? 0 : line[0];
1447
1448                        set_sign = set;
1449                        if (c == '+')
1450                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1451                        else if (c == '@')
1452                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1453                        else if (c == '-')
1454                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1455                        else
1456                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1457                }
1458                emit_line_ws_markup(o, set_sign, set, reset,
1459                                    OUTPUT_INDICATOR_OLD, line, len,
1460                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1461                break;
1462        case DIFF_SYMBOL_WORDS_PORCELAIN:
1463                context = diff_get_color_opt(o, DIFF_CONTEXT);
1464                reset = diff_get_color_opt(o, DIFF_RESET);
1465                emit_line(o, context, reset, line, len);
1466                fputs("~\n", o->file);
1467                break;
1468        case DIFF_SYMBOL_WORDS:
1469                context = diff_get_color_opt(o, DIFF_CONTEXT);
1470                reset = diff_get_color_opt(o, DIFF_RESET);
1471                /*
1472                 * Skip the prefix character, if any.  With
1473                 * diff_suppress_blank_empty, there may be
1474                 * none.
1475                 */
1476                if (line[0] != '\n') {
1477                        line++;
1478                        len--;
1479                }
1480                emit_line(o, context, reset, line, len);
1481                break;
1482        case DIFF_SYMBOL_FILEPAIR_PLUS:
1483                meta = diff_get_color_opt(o, DIFF_METAINFO);
1484                reset = diff_get_color_opt(o, DIFF_RESET);
1485                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1486                        line, reset,
1487                        strchr(line, ' ') ? "\t" : "");
1488                break;
1489        case DIFF_SYMBOL_FILEPAIR_MINUS:
1490                meta = diff_get_color_opt(o, DIFF_METAINFO);
1491                reset = diff_get_color_opt(o, DIFF_RESET);
1492                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1493                        line, reset,
1494                        strchr(line, ' ') ? "\t" : "");
1495                break;
1496        case DIFF_SYMBOL_BINARY_FILES:
1497        case DIFF_SYMBOL_HEADER:
1498                fprintf(o->file, "%s", line);
1499                break;
1500        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1501                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1502                break;
1503        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1504                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1505                break;
1506        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1507                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1508                break;
1509        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1510                fputs(diff_line_prefix(o), o->file);
1511                fputc('\n', o->file);
1512                break;
1513        case DIFF_SYMBOL_REWRITE_DIFF:
1514                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1515                reset = diff_get_color_opt(o, DIFF_RESET);
1516                emit_line(o, fraginfo, reset, line, len);
1517                break;
1518        case DIFF_SYMBOL_SUBMODULE_ADD:
1519                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1520                reset = diff_get_color_opt(o, DIFF_RESET);
1521                emit_line(o, set, reset, line, len);
1522                break;
1523        case DIFF_SYMBOL_SUBMODULE_DEL:
1524                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1525                reset = diff_get_color_opt(o, DIFF_RESET);
1526                emit_line(o, set, reset, line, len);
1527                break;
1528        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1529                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1530                        diff_line_prefix(o), line);
1531                break;
1532        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1533                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1534                        diff_line_prefix(o), line);
1535                break;
1536        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1537                emit_line(o, "", "", " 0 files changed\n",
1538                          strlen(" 0 files changed\n"));
1539                break;
1540        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1541                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1542                break;
1543        case DIFF_SYMBOL_WORD_DIFF:
1544                fprintf(o->file, "%.*s", len, line);
1545                break;
1546        case DIFF_SYMBOL_STAT_SEP:
1547                fputs(o->stat_sep, o->file);
1548                break;
1549        default:
1550                BUG("unknown diff symbol");
1551        }
1552        strbuf_release(&sb);
1553}
1554
1555static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1556                             const char *line, int len, unsigned flags)
1557{
1558        struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
1559
1560        if (o->emitted_symbols)
1561                append_emitted_diff_symbol(o, &e);
1562        else
1563                emit_diff_symbol_from_struct(o, &e);
1564}
1565
1566void diff_emit_submodule_del(struct diff_options *o, const char *line)
1567{
1568        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1569}
1570
1571void diff_emit_submodule_add(struct diff_options *o, const char *line)
1572{
1573        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1574}
1575
1576void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1577{
1578        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1579                         path, strlen(path), 0);
1580}
1581
1582void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1583{
1584        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1585                         path, strlen(path), 0);
1586}
1587
1588void diff_emit_submodule_header(struct diff_options *o, const char *header)
1589{
1590        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1591                         header, strlen(header), 0);
1592}
1593
1594void diff_emit_submodule_error(struct diff_options *o, const char *err)
1595{
1596        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1597}
1598
1599void diff_emit_submodule_pipethrough(struct diff_options *o,
1600                                     const char *line, int len)
1601{
1602        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1603}
1604
1605static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1606{
1607        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1608              ecbdata->blank_at_eof_in_preimage &&
1609              ecbdata->blank_at_eof_in_postimage &&
1610              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1611              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1612                return 0;
1613        return ws_blank_line(line, len, ecbdata->ws_rule);
1614}
1615
1616static void emit_add_line(const char *reset,
1617                          struct emit_callback *ecbdata,
1618                          const char *line, int len)
1619{
1620        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1621        if (new_blank_line_at_eof(ecbdata, line, len))
1622                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1623
1624        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1625}
1626
1627static void emit_del_line(const char *reset,
1628                          struct emit_callback *ecbdata,
1629                          const char *line, int len)
1630{
1631        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1632        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1633}
1634
1635static void emit_context_line(const char *reset,
1636                              struct emit_callback *ecbdata,
1637                              const char *line, int len)
1638{
1639        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1640        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1641}
1642
1643static void emit_hunk_header(struct emit_callback *ecbdata,
1644                             const char *line, int len)
1645{
1646        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1647        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1648        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1649        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1650        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1651        static const char atat[2] = { '@', '@' };
1652        const char *cp, *ep;
1653        struct strbuf msgbuf = STRBUF_INIT;
1654        int org_len = len;
1655        int i = 1;
1656
1657        /*
1658         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1659         * it always is at least 10 bytes long.
1660         */
1661        if (len < 10 ||
1662            memcmp(line, atat, 2) ||
1663            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1664                emit_diff_symbol(ecbdata->opt,
1665                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1666                return;
1667        }
1668        ep += 2; /* skip over @@ */
1669
1670        /* The hunk header in fraginfo color */
1671        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1672                strbuf_addstr(&msgbuf, reverse);
1673        strbuf_addstr(&msgbuf, frag);
1674        strbuf_add(&msgbuf, line, ep - line);
1675        strbuf_addstr(&msgbuf, reset);
1676
1677        /*
1678         * trailing "\r\n"
1679         */
1680        for ( ; i < 3; i++)
1681                if (line[len - i] == '\r' || line[len - i] == '\n')
1682                        len--;
1683
1684        /* blank before the func header */
1685        for (cp = ep; ep - line < len; ep++)
1686                if (*ep != ' ' && *ep != '\t')
1687                        break;
1688        if (ep != cp) {
1689                strbuf_addstr(&msgbuf, context);
1690                strbuf_add(&msgbuf, cp, ep - cp);
1691                strbuf_addstr(&msgbuf, reset);
1692        }
1693
1694        if (ep < line + len) {
1695                strbuf_addstr(&msgbuf, func);
1696                strbuf_add(&msgbuf, ep, line + len - ep);
1697                strbuf_addstr(&msgbuf, reset);
1698        }
1699
1700        strbuf_add(&msgbuf, line + len, org_len - len);
1701        strbuf_complete_line(&msgbuf);
1702        emit_diff_symbol(ecbdata->opt,
1703                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1704        strbuf_release(&msgbuf);
1705}
1706
1707static struct diff_tempfile *claim_diff_tempfile(void)
1708{
1709        int i;
1710        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1711                if (!diff_temp[i].name)
1712                        return diff_temp + i;
1713        BUG("diff is failing to clean up its tempfiles");
1714}
1715
1716static void remove_tempfile(void)
1717{
1718        int i;
1719        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1720                if (is_tempfile_active(diff_temp[i].tempfile))
1721                        delete_tempfile(&diff_temp[i].tempfile);
1722                diff_temp[i].name = NULL;
1723        }
1724}
1725
1726static void add_line_count(struct strbuf *out, int count)
1727{
1728        switch (count) {
1729        case 0:
1730                strbuf_addstr(out, "0,0");
1731                break;
1732        case 1:
1733                strbuf_addstr(out, "1");
1734                break;
1735        default:
1736                strbuf_addf(out, "1,%d", count);
1737                break;
1738        }
1739}
1740
1741static void emit_rewrite_lines(struct emit_callback *ecb,
1742                               int prefix, const char *data, int size)
1743{
1744        const char *endp = NULL;
1745        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1746
1747        while (0 < size) {
1748                int len;
1749
1750                endp = memchr(data, '\n', size);
1751                len = endp ? (endp - data + 1) : size;
1752                if (prefix != '+') {
1753                        ecb->lno_in_preimage++;
1754                        emit_del_line(reset, ecb, data, len);
1755                } else {
1756                        ecb->lno_in_postimage++;
1757                        emit_add_line(reset, ecb, data, len);
1758                }
1759                size -= len;
1760                data += len;
1761        }
1762        if (!endp)
1763                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1764}
1765
1766static void emit_rewrite_diff(const char *name_a,
1767                              const char *name_b,
1768                              struct diff_filespec *one,
1769                              struct diff_filespec *two,
1770                              struct userdiff_driver *textconv_one,
1771                              struct userdiff_driver *textconv_two,
1772                              struct diff_options *o)
1773{
1774        int lc_a, lc_b;
1775        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1776        const char *a_prefix, *b_prefix;
1777        char *data_one, *data_two;
1778        size_t size_one, size_two;
1779        struct emit_callback ecbdata;
1780        struct strbuf out = STRBUF_INIT;
1781
1782        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1783                a_prefix = o->b_prefix;
1784                b_prefix = o->a_prefix;
1785        } else {
1786                a_prefix = o->a_prefix;
1787                b_prefix = o->b_prefix;
1788        }
1789
1790        name_a += (*name_a == '/');
1791        name_b += (*name_b == '/');
1792
1793        strbuf_reset(&a_name);
1794        strbuf_reset(&b_name);
1795        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1796        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1797
1798        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1799        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1800
1801        memset(&ecbdata, 0, sizeof(ecbdata));
1802        ecbdata.color_diff = want_color(o->use_color);
1803        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1804        ecbdata.opt = o;
1805        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1806                mmfile_t mf1, mf2;
1807                mf1.ptr = (char *)data_one;
1808                mf2.ptr = (char *)data_two;
1809                mf1.size = size_one;
1810                mf2.size = size_two;
1811                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1812        }
1813        ecbdata.lno_in_preimage = 1;
1814        ecbdata.lno_in_postimage = 1;
1815
1816        lc_a = count_lines(data_one, size_one);
1817        lc_b = count_lines(data_two, size_two);
1818
1819        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1820                         a_name.buf, a_name.len, 0);
1821        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1822                         b_name.buf, b_name.len, 0);
1823
1824        strbuf_addstr(&out, "@@ -");
1825        if (!o->irreversible_delete)
1826                add_line_count(&out, lc_a);
1827        else
1828                strbuf_addstr(&out, "?,?");
1829        strbuf_addstr(&out, " +");
1830        add_line_count(&out, lc_b);
1831        strbuf_addstr(&out, " @@\n");
1832        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1833        strbuf_release(&out);
1834
1835        if (lc_a && !o->irreversible_delete)
1836                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1837        if (lc_b)
1838                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1839        if (textconv_one)
1840                free((char *)data_one);
1841        if (textconv_two)
1842                free((char *)data_two);
1843}
1844
1845struct diff_words_buffer {
1846        mmfile_t text;
1847        unsigned long alloc;
1848        struct diff_words_orig {
1849                const char *begin, *end;
1850        } *orig;
1851        int orig_nr, orig_alloc;
1852};
1853
1854static void diff_words_append(char *line, unsigned long len,
1855                struct diff_words_buffer *buffer)
1856{
1857        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1858        line++;
1859        len--;
1860        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1861        buffer->text.size += len;
1862        buffer->text.ptr[buffer->text.size] = '\0';
1863}
1864
1865struct diff_words_style_elem {
1866        const char *prefix;
1867        const char *suffix;
1868        const char *color; /* NULL; filled in by the setup code if
1869                            * color is enabled */
1870};
1871
1872struct diff_words_style {
1873        enum diff_words_type type;
1874        struct diff_words_style_elem new_word, old_word, ctx;
1875        const char *newline;
1876};
1877
1878static struct diff_words_style diff_words_styles[] = {
1879        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1880        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1881        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1882};
1883
1884struct diff_words_data {
1885        struct diff_words_buffer minus, plus;
1886        const char *current_plus;
1887        int last_minus;
1888        struct diff_options *opt;
1889        regex_t *word_regex;
1890        enum diff_words_type type;
1891        struct diff_words_style *style;
1892};
1893
1894static int fn_out_diff_words_write_helper(struct diff_options *o,
1895                                          struct diff_words_style_elem *st_el,
1896                                          const char *newline,
1897                                          size_t count, const char *buf)
1898{
1899        int print = 0;
1900        struct strbuf sb = STRBUF_INIT;
1901
1902        while (count) {
1903                char *p = memchr(buf, '\n', count);
1904                if (print)
1905                        strbuf_addstr(&sb, diff_line_prefix(o));
1906
1907                if (p != buf) {
1908                        const char *reset = st_el->color && *st_el->color ?
1909                                            GIT_COLOR_RESET : NULL;
1910                        if (st_el->color && *st_el->color)
1911                                strbuf_addstr(&sb, st_el->color);
1912                        strbuf_addstr(&sb, st_el->prefix);
1913                        strbuf_add(&sb, buf, p ? p - buf : count);
1914                        strbuf_addstr(&sb, st_el->suffix);
1915                        if (reset)
1916                                strbuf_addstr(&sb, reset);
1917                }
1918                if (!p)
1919                        goto out;
1920
1921                strbuf_addstr(&sb, newline);
1922                count -= p + 1 - buf;
1923                buf = p + 1;
1924                print = 1;
1925                if (count) {
1926                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1927                                         sb.buf, sb.len, 0);
1928                        strbuf_reset(&sb);
1929                }
1930        }
1931
1932out:
1933        if (sb.len)
1934                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1935                                 sb.buf, sb.len, 0);
1936        strbuf_release(&sb);
1937        return 0;
1938}
1939
1940/*
1941 * '--color-words' algorithm can be described as:
1942 *
1943 *   1. collect the minus/plus lines of a diff hunk, divided into
1944 *      minus-lines and plus-lines;
1945 *
1946 *   2. break both minus-lines and plus-lines into words and
1947 *      place them into two mmfile_t with one word for each line;
1948 *
1949 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1950 *
1951 * And for the common parts of the both file, we output the plus side text.
1952 * diff_words->current_plus is used to trace the current position of the plus file
1953 * which printed. diff_words->last_minus is used to trace the last minus word
1954 * printed.
1955 *
1956 * For '--graph' to work with '--color-words', we need to output the graph prefix
1957 * on each line of color words output. Generally, there are two conditions on
1958 * which we should output the prefix.
1959 *
1960 *   1. diff_words->last_minus == 0 &&
1961 *      diff_words->current_plus == diff_words->plus.text.ptr
1962 *
1963 *      that is: the plus text must start as a new line, and if there is no minus
1964 *      word printed, a graph prefix must be printed.
1965 *
1966 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1967 *      *(diff_words->current_plus - 1) == '\n'
1968 *
1969 *      that is: a graph prefix must be printed following a '\n'
1970 */
1971static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1972{
1973        if ((diff_words->last_minus == 0 &&
1974                diff_words->current_plus == diff_words->plus.text.ptr) ||
1975                (diff_words->current_plus > diff_words->plus.text.ptr &&
1976                *(diff_words->current_plus - 1) == '\n')) {
1977                return 1;
1978        } else {
1979                return 0;
1980        }
1981}
1982
1983static void fn_out_diff_words_aux(void *priv,
1984                                  long minus_first, long minus_len,
1985                                  long plus_first, long plus_len,
1986                                  const char *func, long funclen)
1987{
1988        struct diff_words_data *diff_words = priv;
1989        struct diff_words_style *style = diff_words->style;
1990        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1991        struct diff_options *opt = diff_words->opt;
1992        const char *line_prefix;
1993
1994        assert(opt);
1995        line_prefix = diff_line_prefix(opt);
1996
1997        /* POSIX requires that first be decremented by one if len == 0... */
1998        if (minus_len) {
1999                minus_begin = diff_words->minus.orig[minus_first].begin;
2000                minus_end =
2001                        diff_words->minus.orig[minus_first + minus_len - 1].end;
2002        } else
2003                minus_begin = minus_end =
2004                        diff_words->minus.orig[minus_first].end;
2005
2006        if (plus_len) {
2007                plus_begin = diff_words->plus.orig[plus_first].begin;
2008                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
2009        } else
2010                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
2011
2012        if (color_words_output_graph_prefix(diff_words)) {
2013                fputs(line_prefix, diff_words->opt->file);
2014        }
2015        if (diff_words->current_plus != plus_begin) {
2016                fn_out_diff_words_write_helper(diff_words->opt,
2017                                &style->ctx, style->newline,
2018                                plus_begin - diff_words->current_plus,
2019                                diff_words->current_plus);
2020        }
2021        if (minus_begin != minus_end) {
2022                fn_out_diff_words_write_helper(diff_words->opt,
2023                                &style->old_word, style->newline,
2024                                minus_end - minus_begin, minus_begin);
2025        }
2026        if (plus_begin != plus_end) {
2027                fn_out_diff_words_write_helper(diff_words->opt,
2028                                &style->new_word, style->newline,
2029                                plus_end - plus_begin, plus_begin);
2030        }
2031
2032        diff_words->current_plus = plus_end;
2033        diff_words->last_minus = minus_first;
2034}
2035
2036/* This function starts looking at *begin, and returns 0 iff a word was found. */
2037static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
2038                int *begin, int *end)
2039{
2040        if (word_regex && *begin < buffer->size) {
2041                regmatch_t match[1];
2042                if (!regexec_buf(word_regex, buffer->ptr + *begin,
2043                                 buffer->size - *begin, 1, match, 0)) {
2044                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
2045                                        '\n', match[0].rm_eo - match[0].rm_so);
2046                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
2047                        *begin += match[0].rm_so;
2048                        return *begin >= *end;
2049                }
2050                return -1;
2051        }
2052
2053        /* find the next word */
2054        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
2055                (*begin)++;
2056        if (*begin >= buffer->size)
2057                return -1;
2058
2059        /* find the end of the word */
2060        *end = *begin + 1;
2061        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
2062                (*end)++;
2063
2064        return 0;
2065}
2066
2067/*
2068 * This function splits the words in buffer->text, stores the list with
2069 * newline separator into out, and saves the offsets of the original words
2070 * in buffer->orig.
2071 */
2072static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2073                regex_t *word_regex)
2074{
2075        int i, j;
2076        long alloc = 0;
2077
2078        out->size = 0;
2079        out->ptr = NULL;
2080
2081        /* fake an empty "0th" word */
2082        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2083        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2084        buffer->orig_nr = 1;
2085
2086        for (i = 0; i < buffer->text.size; i++) {
2087                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2088                        return;
2089
2090                /* store original boundaries */
2091                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2092                                buffer->orig_alloc);
2093                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2094                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2095                buffer->orig_nr++;
2096
2097                /* store one word */
2098                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2099                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2100                out->ptr[out->size + j - i] = '\n';
2101                out->size += j - i + 1;
2102
2103                i = j - 1;
2104        }
2105}
2106
2107/* this executes the word diff on the accumulated buffers */
2108static void diff_words_show(struct diff_words_data *diff_words)
2109{
2110        xpparam_t xpp;
2111        xdemitconf_t xecfg;
2112        mmfile_t minus, plus;
2113        struct diff_words_style *style = diff_words->style;
2114
2115        struct diff_options *opt = diff_words->opt;
2116        const char *line_prefix;
2117
2118        assert(opt);
2119        line_prefix = diff_line_prefix(opt);
2120
2121        /* special case: only removal */
2122        if (!diff_words->plus.text.size) {
2123                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2124                                 line_prefix, strlen(line_prefix), 0);
2125                fn_out_diff_words_write_helper(diff_words->opt,
2126                        &style->old_word, style->newline,
2127                        diff_words->minus.text.size,
2128                        diff_words->minus.text.ptr);
2129                diff_words->minus.text.size = 0;
2130                return;
2131        }
2132
2133        diff_words->current_plus = diff_words->plus.text.ptr;
2134        diff_words->last_minus = 0;
2135
2136        memset(&xpp, 0, sizeof(xpp));
2137        memset(&xecfg, 0, sizeof(xecfg));
2138        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2139        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2140        xpp.flags = 0;
2141        /* as only the hunk header will be parsed, we need a 0-context */
2142        xecfg.ctxlen = 0;
2143        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2144                          diff_words, &xpp, &xecfg))
2145                die("unable to generate word diff");
2146        free(minus.ptr);
2147        free(plus.ptr);
2148        if (diff_words->current_plus != diff_words->plus.text.ptr +
2149                        diff_words->plus.text.size) {
2150                if (color_words_output_graph_prefix(diff_words))
2151                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2152                                         line_prefix, strlen(line_prefix), 0);
2153                fn_out_diff_words_write_helper(diff_words->opt,
2154                        &style->ctx, style->newline,
2155                        diff_words->plus.text.ptr + diff_words->plus.text.size
2156                        - diff_words->current_plus, diff_words->current_plus);
2157        }
2158        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2159}
2160
2161/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2162static void diff_words_flush(struct emit_callback *ecbdata)
2163{
2164        struct diff_options *wo = ecbdata->diff_words->opt;
2165
2166        if (ecbdata->diff_words->minus.text.size ||
2167            ecbdata->diff_words->plus.text.size)
2168                diff_words_show(ecbdata->diff_words);
2169
2170        if (wo->emitted_symbols) {
2171                struct diff_options *o = ecbdata->opt;
2172                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2173                int i;
2174
2175                /*
2176                 * NEEDSWORK:
2177                 * Instead of appending each, concat all words to a line?
2178                 */
2179                for (i = 0; i < wol->nr; i++)
2180                        append_emitted_diff_symbol(o, &wol->buf[i]);
2181
2182                for (i = 0; i < wol->nr; i++)
2183                        free((void *)wol->buf[i].line);
2184
2185                wol->nr = 0;
2186        }
2187}
2188
2189static void diff_filespec_load_driver(struct diff_filespec *one,
2190                                      struct index_state *istate)
2191{
2192        /* Use already-loaded driver */
2193        if (one->driver)
2194                return;
2195
2196        if (S_ISREG(one->mode))
2197                one->driver = userdiff_find_by_path(istate, one->path);
2198
2199        /* Fallback to default settings */
2200        if (!one->driver)
2201                one->driver = userdiff_find_by_name("default");
2202}
2203
2204static const char *userdiff_word_regex(struct diff_filespec *one,
2205                                       struct index_state *istate)
2206{
2207        diff_filespec_load_driver(one, istate);
2208        return one->driver->word_regex;
2209}
2210
2211static void init_diff_words_data(struct emit_callback *ecbdata,
2212                                 struct diff_options *orig_opts,
2213                                 struct diff_filespec *one,
2214                                 struct diff_filespec *two)
2215{
2216        int i;
2217        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2218        memcpy(o, orig_opts, sizeof(struct diff_options));
2219
2220        ecbdata->diff_words =
2221                xcalloc(1, sizeof(struct diff_words_data));
2222        ecbdata->diff_words->type = o->word_diff;
2223        ecbdata->diff_words->opt = o;
2224
2225        if (orig_opts->emitted_symbols)
2226                o->emitted_symbols =
2227                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2228
2229        if (!o->word_regex)
2230                o->word_regex = userdiff_word_regex(one, o->repo->index);
2231        if (!o->word_regex)
2232                o->word_regex = userdiff_word_regex(two, o->repo->index);
2233        if (!o->word_regex)
2234                o->word_regex = diff_word_regex_cfg;
2235        if (o->word_regex) {
2236                ecbdata->diff_words->word_regex = (regex_t *)
2237                        xmalloc(sizeof(regex_t));
2238                if (regcomp(ecbdata->diff_words->word_regex,
2239                            o->word_regex,
2240                            REG_EXTENDED | REG_NEWLINE))
2241                        die("invalid regular expression: %s",
2242                            o->word_regex);
2243        }
2244        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2245                if (o->word_diff == diff_words_styles[i].type) {
2246                        ecbdata->diff_words->style =
2247                                &diff_words_styles[i];
2248                        break;
2249                }
2250        }
2251        if (want_color(o->use_color)) {
2252                struct diff_words_style *st = ecbdata->diff_words->style;
2253                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2254                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2255                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2256        }
2257}
2258
2259static void free_diff_words_data(struct emit_callback *ecbdata)
2260{
2261        if (ecbdata->diff_words) {
2262                diff_words_flush(ecbdata);
2263                free (ecbdata->diff_words->opt->emitted_symbols);
2264                free (ecbdata->diff_words->opt);
2265                free (ecbdata->diff_words->minus.text.ptr);
2266                free (ecbdata->diff_words->minus.orig);
2267                free (ecbdata->diff_words->plus.text.ptr);
2268                free (ecbdata->diff_words->plus.orig);
2269                if (ecbdata->diff_words->word_regex) {
2270                        regfree(ecbdata->diff_words->word_regex);
2271                        free(ecbdata->diff_words->word_regex);
2272                }
2273                FREE_AND_NULL(ecbdata->diff_words);
2274        }
2275}
2276
2277const char *diff_get_color(int diff_use_color, enum color_diff ix)
2278{
2279        if (want_color(diff_use_color))
2280                return diff_colors[ix];
2281        return "";
2282}
2283
2284const char *diff_line_prefix(struct diff_options *opt)
2285{
2286        struct strbuf *msgbuf;
2287        if (!opt->output_prefix)
2288                return "";
2289
2290        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2291        return msgbuf->buf;
2292}
2293
2294static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2295{
2296        const char *cp;
2297        unsigned long allot;
2298        size_t l = len;
2299
2300        cp = line;
2301        allot = l;
2302        while (0 < l) {
2303                (void) utf8_width(&cp, &l);
2304                if (!cp)
2305                        break; /* truncated in the middle? */
2306        }
2307        return allot - l;
2308}
2309
2310static void find_lno(const char *line, struct emit_callback *ecbdata)
2311{
2312        const char *p;
2313        ecbdata->lno_in_preimage = 0;
2314        ecbdata->lno_in_postimage = 0;
2315        p = strchr(line, '-');
2316        if (!p)
2317                return; /* cannot happen */
2318        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2319        p = strchr(p, '+');
2320        if (!p)
2321                return; /* cannot happen */
2322        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2323}
2324
2325static void fn_out_consume(void *priv, char *line, unsigned long len)
2326{
2327        struct emit_callback *ecbdata = priv;
2328        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2329        struct diff_options *o = ecbdata->opt;
2330
2331        o->found_changes = 1;
2332
2333        if (ecbdata->header) {
2334                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2335                                 ecbdata->header->buf, ecbdata->header->len, 0);
2336                strbuf_reset(ecbdata->header);
2337                ecbdata->header = NULL;
2338        }
2339
2340        if (ecbdata->label_path[0]) {
2341                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2342                                 ecbdata->label_path[0],
2343                                 strlen(ecbdata->label_path[0]), 0);
2344                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2345                                 ecbdata->label_path[1],
2346                                 strlen(ecbdata->label_path[1]), 0);
2347                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2348        }
2349
2350        if (diff_suppress_blank_empty
2351            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2352                line[0] = '\n';
2353                len = 1;
2354        }
2355
2356        if (line[0] == '@') {
2357                if (ecbdata->diff_words)
2358                        diff_words_flush(ecbdata);
2359                len = sane_truncate_line(ecbdata, line, len);
2360                find_lno(line, ecbdata);
2361                emit_hunk_header(ecbdata, line, len);
2362                return;
2363        }
2364
2365        if (ecbdata->diff_words) {
2366                enum diff_symbol s =
2367                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2368                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2369                if (line[0] == '-') {
2370                        diff_words_append(line, len,
2371                                          &ecbdata->diff_words->minus);
2372                        return;
2373                } else if (line[0] == '+') {
2374                        diff_words_append(line, len,
2375                                          &ecbdata->diff_words->plus);
2376                        return;
2377                } else if (starts_with(line, "\\ ")) {
2378                        /*
2379                         * Eat the "no newline at eof" marker as if we
2380                         * saw a "+" or "-" line with nothing on it,
2381                         * and return without diff_words_flush() to
2382                         * defer processing. If this is the end of
2383                         * preimage, more "+" lines may come after it.
2384                         */
2385                        return;
2386                }
2387                diff_words_flush(ecbdata);
2388                emit_diff_symbol(o, s, line, len, 0);
2389                return;
2390        }
2391
2392        switch (line[0]) {
2393        case '+':
2394                ecbdata->lno_in_postimage++;
2395                emit_add_line(reset, ecbdata, line + 1, len - 1);
2396                break;
2397        case '-':
2398                ecbdata->lno_in_preimage++;
2399                emit_del_line(reset, ecbdata, line + 1, len - 1);
2400                break;
2401        case ' ':
2402                ecbdata->lno_in_postimage++;
2403                ecbdata->lno_in_preimage++;
2404                emit_context_line(reset, ecbdata, line + 1, len - 1);
2405                break;
2406        default:
2407                /* incomplete line at the end */
2408                ecbdata->lno_in_preimage++;
2409                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2410                                 line, len, 0);
2411                break;
2412        }
2413}
2414
2415static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2416{
2417        const char *old_name = a;
2418        const char *new_name = b;
2419        int pfx_length, sfx_length;
2420        int pfx_adjust_for_slash;
2421        int len_a = strlen(a);
2422        int len_b = strlen(b);
2423        int a_midlen, b_midlen;
2424        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2425        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2426
2427        if (qlen_a || qlen_b) {
2428                quote_c_style(a, name, NULL, 0);
2429                strbuf_addstr(name, " => ");
2430                quote_c_style(b, name, NULL, 0);
2431                return;
2432        }
2433
2434        /* Find common prefix */
2435        pfx_length = 0;
2436        while (*old_name && *new_name && *old_name == *new_name) {
2437                if (*old_name == '/')
2438                        pfx_length = old_name - a + 1;
2439                old_name++;
2440                new_name++;
2441        }
2442
2443        /* Find common suffix */
2444        old_name = a + len_a;
2445        new_name = b + len_b;
2446        sfx_length = 0;
2447        /*
2448         * If there is a common prefix, it must end in a slash.  In
2449         * that case we let this loop run 1 into the prefix to see the
2450         * same slash.
2451         *
2452         * If there is no common prefix, we cannot do this as it would
2453         * underrun the input strings.
2454         */
2455        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2456        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2457               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2458               *old_name == *new_name) {
2459                if (*old_name == '/')
2460                        sfx_length = len_a - (old_name - a);
2461                old_name--;
2462                new_name--;
2463        }
2464
2465        /*
2466         * pfx{mid-a => mid-b}sfx
2467         * {pfx-a => pfx-b}sfx
2468         * pfx{sfx-a => sfx-b}
2469         * name-a => name-b
2470         */
2471        a_midlen = len_a - pfx_length - sfx_length;
2472        b_midlen = len_b - pfx_length - sfx_length;
2473        if (a_midlen < 0)
2474                a_midlen = 0;
2475        if (b_midlen < 0)
2476                b_midlen = 0;
2477
2478        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2479        if (pfx_length + sfx_length) {
2480                strbuf_add(name, a, pfx_length);
2481                strbuf_addch(name, '{');
2482        }
2483        strbuf_add(name, a + pfx_length, a_midlen);
2484        strbuf_addstr(name, " => ");
2485        strbuf_add(name, b + pfx_length, b_midlen);
2486        if (pfx_length + sfx_length) {
2487                strbuf_addch(name, '}');
2488                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2489        }
2490}
2491
2492struct diffstat_t {
2493        int nr;
2494        int alloc;
2495        struct diffstat_file {
2496                char *from_name;
2497                char *name;
2498                char *print_name;
2499                const char *comments;
2500                unsigned is_unmerged:1;
2501                unsigned is_binary:1;
2502                unsigned is_renamed:1;
2503                unsigned is_interesting:1;
2504                uintmax_t added, deleted;
2505        } **files;
2506};
2507
2508static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2509                                          const char *name_a,
2510                                          const char *name_b)
2511{
2512        struct diffstat_file *x;
2513        x = xcalloc(1, sizeof(*x));
2514        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2515        diffstat->files[diffstat->nr++] = x;
2516        if (name_b) {
2517                x->from_name = xstrdup(name_a);
2518                x->name = xstrdup(name_b);
2519                x->is_renamed = 1;
2520        }
2521        else {
2522                x->from_name = NULL;
2523                x->name = xstrdup(name_a);
2524        }
2525        return x;
2526}
2527
2528static void diffstat_consume(void *priv, char *line, unsigned long len)
2529{
2530        struct diffstat_t *diffstat = priv;
2531        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2532
2533        if (line[0] == '+')
2534                x->added++;
2535        else if (line[0] == '-')
2536                x->deleted++;
2537}
2538
2539const char mime_boundary_leader[] = "------------";
2540
2541static int scale_linear(int it, int width, int max_change)
2542{
2543        if (!it)
2544                return 0;
2545        /*
2546         * make sure that at least one '-' or '+' is printed if
2547         * there is any change to this path. The easiest way is to
2548         * scale linearly as if the alloted width is one column shorter
2549         * than it is, and then add 1 to the result.
2550         */
2551        return 1 + (it * (width - 1) / max_change);
2552}
2553
2554static void show_graph(struct strbuf *out, char ch, int cnt,
2555                       const char *set, const char *reset)
2556{
2557        if (cnt <= 0)
2558                return;
2559        strbuf_addstr(out, set);
2560        strbuf_addchars(out, ch, cnt);
2561        strbuf_addstr(out, reset);
2562}
2563
2564static void fill_print_name(struct diffstat_file *file)
2565{
2566        struct strbuf pname = STRBUF_INIT;
2567
2568        if (file->print_name)
2569                return;
2570
2571        if (file->is_renamed)
2572                pprint_rename(&pname, file->from_name, file->name);
2573        else
2574                quote_c_style(file->name, &pname, NULL, 0);
2575
2576        if (file->comments)
2577                strbuf_addf(&pname, " (%s)", file->comments);
2578
2579        file->print_name = strbuf_detach(&pname, NULL);
2580}
2581
2582static void print_stat_summary_inserts_deletes(struct diff_options *options,
2583                int files, int insertions, int deletions)
2584{
2585        struct strbuf sb = STRBUF_INIT;
2586
2587        if (!files) {
2588                assert(insertions == 0 && deletions == 0);
2589                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2590                                 NULL, 0, 0);
2591                return;
2592        }
2593
2594        strbuf_addf(&sb,
2595                    (files == 1) ? " %d file changed" : " %d files changed",
2596                    files);
2597
2598        /*
2599         * For binary diff, the caller may want to print "x files
2600         * changed" with insertions == 0 && deletions == 0.
2601         *
2602         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2603         * is probably less confusing (i.e skip over "2 files changed
2604         * but nothing about added/removed lines? Is this a bug in Git?").
2605         */
2606        if (insertions || deletions == 0) {
2607                strbuf_addf(&sb,
2608                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2609                            insertions);
2610        }
2611
2612        if (deletions || insertions == 0) {
2613                strbuf_addf(&sb,
2614                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2615                            deletions);
2616        }
2617        strbuf_addch(&sb, '\n');
2618        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2619                         sb.buf, sb.len, 0);
2620        strbuf_release(&sb);
2621}
2622
2623void print_stat_summary(FILE *fp, int files,
2624                        int insertions, int deletions)
2625{
2626        struct diff_options o;
2627        memset(&o, 0, sizeof(o));
2628        o.file = fp;
2629
2630        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2631}
2632
2633static void show_stats(struct diffstat_t *data, struct diff_options *options)
2634{
2635        int i, len, add, del, adds = 0, dels = 0;
2636        uintmax_t max_change = 0, max_len = 0;
2637        int total_files = data->nr, count;
2638        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2639        const char *reset, *add_c, *del_c;
2640        int extra_shown = 0;
2641        const char *line_prefix = diff_line_prefix(options);
2642        struct strbuf out = STRBUF_INIT;
2643
2644        if (data->nr == 0)
2645                return;
2646
2647        count = options->stat_count ? options->stat_count : data->nr;
2648
2649        reset = diff_get_color_opt(options, DIFF_RESET);
2650        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2651        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2652
2653        /*
2654         * Find the longest filename and max number of changes
2655         */
2656        for (i = 0; (i < count) && (i < data->nr); i++) {
2657                struct diffstat_file *file = data->files[i];
2658                uintmax_t change = file->added + file->deleted;
2659
2660                if (!file->is_interesting && (change == 0)) {
2661                        count++; /* not shown == room for one more */
2662                        continue;
2663                }
2664                fill_print_name(file);
2665                len = strlen(file->print_name);
2666                if (max_len < len)
2667                        max_len = len;
2668
2669                if (file->is_unmerged) {
2670                        /* "Unmerged" is 8 characters */
2671                        bin_width = bin_width < 8 ? 8 : bin_width;
2672                        continue;
2673                }
2674                if (file->is_binary) {
2675                        /* "Bin XXX -> YYY bytes" */
2676                        int w = 14 + decimal_width(file->added)
2677                                + decimal_width(file->deleted);
2678                        bin_width = bin_width < w ? w : bin_width;
2679                        /* Display change counts aligned with "Bin" */
2680                        number_width = 3;
2681                        continue;
2682                }
2683
2684                if (max_change < change)
2685                        max_change = change;
2686        }
2687        count = i; /* where we can stop scanning in data->files[] */
2688
2689        /*
2690         * We have width = stat_width or term_columns() columns total.
2691         * We want a maximum of min(max_len, stat_name_width) for the name part.
2692         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2693         * We also need 1 for " " and 4 + decimal_width(max_change)
2694         * for " | NNNN " and one the empty column at the end, altogether
2695         * 6 + decimal_width(max_change).
2696         *
2697         * If there's not enough space, we will use the smaller of
2698         * stat_name_width (if set) and 5/8*width for the filename,
2699         * and the rest for constant elements + graph part, but no more
2700         * than stat_graph_width for the graph part.
2701         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2702         * for the standard terminal size).
2703         *
2704         * In other words: stat_width limits the maximum width, and
2705         * stat_name_width fixes the maximum width of the filename,
2706         * and is also used to divide available columns if there
2707         * aren't enough.
2708         *
2709         * Binary files are displayed with "Bin XXX -> YYY bytes"
2710         * instead of the change count and graph. This part is treated
2711         * similarly to the graph part, except that it is not
2712         * "scaled". If total width is too small to accommodate the
2713         * guaranteed minimum width of the filename part and the
2714         * separators and this message, this message will "overflow"
2715         * making the line longer than the maximum width.
2716         */
2717
2718        if (options->stat_width == -1)
2719                width = term_columns() - strlen(line_prefix);
2720        else
2721                width = options->stat_width ? options->stat_width : 80;
2722        number_width = decimal_width(max_change) > number_width ?
2723                decimal_width(max_change) : number_width;
2724
2725        if (options->stat_graph_width == -1)
2726                options->stat_graph_width = diff_stat_graph_width;
2727
2728        /*
2729         * Guarantee 3/8*16==6 for the graph part
2730         * and 5/8*16==10 for the filename part
2731         */
2732        if (width < 16 + 6 + number_width)
2733                width = 16 + 6 + number_width;
2734
2735        /*
2736         * First assign sizes that are wanted, ignoring available width.
2737         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2738         * starting from "XXX" should fit in graph_width.
2739         */
2740        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2741        if (options->stat_graph_width &&
2742            options->stat_graph_width < graph_width)
2743                graph_width = options->stat_graph_width;
2744
2745        name_width = (options->stat_name_width > 0 &&
2746                      options->stat_name_width < max_len) ?
2747                options->stat_name_width : max_len;
2748
2749        /*
2750         * Adjust adjustable widths not to exceed maximum width
2751         */
2752        if (name_width + number_width + 6 + graph_width > width) {
2753                if (graph_width > width * 3/8 - number_width - 6) {
2754                        graph_width = width * 3/8 - number_width - 6;
2755                        if (graph_width < 6)
2756                                graph_width = 6;
2757                }
2758
2759                if (options->stat_graph_width &&
2760                    graph_width > options->stat_graph_width)
2761                        graph_width = options->stat_graph_width;
2762                if (name_width > width - number_width - 6 - graph_width)
2763                        name_width = width - number_width - 6 - graph_width;
2764                else
2765                        graph_width = width - number_width - 6 - name_width;
2766        }
2767
2768        /*
2769         * From here name_width is the width of the name area,
2770         * and graph_width is the width of the graph area.
2771         * max_change is used to scale graph properly.
2772         */
2773        for (i = 0; i < count; i++) {
2774                const char *prefix = "";
2775                struct diffstat_file *file = data->files[i];
2776                char *name = file->print_name;
2777                uintmax_t added = file->added;
2778                uintmax_t deleted = file->deleted;
2779                int name_len;
2780
2781                if (!file->is_interesting && (added + deleted == 0))
2782                        continue;
2783
2784                /*
2785                 * "scale" the filename
2786                 */
2787                len = name_width;
2788                name_len = strlen(name);
2789                if (name_width < name_len) {
2790                        char *slash;
2791                        prefix = "...";
2792                        len -= 3;
2793                        name += name_len - len;
2794                        slash = strchr(name, '/');
2795                        if (slash)
2796                                name = slash;
2797                }
2798
2799                if (file->is_binary) {
2800                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2801                        strbuf_addf(&out, " %*s", number_width, "Bin");
2802                        if (!added && !deleted) {
2803                                strbuf_addch(&out, '\n');
2804                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2805                                                 out.buf, out.len, 0);
2806                                strbuf_reset(&out);
2807                                continue;
2808                        }
2809                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2810                                del_c, deleted, reset);
2811                        strbuf_addstr(&out, " -> ");
2812                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2813                                add_c, added, reset);
2814                        strbuf_addstr(&out, " bytes\n");
2815                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2816                                         out.buf, out.len, 0);
2817                        strbuf_reset(&out);
2818                        continue;
2819                }
2820                else if (file->is_unmerged) {
2821                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2822                        strbuf_addstr(&out, " Unmerged\n");
2823                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2824                                         out.buf, out.len, 0);
2825                        strbuf_reset(&out);
2826                        continue;
2827                }
2828
2829                /*
2830                 * scale the add/delete
2831                 */
2832                add = added;
2833                del = deleted;
2834
2835                if (graph_width <= max_change) {
2836                        int total = scale_linear(add + del, graph_width, max_change);
2837                        if (total < 2 && add && del)
2838                                /* width >= 2 due to the sanity check */
2839                                total = 2;
2840                        if (add < del) {
2841                                add = scale_linear(add, graph_width, max_change);
2842                                del = total - add;
2843                        } else {
2844                                del = scale_linear(del, graph_width, max_change);
2845                                add = total - del;
2846                        }
2847                }
2848                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2849                strbuf_addf(&out, " %*"PRIuMAX"%s",
2850                        number_width, added + deleted,
2851                        added + deleted ? " " : "");
2852                show_graph(&out, '+', add, add_c, reset);
2853                show_graph(&out, '-', del, del_c, reset);
2854                strbuf_addch(&out, '\n');
2855                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2856                                 out.buf, out.len, 0);
2857                strbuf_reset(&out);
2858        }
2859
2860        for (i = 0; i < data->nr; i++) {
2861                struct diffstat_file *file = data->files[i];
2862                uintmax_t added = file->added;
2863                uintmax_t deleted = file->deleted;
2864
2865                if (file->is_unmerged ||
2866                    (!file->is_interesting && (added + deleted == 0))) {
2867                        total_files--;
2868                        continue;
2869                }
2870
2871                if (!file->is_binary) {
2872                        adds += added;
2873                        dels += deleted;
2874                }
2875                if (i < count)
2876                        continue;
2877                if (!extra_shown)
2878                        emit_diff_symbol(options,
2879                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2880                                         NULL, 0, 0);
2881                extra_shown = 1;
2882        }
2883
2884        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2885        strbuf_release(&out);
2886}
2887
2888static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2889{
2890        int i, adds = 0, dels = 0, total_files = data->nr;
2891
2892        if (data->nr == 0)
2893                return;
2894
2895        for (i = 0; i < data->nr; i++) {
2896                int added = data->files[i]->added;
2897                int deleted = data->files[i]->deleted;
2898
2899                if (data->files[i]->is_unmerged ||
2900                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2901                        total_files--;
2902                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2903                        adds += added;
2904                        dels += deleted;
2905                }
2906        }
2907        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2908}
2909
2910static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2911{
2912        int i;
2913
2914        if (data->nr == 0)
2915                return;
2916
2917        for (i = 0; i < data->nr; i++) {
2918                struct diffstat_file *file = data->files[i];
2919
2920                fprintf(options->file, "%s", diff_line_prefix(options));
2921
2922                if (file->is_binary)
2923                        fprintf(options->file, "-\t-\t");
2924                else
2925                        fprintf(options->file,
2926                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2927                                file->added, file->deleted);
2928                if (options->line_termination) {
2929                        fill_print_name(file);
2930                        if (!file->is_renamed)
2931                                write_name_quoted(file->name, options->file,
2932                                                  options->line_termination);
2933                        else {
2934                                fputs(file->print_name, options->file);
2935                                putc(options->line_termination, options->file);
2936                        }
2937                } else {
2938                        if (file->is_renamed) {
2939                                putc('\0', options->file);
2940                                write_name_quoted(file->from_name, options->file, '\0');
2941                        }
2942                        write_name_quoted(file->name, options->file, '\0');
2943                }
2944        }
2945}
2946
2947struct dirstat_file {
2948        const char *name;
2949        unsigned long changed;
2950};
2951
2952struct dirstat_dir {
2953        struct dirstat_file *files;
2954        int alloc, nr, permille, cumulative;
2955};
2956
2957static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2958                unsigned long changed, const char *base, int baselen)
2959{
2960        unsigned long sum_changes = 0;
2961        unsigned int sources = 0;
2962        const char *line_prefix = diff_line_prefix(opt);
2963
2964        while (dir->nr) {
2965                struct dirstat_file *f = dir->files;
2966                int namelen = strlen(f->name);
2967                unsigned long changes;
2968                char *slash;
2969
2970                if (namelen < baselen)
2971                        break;
2972                if (memcmp(f->name, base, baselen))
2973                        break;
2974                slash = strchr(f->name + baselen, '/');
2975                if (slash) {
2976                        int newbaselen = slash + 1 - f->name;
2977                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2978                        sources++;
2979                } else {
2980                        changes = f->changed;
2981                        dir->files++;
2982                        dir->nr--;
2983                        sources += 2;
2984                }
2985                sum_changes += changes;
2986        }
2987
2988        /*
2989         * We don't report dirstat's for
2990         *  - the top level
2991         *  - or cases where everything came from a single directory
2992         *    under this directory (sources == 1).
2993         */
2994        if (baselen && sources != 1) {
2995                if (sum_changes) {
2996                        int permille = sum_changes * 1000 / changed;
2997                        if (permille >= dir->permille) {
2998                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2999                                        permille / 10, permille % 10, baselen, base);
3000                                if (!dir->cumulative)
3001                                        return 0;
3002                        }
3003                }
3004        }
3005        return sum_changes;
3006}
3007
3008static int dirstat_compare(const void *_a, const void *_b)
3009{
3010        const struct dirstat_file *a = _a;
3011        const struct dirstat_file *b = _b;
3012        return strcmp(a->name, b->name);
3013}
3014
3015static void show_dirstat(struct diff_options *options)
3016{
3017        int i;
3018        unsigned long changed;
3019        struct dirstat_dir dir;
3020        struct diff_queue_struct *q = &diff_queued_diff;
3021
3022        dir.files = NULL;
3023        dir.alloc = 0;
3024        dir.nr = 0;
3025        dir.permille = options->dirstat_permille;
3026        dir.cumulative = options->flags.dirstat_cumulative;
3027
3028        changed = 0;
3029        for (i = 0; i < q->nr; i++) {
3030                struct diff_filepair *p = q->queue[i];
3031                const char *name;
3032                unsigned long copied, added, damage;
3033
3034                name = p->two->path ? p->two->path : p->one->path;
3035
3036                if (p->one->oid_valid && p->two->oid_valid &&
3037                    oideq(&p->one->oid, &p->two->oid)) {
3038                        /*
3039                         * The SHA1 has not changed, so pre-/post-content is
3040                         * identical. We can therefore skip looking at the
3041                         * file contents altogether.
3042                         */
3043                        damage = 0;
3044                        goto found_damage;
3045                }
3046
3047                if (options->flags.dirstat_by_file) {
3048                        /*
3049                         * In --dirstat-by-file mode, we don't really need to
3050                         * look at the actual file contents at all.
3051                         * The fact that the SHA1 changed is enough for us to
3052                         * add this file to the list of results
3053                         * (with each file contributing equal damage).
3054                         */
3055                        damage = 1;
3056                        goto found_damage;
3057                }
3058
3059                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
3060                        diff_populate_filespec(options->repo, p->one, 0);
3061                        diff_populate_filespec(options->repo, p->two, 0);
3062                        diffcore_count_changes(options->repo,
3063                                               p->one, p->two, NULL, NULL,
3064                                               &copied, &added);
3065                        diff_free_filespec_data(p->one);
3066                        diff_free_filespec_data(p->two);
3067                } else if (DIFF_FILE_VALID(p->one)) {
3068                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3069                        copied = added = 0;
3070                        diff_free_filespec_data(p->one);
3071                } else if (DIFF_FILE_VALID(p->two)) {
3072                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3073                        copied = 0;
3074                        added = p->two->size;
3075                        diff_free_filespec_data(p->two);
3076                } else
3077                        continue;
3078
3079                /*
3080                 * Original minus copied is the removed material,
3081                 * added is the new material.  They are both damages
3082                 * made to the preimage.
3083                 * If the resulting damage is zero, we know that
3084                 * diffcore_count_changes() considers the two entries to
3085                 * be identical, but since the oid changed, we
3086                 * know that there must have been _some_ kind of change,
3087                 * so we force all entries to have damage > 0.
3088                 */
3089                damage = (p->one->size - copied) + added;
3090                if (!damage)
3091                        damage = 1;
3092
3093found_damage:
3094                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3095                dir.files[dir.nr].name = name;
3096                dir.files[dir.nr].changed = damage;
3097                changed += damage;
3098                dir.nr++;
3099        }
3100
3101        /* This can happen even with many files, if everything was renames */
3102        if (!changed)
3103                return;
3104
3105        /* Show all directories with more than x% of the changes */
3106        QSORT(dir.files, dir.nr, dirstat_compare);
3107        gather_dirstat(options, &dir, changed, "", 0);
3108}
3109
3110static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3111{
3112        int i;
3113        unsigned long changed;
3114        struct dirstat_dir dir;
3115
3116        if (data->nr == 0)
3117                return;
3118
3119        dir.files = NULL;
3120        dir.alloc = 0;
3121        dir.nr = 0;
3122        dir.permille = options->dirstat_permille;
3123        dir.cumulative = options->flags.dirstat_cumulative;
3124
3125        changed = 0;
3126        for (i = 0; i < data->nr; i++) {
3127                struct diffstat_file *file = data->files[i];
3128                unsigned long damage = file->added + file->deleted;
3129                if (file->is_binary)
3130                        /*
3131                         * binary files counts bytes, not lines. Must find some
3132                         * way to normalize binary bytes vs. textual lines.
3133                         * The following heuristic assumes that there are 64
3134                         * bytes per "line".
3135                         * This is stupid and ugly, but very cheap...
3136                         */
3137                        damage = DIV_ROUND_UP(damage, 64);
3138                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3139                dir.files[dir.nr].name = file->name;
3140                dir.files[dir.nr].changed = damage;
3141                changed += damage;
3142                dir.nr++;
3143        }
3144
3145        /* This can happen even with many files, if everything was renames */
3146        if (!changed)
3147                return;
3148
3149        /* Show all directories with more than x% of the changes */
3150        QSORT(dir.files, dir.nr, dirstat_compare);
3151        gather_dirstat(options, &dir, changed, "", 0);
3152}
3153
3154static void free_diffstat_info(struct diffstat_t *diffstat)
3155{
3156        int i;
3157        for (i = 0; i < diffstat->nr; i++) {
3158                struct diffstat_file *f = diffstat->files[i];
3159                free(f->print_name);
3160                free(f->name);
3161                free(f->from_name);
3162                free(f);
3163        }
3164        free(diffstat->files);
3165}
3166
3167struct checkdiff_t {
3168        const char *filename;
3169        int lineno;
3170        int conflict_marker_size;
3171        struct diff_options *o;
3172        unsigned ws_rule;
3173        unsigned status;
3174};
3175
3176static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3177{
3178        char firstchar;
3179        int cnt;
3180
3181        if (len < marker_size + 1)
3182                return 0;
3183        firstchar = line[0];
3184        switch (firstchar) {
3185        case '=': case '>': case '<': case '|':
3186                break;
3187        default:
3188                return 0;
3189        }
3190        for (cnt = 1; cnt < marker_size; cnt++)
3191                if (line[cnt] != firstchar)
3192                        return 0;
3193        /* line[1] thru line[marker_size-1] are same as firstchar */
3194        if (len < marker_size + 1 || !isspace(line[marker_size]))
3195                return 0;
3196        return 1;
3197}
3198
3199static void checkdiff_consume_hunk(void *priv,
3200                                   long ob, long on, long nb, long nn,
3201                                   const char *func, long funclen)
3202
3203{
3204        struct checkdiff_t *data = priv;
3205        data->lineno = nb - 1;
3206}
3207
3208static void checkdiff_consume(void *priv, char *line, unsigned long len)
3209{
3210        struct checkdiff_t *data = priv;
3211        int marker_size = data->conflict_marker_size;
3212        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3213        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3214        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3215        char *err;
3216        const char *line_prefix;
3217
3218        assert(data->o);
3219        line_prefix = diff_line_prefix(data->o);
3220
3221        if (line[0] == '+') {
3222                unsigned bad;
3223                data->lineno++;
3224                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3225                        data->status |= 1;
3226                        fprintf(data->o->file,
3227                                "%s%s:%d: leftover conflict marker\n",
3228                                line_prefix, data->filename, data->lineno);
3229                }
3230                bad = ws_check(line + 1, len - 1, data->ws_rule);
3231                if (!bad)
3232                        return;
3233                data->status |= bad;
3234                err = whitespace_error_string(bad);
3235                fprintf(data->o->file, "%s%s:%d: %s.\n",
3236                        line_prefix, data->filename, data->lineno, err);
3237                free(err);
3238                emit_line(data->o, set, reset, line, 1);
3239                ws_check_emit(line + 1, len - 1, data->ws_rule,
3240                              data->o->file, set, reset, ws);
3241        } else if (line[0] == ' ') {
3242                data->lineno++;
3243        }
3244}
3245
3246static unsigned char *deflate_it(char *data,
3247                                 unsigned long size,
3248                                 unsigned long *result_size)
3249{
3250        int bound;
3251        unsigned char *deflated;
3252        git_zstream stream;
3253
3254        git_deflate_init(&stream, zlib_compression_level);
3255        bound = git_deflate_bound(&stream, size);
3256        deflated = xmalloc(bound);
3257        stream.next_out = deflated;
3258        stream.avail_out = bound;
3259
3260        stream.next_in = (unsigned char *)data;
3261        stream.avail_in = size;
3262        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3263                ; /* nothing */
3264        git_deflate_end(&stream);
3265        *result_size = stream.total_out;
3266        return deflated;
3267}
3268
3269static void emit_binary_diff_body(struct diff_options *o,
3270                                  mmfile_t *one, mmfile_t *two)
3271{
3272        void *cp;
3273        void *delta;
3274        void *deflated;
3275        void *data;
3276        unsigned long orig_size;
3277        unsigned long delta_size;
3278        unsigned long deflate_size;
3279        unsigned long data_size;
3280
3281        /* We could do deflated delta, or we could do just deflated two,
3282         * whichever is smaller.
3283         */
3284        delta = NULL;
3285        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3286        if (one->size && two->size) {
3287                delta = diff_delta(one->ptr, one->size,
3288                                   two->ptr, two->size,
3289                                   &delta_size, deflate_size);
3290                if (delta) {
3291                        void *to_free = delta;
3292                        orig_size = delta_size;
3293                        delta = deflate_it(delta, delta_size, &delta_size);
3294                        free(to_free);
3295                }
3296        }
3297
3298        if (delta && delta_size < deflate_size) {
3299                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3300                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3301                                 s, strlen(s), 0);
3302                free(s);
3303                free(deflated);
3304                data = delta;
3305                data_size = delta_size;
3306        } else {
3307                char *s = xstrfmt("%lu", two->size);
3308                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3309                                 s, strlen(s), 0);
3310                free(s);
3311                free(delta);
3312                data = deflated;
3313                data_size = deflate_size;
3314        }
3315
3316        /* emit data encoded in base85 */
3317        cp = data;
3318        while (data_size) {
3319                int len;
3320                int bytes = (52 < data_size) ? 52 : data_size;
3321                char line[71];
3322                data_size -= bytes;
3323                if (bytes <= 26)
3324                        line[0] = bytes + 'A' - 1;
3325                else
3326                        line[0] = bytes - 26 + 'a' - 1;
3327                encode_85(line + 1, cp, bytes);
3328                cp = (char *) cp + bytes;
3329
3330                len = strlen(line);
3331                line[len++] = '\n';
3332                line[len] = '\0';
3333
3334                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3335                                 line, len, 0);
3336        }
3337        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3338        free(data);
3339}
3340
3341static void emit_binary_diff(struct diff_options *o,
3342                             mmfile_t *one, mmfile_t *two)
3343{
3344        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3345        emit_binary_diff_body(o, one, two);
3346        emit_binary_diff_body(o, two, one);
3347}
3348
3349int diff_filespec_is_binary(struct repository *r,
3350                            struct diff_filespec *one)
3351{
3352        if (one->is_binary == -1) {
3353                diff_filespec_load_driver(one, r->index);
3354                if (one->driver->binary != -1)
3355                        one->is_binary = one->driver->binary;
3356                else {
3357                        if (!one->data && DIFF_FILE_VALID(one))
3358                                diff_populate_filespec(r, one, CHECK_BINARY);
3359                        if (one->is_binary == -1 && one->data)
3360                                one->is_binary = buffer_is_binary(one->data,
3361                                                one->size);
3362                        if (one->is_binary == -1)
3363                                one->is_binary = 0;
3364                }
3365        }
3366        return one->is_binary;
3367}
3368
3369static const struct userdiff_funcname *
3370diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3371{
3372        diff_filespec_load_driver(one, o->repo->index);
3373        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3374}
3375
3376void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3377{
3378        if (!options->a_prefix)
3379                options->a_prefix = a;
3380        if (!options->b_prefix)
3381                options->b_prefix = b;
3382}
3383
3384struct userdiff_driver *get_textconv(struct repository *r,
3385                                     struct diff_filespec *one)
3386{
3387        if (!DIFF_FILE_VALID(one))
3388                return NULL;
3389
3390        diff_filespec_load_driver(one, r->index);
3391        return userdiff_get_textconv(r, one->driver);
3392}
3393
3394static void builtin_diff(const char *name_a,
3395                         const char *name_b,
3396                         struct diff_filespec *one,
3397                         struct diff_filespec *two,
3398                         const char *xfrm_msg,
3399                         int must_show_header,
3400                         struct diff_options *o,
3401                         int complete_rewrite)
3402{
3403        mmfile_t mf1, mf2;
3404        const char *lbl[2];
3405        char *a_one, *b_two;
3406        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3407        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3408        const char *a_prefix, *b_prefix;
3409        struct userdiff_driver *textconv_one = NULL;
3410        struct userdiff_driver *textconv_two = NULL;
3411        struct strbuf header = STRBUF_INIT;
3412        const char *line_prefix = diff_line_prefix(o);
3413
3414        diff_set_mnemonic_prefix(o, "a/", "b/");
3415        if (o->flags.reverse_diff) {
3416                a_prefix = o->b_prefix;
3417                b_prefix = o->a_prefix;
3418        } else {
3419                a_prefix = o->a_prefix;
3420                b_prefix = o->b_prefix;
3421        }
3422
3423        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3424            (!one->mode || S_ISGITLINK(one->mode)) &&
3425            (!two->mode || S_ISGITLINK(two->mode))) {
3426                show_submodule_summary(o, one->path ? one->path : two->path,
3427                                &one->oid, &two->oid,
3428                                two->dirty_submodule);
3429                return;
3430        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3431                   (!one->mode || S_ISGITLINK(one->mode)) &&
3432                   (!two->mode || S_ISGITLINK(two->mode))) {
3433                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3434                                &one->oid, &two->oid,
3435                                two->dirty_submodule);
3436                return;
3437        }
3438
3439        if (o->flags.allow_textconv) {
3440                textconv_one = get_textconv(o->repo, one);
3441                textconv_two = get_textconv(o->repo, two);
3442        }
3443
3444        /* Never use a non-valid filename anywhere if at all possible */
3445        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3446        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3447
3448        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3449        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3450        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3451        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3452        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3453        if (lbl[0][0] == '/') {
3454                /* /dev/null */
3455                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3456                if (xfrm_msg)
3457                        strbuf_addstr(&header, xfrm_msg);
3458                must_show_header = 1;
3459        }
3460        else if (lbl[1][0] == '/') {
3461                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3462                if (xfrm_msg)
3463                        strbuf_addstr(&header, xfrm_msg);
3464                must_show_header = 1;
3465        }
3466        else {
3467                if (one->mode != two->mode) {
3468                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3469                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3470                        must_show_header = 1;
3471                }
3472                if (xfrm_msg)
3473                        strbuf_addstr(&header, xfrm_msg);
3474
3475                /*
3476                 * we do not run diff between different kind
3477                 * of objects.
3478                 */
3479                if ((one->mode ^ two->mode) & S_IFMT)
3480                        goto free_ab_and_return;
3481                if (complete_rewrite &&
3482                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3483                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3484                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3485                                         header.buf, header.len, 0);
3486                        strbuf_reset(&header);
3487                        emit_rewrite_diff(name_a, name_b, one, two,
3488                                          textconv_one, textconv_two, o);
3489                        o->found_changes = 1;
3490                        goto free_ab_and_return;
3491                }
3492        }
3493
3494        if (o->irreversible_delete && lbl[1][0] == '/') {
3495                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3496                                 header.len, 0);
3497                strbuf_reset(&header);
3498                goto free_ab_and_return;
3499        } else if (!o->flags.text &&
3500                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3501                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3502                struct strbuf sb = STRBUF_INIT;
3503                if (!one->data && !two->data &&
3504                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3505                    !o->flags.binary) {
3506                        if (oideq(&one->oid, &two->oid)) {
3507                                if (must_show_header)
3508                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3509                                                         header.buf, header.len,
3510                                                         0);
3511                                goto free_ab_and_return;
3512                        }
3513                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3514                                         header.buf, header.len, 0);
3515                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3516                                    diff_line_prefix(o), lbl[0], lbl[1]);
3517                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3518                                         sb.buf, sb.len, 0);
3519                        strbuf_release(&sb);
3520                        goto free_ab_and_return;
3521                }
3522                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3523                    fill_mmfile(o->repo, &mf2, two) < 0)
3524                        die("unable to read files to diff");
3525                /* Quite common confusing case */
3526                if (mf1.size == mf2.size &&
3527                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3528                        if (must_show_header)
3529                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3530                                                 header.buf, header.len, 0);
3531                        goto free_ab_and_return;
3532                }
3533                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3534                strbuf_reset(&header);
3535                if (o->flags.binary)
3536                        emit_binary_diff(o, &mf1, &mf2);
3537                else {
3538                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3539                                    diff_line_prefix(o), lbl[0], lbl[1]);
3540                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3541                                         sb.buf, sb.len, 0);
3542                        strbuf_release(&sb);
3543                }
3544                o->found_changes = 1;
3545        } else {
3546                /* Crazy xdl interfaces.. */
3547                const char *diffopts;
3548                const char *v;
3549                xpparam_t xpp;
3550                xdemitconf_t xecfg;
3551                struct emit_callback ecbdata;
3552                const struct userdiff_funcname *pe;
3553
3554                if (must_show_header) {
3555                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3556                                         header.buf, header.len, 0);
3557                        strbuf_reset(&header);
3558                }
3559
3560                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3561                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3562
3563                pe = diff_funcname_pattern(o, one);
3564                if (!pe)
3565                        pe = diff_funcname_pattern(o, two);
3566
3567                memset(&xpp, 0, sizeof(xpp));
3568                memset(&xecfg, 0, sizeof(xecfg));
3569                memset(&ecbdata, 0, sizeof(ecbdata));
3570                if (o->flags.suppress_diff_headers)
3571                        lbl[0] = NULL;
3572                ecbdata.label_path = lbl;
3573                ecbdata.color_diff = want_color(o->use_color);
3574                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3575                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3576                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3577                ecbdata.opt = o;
3578                if (header.len && !o->flags.suppress_diff_headers)
3579                        ecbdata.header = &header;
3580                xpp.flags = o->xdl_opts;
3581                xpp.anchors = o->anchors;
3582                xpp.anchors_nr = o->anchors_nr;
3583                xecfg.ctxlen = o->context;
3584                xecfg.interhunkctxlen = o->interhunkcontext;
3585                xecfg.flags = XDL_EMIT_FUNCNAMES;
3586                if (o->flags.funccontext)
3587                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3588                if (pe)
3589                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3590
3591                diffopts = getenv("GIT_DIFF_OPTS");
3592                if (!diffopts)
3593                        ;
3594                else if (skip_prefix(diffopts, "--unified=", &v))
3595                        xecfg.ctxlen = strtoul(v, NULL, 10);
3596                else if (skip_prefix(diffopts, "-u", &v))
3597                        xecfg.ctxlen = strtoul(v, NULL, 10);
3598
3599                if (o->word_diff)
3600                        init_diff_words_data(&ecbdata, o, one, two);
3601                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3602                                  &ecbdata, &xpp, &xecfg))
3603                        die("unable to generate diff for %s", one->path);
3604                if (o->word_diff)
3605                        free_diff_words_data(&ecbdata);
3606                if (textconv_one)
3607                        free(mf1.ptr);
3608                if (textconv_two)
3609                        free(mf2.ptr);
3610                xdiff_clear_find_func(&xecfg);
3611        }
3612
3613 free_ab_and_return:
3614        strbuf_release(&header);
3615        diff_free_filespec_data(one);
3616        diff_free_filespec_data(two);
3617        free(a_one);
3618        free(b_two);
3619        return;
3620}
3621
3622static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3623{
3624        if (!is_renamed) {
3625                if (p->status == DIFF_STATUS_ADDED) {
3626                        if (S_ISLNK(p->two->mode))
3627                                return "new +l";
3628                        else if ((p->two->mode & 0777) == 0755)
3629                                return "new +x";
3630                        else
3631                                return "new";
3632                } else if (p->status == DIFF_STATUS_DELETED)
3633                        return "gone";
3634        }
3635        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3636                return "mode -l";
3637        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3638                return "mode +l";
3639        else if ((p->one->mode & 0777) == 0644 &&
3640                 (p->two->mode & 0777) == 0755)
3641                return "mode +x";
3642        else if ((p->one->mode & 0777) == 0755 &&
3643                 (p->two->mode & 0777) == 0644)
3644                return "mode -x";
3645        return NULL;
3646}
3647
3648static void builtin_diffstat(const char *name_a, const char *name_b,
3649                             struct diff_filespec *one,
3650                             struct diff_filespec *two,
3651                             struct diffstat_t *diffstat,
3652                             struct diff_options *o,
3653                             struct diff_filepair *p)
3654{
3655        mmfile_t mf1, mf2;
3656        struct diffstat_file *data;
3657        int same_contents;
3658        int complete_rewrite = 0;
3659
3660        if (!DIFF_PAIR_UNMERGED(p)) {
3661                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3662                        complete_rewrite = 1;
3663        }
3664
3665        data = diffstat_add(diffstat, name_a, name_b);
3666        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3667        if (o->flags.stat_with_summary)
3668                data->comments = get_compact_summary(p, data->is_renamed);
3669
3670        if (!one || !two) {
3671                data->is_unmerged = 1;
3672                return;
3673        }
3674
3675        same_contents = oideq(&one->oid, &two->oid);
3676
3677        if (diff_filespec_is_binary(o->repo, one) ||
3678            diff_filespec_is_binary(o->repo, two)) {
3679                data->is_binary = 1;
3680                if (same_contents) {
3681                        data->added = 0;
3682                        data->deleted = 0;
3683                } else {
3684                        data->added = diff_filespec_size(o->repo, two);
3685                        data->deleted = diff_filespec_size(o->repo, one);
3686                }
3687        }
3688
3689        else if (complete_rewrite) {
3690                diff_populate_filespec(o->repo, one, 0);
3691                diff_populate_filespec(o->repo, two, 0);
3692                data->deleted = count_lines(one->data, one->size);
3693                data->added = count_lines(two->data, two->size);
3694        }
3695
3696        else if (!same_contents) {
3697                /* Crazy xdl interfaces.. */
3698                xpparam_t xpp;
3699                xdemitconf_t xecfg;
3700
3701                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3702                    fill_mmfile(o->repo, &mf2, two) < 0)
3703                        die("unable to read files to diff");
3704
3705                memset(&xpp, 0, sizeof(xpp));
3706                memset(&xecfg, 0, sizeof(xecfg));
3707                xpp.flags = o->xdl_opts;
3708                xpp.anchors = o->anchors;
3709                xpp.anchors_nr = o->anchors_nr;
3710                xecfg.ctxlen = o->context;
3711                xecfg.interhunkctxlen = o->interhunkcontext;
3712                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3713                                  diffstat_consume, diffstat, &xpp, &xecfg))
3714                        die("unable to generate diffstat for %s", one->path);
3715        }
3716
3717        diff_free_filespec_data(one);
3718        diff_free_filespec_data(two);
3719}
3720
3721static void builtin_checkdiff(const char *name_a, const char *name_b,
3722                              const char *attr_path,
3723                              struct diff_filespec *one,
3724                              struct diff_filespec *two,
3725                              struct diff_options *o)
3726{
3727        mmfile_t mf1, mf2;
3728        struct checkdiff_t data;
3729
3730        if (!two)
3731                return;
3732
3733        memset(&data, 0, sizeof(data));
3734        data.filename = name_b ? name_b : name_a;
3735        data.lineno = 0;
3736        data.o = o;
3737        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3738        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3739
3740        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3741            fill_mmfile(o->repo, &mf2, two) < 0)
3742                die("unable to read files to diff");
3743
3744        /*
3745         * All the other codepaths check both sides, but not checking
3746         * the "old" side here is deliberate.  We are checking the newly
3747         * introduced changes, and as long as the "new" side is text, we
3748         * can and should check what it introduces.
3749         */
3750        if (diff_filespec_is_binary(o->repo, two))
3751                goto free_and_return;
3752        else {
3753                /* Crazy xdl interfaces.. */
3754                xpparam_t xpp;
3755                xdemitconf_t xecfg;
3756
3757                memset(&xpp, 0, sizeof(xpp));
3758                memset(&xecfg, 0, sizeof(xecfg));
3759                xecfg.ctxlen = 1; /* at least one context line */
3760                xpp.flags = 0;
3761                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3762                                  checkdiff_consume, &data,
3763                                  &xpp, &xecfg))
3764                        die("unable to generate checkdiff for %s", one->path);
3765
3766                if (data.ws_rule & WS_BLANK_AT_EOF) {
3767                        struct emit_callback ecbdata;
3768                        int blank_at_eof;
3769
3770                        ecbdata.ws_rule = data.ws_rule;
3771                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3772                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3773
3774                        if (blank_at_eof) {
3775                                static char *err;
3776                                if (!err)
3777                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3778                                fprintf(o->file, "%s:%d: %s.\n",
3779                                        data.filename, blank_at_eof, err);
3780                                data.status = 1; /* report errors */
3781                        }
3782                }
3783        }
3784 free_and_return:
3785        diff_free_filespec_data(one);
3786        diff_free_filespec_data(two);
3787        if (data.status)
3788                o->flags.check_failed = 1;
3789}
3790
3791struct diff_filespec *alloc_filespec(const char *path)
3792{
3793        struct diff_filespec *spec;
3794
3795        FLEXPTR_ALLOC_STR(spec, path, path);
3796        spec->count = 1;
3797        spec->is_binary = -1;
3798        return spec;
3799}
3800
3801void free_filespec(struct diff_filespec *spec)
3802{
3803        if (!--spec->count) {
3804                diff_free_filespec_data(spec);
3805                free(spec);
3806        }
3807}
3808
3809void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3810                   int oid_valid, unsigned short mode)
3811{
3812        if (mode) {
3813                spec->mode = canon_mode(mode);
3814                oidcpy(&spec->oid, oid);
3815                spec->oid_valid = oid_valid;
3816        }
3817}
3818
3819/*
3820 * Given a name and sha1 pair, if the index tells us the file in
3821 * the work tree has that object contents, return true, so that
3822 * prepare_temp_file() does not have to inflate and extract.
3823 */
3824static int reuse_worktree_file(struct index_state *istate,
3825                               const char *name,
3826                               const struct object_id *oid,
3827                               int want_file)
3828{
3829        const struct cache_entry *ce;
3830        struct stat st;
3831        int pos, len;
3832
3833        /*
3834         * We do not read the cache ourselves here, because the
3835         * benchmark with my previous version that always reads cache
3836         * shows that it makes things worse for diff-tree comparing
3837         * two linux-2.6 kernel trees in an already checked out work
3838         * tree.  This is because most diff-tree comparisons deal with
3839         * only a small number of files, while reading the cache is
3840         * expensive for a large project, and its cost outweighs the
3841         * savings we get by not inflating the object to a temporary
3842         * file.  Practically, this code only helps when we are used
3843         * by diff-cache --cached, which does read the cache before
3844         * calling us.
3845         */
3846        if (!istate->cache)
3847                return 0;
3848
3849        /* We want to avoid the working directory if our caller
3850         * doesn't need the data in a normal file, this system
3851         * is rather slow with its stat/open/mmap/close syscalls,
3852         * and the object is contained in a pack file.  The pack
3853         * is probably already open and will be faster to obtain
3854         * the data through than the working directory.  Loose
3855         * objects however would tend to be slower as they need
3856         * to be individually opened and inflated.
3857         */
3858        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3859                return 0;
3860
3861        /*
3862         * Similarly, if we'd have to convert the file contents anyway, that
3863         * makes the optimization not worthwhile.
3864         */
3865        if (!want_file && would_convert_to_git(istate, name))
3866                return 0;
3867
3868        len = strlen(name);
3869        pos = index_name_pos(istate, name, len);
3870        if (pos < 0)
3871                return 0;
3872        ce = istate->cache[pos];
3873
3874        /*
3875         * This is not the sha1 we are looking for, or
3876         * unreusable because it is not a regular file.
3877         */
3878        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3879                return 0;
3880
3881        /*
3882         * If ce is marked as "assume unchanged", there is no
3883         * guarantee that work tree matches what we are looking for.
3884         */
3885        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3886                return 0;
3887
3888        /*
3889         * If ce matches the file in the work tree, we can reuse it.
3890         */
3891        if (ce_uptodate(ce) ||
3892            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3893                return 1;
3894
3895        return 0;
3896}
3897
3898static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3899{
3900        struct strbuf buf = STRBUF_INIT;
3901        char *dirty = "";
3902
3903        /* Are we looking at the work tree? */
3904        if (s->dirty_submodule)
3905                dirty = "-dirty";
3906
3907        strbuf_addf(&buf, "Subproject commit %s%s\n",
3908                    oid_to_hex(&s->oid), dirty);
3909        s->size = buf.len;
3910        if (size_only) {
3911                s->data = NULL;
3912                strbuf_release(&buf);
3913        } else {
3914                s->data = strbuf_detach(&buf, NULL);
3915                s->should_free = 1;
3916        }
3917        return 0;
3918}
3919
3920/*
3921 * While doing rename detection and pickaxe operation, we may need to
3922 * grab the data for the blob (or file) for our own in-core comparison.
3923 * diff_filespec has data and size fields for this purpose.
3924 */
3925int diff_populate_filespec(struct repository *r,
3926                           struct diff_filespec *s,
3927                           unsigned int flags)
3928{
3929        int size_only = flags & CHECK_SIZE_ONLY;
3930        int err = 0;
3931        int conv_flags = global_conv_flags_eol;
3932        /*
3933         * demote FAIL to WARN to allow inspecting the situation
3934         * instead of refusing.
3935         */
3936        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3937                conv_flags = CONV_EOL_RNDTRP_WARN;
3938
3939        if (!DIFF_FILE_VALID(s))
3940                die("internal error: asking to populate invalid file.");
3941        if (S_ISDIR(s->mode))
3942                return -1;
3943
3944        if (s->data)
3945                return 0;
3946
3947        if (size_only && 0 < s->size)
3948                return 0;
3949
3950        if (S_ISGITLINK(s->mode))
3951                return diff_populate_gitlink(s, size_only);
3952
3953        if (!s->oid_valid ||
3954            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3955                struct strbuf buf = STRBUF_INIT;
3956                struct stat st;
3957                int fd;
3958
3959                if (lstat(s->path, &st) < 0) {
3960                err_empty:
3961                        err = -1;
3962                empty:
3963                        s->data = (char *)"";
3964                        s->size = 0;
3965                        return err;
3966                }
3967                s->size = xsize_t(st.st_size);
3968                if (!s->size)
3969                        goto empty;
3970                if (S_ISLNK(st.st_mode)) {
3971                        struct strbuf sb = STRBUF_INIT;
3972
3973                        if (strbuf_readlink(&sb, s->path, s->size))
3974                                goto err_empty;
3975                        s->size = sb.len;
3976                        s->data = strbuf_detach(&sb, NULL);
3977                        s->should_free = 1;
3978                        return 0;
3979                }
3980
3981                /*
3982                 * Even if the caller would be happy with getting
3983                 * only the size, we cannot return early at this
3984                 * point if the path requires us to run the content
3985                 * conversion.
3986                 */
3987                if (size_only && !would_convert_to_git(r->index, s->path))
3988                        return 0;
3989
3990                /*
3991                 * Note: this check uses xsize_t(st.st_size) that may
3992                 * not be the true size of the blob after it goes
3993                 * through convert_to_git().  This may not strictly be
3994                 * correct, but the whole point of big_file_threshold
3995                 * and is_binary check being that we want to avoid
3996                 * opening the file and inspecting the contents, this
3997                 * is probably fine.
3998                 */
3999                if ((flags & CHECK_BINARY) &&
4000                    s->size > big_file_threshold && s->is_binary == -1) {
4001                        s->is_binary = 1;
4002                        return 0;
4003                }
4004                fd = open(s->path, O_RDONLY);
4005                if (fd < 0)
4006                        goto err_empty;
4007                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
4008                close(fd);
4009                s->should_munmap = 1;
4010
4011                /*
4012                 * Convert from working tree format to canonical git format
4013                 */
4014                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
4015                        size_t size = 0;
4016                        munmap(s->data, s->size);
4017                        s->should_munmap = 0;
4018                        s->data = strbuf_detach(&buf, &size);
4019                        s->size = size;
4020                        s->should_free = 1;
4021                }
4022        }
4023        else {
4024                enum object_type type;
4025                if (size_only || (flags & CHECK_BINARY)) {
4026                        type = oid_object_info(r, &s->oid, &s->size);
4027                        if (type < 0)
4028                                die("unable to read %s",
4029                                    oid_to_hex(&s->oid));
4030                        if (size_only)
4031                                return 0;
4032                        if (s->size > big_file_threshold && s->is_binary == -1) {
4033                                s->is_binary = 1;
4034                                return 0;
4035                        }
4036                }
4037                s->data = read_object_file(&s->oid, &type, &s->size);
4038                if (!s->data)
4039                        die("unable to read %s", oid_to_hex(&s->oid));
4040                s->should_free = 1;
4041        }
4042        return 0;
4043}
4044
4045void diff_free_filespec_blob(struct diff_filespec *s)
4046{
4047        if (s->should_free)
4048                free(s->data);
4049        else if (s->should_munmap)
4050                munmap(s->data, s->size);
4051
4052        if (s->should_free || s->should_munmap) {
4053                s->should_free = s->should_munmap = 0;
4054                s->data = NULL;
4055        }
4056}
4057
4058void diff_free_filespec_data(struct diff_filespec *s)
4059{
4060        diff_free_filespec_blob(s);
4061        FREE_AND_NULL(s->cnt_data);
4062}
4063
4064static void prep_temp_blob(struct index_state *istate,
4065                           const char *path, struct diff_tempfile *temp,
4066                           void *blob,
4067                           unsigned long size,
4068                           const struct object_id *oid,
4069                           int mode)
4070{
4071        struct strbuf buf = STRBUF_INIT;
4072        struct strbuf tempfile = STRBUF_INIT;
4073        char *path_dup = xstrdup(path);
4074        const char *base = basename(path_dup);
4075
4076        /* Generate "XXXXXX_basename.ext" */
4077        strbuf_addstr(&tempfile, "XXXXXX_");
4078        strbuf_addstr(&tempfile, base);
4079
4080        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4081        if (!temp->tempfile)
4082                die_errno("unable to create temp-file");
4083        if (convert_to_working_tree(istate, path,
4084                        (const char *)blob, (size_t)size, &buf)) {
4085                blob = buf.buf;
4086                size = buf.len;
4087        }
4088        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4089            close_tempfile_gently(temp->tempfile))
4090                die_errno("unable to write temp-file");
4091        temp->name = get_tempfile_path(temp->tempfile);
4092        oid_to_hex_r(temp->hex, oid);
4093        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4094        strbuf_release(&buf);
4095        strbuf_release(&tempfile);
4096        free(path_dup);
4097}
4098
4099static struct diff_tempfile *prepare_temp_file(struct repository *r,
4100                                               const char *name,
4101                                               struct diff_filespec *one)
4102{
4103        struct diff_tempfile *temp = claim_diff_tempfile();
4104
4105        if (!DIFF_FILE_VALID(one)) {
4106        not_a_valid_file:
4107                /* A '-' entry produces this for file-2, and
4108                 * a '+' entry produces this for file-1.
4109                 */
4110                temp->name = "/dev/null";
4111                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4112                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4113                return temp;
4114        }
4115
4116        if (!S_ISGITLINK(one->mode) &&
4117            (!one->oid_valid ||
4118             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4119                struct stat st;
4120                if (lstat(name, &st) < 0) {
4121                        if (errno == ENOENT)
4122                                goto not_a_valid_file;
4123                        die_errno("stat(%s)", name);
4124                }
4125                if (S_ISLNK(st.st_mode)) {
4126                        struct strbuf sb = STRBUF_INIT;
4127                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4128                                die_errno("readlink(%s)", name);
4129                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4130                                       (one->oid_valid ?
4131                                        &one->oid : &null_oid),
4132                                       (one->oid_valid ?
4133                                        one->mode : S_IFLNK));
4134                        strbuf_release(&sb);
4135                }
4136                else {
4137                        /* we can borrow from the file in the work tree */
4138                        temp->name = name;
4139                        if (!one->oid_valid)
4140                                oid_to_hex_r(temp->hex, &null_oid);
4141                        else
4142                                oid_to_hex_r(temp->hex, &one->oid);
4143                        /* Even though we may sometimes borrow the
4144                         * contents from the work tree, we always want
4145                         * one->mode.  mode is trustworthy even when
4146                         * !(one->oid_valid), as long as
4147                         * DIFF_FILE_VALID(one).
4148                         */
4149                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4150                }
4151                return temp;
4152        }
4153        else {
4154                if (diff_populate_filespec(r, one, 0))
4155                        die("cannot read data blob for %s", one->path);
4156                prep_temp_blob(r->index, name, temp,
4157                               one->data, one->size,
4158                               &one->oid, one->mode);
4159        }
4160        return temp;
4161}
4162
4163static void add_external_diff_name(struct repository *r,
4164                                   struct argv_array *argv,
4165                                   const char *name,
4166                                   struct diff_filespec *df)
4167{
4168        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4169        argv_array_push(argv, temp->name);
4170        argv_array_push(argv, temp->hex);
4171        argv_array_push(argv, temp->mode);
4172}
4173
4174/* An external diff command takes:
4175 *
4176 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4177 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4178 *
4179 */
4180static void run_external_diff(const char *pgm,
4181                              const char *name,
4182                              const char *other,
4183                              struct diff_filespec *one,
4184                              struct diff_filespec *two,
4185                              const char *xfrm_msg,
4186                              int complete_rewrite,
4187                              struct diff_options *o)
4188{
4189        struct argv_array argv = ARGV_ARRAY_INIT;
4190        struct argv_array env = ARGV_ARRAY_INIT;
4191        struct diff_queue_struct *q = &diff_queued_diff;
4192
4193        argv_array_push(&argv, pgm);
4194        argv_array_push(&argv, name);
4195
4196        if (one && two) {
4197                add_external_diff_name(o->repo, &argv, name, one);
4198                if (!other)
4199                        add_external_diff_name(o->repo, &argv, name, two);
4200                else {
4201                        add_external_diff_name(o->repo, &argv, other, two);
4202                        argv_array_push(&argv, other);
4203                        argv_array_push(&argv, xfrm_msg);
4204                }
4205        }
4206
4207        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4208        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4209
4210        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4211                die(_("external diff died, stopping at %s"), name);
4212
4213        remove_tempfile();
4214        argv_array_clear(&argv);
4215        argv_array_clear(&env);
4216}
4217
4218static int similarity_index(struct diff_filepair *p)
4219{
4220        return p->score * 100 / MAX_SCORE;
4221}
4222
4223static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4224{
4225        if (startup_info->have_repository)
4226                return find_unique_abbrev(oid, abbrev);
4227        else {
4228                char *hex = oid_to_hex(oid);
4229                if (abbrev < 0)
4230                        abbrev = FALLBACK_DEFAULT_ABBREV;
4231                if (abbrev > the_hash_algo->hexsz)
4232                        BUG("oid abbreviation out of range: %d", abbrev);
4233                if (abbrev)
4234                        hex[abbrev] = '\0';
4235                return hex;
4236        }
4237}
4238
4239static void fill_metainfo(struct strbuf *msg,
4240                          const char *name,
4241                          const char *other,
4242                          struct diff_filespec *one,
4243                          struct diff_filespec *two,
4244                          struct diff_options *o,
4245                          struct diff_filepair *p,
4246                          int *must_show_header,
4247                          int use_color)
4248{
4249        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4250        const char *reset = diff_get_color(use_color, DIFF_RESET);
4251        const char *line_prefix = diff_line_prefix(o);
4252
4253        *must_show_header = 1;
4254        strbuf_init(msg, PATH_MAX * 2 + 300);
4255        switch (p->status) {
4256        case DIFF_STATUS_COPIED:
4257                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4258                            line_prefix, set, similarity_index(p));
4259                strbuf_addf(msg, "%s\n%s%scopy from ",
4260                            reset,  line_prefix, set);
4261                quote_c_style(name, msg, NULL, 0);
4262                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4263                quote_c_style(other, msg, NULL, 0);
4264                strbuf_addf(msg, "%s\n", reset);
4265                break;
4266        case DIFF_STATUS_RENAMED:
4267                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4268                            line_prefix, set, similarity_index(p));
4269                strbuf_addf(msg, "%s\n%s%srename from ",
4270                            reset, line_prefix, set);
4271                quote_c_style(name, msg, NULL, 0);
4272                strbuf_addf(msg, "%s\n%s%srename to ",
4273                            reset, line_prefix, set);
4274                quote_c_style(other, msg, NULL, 0);
4275                strbuf_addf(msg, "%s\n", reset);
4276                break;
4277        case DIFF_STATUS_MODIFIED:
4278                if (p->score) {
4279                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4280                                    line_prefix,
4281                                    set, similarity_index(p), reset);
4282                        break;
4283                }
4284                /* fallthru */
4285        default:
4286                *must_show_header = 0;
4287        }
4288        if (one && two && !oideq(&one->oid, &two->oid)) {
4289                const unsigned hexsz = the_hash_algo->hexsz;
4290                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4291
4292                if (o->flags.binary) {
4293                        mmfile_t mf;
4294                        if ((!fill_mmfile(o->repo, &mf, one) &&
4295                             diff_filespec_is_binary(o->repo, one)) ||
4296                            (!fill_mmfile(o->repo, &mf, two) &&
4297                             diff_filespec_is_binary(o->repo, two)))
4298                                abbrev = hexsz;
4299                }
4300                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4301                            diff_abbrev_oid(&one->oid, abbrev),
4302                            diff_abbrev_oid(&two->oid, abbrev));
4303                if (one->mode == two->mode)
4304                        strbuf_addf(msg, " %06o", one->mode);
4305                strbuf_addf(msg, "%s\n", reset);
4306        }
4307}
4308
4309static void run_diff_cmd(const char *pgm,
4310                         const char *name,
4311                         const char *other,
4312                         const char *attr_path,
4313                         struct diff_filespec *one,
4314                         struct diff_filespec *two,
4315                         struct strbuf *msg,
4316                         struct diff_options *o,
4317                         struct diff_filepair *p)
4318{
4319        const char *xfrm_msg = NULL;
4320        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4321        int must_show_header = 0;
4322
4323
4324        if (o->flags.allow_external) {
4325                struct userdiff_driver *drv;
4326
4327                drv = userdiff_find_by_path(o->repo->index, attr_path);
4328                if (drv && drv->external)
4329                        pgm = drv->external;
4330        }
4331
4332        if (msg) {
4333                /*
4334                 * don't use colors when the header is intended for an
4335                 * external diff driver
4336                 */
4337                fill_metainfo(msg, name, other, one, two, o, p,
4338                              &must_show_header,
4339                              want_color(o->use_color) && !pgm);
4340                xfrm_msg = msg->len ? msg->buf : NULL;
4341        }
4342
4343        if (pgm) {
4344                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4345                                  complete_rewrite, o);
4346                return;
4347        }
4348        if (one && two)
4349                builtin_diff(name, other ? other : name,
4350                             one, two, xfrm_msg, must_show_header,
4351                             o, complete_rewrite);
4352        else
4353                fprintf(o->file, "* Unmerged path %s\n", name);
4354}
4355
4356static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4357{
4358        if (DIFF_FILE_VALID(one)) {
4359                if (!one->oid_valid) {
4360                        struct stat st;
4361                        if (one->is_stdin) {
4362                                oidclr(&one->oid);
4363                                return;
4364                        }
4365                        if (lstat(one->path, &st) < 0)
4366                                die_errno("stat '%s'", one->path);
4367                        if (index_path(istate, &one->oid, one->path, &st, 0))
4368                                die("cannot hash %s", one->path);
4369                }
4370        }
4371        else
4372                oidclr(&one->oid);
4373}
4374
4375static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4376{
4377        /* Strip the prefix but do not molest /dev/null and absolute paths */
4378        if (*namep && !is_absolute_path(*namep)) {
4379                *namep += prefix_length;
4380                if (**namep == '/')
4381                        ++*namep;
4382        }
4383        if (*otherp && !is_absolute_path(*otherp)) {
4384                *otherp += prefix_length;
4385                if (**otherp == '/')
4386                        ++*otherp;
4387        }
4388}
4389
4390static void run_diff(struct diff_filepair *p, struct diff_options *o)
4391{
4392        const char *pgm = external_diff();
4393        struct strbuf msg;
4394        struct diff_filespec *one = p->one;
4395        struct diff_filespec *two = p->two;
4396        const char *name;
4397        const char *other;
4398        const char *attr_path;
4399
4400        name  = one->path;
4401        other = (strcmp(name, two->path) ? two->path : NULL);
4402        attr_path = name;
4403        if (o->prefix_length)
4404                strip_prefix(o->prefix_length, &name, &other);
4405
4406        if (!o->flags.allow_external)
4407                pgm = NULL;
4408
4409        if (DIFF_PAIR_UNMERGED(p)) {
4410                run_diff_cmd(pgm, name, NULL, attr_path,
4411                             NULL, NULL, NULL, o, p);
4412                return;
4413        }
4414
4415        diff_fill_oid_info(one, o->repo->index);
4416        diff_fill_oid_info(two, o->repo->index);
4417
4418        if (!pgm &&
4419            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4420            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4421                /*
4422                 * a filepair that changes between file and symlink
4423                 * needs to be split into deletion and creation.
4424                 */
4425                struct diff_filespec *null = alloc_filespec(two->path);
4426                run_diff_cmd(NULL, name, other, attr_path,
4427                             one, null, &msg,
4428                             o, p);
4429                free(null);
4430                strbuf_release(&msg);
4431
4432                null = alloc_filespec(one->path);
4433                run_diff_cmd(NULL, name, other, attr_path,
4434                             null, two, &msg, o, p);
4435                free(null);
4436        }
4437        else
4438                run_diff_cmd(pgm, name, other, attr_path,
4439                             one, two, &msg, o, p);
4440
4441        strbuf_release(&msg);
4442}
4443
4444static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4445                         struct diffstat_t *diffstat)
4446{
4447        const char *name;
4448        const char *other;
4449
4450        if (DIFF_PAIR_UNMERGED(p)) {
4451                /* unmerged */
4452                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4453                                 diffstat, o, p);
4454                return;
4455        }
4456
4457        name = p->one->path;
4458        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4459
4460        if (o->prefix_length)
4461                strip_prefix(o->prefix_length, &name, &other);
4462
4463        diff_fill_oid_info(p->one, o->repo->index);
4464        diff_fill_oid_info(p->two, o->repo->index);
4465
4466        builtin_diffstat(name, other, p->one, p->two,
4467                         diffstat, o, p);
4468}
4469
4470static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4471{
4472        const char *name;
4473        const char *other;
4474        const char *attr_path;
4475
4476        if (DIFF_PAIR_UNMERGED(p)) {
4477                /* unmerged */
4478                return;
4479        }
4480
4481        name = p->one->path;
4482        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4483        attr_path = other ? other : name;
4484
4485        if (o->prefix_length)
4486                strip_prefix(o->prefix_length, &name, &other);
4487
4488        diff_fill_oid_info(p->one, o->repo->index);
4489        diff_fill_oid_info(p->two, o->repo->index);
4490
4491        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4492}
4493
4494void repo_diff_setup(struct repository *r, struct diff_options *options)
4495{
4496        memcpy(options, &default_diff_options, sizeof(*options));
4497
4498        options->file = stdout;
4499        options->repo = r;
4500
4501        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4502        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4503        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4504        options->abbrev = DEFAULT_ABBREV;
4505        options->line_termination = '\n';
4506        options->break_opt = -1;
4507        options->rename_limit = -1;
4508        options->dirstat_permille = diff_dirstat_permille_default;
4509        options->context = diff_context_default;
4510        options->interhunkcontext = diff_interhunk_context_default;
4511        options->ws_error_highlight = ws_error_highlight_default;
4512        options->flags.rename_empty = 1;
4513        options->objfind = NULL;
4514
4515        /* pathchange left =NULL by default */
4516        options->change = diff_change;
4517        options->add_remove = diff_addremove;
4518        options->use_color = diff_use_color_default;
4519        options->detect_rename = diff_detect_rename_default;
4520        options->xdl_opts |= diff_algorithm;
4521        if (diff_indent_heuristic)
4522                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4523
4524        options->orderfile = diff_order_file_cfg;
4525
4526        if (diff_no_prefix) {
4527                options->a_prefix = options->b_prefix = "";
4528        } else if (!diff_mnemonic_prefix) {
4529                options->a_prefix = "a/";
4530                options->b_prefix = "b/";
4531        }
4532
4533        options->color_moved = diff_color_moved_default;
4534        options->color_moved_ws_handling = diff_color_moved_ws_default;
4535}
4536
4537void diff_setup_done(struct diff_options *options)
4538{
4539        unsigned check_mask = DIFF_FORMAT_NAME |
4540                              DIFF_FORMAT_NAME_STATUS |
4541                              DIFF_FORMAT_CHECKDIFF |
4542                              DIFF_FORMAT_NO_OUTPUT;
4543        /*
4544         * This must be signed because we're comparing against a potentially
4545         * negative value.
4546         */
4547        const int hexsz = the_hash_algo->hexsz;
4548
4549        if (options->set_default)
4550                options->set_default(options);
4551
4552        if (HAS_MULTI_BITS(options->output_format & check_mask))
4553                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4554
4555        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4556                die(_("-G, -S and --find-object are mutually exclusive"));
4557
4558        /*
4559         * Most of the time we can say "there are changes"
4560         * only by checking if there are changed paths, but
4561         * --ignore-whitespace* options force us to look
4562         * inside contents.
4563         */
4564
4565        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4566                options->flags.diff_from_contents = 1;
4567        else
4568                options->flags.diff_from_contents = 0;
4569
4570        if (options->flags.find_copies_harder)
4571                options->detect_rename = DIFF_DETECT_COPY;
4572
4573        if (!options->flags.relative_name)
4574                options->prefix = NULL;
4575        if (options->prefix)
4576                options->prefix_length = strlen(options->prefix);
4577        else
4578                options->prefix_length = 0;
4579
4580        if (options->output_format & (DIFF_FORMAT_NAME |
4581                                      DIFF_FORMAT_NAME_STATUS |
4582                                      DIFF_FORMAT_CHECKDIFF |
4583                                      DIFF_FORMAT_NO_OUTPUT))
4584                options->output_format &= ~(DIFF_FORMAT_RAW |
4585                                            DIFF_FORMAT_NUMSTAT |
4586                                            DIFF_FORMAT_DIFFSTAT |
4587                                            DIFF_FORMAT_SHORTSTAT |
4588                                            DIFF_FORMAT_DIRSTAT |
4589                                            DIFF_FORMAT_SUMMARY |
4590                                            DIFF_FORMAT_PATCH);
4591
4592        /*
4593         * These cases always need recursive; we do not drop caller-supplied
4594         * recursive bits for other formats here.
4595         */
4596        if (options->output_format & (DIFF_FORMAT_PATCH |
4597                                      DIFF_FORMAT_NUMSTAT |
4598                                      DIFF_FORMAT_DIFFSTAT |
4599                                      DIFF_FORMAT_SHORTSTAT |
4600                                      DIFF_FORMAT_DIRSTAT |
4601                                      DIFF_FORMAT_SUMMARY |
4602                                      DIFF_FORMAT_CHECKDIFF))
4603                options->flags.recursive = 1;
4604        /*
4605         * Also pickaxe would not work very well if you do not say recursive
4606         */
4607        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4608                options->flags.recursive = 1;
4609        /*
4610         * When patches are generated, submodules diffed against the work tree
4611         * must be checked for dirtiness too so it can be shown in the output
4612         */
4613        if (options->output_format & DIFF_FORMAT_PATCH)
4614                options->flags.dirty_submodules = 1;
4615
4616        if (options->detect_rename && options->rename_limit < 0)
4617                options->rename_limit = diff_rename_limit_default;
4618        if (hexsz < options->abbrev)
4619                options->abbrev = hexsz; /* full */
4620
4621        /*
4622         * It does not make sense to show the first hit we happened
4623         * to have found.  It does not make sense not to return with
4624         * exit code in such a case either.
4625         */
4626        if (options->flags.quick) {
4627                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4628                options->flags.exit_with_status = 1;
4629        }
4630
4631        options->diff_path_counter = 0;
4632
4633        if (options->flags.follow_renames && options->pathspec.nr != 1)
4634                die(_("--follow requires exactly one pathspec"));
4635
4636        if (!options->use_color || external_diff())
4637                options->color_moved = 0;
4638}
4639
4640static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4641{
4642        char c, *eq;
4643        int len;
4644
4645        if (*arg != '-')
4646                return 0;
4647        c = *++arg;
4648        if (!c)
4649                return 0;
4650        if (c == arg_short) {
4651                c = *++arg;
4652                if (!c)
4653                        return 1;
4654                if (val && isdigit(c)) {
4655                        char *end;
4656                        int n = strtoul(arg, &end, 10);
4657                        if (*end)
4658                                return 0;
4659                        *val = n;
4660                        return 1;
4661                }
4662                return 0;
4663        }
4664        if (c != '-')
4665                return 0;
4666        arg++;
4667        eq = strchrnul(arg, '=');
4668        len = eq - arg;
4669        if (!len || strncmp(arg, arg_long, len))
4670                return 0;
4671        if (*eq) {
4672                int n;
4673                char *end;
4674                if (!isdigit(*++eq))
4675                        return 0;
4676                n = strtoul(eq, &end, 10);
4677                if (*end)
4678                        return 0;
4679                *val = n;
4680        }
4681        return 1;
4682}
4683
4684static int diff_scoreopt_parse(const char *opt);
4685
4686static inline int short_opt(char opt, const char **argv,
4687                            const char **optarg)
4688{
4689        const char *arg = argv[0];
4690        if (arg[0] != '-' || arg[1] != opt)
4691                return 0;
4692        if (arg[2] != '\0') {
4693                *optarg = arg + 2;
4694                return 1;
4695        }
4696        if (!argv[1])
4697                die("Option '%c' requires a value", opt);
4698        *optarg = argv[1];
4699        return 2;
4700}
4701
4702int parse_long_opt(const char *opt, const char **argv,
4703                   const char **optarg)
4704{
4705        const char *arg = argv[0];
4706        if (!skip_prefix(arg, "--", &arg))
4707                return 0;
4708        if (!skip_prefix(arg, opt, &arg))
4709                return 0;
4710        if (*arg == '=') { /* stuck form: --option=value */
4711                *optarg = arg + 1;
4712                return 1;
4713        }
4714        if (*arg != '\0')
4715                return 0;
4716        /* separate form: --option value */
4717        if (!argv[1])
4718                die("Option '--%s' requires a value", opt);
4719        *optarg = argv[1];
4720        return 2;
4721}
4722
4723static int stat_opt(struct diff_options *options, const char **av)
4724{
4725        const char *arg = av[0];
4726        char *end;
4727        int width = options->stat_width;
4728        int name_width = options->stat_name_width;
4729        int graph_width = options->stat_graph_width;
4730        int count = options->stat_count;
4731        int argcount = 1;
4732
4733        if (!skip_prefix(arg, "--stat", &arg))
4734                BUG("stat option does not begin with --stat: %s", arg);
4735        end = (char *)arg;
4736
4737        switch (*arg) {
4738        case '-':
4739                if (skip_prefix(arg, "-width", &arg)) {
4740                        if (*arg == '=')
4741                                width = strtoul(arg + 1, &end, 10);
4742                        else if (!*arg && !av[1])
4743                                die_want_option("--stat-width");
4744                        else if (!*arg) {
4745                                width = strtoul(av[1], &end, 10);
4746                                argcount = 2;
4747                        }
4748                } else if (skip_prefix(arg, "-name-width", &arg)) {
4749                        if (*arg == '=')
4750                                name_width = strtoul(arg + 1, &end, 10);
4751                        else if (!*arg && !av[1])
4752                                die_want_option("--stat-name-width");
4753                        else if (!*arg) {
4754                                name_width = strtoul(av[1], &end, 10);
4755                                argcount = 2;
4756                        }
4757                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4758                        if (*arg == '=')
4759                                graph_width = strtoul(arg + 1, &end, 10);
4760                        else if (!*arg && !av[1])
4761                                die_want_option("--stat-graph-width");
4762                        else if (!*arg) {
4763                                graph_width = strtoul(av[1], &end, 10);
4764                                argcount = 2;
4765                        }
4766                } else if (skip_prefix(arg, "-count", &arg)) {
4767                        if (*arg == '=')
4768                                count = strtoul(arg + 1, &end, 10);
4769                        else if (!*arg && !av[1])
4770                                die_want_option("--stat-count");
4771                        else if (!*arg) {
4772                                count = strtoul(av[1], &end, 10);
4773                                argcount = 2;
4774                        }
4775                }
4776                break;
4777        case '=':
4778                width = strtoul(arg+1, &end, 10);
4779                if (*end == ',')
4780                        name_width = strtoul(end+1, &end, 10);
4781                if (*end == ',')
4782                        count = strtoul(end+1, &end, 10);
4783        }
4784
4785        /* Important! This checks all the error cases! */
4786        if (*end)
4787                return 0;
4788        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4789        options->stat_name_width = name_width;
4790        options->stat_graph_width = graph_width;
4791        options->stat_width = width;
4792        options->stat_count = count;
4793        return argcount;
4794}
4795
4796static int parse_dirstat_opt(struct diff_options *options, const char *params)
4797{
4798        struct strbuf errmsg = STRBUF_INIT;
4799        if (parse_dirstat_params(options, params, &errmsg))
4800                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4801                    errmsg.buf);
4802        strbuf_release(&errmsg);
4803        /*
4804         * The caller knows a dirstat-related option is given from the command
4805         * line; allow it to say "return this_function();"
4806         */
4807        options->output_format |= DIFF_FORMAT_DIRSTAT;
4808        return 1;
4809}
4810
4811static int parse_submodule_opt(struct diff_options *options, const char *value)
4812{
4813        if (parse_submodule_params(options, value))
4814                die(_("Failed to parse --submodule option parameter: '%s'"),
4815                        value);
4816        return 1;
4817}
4818
4819static const char diff_status_letters[] = {
4820        DIFF_STATUS_ADDED,
4821        DIFF_STATUS_COPIED,
4822        DIFF_STATUS_DELETED,
4823        DIFF_STATUS_MODIFIED,
4824        DIFF_STATUS_RENAMED,
4825        DIFF_STATUS_TYPE_CHANGED,
4826        DIFF_STATUS_UNKNOWN,
4827        DIFF_STATUS_UNMERGED,
4828        DIFF_STATUS_FILTER_AON,
4829        DIFF_STATUS_FILTER_BROKEN,
4830        '\0',
4831};
4832
4833static unsigned int filter_bit['Z' + 1];
4834
4835static void prepare_filter_bits(void)
4836{
4837        int i;
4838
4839        if (!filter_bit[DIFF_STATUS_ADDED]) {
4840                for (i = 0; diff_status_letters[i]; i++)
4841                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4842        }
4843}
4844
4845static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4846{
4847        return opt->filter & filter_bit[(int) status];
4848}
4849
4850static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4851{
4852        int i, optch;
4853
4854        prepare_filter_bits();
4855
4856        /*
4857         * If there is a negation e.g. 'd' in the input, and we haven't
4858         * initialized the filter field with another --diff-filter, start
4859         * from full set of bits, except for AON.
4860         */
4861        if (!opt->filter) {
4862                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4863                        if (optch < 'a' || 'z' < optch)
4864                                continue;
4865                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4866                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4867                        break;
4868                }
4869        }
4870
4871        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4872                unsigned int bit;
4873                int negate;
4874
4875                if ('a' <= optch && optch <= 'z') {
4876                        negate = 1;
4877                        optch = toupper(optch);
4878                } else {
4879                        negate = 0;
4880                }
4881
4882                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4883                if (!bit)
4884                        return optarg[i];
4885                if (negate)
4886                        opt->filter &= ~bit;
4887                else
4888                        opt->filter |= bit;
4889        }
4890        return 0;
4891}
4892
4893static void enable_patch_output(int *fmt)
4894{
4895        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4896        *fmt |= DIFF_FORMAT_PATCH;
4897}
4898
4899static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4900{
4901        int val = parse_ws_error_highlight(arg);
4902
4903        if (val < 0) {
4904                error("unknown value after ws-error-highlight=%.*s",
4905                      -1 - val, arg);
4906                return 0;
4907        }
4908        opt->ws_error_highlight = val;
4909        return 1;
4910}
4911
4912static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4913{
4914        struct object_id oid;
4915
4916        if (get_oid(arg, &oid))
4917                return error("unable to resolve '%s'", arg);
4918
4919        if (!opt->objfind)
4920                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4921
4922        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4923        opt->flags.recursive = 1;
4924        opt->flags.tree_in_recursive = 1;
4925        oidset_insert(opt->objfind, &oid);
4926        return 1;
4927}
4928
4929int diff_opt_parse(struct diff_options *options,
4930                   const char **av, int ac, const char *prefix)
4931{
4932        const char *arg = av[0];
4933        const char *optarg;
4934        int argcount;
4935
4936        if (!prefix)
4937                prefix = "";
4938
4939        /* Output format options */
4940        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4941            || opt_arg(arg, 'U', "unified", &options->context))
4942                enable_patch_output(&options->output_format);
4943        else if (!strcmp(arg, "--raw"))
4944                options->output_format |= DIFF_FORMAT_RAW;
4945        else if (!strcmp(arg, "--patch-with-raw")) {
4946                enable_patch_output(&options->output_format);
4947                options->output_format |= DIFF_FORMAT_RAW;
4948        } else if (!strcmp(arg, "--numstat"))
4949                options->output_format |= DIFF_FORMAT_NUMSTAT;
4950        else if (!strcmp(arg, "--shortstat"))
4951                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4952        else if (skip_prefix(arg, "-X", &arg) ||
4953                 skip_to_optional_arg(arg, "--dirstat", &arg))
4954                return parse_dirstat_opt(options, arg);
4955        else if (!strcmp(arg, "--cumulative"))
4956                return parse_dirstat_opt(options, "cumulative");
4957        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4958                parse_dirstat_opt(options, "files");
4959                return parse_dirstat_opt(options, arg);
4960        }
4961        else if (!strcmp(arg, "--check"))
4962                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4963        else if (!strcmp(arg, "--summary"))
4964                options->output_format |= DIFF_FORMAT_SUMMARY;
4965        else if (!strcmp(arg, "--patch-with-stat")) {
4966                enable_patch_output(&options->output_format);
4967                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4968        } else if (!strcmp(arg, "--name-only"))
4969                options->output_format |= DIFF_FORMAT_NAME;
4970        else if (!strcmp(arg, "--name-status"))
4971                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4972        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4973                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4974        else if (starts_with(arg, "--stat"))
4975                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4976                return stat_opt(options, av);
4977        else if (!strcmp(arg, "--compact-summary")) {
4978                 options->flags.stat_with_summary = 1;
4979                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4980        } else if (!strcmp(arg, "--no-compact-summary"))
4981                 options->flags.stat_with_summary = 0;
4982        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4983                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4984        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4985                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4986        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4987                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4988
4989        /* renames options */
4990        else if (starts_with(arg, "-B") ||
4991                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4992                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4993                        return error("invalid argument to -B: %s", arg+2);
4994        }
4995        else if (starts_with(arg, "-M") ||
4996                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4997                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4998                        return error("invalid argument to -M: %s", arg+2);
4999                options->detect_rename = DIFF_DETECT_RENAME;
5000        }
5001        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
5002                options->irreversible_delete = 1;
5003        }
5004        else if (starts_with(arg, "-C") ||
5005                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
5006                if (options->detect_rename == DIFF_DETECT_COPY)
5007                        options->flags.find_copies_harder = 1;
5008                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
5009                        return error("invalid argument to -C: %s", arg+2);
5010                options->detect_rename = DIFF_DETECT_COPY;
5011        }
5012        else if (!strcmp(arg, "--no-renames"))
5013                options->detect_rename = 0;
5014        else if (!strcmp(arg, "--rename-empty"))
5015                options->flags.rename_empty = 1;
5016        else if (!strcmp(arg, "--no-rename-empty"))
5017                options->flags.rename_empty = 0;
5018        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
5019                options->flags.relative_name = 1;
5020                if (arg)
5021                        options->prefix = arg;
5022        }
5023
5024        /* xdiff options */
5025        else if (!strcmp(arg, "--minimal"))
5026                DIFF_XDL_SET(options, NEED_MINIMAL);
5027        else if (!strcmp(arg, "--no-minimal"))
5028                DIFF_XDL_CLR(options, NEED_MINIMAL);
5029        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
5030                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
5031        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
5032                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
5033        else if (!strcmp(arg, "--ignore-space-at-eol"))
5034                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
5035        else if (!strcmp(arg, "--ignore-cr-at-eol"))
5036                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
5037        else if (!strcmp(arg, "--ignore-blank-lines"))
5038                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
5039        else if (!strcmp(arg, "--indent-heuristic"))
5040                DIFF_XDL_SET(options, INDENT_HEURISTIC);
5041        else if (!strcmp(arg, "--no-indent-heuristic"))
5042                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
5043        else if (!strcmp(arg, "--patience")) {
5044                int i;
5045                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5046                /*
5047                 * Both --patience and --anchored use PATIENCE_DIFF
5048                 * internally, so remove any anchors previously
5049                 * specified.
5050                 */
5051                for (i = 0; i < options->anchors_nr; i++)
5052                        free(options->anchors[i]);
5053                options->anchors_nr = 0;
5054        } else if (!strcmp(arg, "--histogram"))
5055                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
5056        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
5057                long value = parse_algorithm_value(optarg);
5058                if (value < 0)
5059                        return error("option diff-algorithm accepts \"myers\", "
5060                                     "\"minimal\", \"patience\" and \"histogram\"");
5061                /* clear out previous settings */
5062                DIFF_XDL_CLR(options, NEED_MINIMAL);
5063                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
5064                options->xdl_opts |= value;
5065                return argcount;
5066        } else if (skip_prefix(arg, "--anchored=", &arg)) {
5067                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5068                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
5069                           options->anchors_alloc);
5070                options->anchors[options->anchors_nr++] = xstrdup(arg);
5071        }
5072
5073        /* flags options */
5074        else if (!strcmp(arg, "--binary")) {
5075                enable_patch_output(&options->output_format);
5076                options->flags.binary = 1;
5077        }
5078        else if (!strcmp(arg, "--full-index"))
5079                options->flags.full_index = 1;
5080        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5081                options->flags.text = 1;
5082        else if (!strcmp(arg, "-R"))
5083                options->flags.reverse_diff = 1;
5084        else if (!strcmp(arg, "--find-copies-harder"))
5085                options->flags.find_copies_harder = 1;
5086        else if (!strcmp(arg, "--follow"))
5087                options->flags.follow_renames = 1;
5088        else if (!strcmp(arg, "--no-follow")) {
5089                options->flags.follow_renames = 0;
5090                options->flags.default_follow_renames = 0;
5091        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5092                int value = git_config_colorbool(NULL, arg);
5093                if (value < 0)
5094                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5095                options->use_color = value;
5096        }
5097        else if (!strcmp(arg, "--no-color"))
5098                options->use_color = 0;
5099        else if (!strcmp(arg, "--color-moved")) {
5100                if (diff_color_moved_default)
5101                        options->color_moved = diff_color_moved_default;
5102                if (options->color_moved == COLOR_MOVED_NO)
5103                        options->color_moved = COLOR_MOVED_DEFAULT;
5104        } else if (!strcmp(arg, "--no-color-moved"))
5105                options->color_moved = COLOR_MOVED_NO;
5106        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5107                int cm = parse_color_moved(arg);
5108                if (cm < 0)
5109                        return error("bad --color-moved argument: %s", arg);
5110                options->color_moved = cm;
5111        } else if (!strcmp(arg, "--no-color-moved-ws")) {
5112                options->color_moved_ws_handling = 0;
5113        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5114                unsigned cm = parse_color_moved_ws(arg);
5115                if (cm & COLOR_MOVED_WS_ERROR)
5116                        return -1;
5117                options->color_moved_ws_handling = cm;
5118        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5119                options->use_color = 1;
5120                options->word_diff = DIFF_WORDS_COLOR;
5121        }
5122        else if (!strcmp(arg, "--word-diff")) {
5123                if (options->word_diff == DIFF_WORDS_NONE)
5124                        options->word_diff = DIFF_WORDS_PLAIN;
5125        }
5126        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5127                if (!strcmp(arg, "plain"))
5128                        options->word_diff = DIFF_WORDS_PLAIN;
5129                else if (!strcmp(arg, "color")) {
5130                        options->use_color = 1;
5131                        options->word_diff = DIFF_WORDS_COLOR;
5132                }
5133                else if (!strcmp(arg, "porcelain"))
5134                        options->word_diff = DIFF_WORDS_PORCELAIN;
5135                else if (!strcmp(arg, "none"))
5136                        options->word_diff = DIFF_WORDS_NONE;
5137                else
5138                        die("bad --word-diff argument: %s", arg);
5139        }
5140        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5141                if (options->word_diff == DIFF_WORDS_NONE)
5142                        options->word_diff = DIFF_WORDS_PLAIN;
5143                options->word_regex = optarg;
5144                return argcount;
5145        }
5146        else if (!strcmp(arg, "--exit-code"))
5147                options->flags.exit_with_status = 1;
5148        else if (!strcmp(arg, "--quiet"))
5149                options->flags.quick = 1;
5150        else if (!strcmp(arg, "--ext-diff"))
5151                options->flags.allow_external = 1;
5152        else if (!strcmp(arg, "--no-ext-diff"))
5153                options->flags.allow_external = 0;
5154        else if (!strcmp(arg, "--textconv")) {
5155                options->flags.allow_textconv = 1;
5156                options->flags.textconv_set_via_cmdline = 1;
5157        } else if (!strcmp(arg, "--no-textconv"))
5158                options->flags.allow_textconv = 0;
5159        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5160                options->flags.override_submodule_config = 1;
5161                handle_ignore_submodules_arg(options, arg);
5162        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5163                return parse_submodule_opt(options, arg);
5164        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5165                return parse_ws_error_highlight_opt(options, arg);
5166        else if (!strcmp(arg, "--ita-invisible-in-index"))
5167                options->ita_invisible_in_index = 1;
5168        else if (!strcmp(arg, "--ita-visible-in-index"))
5169                options->ita_invisible_in_index = 0;
5170
5171        /* misc options */
5172        else if (!strcmp(arg, "-z"))
5173                options->line_termination = 0;
5174        else if ((argcount = short_opt('l', av, &optarg))) {
5175                options->rename_limit = strtoul(optarg, NULL, 10);
5176                return argcount;
5177        }
5178        else if ((argcount = short_opt('S', av, &optarg))) {
5179                options->pickaxe = optarg;
5180                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5181                return argcount;
5182        } else if ((argcount = short_opt('G', av, &optarg))) {
5183                options->pickaxe = optarg;
5184                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5185                return argcount;
5186        }
5187        else if (!strcmp(arg, "--pickaxe-all"))
5188                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5189        else if (!strcmp(arg, "--pickaxe-regex"))
5190                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5191        else if ((argcount = short_opt('O', av, &optarg))) {
5192                options->orderfile = prefix_filename(prefix, optarg);
5193                return argcount;
5194        } else if (skip_prefix(arg, "--find-object=", &arg))
5195                return parse_objfind_opt(options, arg);
5196        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5197                int offending = parse_diff_filter_opt(optarg, options);
5198                if (offending)
5199                        die("unknown change class '%c' in --diff-filter=%s",
5200                            offending, optarg);
5201                return argcount;
5202        }
5203        else if (!strcmp(arg, "--no-abbrev"))
5204                options->abbrev = 0;
5205        else if (!strcmp(arg, "--abbrev"))
5206                options->abbrev = DEFAULT_ABBREV;
5207        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5208                options->abbrev = strtoul(arg, NULL, 10);
5209                if (options->abbrev < MINIMUM_ABBREV)
5210                        options->abbrev = MINIMUM_ABBREV;
5211                else if (the_hash_algo->hexsz < options->abbrev)
5212                        options->abbrev = the_hash_algo->hexsz;
5213        }
5214        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5215                options->a_prefix = optarg;
5216                return argcount;
5217        }
5218        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5219                options->line_prefix = optarg;
5220                options->line_prefix_length = strlen(options->line_prefix);
5221                graph_setup_line_prefix(options);
5222                return argcount;
5223        }
5224        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5225                options->b_prefix = optarg;
5226                return argcount;
5227        }
5228        else if (!strcmp(arg, "--no-prefix"))
5229                options->a_prefix = options->b_prefix = "";
5230        else if (opt_arg(arg, '\0', "inter-hunk-context",
5231                         &options->interhunkcontext))
5232                ;
5233        else if (!strcmp(arg, "-W"))
5234                options->flags.funccontext = 1;
5235        else if (!strcmp(arg, "--function-context"))
5236                options->flags.funccontext = 1;
5237        else if (!strcmp(arg, "--no-function-context"))
5238                options->flags.funccontext = 0;
5239        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5240                char *path = prefix_filename(prefix, optarg);
5241                options->file = xfopen(path, "w");
5242                options->close_file = 1;
5243                if (options->use_color != GIT_COLOR_ALWAYS)
5244                        options->use_color = GIT_COLOR_NEVER;
5245                free(path);
5246                return argcount;
5247        } else
5248                return 0;
5249        return 1;
5250}
5251
5252int parse_rename_score(const char **cp_p)
5253{
5254        unsigned long num, scale;
5255        int ch, dot;
5256        const char *cp = *cp_p;
5257
5258        num = 0;
5259        scale = 1;
5260        dot = 0;
5261        for (;;) {
5262                ch = *cp;
5263                if ( !dot && ch == '.' ) {
5264                        scale = 1;
5265                        dot = 1;
5266                } else if ( ch == '%' ) {
5267                        scale = dot ? scale*100 : 100;
5268                        cp++;   /* % is always at the end */
5269                        break;
5270                } else if ( ch >= '0' && ch <= '9' ) {
5271                        if ( scale < 100000 ) {
5272                                scale *= 10;
5273                                num = (num*10) + (ch-'0');
5274                        }
5275                } else {
5276                        break;
5277                }
5278                cp++;
5279        }
5280        *cp_p = cp;
5281
5282        /* user says num divided by scale and we say internally that
5283         * is MAX_SCORE * num / scale.
5284         */
5285        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5286}
5287
5288static int diff_scoreopt_parse(const char *opt)
5289{
5290        int opt1, opt2, cmd;
5291
5292        if (*opt++ != '-')
5293                return -1;
5294        cmd = *opt++;
5295        if (cmd == '-') {
5296                /* convert the long-form arguments into short-form versions */
5297                if (skip_prefix(opt, "break-rewrites", &opt)) {
5298                        if (*opt == 0 || *opt++ == '=')
5299                                cmd = 'B';
5300                } else if (skip_prefix(opt, "find-copies", &opt)) {
5301                        if (*opt == 0 || *opt++ == '=')
5302                                cmd = 'C';
5303                } else if (skip_prefix(opt, "find-renames", &opt)) {
5304                        if (*opt == 0 || *opt++ == '=')
5305                                cmd = 'M';
5306                }
5307        }
5308        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5309                return -1; /* that is not a -M, -C, or -B option */
5310
5311        opt1 = parse_rename_score(&opt);
5312        if (cmd != 'B')
5313                opt2 = 0;
5314        else {
5315                if (*opt == 0)
5316                        opt2 = 0;
5317                else if (*opt != '/')
5318                        return -1; /* we expect -B80/99 or -B80 */
5319                else {
5320                        opt++;
5321                        opt2 = parse_rename_score(&opt);
5322                }
5323        }
5324        if (*opt != 0)
5325                return -1;
5326        return opt1 | (opt2 << 16);
5327}
5328
5329struct diff_queue_struct diff_queued_diff;
5330
5331void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5332{
5333        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5334        queue->queue[queue->nr++] = dp;
5335}
5336
5337struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5338                                 struct diff_filespec *one,
5339                                 struct diff_filespec *two)
5340{
5341        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5342        dp->one = one;
5343        dp->two = two;
5344        if (queue)
5345                diff_q(queue, dp);
5346        return dp;
5347}
5348
5349void diff_free_filepair(struct diff_filepair *p)
5350{
5351        free_filespec(p->one);
5352        free_filespec(p->two);
5353        free(p);
5354}
5355
5356const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5357{
5358        int abblen;
5359        const char *abbrev;
5360
5361        /* Do we want all 40 hex characters? */
5362        if (len == the_hash_algo->hexsz)
5363                return oid_to_hex(oid);
5364
5365        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5366        abbrev = diff_abbrev_oid(oid, len);
5367
5368        if (!print_sha1_ellipsis())
5369                return abbrev;
5370
5371        abblen = strlen(abbrev);
5372
5373        /*
5374         * In well-behaved cases, where the abbreviated result is the
5375         * same as the requested length, append three dots after the
5376         * abbreviation (hence the whole logic is limited to the case
5377         * where abblen < 37); when the actual abbreviated result is a
5378         * bit longer than the requested length, we reduce the number
5379         * of dots so that they match the well-behaved ones.  However,
5380         * if the actual abbreviation is longer than the requested
5381         * length by more than three, we give up on aligning, and add
5382         * three dots anyway, to indicate that the output is not the
5383         * full object name.  Yes, this may be suboptimal, but this
5384         * appears only in "diff --raw --abbrev" output and it is not
5385         * worth the effort to change it now.  Note that this would
5386         * likely to work fine when the automatic sizing of default
5387         * abbreviation length is used--we would be fed -1 in "len" in
5388         * that case, and will end up always appending three-dots, but
5389         * the automatic sizing is supposed to give abblen that ensures
5390         * uniqueness across all objects (statistically speaking).
5391         */
5392        if (abblen < the_hash_algo->hexsz - 3) {
5393                static char hex[GIT_MAX_HEXSZ + 1];
5394                if (len < abblen && abblen <= len + 2)
5395                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5396                else
5397                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5398                return hex;
5399        }
5400
5401        return oid_to_hex(oid);
5402}
5403
5404static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5405{
5406        int line_termination = opt->line_termination;
5407        int inter_name_termination = line_termination ? '\t' : '\0';
5408
5409        fprintf(opt->file, "%s", diff_line_prefix(opt));
5410        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5411                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5412                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5413                fprintf(opt->file, "%s ",
5414                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5415        }
5416        if (p->score) {
5417                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5418                        inter_name_termination);
5419        } else {
5420                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5421        }
5422
5423        if (p->status == DIFF_STATUS_COPIED ||
5424            p->status == DIFF_STATUS_RENAMED) {
5425                const char *name_a, *name_b;
5426                name_a = p->one->path;
5427                name_b = p->two->path;
5428                strip_prefix(opt->prefix_length, &name_a, &name_b);
5429                write_name_quoted(name_a, opt->file, inter_name_termination);
5430                write_name_quoted(name_b, opt->file, line_termination);
5431        } else {
5432                const char *name_a, *name_b;
5433                name_a = p->one->mode ? p->one->path : p->two->path;
5434                name_b = NULL;
5435                strip_prefix(opt->prefix_length, &name_a, &name_b);
5436                write_name_quoted(name_a, opt->file, line_termination);
5437        }
5438}
5439
5440int diff_unmodified_pair(struct diff_filepair *p)
5441{
5442        /* This function is written stricter than necessary to support
5443         * the currently implemented transformers, but the idea is to
5444         * let transformers to produce diff_filepairs any way they want,
5445         * and filter and clean them up here before producing the output.
5446         */
5447        struct diff_filespec *one = p->one, *two = p->two;
5448
5449        if (DIFF_PAIR_UNMERGED(p))
5450                return 0; /* unmerged is interesting */
5451
5452        /* deletion, addition, mode or type change
5453         * and rename are all interesting.
5454         */
5455        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5456            DIFF_PAIR_MODE_CHANGED(p) ||
5457            strcmp(one->path, two->path))
5458                return 0;
5459
5460        /* both are valid and point at the same path.  that is, we are
5461         * dealing with a change.
5462         */
5463        if (one->oid_valid && two->oid_valid &&
5464            oideq(&one->oid, &two->oid) &&
5465            !one->dirty_submodule && !two->dirty_submodule)
5466                return 1; /* no change */
5467        if (!one->oid_valid && !two->oid_valid)
5468                return 1; /* both look at the same file on the filesystem. */
5469        return 0;
5470}
5471
5472static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5473{
5474        if (diff_unmodified_pair(p))
5475                return;
5476
5477        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5478            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5479                return; /* no tree diffs in patch format */
5480
5481        run_diff(p, o);
5482}
5483
5484static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5485                            struct diffstat_t *diffstat)
5486{
5487        if (diff_unmodified_pair(p))
5488                return;
5489
5490        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5491            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5492                return; /* no useful stat for tree diffs */
5493
5494        run_diffstat(p, o, diffstat);
5495}
5496
5497static void diff_flush_checkdiff(struct diff_filepair *p,
5498                struct diff_options *o)
5499{
5500        if (diff_unmodified_pair(p))
5501                return;
5502
5503        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5504            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5505                return; /* nothing to check in tree diffs */
5506
5507        run_checkdiff(p, o);
5508}
5509
5510int diff_queue_is_empty(void)
5511{
5512        struct diff_queue_struct *q = &diff_queued_diff;
5513        int i;
5514        for (i = 0; i < q->nr; i++)
5515                if (!diff_unmodified_pair(q->queue[i]))
5516                        return 0;
5517        return 1;
5518}
5519
5520#if DIFF_DEBUG
5521void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5522{
5523        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5524                x, one ? one : "",
5525                s->path,
5526                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5527                s->mode,
5528                s->oid_valid ? oid_to_hex(&s->oid) : "");
5529        fprintf(stderr, "queue[%d] %s size %lu\n",
5530                x, one ? one : "",
5531                s->size);
5532}
5533
5534void diff_debug_filepair(const struct diff_filepair *p, int i)
5535{
5536        diff_debug_filespec(p->one, i, "one");
5537        diff_debug_filespec(p->two, i, "two");
5538        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5539                p->score, p->status ? p->status : '?',
5540                p->one->rename_used, p->broken_pair);
5541}
5542
5543void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5544{
5545        int i;
5546        if (msg)
5547                fprintf(stderr, "%s\n", msg);
5548        fprintf(stderr, "q->nr = %d\n", q->nr);
5549        for (i = 0; i < q->nr; i++) {
5550                struct diff_filepair *p = q->queue[i];
5551                diff_debug_filepair(p, i);
5552        }
5553}
5554#endif
5555
5556static void diff_resolve_rename_copy(void)
5557{
5558        int i;
5559        struct diff_filepair *p;
5560        struct diff_queue_struct *q = &diff_queued_diff;
5561
5562        diff_debug_queue("resolve-rename-copy", q);
5563
5564        for (i = 0; i < q->nr; i++) {
5565                p = q->queue[i];
5566                p->status = 0; /* undecided */
5567                if (DIFF_PAIR_UNMERGED(p))
5568                        p->status = DIFF_STATUS_UNMERGED;
5569                else if (!DIFF_FILE_VALID(p->one))
5570                        p->status = DIFF_STATUS_ADDED;
5571                else if (!DIFF_FILE_VALID(p->two))
5572                        p->status = DIFF_STATUS_DELETED;
5573                else if (DIFF_PAIR_TYPE_CHANGED(p))
5574                        p->status = DIFF_STATUS_TYPE_CHANGED;
5575
5576                /* from this point on, we are dealing with a pair
5577                 * whose both sides are valid and of the same type, i.e.
5578                 * either in-place edit or rename/copy edit.
5579                 */
5580                else if (DIFF_PAIR_RENAME(p)) {
5581                        /*
5582                         * A rename might have re-connected a broken
5583                         * pair up, causing the pathnames to be the
5584                         * same again. If so, that's not a rename at
5585                         * all, just a modification..
5586                         *
5587                         * Otherwise, see if this source was used for
5588                         * multiple renames, in which case we decrement
5589                         * the count, and call it a copy.
5590                         */
5591                        if (!strcmp(p->one->path, p->two->path))
5592                                p->status = DIFF_STATUS_MODIFIED;
5593                        else if (--p->one->rename_used > 0)
5594                                p->status = DIFF_STATUS_COPIED;
5595                        else
5596                                p->status = DIFF_STATUS_RENAMED;
5597                }
5598                else if (!oideq(&p->one->oid, &p->two->oid) ||
5599                         p->one->mode != p->two->mode ||
5600                         p->one->dirty_submodule ||
5601                         p->two->dirty_submodule ||
5602                         is_null_oid(&p->one->oid))
5603                        p->status = DIFF_STATUS_MODIFIED;
5604                else {
5605                        /* This is a "no-change" entry and should not
5606                         * happen anymore, but prepare for broken callers.
5607                         */
5608                        error("feeding unmodified %s to diffcore",
5609                              p->one->path);
5610                        p->status = DIFF_STATUS_UNKNOWN;
5611                }
5612        }
5613        diff_debug_queue("resolve-rename-copy done", q);
5614}
5615
5616static int check_pair_status(struct diff_filepair *p)
5617{
5618        switch (p->status) {
5619        case DIFF_STATUS_UNKNOWN:
5620                return 0;
5621        case 0:
5622                die("internal error in diff-resolve-rename-copy");
5623        default:
5624                return 1;
5625        }
5626}
5627
5628static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5629{
5630        int fmt = opt->output_format;
5631
5632        if (fmt & DIFF_FORMAT_CHECKDIFF)
5633                diff_flush_checkdiff(p, opt);
5634        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5635                diff_flush_raw(p, opt);
5636        else if (fmt & DIFF_FORMAT_NAME) {
5637                const char *name_a, *name_b;
5638                name_a = p->two->path;
5639                name_b = NULL;
5640                strip_prefix(opt->prefix_length, &name_a, &name_b);
5641                fprintf(opt->file, "%s", diff_line_prefix(opt));
5642                write_name_quoted(name_a, opt->file, opt->line_termination);
5643        }
5644}
5645
5646static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5647{
5648        struct strbuf sb = STRBUF_INIT;
5649        if (fs->mode)
5650                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5651        else
5652                strbuf_addf(&sb, " %s ", newdelete);
5653
5654        quote_c_style(fs->path, &sb, NULL, 0);
5655        strbuf_addch(&sb, '\n');
5656        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5657                         sb.buf, sb.len, 0);
5658        strbuf_release(&sb);
5659}
5660
5661static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5662                int show_name)
5663{
5664        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5665                struct strbuf sb = STRBUF_INIT;
5666                strbuf_addf(&sb, " mode change %06o => %06o",
5667                            p->one->mode, p->two->mode);
5668                if (show_name) {
5669                        strbuf_addch(&sb, ' ');
5670                        quote_c_style(p->two->path, &sb, NULL, 0);
5671                }
5672                strbuf_addch(&sb, '\n');
5673                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5674                                 sb.buf, sb.len, 0);
5675                strbuf_release(&sb);
5676        }
5677}
5678
5679static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5680                struct diff_filepair *p)
5681{
5682        struct strbuf sb = STRBUF_INIT;
5683        struct strbuf names = STRBUF_INIT;
5684
5685        pprint_rename(&names, p->one->path, p->two->path);
5686        strbuf_addf(&sb, " %s %s (%d%%)\n",
5687                    renamecopy, names.buf, similarity_index(p));
5688        strbuf_release(&names);
5689        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5690                                 sb.buf, sb.len, 0);
5691        show_mode_change(opt, p, 0);
5692        strbuf_release(&sb);
5693}
5694
5695static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5696{
5697        switch(p->status) {
5698        case DIFF_STATUS_DELETED:
5699                show_file_mode_name(opt, "delete", p->one);
5700                break;
5701        case DIFF_STATUS_ADDED:
5702                show_file_mode_name(opt, "create", p->two);
5703                break;
5704        case DIFF_STATUS_COPIED:
5705                show_rename_copy(opt, "copy", p);
5706                break;
5707        case DIFF_STATUS_RENAMED:
5708                show_rename_copy(opt, "rename", p);
5709                break;
5710        default:
5711                if (p->score) {
5712                        struct strbuf sb = STRBUF_INIT;
5713                        strbuf_addstr(&sb, " rewrite ");
5714                        quote_c_style(p->two->path, &sb, NULL, 0);
5715                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5716                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5717                                         sb.buf, sb.len, 0);
5718                        strbuf_release(&sb);
5719                }
5720                show_mode_change(opt, p, !p->score);
5721                break;
5722        }
5723}
5724
5725struct patch_id_t {
5726        git_SHA_CTX *ctx;
5727        int patchlen;
5728};
5729
5730static int remove_space(char *line, int len)
5731{
5732        int i;
5733        char *dst = line;
5734        unsigned char c;
5735
5736        for (i = 0; i < len; i++)
5737                if (!isspace((c = line[i])))
5738                        *dst++ = c;
5739
5740        return dst - line;
5741}
5742
5743static void patch_id_consume(void *priv, char *line, unsigned long len)
5744{
5745        struct patch_id_t *data = priv;
5746        int new_len;
5747
5748        new_len = remove_space(line, len);
5749
5750        git_SHA1_Update(data->ctx, line, new_len);
5751        data->patchlen += new_len;
5752}
5753
5754static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5755{
5756        git_SHA1_Update(ctx, str, strlen(str));
5757}
5758
5759static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5760{
5761        /* large enough for 2^32 in octal */
5762        char buf[12];
5763        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5764        git_SHA1_Update(ctx, buf, len);
5765}
5766
5767/* returns 0 upon success, and writes result into sha1 */
5768static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5769{
5770        struct diff_queue_struct *q = &diff_queued_diff;
5771        int i;
5772        git_SHA_CTX ctx;
5773        struct patch_id_t data;
5774
5775        git_SHA1_Init(&ctx);
5776        memset(&data, 0, sizeof(struct patch_id_t));
5777        data.ctx = &ctx;
5778
5779        for (i = 0; i < q->nr; i++) {
5780                xpparam_t xpp;
5781                xdemitconf_t xecfg;
5782                mmfile_t mf1, mf2;
5783                struct diff_filepair *p = q->queue[i];
5784                int len1, len2;
5785
5786                memset(&xpp, 0, sizeof(xpp));
5787                memset(&xecfg, 0, sizeof(xecfg));
5788                if (p->status == 0)
5789                        return error("internal diff status error");
5790                if (p->status == DIFF_STATUS_UNKNOWN)
5791                        continue;
5792                if (diff_unmodified_pair(p))
5793                        continue;
5794                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5795                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5796                        continue;
5797                if (DIFF_PAIR_UNMERGED(p))
5798                        continue;
5799
5800                diff_fill_oid_info(p->one, options->repo->index);
5801                diff_fill_oid_info(p->two, options->repo->index);
5802
5803                len1 = remove_space(p->one->path, strlen(p->one->path));
5804                len2 = remove_space(p->two->path, strlen(p->two->path));
5805                patch_id_add_string(&ctx, "diff--git");
5806                patch_id_add_string(&ctx, "a/");
5807                git_SHA1_Update(&ctx, p->one->path, len1);
5808                patch_id_add_string(&ctx, "b/");
5809                git_SHA1_Update(&ctx, p->two->path, len2);
5810
5811                if (p->one->mode == 0) {
5812                        patch_id_add_string(&ctx, "newfilemode");
5813                        patch_id_add_mode(&ctx, p->two->mode);
5814                        patch_id_add_string(&ctx, "---/dev/null");
5815                        patch_id_add_string(&ctx, "+++b/");
5816                        git_SHA1_Update(&ctx, p->two->path, len2);
5817                } else if (p->two->mode == 0) {
5818                        patch_id_add_string(&ctx, "deletedfilemode");
5819                        patch_id_add_mode(&ctx, p->one->mode);
5820                        patch_id_add_string(&ctx, "---a/");
5821                        git_SHA1_Update(&ctx, p->one->path, len1);
5822                        patch_id_add_string(&ctx, "+++/dev/null");
5823                } else {
5824                        patch_id_add_string(&ctx, "---a/");
5825                        git_SHA1_Update(&ctx, p->one->path, len1);
5826                        patch_id_add_string(&ctx, "+++b/");
5827                        git_SHA1_Update(&ctx, p->two->path, len2);
5828                }
5829
5830                if (diff_header_only)
5831                        continue;
5832
5833                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5834                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5835                        return error("unable to read files to diff");
5836
5837                if (diff_filespec_is_binary(options->repo, p->one) ||
5838                    diff_filespec_is_binary(options->repo, p->two)) {
5839                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5840                                        GIT_SHA1_HEXSZ);
5841                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5842                                        GIT_SHA1_HEXSZ);
5843                        continue;
5844                }
5845
5846                xpp.flags = 0;
5847                xecfg.ctxlen = 3;
5848                xecfg.flags = 0;
5849                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5850                                  patch_id_consume, &data, &xpp, &xecfg))
5851                        return error("unable to generate patch-id diff for %s",
5852                                     p->one->path);
5853        }
5854
5855        git_SHA1_Final(oid->hash, &ctx);
5856        return 0;
5857}
5858
5859int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5860{
5861        struct diff_queue_struct *q = &diff_queued_diff;
5862        int i;
5863        int result = diff_get_patch_id(options, oid, diff_header_only);
5864
5865        for (i = 0; i < q->nr; i++)
5866                diff_free_filepair(q->queue[i]);
5867
5868        free(q->queue);
5869        DIFF_QUEUE_CLEAR(q);
5870
5871        return result;
5872}
5873
5874static int is_summary_empty(const struct diff_queue_struct *q)
5875{
5876        int i;
5877
5878        for (i = 0; i < q->nr; i++) {
5879                const struct diff_filepair *p = q->queue[i];
5880
5881                switch (p->status) {
5882                case DIFF_STATUS_DELETED:
5883                case DIFF_STATUS_ADDED:
5884                case DIFF_STATUS_COPIED:
5885                case DIFF_STATUS_RENAMED:
5886                        return 0;
5887                default:
5888                        if (p->score)
5889                                return 0;
5890                        if (p->one->mode && p->two->mode &&
5891                            p->one->mode != p->two->mode)
5892                                return 0;
5893                        break;
5894                }
5895        }
5896        return 1;
5897}
5898
5899static const char rename_limit_warning[] =
5900N_("inexact rename detection was skipped due to too many files.");
5901
5902static const char degrade_cc_to_c_warning[] =
5903N_("only found copies from modified paths due to too many files.");
5904
5905static const char rename_limit_advice[] =
5906N_("you may want to set your %s variable to at least "
5907   "%d and retry the command.");
5908
5909void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5910{
5911        fflush(stdout);
5912        if (degraded_cc)
5913                warning(_(degrade_cc_to_c_warning));
5914        else if (needed)
5915                warning(_(rename_limit_warning));
5916        else
5917                return;
5918        if (0 < needed)
5919                warning(_(rename_limit_advice), varname, needed);
5920}
5921
5922static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5923{
5924        int i;
5925        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5926        struct diff_queue_struct *q = &diff_queued_diff;
5927
5928        if (WSEH_NEW & WS_RULE_MASK)
5929                BUG("WS rules bit mask overlaps with diff symbol flags");
5930
5931        if (o->color_moved)
5932                o->emitted_symbols = &esm;
5933
5934        for (i = 0; i < q->nr; i++) {
5935                struct diff_filepair *p = q->queue[i];
5936                if (check_pair_status(p))
5937                        diff_flush_patch(p, o);
5938        }
5939
5940        if (o->emitted_symbols) {
5941                if (o->color_moved) {
5942                        struct hashmap add_lines, del_lines;
5943
5944                        if (o->color_moved_ws_handling &
5945                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5946                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5947
5948                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5949                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5950
5951                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5952                        mark_color_as_moved(o, &add_lines, &del_lines);
5953                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5954                                dim_moved_lines(o);
5955
5956                        hashmap_free(&add_lines, 1);
5957                        hashmap_free(&del_lines, 1);
5958                }
5959
5960                for (i = 0; i < esm.nr; i++)
5961                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5962
5963                for (i = 0; i < esm.nr; i++)
5964                        free((void *)esm.buf[i].line);
5965                esm.nr = 0;
5966
5967                o->emitted_symbols = NULL;
5968        }
5969}
5970
5971void diff_flush(struct diff_options *options)
5972{
5973        struct diff_queue_struct *q = &diff_queued_diff;
5974        int i, output_format = options->output_format;
5975        int separator = 0;
5976        int dirstat_by_line = 0;
5977
5978        /*
5979         * Order: raw, stat, summary, patch
5980         * or:    name/name-status/checkdiff (other bits clear)
5981         */
5982        if (!q->nr)
5983                goto free_queue;
5984
5985        if (output_format & (DIFF_FORMAT_RAW |
5986                             DIFF_FORMAT_NAME |
5987                             DIFF_FORMAT_NAME_STATUS |
5988                             DIFF_FORMAT_CHECKDIFF)) {
5989                for (i = 0; i < q->nr; i++) {
5990                        struct diff_filepair *p = q->queue[i];
5991                        if (check_pair_status(p))
5992                                flush_one_pair(p, options);
5993                }
5994                separator++;
5995        }
5996
5997        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5998                dirstat_by_line = 1;
5999
6000        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
6001            dirstat_by_line) {
6002                struct diffstat_t diffstat;
6003
6004                memset(&diffstat, 0, sizeof(struct diffstat_t));
6005                for (i = 0; i < q->nr; i++) {
6006                        struct diff_filepair *p = q->queue[i];
6007                        if (check_pair_status(p))
6008                                diff_flush_stat(p, options, &diffstat);
6009                }
6010                if (output_format & DIFF_FORMAT_NUMSTAT)
6011                        show_numstat(&diffstat, options);
6012                if (output_format & DIFF_FORMAT_DIFFSTAT)
6013                        show_stats(&diffstat, options);
6014                if (output_format & DIFF_FORMAT_SHORTSTAT)
6015                        show_shortstats(&diffstat, options);
6016                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
6017                        show_dirstat_by_line(&diffstat, options);
6018                free_diffstat_info(&diffstat);
6019                separator++;
6020        }
6021        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
6022                show_dirstat(options);
6023
6024        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
6025                for (i = 0; i < q->nr; i++) {
6026                        diff_summary(options, q->queue[i]);
6027                }
6028                separator++;
6029        }
6030
6031        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
6032            options->flags.exit_with_status &&
6033            options->flags.diff_from_contents) {
6034                /*
6035                 * run diff_flush_patch for the exit status. setting
6036                 * options->file to /dev/null should be safe, because we
6037                 * aren't supposed to produce any output anyway.
6038                 */
6039                if (options->close_file)
6040                        fclose(options->file);
6041                options->file = xfopen("/dev/null", "w");
6042                options->close_file = 1;
6043                options->color_moved = 0;
6044                for (i = 0; i < q->nr; i++) {
6045                        struct diff_filepair *p = q->queue[i];
6046                        if (check_pair_status(p))
6047                                diff_flush_patch(p, options);
6048                        if (options->found_changes)
6049                                break;
6050                }
6051        }
6052
6053        if (output_format & DIFF_FORMAT_PATCH) {
6054                if (separator) {
6055                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
6056                        if (options->stat_sep)
6057                                /* attach patch instead of inline */
6058                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
6059                                                 NULL, 0, 0);
6060                }
6061
6062                diff_flush_patch_all_file_pairs(options);
6063        }
6064
6065        if (output_format & DIFF_FORMAT_CALLBACK)
6066                options->format_callback(q, options, options->format_callback_data);
6067
6068        for (i = 0; i < q->nr; i++)
6069                diff_free_filepair(q->queue[i]);
6070free_queue:
6071        free(q->queue);
6072        DIFF_QUEUE_CLEAR(q);
6073        if (options->close_file)
6074                fclose(options->file);
6075
6076        /*
6077         * Report the content-level differences with HAS_CHANGES;
6078         * diff_addremove/diff_change does not set the bit when
6079         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6080         */
6081        if (options->flags.diff_from_contents) {
6082                if (options->found_changes)
6083                        options->flags.has_changes = 1;
6084                else
6085                        options->flags.has_changes = 0;
6086        }
6087}
6088
6089static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6090{
6091        return (((p->status == DIFF_STATUS_MODIFIED) &&
6092                 ((p->score &&
6093                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6094                  (!p->score &&
6095                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6096                ((p->status != DIFF_STATUS_MODIFIED) &&
6097                 filter_bit_tst(p->status, options)));
6098}
6099
6100static void diffcore_apply_filter(struct diff_options *options)
6101{
6102        int i;
6103        struct diff_queue_struct *q = &diff_queued_diff;
6104        struct diff_queue_struct outq;
6105
6106        DIFF_QUEUE_CLEAR(&outq);
6107
6108        if (!options->filter)
6109                return;
6110
6111        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6112                int found;
6113                for (i = found = 0; !found && i < q->nr; i++) {
6114                        if (match_filter(options, q->queue[i]))
6115                                found++;
6116                }
6117                if (found)
6118                        return;
6119
6120                /* otherwise we will clear the whole queue
6121                 * by copying the empty outq at the end of this
6122                 * function, but first clear the current entries
6123                 * in the queue.
6124                 */
6125                for (i = 0; i < q->nr; i++)
6126                        diff_free_filepair(q->queue[i]);
6127        }
6128        else {
6129                /* Only the matching ones */
6130                for (i = 0; i < q->nr; i++) {
6131                        struct diff_filepair *p = q->queue[i];
6132                        if (match_filter(options, p))
6133                                diff_q(&outq, p);
6134                        else
6135                                diff_free_filepair(p);
6136                }
6137        }
6138        free(q->queue);
6139        *q = outq;
6140}
6141
6142/* Check whether two filespecs with the same mode and size are identical */
6143static int diff_filespec_is_identical(struct repository *r,
6144                                      struct diff_filespec *one,
6145                                      struct diff_filespec *two)
6146{
6147        if (S_ISGITLINK(one->mode))
6148                return 0;
6149        if (diff_populate_filespec(r, one, 0))
6150                return 0;
6151        if (diff_populate_filespec(r, two, 0))
6152                return 0;
6153        return !memcmp(one->data, two->data, one->size);
6154}
6155
6156static int diff_filespec_check_stat_unmatch(struct repository *r,
6157                                            struct diff_filepair *p)
6158{
6159        if (p->done_skip_stat_unmatch)
6160                return p->skip_stat_unmatch_result;
6161
6162        p->done_skip_stat_unmatch = 1;
6163        p->skip_stat_unmatch_result = 0;
6164        /*
6165         * 1. Entries that come from stat info dirtiness
6166         *    always have both sides (iow, not create/delete),
6167         *    one side of the object name is unknown, with
6168         *    the same mode and size.  Keep the ones that
6169         *    do not match these criteria.  They have real
6170         *    differences.
6171         *
6172         * 2. At this point, the file is known to be modified,
6173         *    with the same mode and size, and the object
6174         *    name of one side is unknown.  Need to inspect
6175         *    the identical contents.
6176         */
6177        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6178            !DIFF_FILE_VALID(p->two) ||
6179            (p->one->oid_valid && p->two->oid_valid) ||
6180            (p->one->mode != p->two->mode) ||
6181            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6182            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6183            (p->one->size != p->two->size) ||
6184            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6185                p->skip_stat_unmatch_result = 1;
6186        return p->skip_stat_unmatch_result;
6187}
6188
6189static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6190{
6191        int i;
6192        struct diff_queue_struct *q = &diff_queued_diff;
6193        struct diff_queue_struct outq;
6194        DIFF_QUEUE_CLEAR(&outq);
6195
6196        for (i = 0; i < q->nr; i++) {
6197                struct diff_filepair *p = q->queue[i];
6198
6199                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6200                        diff_q(&outq, p);
6201                else {
6202                        /*
6203                         * The caller can subtract 1 from skip_stat_unmatch
6204                         * to determine how many paths were dirty only
6205                         * due to stat info mismatch.
6206                         */
6207                        if (!diffopt->flags.no_index)
6208                                diffopt->skip_stat_unmatch++;
6209                        diff_free_filepair(p);
6210                }
6211        }
6212        free(q->queue);
6213        *q = outq;
6214}
6215
6216static int diffnamecmp(const void *a_, const void *b_)
6217{
6218        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6219        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6220        const char *name_a, *name_b;
6221
6222        name_a = a->one ? a->one->path : a->two->path;
6223        name_b = b->one ? b->one->path : b->two->path;
6224        return strcmp(name_a, name_b);
6225}
6226
6227void diffcore_fix_diff_index(struct diff_options *options)
6228{
6229        struct diff_queue_struct *q = &diff_queued_diff;
6230        QSORT(q->queue, q->nr, diffnamecmp);
6231}
6232
6233void diffcore_std(struct diff_options *options)
6234{
6235        /* NOTE please keep the following in sync with diff_tree_combined() */
6236        if (options->skip_stat_unmatch)
6237                diffcore_skip_stat_unmatch(options);
6238        if (!options->found_follow) {
6239                /* See try_to_follow_renames() in tree-diff.c */
6240                if (options->break_opt != -1)
6241                        diffcore_break(options->repo,
6242                                       options->break_opt);
6243                if (options->detect_rename)
6244                        diffcore_rename(options);
6245                if (options->break_opt != -1)
6246                        diffcore_merge_broken();
6247        }
6248        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6249                diffcore_pickaxe(options);
6250        if (options->orderfile)
6251                diffcore_order(options->orderfile);
6252        if (!options->found_follow)
6253                /* See try_to_follow_renames() in tree-diff.c */
6254                diff_resolve_rename_copy();
6255        diffcore_apply_filter(options);
6256
6257        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6258                options->flags.has_changes = 1;
6259        else
6260                options->flags.has_changes = 0;
6261
6262        options->found_follow = 0;
6263}
6264
6265int diff_result_code(struct diff_options *opt, int status)
6266{
6267        int result = 0;
6268
6269        diff_warn_rename_limit("diff.renameLimit",
6270                               opt->needed_rename_limit,
6271                               opt->degraded_cc_to_c);
6272        if (!opt->flags.exit_with_status &&
6273            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6274                return status;
6275        if (opt->flags.exit_with_status &&
6276            opt->flags.has_changes)
6277                result |= 01;
6278        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6279            opt->flags.check_failed)
6280                result |= 02;
6281        return result;
6282}
6283
6284int diff_can_quit_early(struct diff_options *opt)
6285{
6286        return (opt->flags.quick &&
6287                !opt->filter &&
6288                opt->flags.has_changes);
6289}
6290
6291/*
6292 * Shall changes to this submodule be ignored?
6293 *
6294 * Submodule changes can be configured to be ignored separately for each path,
6295 * but that configuration can be overridden from the command line.
6296 */
6297static int is_submodule_ignored(const char *path, struct diff_options *options)
6298{
6299        int ignored = 0;
6300        struct diff_flags orig_flags = options->flags;
6301        if (!options->flags.override_submodule_config)
6302                set_diffopt_flags_from_submodule_config(options, path);
6303        if (options->flags.ignore_submodules)
6304                ignored = 1;
6305        options->flags = orig_flags;
6306        return ignored;
6307}
6308
6309void diff_addremove(struct diff_options *options,
6310                    int addremove, unsigned mode,
6311                    const struct object_id *oid,
6312                    int oid_valid,
6313                    const char *concatpath, unsigned dirty_submodule)
6314{
6315        struct diff_filespec *one, *two;
6316
6317        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6318                return;
6319
6320        /* This may look odd, but it is a preparation for
6321         * feeding "there are unchanged files which should
6322         * not produce diffs, but when you are doing copy
6323         * detection you would need them, so here they are"
6324         * entries to the diff-core.  They will be prefixed
6325         * with something like '=' or '*' (I haven't decided
6326         * which but should not make any difference).
6327         * Feeding the same new and old to diff_change()
6328         * also has the same effect.
6329         * Before the final output happens, they are pruned after
6330         * merged into rename/copy pairs as appropriate.
6331         */
6332        if (options->flags.reverse_diff)
6333                addremove = (addremove == '+' ? '-' :
6334                             addremove == '-' ? '+' : addremove);
6335
6336        if (options->prefix &&
6337            strncmp(concatpath, options->prefix, options->prefix_length))
6338                return;
6339
6340        one = alloc_filespec(concatpath);
6341        two = alloc_filespec(concatpath);
6342
6343        if (addremove != '+')
6344                fill_filespec(one, oid, oid_valid, mode);
6345        if (addremove != '-') {
6346                fill_filespec(two, oid, oid_valid, mode);
6347                two->dirty_submodule = dirty_submodule;
6348        }
6349
6350        diff_queue(&diff_queued_diff, one, two);
6351        if (!options->flags.diff_from_contents)
6352                options->flags.has_changes = 1;
6353}
6354
6355void diff_change(struct diff_options *options,
6356                 unsigned old_mode, unsigned new_mode,
6357                 const struct object_id *old_oid,
6358                 const struct object_id *new_oid,
6359                 int old_oid_valid, int new_oid_valid,
6360                 const char *concatpath,
6361                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6362{
6363        struct diff_filespec *one, *two;
6364        struct diff_filepair *p;
6365
6366        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6367            is_submodule_ignored(concatpath, options))
6368                return;
6369
6370        if (options->flags.reverse_diff) {
6371                SWAP(old_mode, new_mode);
6372                SWAP(old_oid, new_oid);
6373                SWAP(old_oid_valid, new_oid_valid);
6374                SWAP(old_dirty_submodule, new_dirty_submodule);
6375        }
6376
6377        if (options->prefix &&
6378            strncmp(concatpath, options->prefix, options->prefix_length))
6379                return;
6380
6381        one = alloc_filespec(concatpath);
6382        two = alloc_filespec(concatpath);
6383        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6384        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6385        one->dirty_submodule = old_dirty_submodule;
6386        two->dirty_submodule = new_dirty_submodule;
6387        p = diff_queue(&diff_queued_diff, one, two);
6388
6389        if (options->flags.diff_from_contents)
6390                return;
6391
6392        if (options->flags.quick && options->skip_stat_unmatch &&
6393            !diff_filespec_check_stat_unmatch(options->repo, p))
6394                return;
6395
6396        options->flags.has_changes = 1;
6397}
6398
6399struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6400{
6401        struct diff_filepair *pair;
6402        struct diff_filespec *one, *two;
6403
6404        if (options->prefix &&
6405            strncmp(path, options->prefix, options->prefix_length))
6406                return NULL;
6407
6408        one = alloc_filespec(path);
6409        two = alloc_filespec(path);
6410        pair = diff_queue(&diff_queued_diff, one, two);
6411        pair->is_unmerged = 1;
6412        return pair;
6413}
6414
6415static char *run_textconv(struct repository *r,
6416                          const char *pgm,
6417                          struct diff_filespec *spec,
6418                          size_t *outsize)
6419{
6420        struct diff_tempfile *temp;
6421        const char *argv[3];
6422        const char **arg = argv;
6423        struct child_process child = CHILD_PROCESS_INIT;
6424        struct strbuf buf = STRBUF_INIT;
6425        int err = 0;
6426
6427        temp = prepare_temp_file(r, spec->path, spec);
6428        *arg++ = pgm;
6429        *arg++ = temp->name;
6430        *arg = NULL;
6431
6432        child.use_shell = 1;
6433        child.argv = argv;
6434        child.out = -1;
6435        if (start_command(&child)) {
6436                remove_tempfile();
6437                return NULL;
6438        }
6439
6440        if (strbuf_read(&buf, child.out, 0) < 0)
6441                err = error("error reading from textconv command '%s'", pgm);
6442        close(child.out);
6443
6444        if (finish_command(&child) || err) {
6445                strbuf_release(&buf);
6446                remove_tempfile();
6447                return NULL;
6448        }
6449        remove_tempfile();
6450
6451        return strbuf_detach(&buf, outsize);
6452}
6453
6454size_t fill_textconv(struct repository *r,
6455                     struct userdiff_driver *driver,
6456                     struct diff_filespec *df,
6457                     char **outbuf)
6458{
6459        size_t size;
6460
6461        if (!driver) {
6462                if (!DIFF_FILE_VALID(df)) {
6463                        *outbuf = "";
6464                        return 0;
6465                }
6466                if (diff_populate_filespec(r, df, 0))
6467                        die("unable to read files to diff");
6468                *outbuf = df->data;
6469                return df->size;
6470        }
6471
6472        if (!driver->textconv)
6473                BUG("fill_textconv called with non-textconv driver");
6474
6475        if (driver->textconv_cache && df->oid_valid) {
6476                *outbuf = notes_cache_get(driver->textconv_cache,
6477                                          &df->oid,
6478                                          &size);
6479                if (*outbuf)
6480                        return size;
6481        }
6482
6483        *outbuf = run_textconv(r, driver->textconv, df, &size);
6484        if (!*outbuf)
6485                die("unable to read files to diff");
6486
6487        if (driver->textconv_cache && df->oid_valid) {
6488                /* ignore errors, as we might be in a readonly repository */
6489                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6490                                size);
6491                /*
6492                 * we could save up changes and flush them all at the end,
6493                 * but we would need an extra call after all diffing is done.
6494                 * Since generating a cache entry is the slow path anyway,
6495                 * this extra overhead probably isn't a big deal.
6496                 */
6497                notes_cache_write(driver->textconv_cache);
6498        }
6499
6500        return size;
6501}
6502
6503int textconv_object(struct repository *r,
6504                    const char *path,
6505                    unsigned mode,
6506                    const struct object_id *oid,
6507                    int oid_valid,
6508                    char **buf,
6509                    unsigned long *buf_size)
6510{
6511        struct diff_filespec *df;
6512        struct userdiff_driver *textconv;
6513
6514        df = alloc_filespec(path);
6515        fill_filespec(df, oid, oid_valid, mode);
6516        textconv = get_textconv(r, df);
6517        if (!textconv) {
6518                free_filespec(df);
6519                return 0;
6520        }
6521
6522        *buf_size = fill_textconv(r, textconv, df, buf);
6523        free_filespec(df);
6524        return 1;
6525}
6526
6527void setup_diff_pager(struct diff_options *opt)
6528{
6529        /*
6530         * If the user asked for our exit code, then either they want --quiet
6531         * or --exit-code. We should definitely not bother with a pager in the
6532         * former case, as we will generate no output. Since we still properly
6533         * report our exit code even when a pager is run, we _could_ run a
6534         * pager with --exit-code. But since we have not done so historically,
6535         * and because it is easy to find people oneline advising "git diff
6536         * --exit-code" in hooks and other scripts, we do not do so.
6537         */
6538        if (!opt->flags.exit_with_status &&
6539            check_pager_config("diff") != 0)
6540                setup_pager();
6541}