diff.con commit sequencer: refactor transform_todos() to work on a todo_list (cbef27d)
   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 int 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, "ignore-space-change"))
 308                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 309                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 310                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 311                else if (!strcmp(sb.buf, "ignore-all-space"))
 312                        ret |= XDF_IGNORE_WHITESPACE;
 313                else if (!strcmp(sb.buf, "allow-indentation-change"))
 314                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 315                else
 316                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 317
 318                strbuf_release(&sb);
 319        }
 320
 321        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 322            (ret & XDF_WHITESPACE_FLAGS))
 323                die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 324
 325        string_list_clear(&l, 0);
 326
 327        return ret;
 328}
 329
 330int git_diff_ui_config(const char *var, const char *value, void *cb)
 331{
 332        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 333                diff_use_color_default = git_config_colorbool(var, value);
 334                return 0;
 335        }
 336        if (!strcmp(var, "diff.colormoved")) {
 337                int cm = parse_color_moved(value);
 338                if (cm < 0)
 339                        return -1;
 340                diff_color_moved_default = cm;
 341                return 0;
 342        }
 343        if (!strcmp(var, "diff.colormovedws")) {
 344                int cm = parse_color_moved_ws(value);
 345                if (cm < 0)
 346                        return -1;
 347                diff_color_moved_ws_default = cm;
 348                return 0;
 349        }
 350        if (!strcmp(var, "diff.context")) {
 351                diff_context_default = git_config_int(var, value);
 352                if (diff_context_default < 0)
 353                        return -1;
 354                return 0;
 355        }
 356        if (!strcmp(var, "diff.interhunkcontext")) {
 357                diff_interhunk_context_default = git_config_int(var, value);
 358                if (diff_interhunk_context_default < 0)
 359                        return -1;
 360                return 0;
 361        }
 362        if (!strcmp(var, "diff.renames")) {
 363                diff_detect_rename_default = git_config_rename(var, value);
 364                return 0;
 365        }
 366        if (!strcmp(var, "diff.autorefreshindex")) {
 367                diff_auto_refresh_index = git_config_bool(var, value);
 368                return 0;
 369        }
 370        if (!strcmp(var, "diff.mnemonicprefix")) {
 371                diff_mnemonic_prefix = git_config_bool(var, value);
 372                return 0;
 373        }
 374        if (!strcmp(var, "diff.noprefix")) {
 375                diff_no_prefix = git_config_bool(var, value);
 376                return 0;
 377        }
 378        if (!strcmp(var, "diff.statgraphwidth")) {
 379                diff_stat_graph_width = git_config_int(var, value);
 380                return 0;
 381        }
 382        if (!strcmp(var, "diff.external"))
 383                return git_config_string(&external_diff_cmd_cfg, var, value);
 384        if (!strcmp(var, "diff.wordregex"))
 385                return git_config_string(&diff_word_regex_cfg, var, value);
 386        if (!strcmp(var, "diff.orderfile"))
 387                return git_config_pathname(&diff_order_file_cfg, var, value);
 388
 389        if (!strcmp(var, "diff.ignoresubmodules"))
 390                handle_ignore_submodules_arg(&default_diff_options, value);
 391
 392        if (!strcmp(var, "diff.submodule")) {
 393                if (parse_submodule_params(&default_diff_options, value))
 394                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 395                                value);
 396                return 0;
 397        }
 398
 399        if (!strcmp(var, "diff.algorithm")) {
 400                diff_algorithm = parse_algorithm_value(value);
 401                if (diff_algorithm < 0)
 402                        return -1;
 403                return 0;
 404        }
 405
 406        if (!strcmp(var, "diff.wserrorhighlight")) {
 407                int val = parse_ws_error_highlight(value);
 408                if (val < 0)
 409                        return -1;
 410                ws_error_highlight_default = val;
 411                return 0;
 412        }
 413
 414        if (git_color_config(var, value, cb) < 0)
 415                return -1;
 416
 417        return git_diff_basic_config(var, value, cb);
 418}
 419
 420int git_diff_basic_config(const char *var, const char *value, void *cb)
 421{
 422        const char *name;
 423
 424        if (!strcmp(var, "diff.renamelimit")) {
 425                diff_rename_limit_default = git_config_int(var, value);
 426                return 0;
 427        }
 428
 429        if (userdiff_config(var, value) < 0)
 430                return -1;
 431
 432        if (skip_prefix(var, "diff.color.", &name) ||
 433            skip_prefix(var, "color.diff.", &name)) {
 434                int slot = parse_diff_color_slot(name);
 435                if (slot < 0)
 436                        return 0;
 437                if (!value)
 438                        return config_error_nonbool(var);
 439                return color_parse(value, diff_colors[slot]);
 440        }
 441
 442        /* like GNU diff's --suppress-blank-empty option  */
 443        if (!strcmp(var, "diff.suppressblankempty") ||
 444                        /* for backwards compatibility */
 445                        !strcmp(var, "diff.suppress-blank-empty")) {
 446                diff_suppress_blank_empty = git_config_bool(var, value);
 447                return 0;
 448        }
 449
 450        if (!strcmp(var, "diff.dirstat")) {
 451                struct strbuf errmsg = STRBUF_INIT;
 452                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 453                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 454                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 455                                errmsg.buf);
 456                strbuf_release(&errmsg);
 457                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 458                return 0;
 459        }
 460
 461        if (git_diff_heuristic_config(var, value, cb) < 0)
 462                return -1;
 463
 464        return git_default_config(var, value, cb);
 465}
 466
 467static char *quote_two(const char *one, const char *two)
 468{
 469        int need_one = quote_c_style(one, NULL, NULL, 1);
 470        int need_two = quote_c_style(two, NULL, NULL, 1);
 471        struct strbuf res = STRBUF_INIT;
 472
 473        if (need_one + need_two) {
 474                strbuf_addch(&res, '"');
 475                quote_c_style(one, &res, NULL, 1);
 476                quote_c_style(two, &res, NULL, 1);
 477                strbuf_addch(&res, '"');
 478        } else {
 479                strbuf_addstr(&res, one);
 480                strbuf_addstr(&res, two);
 481        }
 482        return strbuf_detach(&res, NULL);
 483}
 484
 485static const char *external_diff(void)
 486{
 487        static const char *external_diff_cmd = NULL;
 488        static int done_preparing = 0;
 489
 490        if (done_preparing)
 491                return external_diff_cmd;
 492        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 493        if (!external_diff_cmd)
 494                external_diff_cmd = external_diff_cmd_cfg;
 495        done_preparing = 1;
 496        return external_diff_cmd;
 497}
 498
 499/*
 500 * Keep track of files used for diffing. Sometimes such an entry
 501 * refers to a temporary file, sometimes to an existing file, and
 502 * sometimes to "/dev/null".
 503 */
 504static struct diff_tempfile {
 505        /*
 506         * filename external diff should read from, or NULL if this
 507         * entry is currently not in use:
 508         */
 509        const char *name;
 510
 511        char hex[GIT_MAX_HEXSZ + 1];
 512        char mode[10];
 513
 514        /*
 515         * If this diff_tempfile instance refers to a temporary file,
 516         * this tempfile object is used to manage its lifetime.
 517         */
 518        struct tempfile *tempfile;
 519} diff_temp[2];
 520
 521struct emit_callback {
 522        int color_diff;
 523        unsigned ws_rule;
 524        int blank_at_eof_in_preimage;
 525        int blank_at_eof_in_postimage;
 526        int lno_in_preimage;
 527        int lno_in_postimage;
 528        const char **label_path;
 529        struct diff_words_data *diff_words;
 530        struct diff_options *opt;
 531        struct strbuf *header;
 532};
 533
 534static int count_lines(const char *data, int size)
 535{
 536        int count, ch, completely_empty = 1, nl_just_seen = 0;
 537        count = 0;
 538        while (0 < size--) {
 539                ch = *data++;
 540                if (ch == '\n') {
 541                        count++;
 542                        nl_just_seen = 1;
 543                        completely_empty = 0;
 544                }
 545                else {
 546                        nl_just_seen = 0;
 547                        completely_empty = 0;
 548                }
 549        }
 550        if (completely_empty)
 551                return 0;
 552        if (!nl_just_seen)
 553                count++; /* no trailing newline */
 554        return count;
 555}
 556
 557static int fill_mmfile(struct repository *r, mmfile_t *mf,
 558                       struct diff_filespec *one)
 559{
 560        if (!DIFF_FILE_VALID(one)) {
 561                mf->ptr = (char *)""; /* does not matter */
 562                mf->size = 0;
 563                return 0;
 564        }
 565        else if (diff_populate_filespec(r, one, 0))
 566                return -1;
 567
 568        mf->ptr = one->data;
 569        mf->size = one->size;
 570        return 0;
 571}
 572
 573/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 574static unsigned long diff_filespec_size(struct repository *r,
 575                                        struct diff_filespec *one)
 576{
 577        if (!DIFF_FILE_VALID(one))
 578                return 0;
 579        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 580        return one->size;
 581}
 582
 583static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 584{
 585        char *ptr = mf->ptr;
 586        long size = mf->size;
 587        int cnt = 0;
 588
 589        if (!size)
 590                return cnt;
 591        ptr += size - 1; /* pointing at the very end */
 592        if (*ptr != '\n')
 593                ; /* incomplete line */
 594        else
 595                ptr--; /* skip the last LF */
 596        while (mf->ptr < ptr) {
 597                char *prev_eol;
 598                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 599                        if (*prev_eol == '\n')
 600                                break;
 601                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 602                        break;
 603                cnt++;
 604                ptr = prev_eol - 1;
 605        }
 606        return cnt;
 607}
 608
 609static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 610                               struct emit_callback *ecbdata)
 611{
 612        int l1, l2, at;
 613        unsigned ws_rule = ecbdata->ws_rule;
 614        l1 = count_trailing_blank(mf1, ws_rule);
 615        l2 = count_trailing_blank(mf2, ws_rule);
 616        if (l2 <= l1) {
 617                ecbdata->blank_at_eof_in_preimage = 0;
 618                ecbdata->blank_at_eof_in_postimage = 0;
 619                return;
 620        }
 621        at = count_lines(mf1->ptr, mf1->size);
 622        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 623
 624        at = count_lines(mf2->ptr, mf2->size);
 625        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 626}
 627
 628static void emit_line_0(struct diff_options *o,
 629                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 630                        int first, const char *line, int len)
 631{
 632        int has_trailing_newline, has_trailing_carriage_return;
 633        int needs_reset = 0; /* at the end of the line */
 634        FILE *file = o->file;
 635
 636        fputs(diff_line_prefix(o), file);
 637
 638        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 639        if (has_trailing_newline)
 640                len--;
 641
 642        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 643        if (has_trailing_carriage_return)
 644                len--;
 645
 646        if (!len && !first)
 647                goto end_of_line;
 648
 649        if (reverse && want_color(o->use_color)) {
 650                fputs(GIT_COLOR_REVERSE, file);
 651                needs_reset = 1;
 652        }
 653
 654        if (set_sign) {
 655                fputs(set_sign, file);
 656                needs_reset = 1;
 657        }
 658
 659        if (first)
 660                fputc(first, file);
 661
 662        if (!len)
 663                goto end_of_line;
 664
 665        if (set) {
 666                if (set_sign && set != set_sign)
 667                        fputs(reset, file);
 668                fputs(set, file);
 669                needs_reset = 1;
 670        }
 671        fwrite(line, len, 1, file);
 672        needs_reset = 1; /* 'line' may contain color codes. */
 673
 674end_of_line:
 675        if (needs_reset)
 676                fputs(reset, file);
 677        if (has_trailing_carriage_return)
 678                fputc('\r', file);
 679        if (has_trailing_newline)
 680                fputc('\n', file);
 681}
 682
 683static void emit_line(struct diff_options *o, const char *set, const char *reset,
 684                      const char *line, int len)
 685{
 686        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 687}
 688
 689enum diff_symbol {
 690        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 691        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 692        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 693        DIFF_SYMBOL_BINARY_DIFF_BODY,
 694        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 695        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 696        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 697        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 698        DIFF_SYMBOL_STATS_LINE,
 699        DIFF_SYMBOL_WORD_DIFF,
 700        DIFF_SYMBOL_STAT_SEP,
 701        DIFF_SYMBOL_SUMMARY,
 702        DIFF_SYMBOL_SUBMODULE_ADD,
 703        DIFF_SYMBOL_SUBMODULE_DEL,
 704        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 705        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 706        DIFF_SYMBOL_SUBMODULE_HEADER,
 707        DIFF_SYMBOL_SUBMODULE_ERROR,
 708        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 709        DIFF_SYMBOL_REWRITE_DIFF,
 710        DIFF_SYMBOL_BINARY_FILES,
 711        DIFF_SYMBOL_HEADER,
 712        DIFF_SYMBOL_FILEPAIR_PLUS,
 713        DIFF_SYMBOL_FILEPAIR_MINUS,
 714        DIFF_SYMBOL_WORDS_PORCELAIN,
 715        DIFF_SYMBOL_WORDS,
 716        DIFF_SYMBOL_CONTEXT,
 717        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 718        DIFF_SYMBOL_PLUS,
 719        DIFF_SYMBOL_MINUS,
 720        DIFF_SYMBOL_NO_LF_EOF,
 721        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 722        DIFF_SYMBOL_CONTEXT_MARKER,
 723        DIFF_SYMBOL_SEPARATOR
 724};
 725/*
 726 * Flags for content lines:
 727 * 0..12 are whitespace rules
 728 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 729 * 16 is marking if the line is blank at EOF
 730 */
 731#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 732#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 733#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 734#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 735#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 736
 737/*
 738 * This struct is used when we need to buffer the output of the diff output.
 739 *
 740 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 741 * into the pre/post image file. This pointer could be a union with the
 742 * line pointer. By storing an offset into the file instead of the literal line,
 743 * we can decrease the memory footprint for the buffered output. At first we
 744 * may want to only have indirection for the content lines, but we could also
 745 * enhance the state for emitting prefabricated lines, e.g. the similarity
 746 * score line or hunk/file headers would only need to store a number or path
 747 * and then the output can be constructed later on depending on state.
 748 */
 749struct emitted_diff_symbol {
 750        const char *line;
 751        int len;
 752        int flags;
 753        enum diff_symbol s;
 754};
 755#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 756
 757struct emitted_diff_symbols {
 758        struct emitted_diff_symbol *buf;
 759        int nr, alloc;
 760};
 761#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 762
 763static void append_emitted_diff_symbol(struct diff_options *o,
 764                                       struct emitted_diff_symbol *e)
 765{
 766        struct emitted_diff_symbol *f;
 767
 768        ALLOC_GROW(o->emitted_symbols->buf,
 769                   o->emitted_symbols->nr + 1,
 770                   o->emitted_symbols->alloc);
 771        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 772
 773        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 774        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 775}
 776
 777struct moved_entry {
 778        struct hashmap_entry ent;
 779        const struct emitted_diff_symbol *es;
 780        struct moved_entry *next_line;
 781};
 782
 783/**
 784 * The struct ws_delta holds white space differences between moved lines, i.e.
 785 * between '+' and '-' lines that have been detected to be a move.
 786 * The string contains the difference in leading white spaces, before the
 787 * rest of the line is compared using the white space config for move
 788 * coloring. The current_longer indicates if the first string in the
 789 * comparision is longer than the second.
 790 */
 791struct ws_delta {
 792        char *string;
 793        unsigned int current_longer : 1;
 794};
 795#define WS_DELTA_INIT { NULL, 0 }
 796
 797struct moved_block {
 798        struct moved_entry *match;
 799        struct ws_delta wsd;
 800};
 801
 802static void moved_block_clear(struct moved_block *b)
 803{
 804        FREE_AND_NULL(b->wsd.string);
 805        b->match = NULL;
 806}
 807
 808static int compute_ws_delta(const struct emitted_diff_symbol *a,
 809                             const struct emitted_diff_symbol *b,
 810                             struct ws_delta *out)
 811{
 812        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 813        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 814        int d = longer->len - shorter->len;
 815
 816        if (strncmp(longer->line + d, shorter->line, shorter->len))
 817                return 0;
 818
 819        out->string = xmemdupz(longer->line, d);
 820        out->current_longer = (a == longer);
 821
 822        return 1;
 823}
 824
 825static int cmp_in_block_with_wsd(const struct diff_options *o,
 826                                 const struct moved_entry *cur,
 827                                 const struct moved_entry *match,
 828                                 struct moved_block *pmb,
 829                                 int n)
 830{
 831        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 832        int al = cur->es->len, cl = l->len;
 833        const char *a = cur->es->line,
 834                   *b = match->es->line,
 835                   *c = l->line;
 836
 837        int wslen;
 838
 839        /*
 840         * We need to check if 'cur' is equal to 'match'.
 841         * As those are from the same (+/-) side, we do not need to adjust for
 842         * indent changes. However these were found using fuzzy matching
 843         * so we do have to check if they are equal.
 844         */
 845        if (strcmp(a, b))
 846                return 1;
 847
 848        if (!pmb->wsd.string)
 849                /*
 850                 * The white space delta is not active? This can happen
 851                 * when we exit early in this function.
 852                 */
 853                return 1;
 854
 855        /*
 856         * The indent changes of the block are known and stored in
 857         * pmb->wsd; however we need to check if the indent changes of the
 858         * current line are still the same as before.
 859         *
 860         * To do so we need to compare 'l' to 'cur', adjusting the
 861         * one of them for the white spaces, depending which was longer.
 862         */
 863
 864        wslen = strlen(pmb->wsd.string);
 865        if (pmb->wsd.current_longer) {
 866                c += wslen;
 867                cl -= wslen;
 868        } else {
 869                a += wslen;
 870                al -= wslen;
 871        }
 872
 873        if (al != cl || memcmp(a, c, al))
 874                return 1;
 875
 876        return 0;
 877}
 878
 879static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 880                           const void *entry,
 881                           const void *entry_or_key,
 882                           const void *keydata)
 883{
 884        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 885        const struct moved_entry *a = entry;
 886        const struct moved_entry *b = entry_or_key;
 887        unsigned flags = diffopt->color_moved_ws_handling
 888                         & XDF_WHITESPACE_FLAGS;
 889
 890        if (diffopt->color_moved_ws_handling &
 891            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 892                /*
 893                 * As there is not specific white space config given,
 894                 * we'd need to check for a new block, so ignore all
 895                 * white space. The setup of the white space
 896                 * configuration for the next block is done else where
 897                 */
 898                flags |= XDF_IGNORE_WHITESPACE;
 899
 900        return !xdiff_compare_lines(a->es->line, a->es->len,
 901                                    b->es->line, b->es->len,
 902                                    flags);
 903}
 904
 905static struct moved_entry *prepare_entry(struct diff_options *o,
 906                                         int line_no)
 907{
 908        struct moved_entry *ret = xmalloc(sizeof(*ret));
 909        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 910        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 911
 912        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 913        ret->es = l;
 914        ret->next_line = NULL;
 915
 916        return ret;
 917}
 918
 919static void add_lines_to_move_detection(struct diff_options *o,
 920                                        struct hashmap *add_lines,
 921                                        struct hashmap *del_lines)
 922{
 923        struct moved_entry *prev_line = NULL;
 924
 925        int n;
 926        for (n = 0; n < o->emitted_symbols->nr; n++) {
 927                struct hashmap *hm;
 928                struct moved_entry *key;
 929
 930                switch (o->emitted_symbols->buf[n].s) {
 931                case DIFF_SYMBOL_PLUS:
 932                        hm = add_lines;
 933                        break;
 934                case DIFF_SYMBOL_MINUS:
 935                        hm = del_lines;
 936                        break;
 937                default:
 938                        prev_line = NULL;
 939                        continue;
 940                }
 941
 942                key = prepare_entry(o, n);
 943                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 944                        prev_line->next_line = key;
 945
 946                hashmap_add(hm, key);
 947                prev_line = key;
 948        }
 949}
 950
 951static void pmb_advance_or_null(struct diff_options *o,
 952                                struct moved_entry *match,
 953                                struct hashmap *hm,
 954                                struct moved_block *pmb,
 955                                int pmb_nr)
 956{
 957        int i;
 958        for (i = 0; i < pmb_nr; i++) {
 959                struct moved_entry *prev = pmb[i].match;
 960                struct moved_entry *cur = (prev && prev->next_line) ?
 961                                prev->next_line : NULL;
 962                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 963                        pmb[i].match = cur;
 964                } else {
 965                        pmb[i].match = NULL;
 966                }
 967        }
 968}
 969
 970static void pmb_advance_or_null_multi_match(struct diff_options *o,
 971                                            struct moved_entry *match,
 972                                            struct hashmap *hm,
 973                                            struct moved_block *pmb,
 974                                            int pmb_nr, int n)
 975{
 976        int i;
 977        char *got_match = xcalloc(1, pmb_nr);
 978
 979        for (; match; match = hashmap_get_next(hm, match)) {
 980                for (i = 0; i < pmb_nr; i++) {
 981                        struct moved_entry *prev = pmb[i].match;
 982                        struct moved_entry *cur = (prev && prev->next_line) ?
 983                                        prev->next_line : NULL;
 984                        if (!cur)
 985                                continue;
 986                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
 987                                got_match[i] |= 1;
 988                }
 989        }
 990
 991        for (i = 0; i < pmb_nr; i++) {
 992                if (got_match[i]) {
 993                        /* Advance to the next line */
 994                        pmb[i].match = pmb[i].match->next_line;
 995                } else {
 996                        moved_block_clear(&pmb[i]);
 997                }
 998        }
 999
1000        free(got_match);
1001}
1002
1003static int shrink_potential_moved_blocks(struct moved_block *pmb,
1004                                         int pmb_nr)
1005{
1006        int lp, rp;
1007
1008        /* Shrink the set of potential block to the remaining running */
1009        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1010                while (lp < pmb_nr && pmb[lp].match)
1011                        lp++;
1012                /* lp points at the first NULL now */
1013
1014                while (rp > -1 && !pmb[rp].match)
1015                        rp--;
1016                /* rp points at the last non-NULL */
1017
1018                if (lp < pmb_nr && rp > -1 && lp < rp) {
1019                        pmb[lp] = pmb[rp];
1020                        pmb[rp].match = NULL;
1021                        pmb[rp].wsd.string = NULL;
1022                        rp--;
1023                        lp++;
1024                }
1025        }
1026
1027        /* Remember the number of running sets */
1028        return rp + 1;
1029}
1030
1031/*
1032 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1033 *
1034 * Otherwise, if the last block has fewer alphanumeric characters than
1035 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1036 * that block.
1037 *
1038 * The last block consists of the (n - block_length)'th line up to but not
1039 * including the nth line.
1040 *
1041 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1042 * Think of a way to unify them.
1043 */
1044static void adjust_last_block(struct diff_options *o, int n, int block_length)
1045{
1046        int i, alnum_count = 0;
1047        if (o->color_moved == COLOR_MOVED_PLAIN)
1048                return;
1049        for (i = 1; i < block_length + 1; i++) {
1050                const char *c = o->emitted_symbols->buf[n - i].line;
1051                for (; *c; c++) {
1052                        if (!isalnum(*c))
1053                                continue;
1054                        alnum_count++;
1055                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1056                                return;
1057                }
1058        }
1059        for (i = 1; i < block_length + 1; i++)
1060                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1061}
1062
1063/* Find blocks of moved code, delegate actual coloring decision to helper */
1064static void mark_color_as_moved(struct diff_options *o,
1065                                struct hashmap *add_lines,
1066                                struct hashmap *del_lines)
1067{
1068        struct moved_block *pmb = NULL; /* potentially moved blocks */
1069        int pmb_nr = 0, pmb_alloc = 0;
1070        int n, flipped_block = 1, block_length = 0;
1071
1072
1073        for (n = 0; n < o->emitted_symbols->nr; n++) {
1074                struct hashmap *hm = NULL;
1075                struct moved_entry *key;
1076                struct moved_entry *match = NULL;
1077                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1078
1079                switch (l->s) {
1080                case DIFF_SYMBOL_PLUS:
1081                        hm = del_lines;
1082                        key = prepare_entry(o, n);
1083                        match = hashmap_get(hm, key, NULL);
1084                        free(key);
1085                        break;
1086                case DIFF_SYMBOL_MINUS:
1087                        hm = add_lines;
1088                        key = prepare_entry(o, n);
1089                        match = hashmap_get(hm, key, NULL);
1090                        free(key);
1091                        break;
1092                default:
1093                        flipped_block = 1;
1094                }
1095
1096                if (!match) {
1097                        int i;
1098
1099                        adjust_last_block(o, n, block_length);
1100                        for(i = 0; i < pmb_nr; i++)
1101                                moved_block_clear(&pmb[i]);
1102                        pmb_nr = 0;
1103                        block_length = 0;
1104                        continue;
1105                }
1106
1107                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1108
1109                if (o->color_moved == COLOR_MOVED_PLAIN)
1110                        continue;
1111
1112                if (o->color_moved_ws_handling &
1113                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1114                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1115                else
1116                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1117
1118                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1119
1120                if (pmb_nr == 0) {
1121                        /*
1122                         * The current line is the start of a new block.
1123                         * Setup the set of potential blocks.
1124                         */
1125                        for (; match; match = hashmap_get_next(hm, match)) {
1126                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1127                                if (o->color_moved_ws_handling &
1128                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1129                                        if (compute_ws_delta(l, match->es,
1130                                                             &pmb[pmb_nr].wsd))
1131                                                pmb[pmb_nr++].match = match;
1132                                } else {
1133                                        pmb[pmb_nr].wsd.string = NULL;
1134                                        pmb[pmb_nr++].match = match;
1135                                }
1136                        }
1137
1138                        flipped_block = (flipped_block + 1) % 2;
1139
1140                        adjust_last_block(o, n, block_length);
1141                        block_length = 0;
1142                }
1143
1144                block_length++;
1145
1146                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1147                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1148        }
1149        adjust_last_block(o, n, block_length);
1150
1151        for(n = 0; n < pmb_nr; n++)
1152                moved_block_clear(&pmb[n]);
1153        free(pmb);
1154}
1155
1156#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1157  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1158static void dim_moved_lines(struct diff_options *o)
1159{
1160        int n;
1161        for (n = 0; n < o->emitted_symbols->nr; n++) {
1162                struct emitted_diff_symbol *prev = (n != 0) ?
1163                                &o->emitted_symbols->buf[n - 1] : NULL;
1164                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1165                struct emitted_diff_symbol *next =
1166                                (n < o->emitted_symbols->nr - 1) ?
1167                                &o->emitted_symbols->buf[n + 1] : NULL;
1168
1169                /* Not a plus or minus line? */
1170                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1171                        continue;
1172
1173                /* Not a moved line? */
1174                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1175                        continue;
1176
1177                /*
1178                 * If prev or next are not a plus or minus line,
1179                 * pretend they don't exist
1180                 */
1181                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1182                            prev->s != DIFF_SYMBOL_MINUS)
1183                        prev = NULL;
1184                if (next && next->s != DIFF_SYMBOL_PLUS &&
1185                            next->s != DIFF_SYMBOL_MINUS)
1186                        next = NULL;
1187
1188                /* Inside a block? */
1189                if ((prev &&
1190                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1191                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1192                    (next &&
1193                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1194                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1195                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1196                        continue;
1197                }
1198
1199                /* Check if we are at an interesting bound: */
1200                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1201                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1202                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1203                        continue;
1204                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1205                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1206                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1207                        continue;
1208
1209                /*
1210                 * The boundary to prev and next are not interesting,
1211                 * so this line is not interesting as a whole
1212                 */
1213                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1214        }
1215}
1216
1217static void emit_line_ws_markup(struct diff_options *o,
1218                                const char *set_sign, const char *set,
1219                                const char *reset,
1220                                int sign_index, const char *line, int len,
1221                                unsigned ws_rule, int blank_at_eof)
1222{
1223        const char *ws = NULL;
1224        int sign = o->output_indicators[sign_index];
1225
1226        if (o->ws_error_highlight & ws_rule) {
1227                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1228                if (!*ws)
1229                        ws = NULL;
1230        }
1231
1232        if (!ws && !set_sign)
1233                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1234        else if (!ws) {
1235                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1236        } else if (blank_at_eof)
1237                /* Blank line at EOF - paint '+' as well */
1238                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1239        else {
1240                /* Emit just the prefix, then the rest. */
1241                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1242                            sign, "", 0);
1243                ws_check_emit(line, len, ws_rule,
1244                              o->file, set, reset, ws);
1245        }
1246}
1247
1248static void emit_diff_symbol_from_struct(struct diff_options *o,
1249                                         struct emitted_diff_symbol *eds)
1250{
1251        static const char *nneof = " No newline at end of file\n";
1252        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1253        struct strbuf sb = STRBUF_INIT;
1254
1255        enum diff_symbol s = eds->s;
1256        const char *line = eds->line;
1257        int len = eds->len;
1258        unsigned flags = eds->flags;
1259
1260        switch (s) {
1261        case DIFF_SYMBOL_NO_LF_EOF:
1262                context = diff_get_color_opt(o, DIFF_CONTEXT);
1263                reset = diff_get_color_opt(o, DIFF_RESET);
1264                putc('\n', o->file);
1265                emit_line_0(o, context, NULL, 0, reset, '\\',
1266                            nneof, strlen(nneof));
1267                break;
1268        case DIFF_SYMBOL_SUBMODULE_HEADER:
1269        case DIFF_SYMBOL_SUBMODULE_ERROR:
1270        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1271        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1272        case DIFF_SYMBOL_SUMMARY:
1273        case DIFF_SYMBOL_STATS_LINE:
1274        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1275        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1276                emit_line(o, "", "", line, len);
1277                break;
1278        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1279        case DIFF_SYMBOL_CONTEXT_MARKER:
1280                context = diff_get_color_opt(o, DIFF_CONTEXT);
1281                reset = diff_get_color_opt(o, DIFF_RESET);
1282                emit_line(o, context, reset, line, len);
1283                break;
1284        case DIFF_SYMBOL_SEPARATOR:
1285                fprintf(o->file, "%s%c",
1286                        diff_line_prefix(o),
1287                        o->line_termination);
1288                break;
1289        case DIFF_SYMBOL_CONTEXT:
1290                set = diff_get_color_opt(o, DIFF_CONTEXT);
1291                reset = diff_get_color_opt(o, DIFF_RESET);
1292                set_sign = NULL;
1293                if (o->flags.dual_color_diffed_diffs) {
1294                        char c = !len ? 0 : line[0];
1295
1296                        if (c == '+')
1297                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1298                        else if (c == '@')
1299                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1300                        else if (c == '-')
1301                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1302                }
1303                emit_line_ws_markup(o, set_sign, set, reset,
1304                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1305                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1306                break;
1307        case DIFF_SYMBOL_PLUS:
1308                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1309                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1310                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1311                case DIFF_SYMBOL_MOVED_LINE |
1312                     DIFF_SYMBOL_MOVED_LINE_ALT |
1313                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1314                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1315                        break;
1316                case DIFF_SYMBOL_MOVED_LINE |
1317                     DIFF_SYMBOL_MOVED_LINE_ALT:
1318                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1319                        break;
1320                case DIFF_SYMBOL_MOVED_LINE |
1321                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1322                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1323                        break;
1324                case DIFF_SYMBOL_MOVED_LINE:
1325                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1326                        break;
1327                default:
1328                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1329                }
1330                reset = diff_get_color_opt(o, DIFF_RESET);
1331                if (!o->flags.dual_color_diffed_diffs)
1332                        set_sign = NULL;
1333                else {
1334                        char c = !len ? 0 : line[0];
1335
1336                        set_sign = set;
1337                        if (c == '-')
1338                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1339                        else if (c == '@')
1340                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1341                        else if (c == '+')
1342                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1343                        else
1344                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1345                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1346                }
1347                emit_line_ws_markup(o, set_sign, set, reset,
1348                                    OUTPUT_INDICATOR_NEW, line, len,
1349                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1350                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1351                break;
1352        case DIFF_SYMBOL_MINUS:
1353                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1354                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1355                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1356                case DIFF_SYMBOL_MOVED_LINE |
1357                     DIFF_SYMBOL_MOVED_LINE_ALT |
1358                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1359                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1360                        break;
1361                case DIFF_SYMBOL_MOVED_LINE |
1362                     DIFF_SYMBOL_MOVED_LINE_ALT:
1363                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1364                        break;
1365                case DIFF_SYMBOL_MOVED_LINE |
1366                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1367                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1368                        break;
1369                case DIFF_SYMBOL_MOVED_LINE:
1370                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1371                        break;
1372                default:
1373                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1374                }
1375                reset = diff_get_color_opt(o, DIFF_RESET);
1376                if (!o->flags.dual_color_diffed_diffs)
1377                        set_sign = NULL;
1378                else {
1379                        char c = !len ? 0 : line[0];
1380
1381                        set_sign = set;
1382                        if (c == '+')
1383                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1384                        else if (c == '@')
1385                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1386                        else if (c == '-')
1387                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1388                        else
1389                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1390                }
1391                emit_line_ws_markup(o, set_sign, set, reset,
1392                                    OUTPUT_INDICATOR_OLD, line, len,
1393                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1394                break;
1395        case DIFF_SYMBOL_WORDS_PORCELAIN:
1396                context = diff_get_color_opt(o, DIFF_CONTEXT);
1397                reset = diff_get_color_opt(o, DIFF_RESET);
1398                emit_line(o, context, reset, line, len);
1399                fputs("~\n", o->file);
1400                break;
1401        case DIFF_SYMBOL_WORDS:
1402                context = diff_get_color_opt(o, DIFF_CONTEXT);
1403                reset = diff_get_color_opt(o, DIFF_RESET);
1404                /*
1405                 * Skip the prefix character, if any.  With
1406                 * diff_suppress_blank_empty, there may be
1407                 * none.
1408                 */
1409                if (line[0] != '\n') {
1410                        line++;
1411                        len--;
1412                }
1413                emit_line(o, context, reset, line, len);
1414                break;
1415        case DIFF_SYMBOL_FILEPAIR_PLUS:
1416                meta = diff_get_color_opt(o, DIFF_METAINFO);
1417                reset = diff_get_color_opt(o, DIFF_RESET);
1418                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1419                        line, reset,
1420                        strchr(line, ' ') ? "\t" : "");
1421                break;
1422        case DIFF_SYMBOL_FILEPAIR_MINUS:
1423                meta = diff_get_color_opt(o, DIFF_METAINFO);
1424                reset = diff_get_color_opt(o, DIFF_RESET);
1425                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1426                        line, reset,
1427                        strchr(line, ' ') ? "\t" : "");
1428                break;
1429        case DIFF_SYMBOL_BINARY_FILES:
1430        case DIFF_SYMBOL_HEADER:
1431                fprintf(o->file, "%s", line);
1432                break;
1433        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1434                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1435                break;
1436        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1437                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1438                break;
1439        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1440                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1441                break;
1442        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1443                fputs(diff_line_prefix(o), o->file);
1444                fputc('\n', o->file);
1445                break;
1446        case DIFF_SYMBOL_REWRITE_DIFF:
1447                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1448                reset = diff_get_color_opt(o, DIFF_RESET);
1449                emit_line(o, fraginfo, reset, line, len);
1450                break;
1451        case DIFF_SYMBOL_SUBMODULE_ADD:
1452                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1453                reset = diff_get_color_opt(o, DIFF_RESET);
1454                emit_line(o, set, reset, line, len);
1455                break;
1456        case DIFF_SYMBOL_SUBMODULE_DEL:
1457                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1458                reset = diff_get_color_opt(o, DIFF_RESET);
1459                emit_line(o, set, reset, line, len);
1460                break;
1461        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1462                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1463                        diff_line_prefix(o), line);
1464                break;
1465        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1466                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1467                        diff_line_prefix(o), line);
1468                break;
1469        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1470                emit_line(o, "", "", " 0 files changed\n",
1471                          strlen(" 0 files changed\n"));
1472                break;
1473        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1474                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1475                break;
1476        case DIFF_SYMBOL_WORD_DIFF:
1477                fprintf(o->file, "%.*s", len, line);
1478                break;
1479        case DIFF_SYMBOL_STAT_SEP:
1480                fputs(o->stat_sep, o->file);
1481                break;
1482        default:
1483                BUG("unknown diff symbol");
1484        }
1485        strbuf_release(&sb);
1486}
1487
1488static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1489                             const char *line, int len, unsigned flags)
1490{
1491        struct emitted_diff_symbol e = {line, len, flags, s};
1492
1493        if (o->emitted_symbols)
1494                append_emitted_diff_symbol(o, &e);
1495        else
1496                emit_diff_symbol_from_struct(o, &e);
1497}
1498
1499void diff_emit_submodule_del(struct diff_options *o, const char *line)
1500{
1501        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1502}
1503
1504void diff_emit_submodule_add(struct diff_options *o, const char *line)
1505{
1506        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1507}
1508
1509void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1510{
1511        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1512                         path, strlen(path), 0);
1513}
1514
1515void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1516{
1517        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1518                         path, strlen(path), 0);
1519}
1520
1521void diff_emit_submodule_header(struct diff_options *o, const char *header)
1522{
1523        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1524                         header, strlen(header), 0);
1525}
1526
1527void diff_emit_submodule_error(struct diff_options *o, const char *err)
1528{
1529        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1530}
1531
1532void diff_emit_submodule_pipethrough(struct diff_options *o,
1533                                     const char *line, int len)
1534{
1535        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1536}
1537
1538static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1539{
1540        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1541              ecbdata->blank_at_eof_in_preimage &&
1542              ecbdata->blank_at_eof_in_postimage &&
1543              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1544              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1545                return 0;
1546        return ws_blank_line(line, len, ecbdata->ws_rule);
1547}
1548
1549static void emit_add_line(const char *reset,
1550                          struct emit_callback *ecbdata,
1551                          const char *line, int len)
1552{
1553        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1554        if (new_blank_line_at_eof(ecbdata, line, len))
1555                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1556
1557        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1558}
1559
1560static void emit_del_line(const char *reset,
1561                          struct emit_callback *ecbdata,
1562                          const char *line, int len)
1563{
1564        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1565        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1566}
1567
1568static void emit_context_line(const char *reset,
1569                              struct emit_callback *ecbdata,
1570                              const char *line, int len)
1571{
1572        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1573        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1574}
1575
1576static void emit_hunk_header(struct emit_callback *ecbdata,
1577                             const char *line, int len)
1578{
1579        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1580        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1581        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1582        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1583        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1584        static const char atat[2] = { '@', '@' };
1585        const char *cp, *ep;
1586        struct strbuf msgbuf = STRBUF_INIT;
1587        int org_len = len;
1588        int i = 1;
1589
1590        /*
1591         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1592         * it always is at least 10 bytes long.
1593         */
1594        if (len < 10 ||
1595            memcmp(line, atat, 2) ||
1596            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1597                emit_diff_symbol(ecbdata->opt,
1598                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1599                return;
1600        }
1601        ep += 2; /* skip over @@ */
1602
1603        /* The hunk header in fraginfo color */
1604        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1605                strbuf_addstr(&msgbuf, reverse);
1606        strbuf_addstr(&msgbuf, frag);
1607        strbuf_add(&msgbuf, line, ep - line);
1608        strbuf_addstr(&msgbuf, reset);
1609
1610        /*
1611         * trailing "\r\n"
1612         */
1613        for ( ; i < 3; i++)
1614                if (line[len - i] == '\r' || line[len - i] == '\n')
1615                        len--;
1616
1617        /* blank before the func header */
1618        for (cp = ep; ep - line < len; ep++)
1619                if (*ep != ' ' && *ep != '\t')
1620                        break;
1621        if (ep != cp) {
1622                strbuf_addstr(&msgbuf, context);
1623                strbuf_add(&msgbuf, cp, ep - cp);
1624                strbuf_addstr(&msgbuf, reset);
1625        }
1626
1627        if (ep < line + len) {
1628                strbuf_addstr(&msgbuf, func);
1629                strbuf_add(&msgbuf, ep, line + len - ep);
1630                strbuf_addstr(&msgbuf, reset);
1631        }
1632
1633        strbuf_add(&msgbuf, line + len, org_len - len);
1634        strbuf_complete_line(&msgbuf);
1635        emit_diff_symbol(ecbdata->opt,
1636                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1637        strbuf_release(&msgbuf);
1638}
1639
1640static struct diff_tempfile *claim_diff_tempfile(void) {
1641        int i;
1642        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1643                if (!diff_temp[i].name)
1644                        return diff_temp + i;
1645        BUG("diff is failing to clean up its tempfiles");
1646}
1647
1648static void remove_tempfile(void)
1649{
1650        int i;
1651        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1652                if (is_tempfile_active(diff_temp[i].tempfile))
1653                        delete_tempfile(&diff_temp[i].tempfile);
1654                diff_temp[i].name = NULL;
1655        }
1656}
1657
1658static void add_line_count(struct strbuf *out, int count)
1659{
1660        switch (count) {
1661        case 0:
1662                strbuf_addstr(out, "0,0");
1663                break;
1664        case 1:
1665                strbuf_addstr(out, "1");
1666                break;
1667        default:
1668                strbuf_addf(out, "1,%d", count);
1669                break;
1670        }
1671}
1672
1673static void emit_rewrite_lines(struct emit_callback *ecb,
1674                               int prefix, const char *data, int size)
1675{
1676        const char *endp = NULL;
1677        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1678
1679        while (0 < size) {
1680                int len;
1681
1682                endp = memchr(data, '\n', size);
1683                len = endp ? (endp - data + 1) : size;
1684                if (prefix != '+') {
1685                        ecb->lno_in_preimage++;
1686                        emit_del_line(reset, ecb, data, len);
1687                } else {
1688                        ecb->lno_in_postimage++;
1689                        emit_add_line(reset, ecb, data, len);
1690                }
1691                size -= len;
1692                data += len;
1693        }
1694        if (!endp)
1695                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1696}
1697
1698static void emit_rewrite_diff(const char *name_a,
1699                              const char *name_b,
1700                              struct diff_filespec *one,
1701                              struct diff_filespec *two,
1702                              struct userdiff_driver *textconv_one,
1703                              struct userdiff_driver *textconv_two,
1704                              struct diff_options *o)
1705{
1706        int lc_a, lc_b;
1707        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1708        const char *a_prefix, *b_prefix;
1709        char *data_one, *data_two;
1710        size_t size_one, size_two;
1711        struct emit_callback ecbdata;
1712        struct strbuf out = STRBUF_INIT;
1713
1714        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1715                a_prefix = o->b_prefix;
1716                b_prefix = o->a_prefix;
1717        } else {
1718                a_prefix = o->a_prefix;
1719                b_prefix = o->b_prefix;
1720        }
1721
1722        name_a += (*name_a == '/');
1723        name_b += (*name_b == '/');
1724
1725        strbuf_reset(&a_name);
1726        strbuf_reset(&b_name);
1727        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1728        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1729
1730        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1731        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1732
1733        memset(&ecbdata, 0, sizeof(ecbdata));
1734        ecbdata.color_diff = want_color(o->use_color);
1735        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1736        ecbdata.opt = o;
1737        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1738                mmfile_t mf1, mf2;
1739                mf1.ptr = (char *)data_one;
1740                mf2.ptr = (char *)data_two;
1741                mf1.size = size_one;
1742                mf2.size = size_two;
1743                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1744        }
1745        ecbdata.lno_in_preimage = 1;
1746        ecbdata.lno_in_postimage = 1;
1747
1748        lc_a = count_lines(data_one, size_one);
1749        lc_b = count_lines(data_two, size_two);
1750
1751        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1752                         a_name.buf, a_name.len, 0);
1753        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1754                         b_name.buf, b_name.len, 0);
1755
1756        strbuf_addstr(&out, "@@ -");
1757        if (!o->irreversible_delete)
1758                add_line_count(&out, lc_a);
1759        else
1760                strbuf_addstr(&out, "?,?");
1761        strbuf_addstr(&out, " +");
1762        add_line_count(&out, lc_b);
1763        strbuf_addstr(&out, " @@\n");
1764        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1765        strbuf_release(&out);
1766
1767        if (lc_a && !o->irreversible_delete)
1768                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1769        if (lc_b)
1770                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1771        if (textconv_one)
1772                free((char *)data_one);
1773        if (textconv_two)
1774                free((char *)data_two);
1775}
1776
1777struct diff_words_buffer {
1778        mmfile_t text;
1779        unsigned long alloc;
1780        struct diff_words_orig {
1781                const char *begin, *end;
1782        } *orig;
1783        int orig_nr, orig_alloc;
1784};
1785
1786static void diff_words_append(char *line, unsigned long len,
1787                struct diff_words_buffer *buffer)
1788{
1789        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1790        line++;
1791        len--;
1792        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1793        buffer->text.size += len;
1794        buffer->text.ptr[buffer->text.size] = '\0';
1795}
1796
1797struct diff_words_style_elem {
1798        const char *prefix;
1799        const char *suffix;
1800        const char *color; /* NULL; filled in by the setup code if
1801                            * color is enabled */
1802};
1803
1804struct diff_words_style {
1805        enum diff_words_type type;
1806        struct diff_words_style_elem new_word, old_word, ctx;
1807        const char *newline;
1808};
1809
1810static struct diff_words_style diff_words_styles[] = {
1811        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1812        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1813        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1814};
1815
1816struct diff_words_data {
1817        struct diff_words_buffer minus, plus;
1818        const char *current_plus;
1819        int last_minus;
1820        struct diff_options *opt;
1821        regex_t *word_regex;
1822        enum diff_words_type type;
1823        struct diff_words_style *style;
1824};
1825
1826static int fn_out_diff_words_write_helper(struct diff_options *o,
1827                                          struct diff_words_style_elem *st_el,
1828                                          const char *newline,
1829                                          size_t count, const char *buf)
1830{
1831        int print = 0;
1832        struct strbuf sb = STRBUF_INIT;
1833
1834        while (count) {
1835                char *p = memchr(buf, '\n', count);
1836                if (print)
1837                        strbuf_addstr(&sb, diff_line_prefix(o));
1838
1839                if (p != buf) {
1840                        const char *reset = st_el->color && *st_el->color ?
1841                                            GIT_COLOR_RESET : NULL;
1842                        if (st_el->color && *st_el->color)
1843                                strbuf_addstr(&sb, st_el->color);
1844                        strbuf_addstr(&sb, st_el->prefix);
1845                        strbuf_add(&sb, buf, p ? p - buf : count);
1846                        strbuf_addstr(&sb, st_el->suffix);
1847                        if (reset)
1848                                strbuf_addstr(&sb, reset);
1849                }
1850                if (!p)
1851                        goto out;
1852
1853                strbuf_addstr(&sb, newline);
1854                count -= p + 1 - buf;
1855                buf = p + 1;
1856                print = 1;
1857                if (count) {
1858                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1859                                         sb.buf, sb.len, 0);
1860                        strbuf_reset(&sb);
1861                }
1862        }
1863
1864out:
1865        if (sb.len)
1866                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1867                                 sb.buf, sb.len, 0);
1868        strbuf_release(&sb);
1869        return 0;
1870}
1871
1872/*
1873 * '--color-words' algorithm can be described as:
1874 *
1875 *   1. collect the minus/plus lines of a diff hunk, divided into
1876 *      minus-lines and plus-lines;
1877 *
1878 *   2. break both minus-lines and plus-lines into words and
1879 *      place them into two mmfile_t with one word for each line;
1880 *
1881 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1882 *
1883 * And for the common parts of the both file, we output the plus side text.
1884 * diff_words->current_plus is used to trace the current position of the plus file
1885 * which printed. diff_words->last_minus is used to trace the last minus word
1886 * printed.
1887 *
1888 * For '--graph' to work with '--color-words', we need to output the graph prefix
1889 * on each line of color words output. Generally, there are two conditions on
1890 * which we should output the prefix.
1891 *
1892 *   1. diff_words->last_minus == 0 &&
1893 *      diff_words->current_plus == diff_words->plus.text.ptr
1894 *
1895 *      that is: the plus text must start as a new line, and if there is no minus
1896 *      word printed, a graph prefix must be printed.
1897 *
1898 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1899 *      *(diff_words->current_plus - 1) == '\n'
1900 *
1901 *      that is: a graph prefix must be printed following a '\n'
1902 */
1903static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1904{
1905        if ((diff_words->last_minus == 0 &&
1906                diff_words->current_plus == diff_words->plus.text.ptr) ||
1907                (diff_words->current_plus > diff_words->plus.text.ptr &&
1908                *(diff_words->current_plus - 1) == '\n')) {
1909                return 1;
1910        } else {
1911                return 0;
1912        }
1913}
1914
1915static void fn_out_diff_words_aux(void *priv,
1916                                  long minus_first, long minus_len,
1917                                  long plus_first, long plus_len,
1918                                  const char *func, long funclen)
1919{
1920        struct diff_words_data *diff_words = priv;
1921        struct diff_words_style *style = diff_words->style;
1922        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1923        struct diff_options *opt = diff_words->opt;
1924        const char *line_prefix;
1925
1926        assert(opt);
1927        line_prefix = diff_line_prefix(opt);
1928
1929        /* POSIX requires that first be decremented by one if len == 0... */
1930        if (minus_len) {
1931                minus_begin = diff_words->minus.orig[minus_first].begin;
1932                minus_end =
1933                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1934        } else
1935                minus_begin = minus_end =
1936                        diff_words->minus.orig[minus_first].end;
1937
1938        if (plus_len) {
1939                plus_begin = diff_words->plus.orig[plus_first].begin;
1940                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1941        } else
1942                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1943
1944        if (color_words_output_graph_prefix(diff_words)) {
1945                fputs(line_prefix, diff_words->opt->file);
1946        }
1947        if (diff_words->current_plus != plus_begin) {
1948                fn_out_diff_words_write_helper(diff_words->opt,
1949                                &style->ctx, style->newline,
1950                                plus_begin - diff_words->current_plus,
1951                                diff_words->current_plus);
1952        }
1953        if (minus_begin != minus_end) {
1954                fn_out_diff_words_write_helper(diff_words->opt,
1955                                &style->old_word, style->newline,
1956                                minus_end - minus_begin, minus_begin);
1957        }
1958        if (plus_begin != plus_end) {
1959                fn_out_diff_words_write_helper(diff_words->opt,
1960                                &style->new_word, style->newline,
1961                                plus_end - plus_begin, plus_begin);
1962        }
1963
1964        diff_words->current_plus = plus_end;
1965        diff_words->last_minus = minus_first;
1966}
1967
1968/* This function starts looking at *begin, and returns 0 iff a word was found. */
1969static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1970                int *begin, int *end)
1971{
1972        if (word_regex && *begin < buffer->size) {
1973                regmatch_t match[1];
1974                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1975                                 buffer->size - *begin, 1, match, 0)) {
1976                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1977                                        '\n', match[0].rm_eo - match[0].rm_so);
1978                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1979                        *begin += match[0].rm_so;
1980                        return *begin >= *end;
1981                }
1982                return -1;
1983        }
1984
1985        /* find the next word */
1986        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1987                (*begin)++;
1988        if (*begin >= buffer->size)
1989                return -1;
1990
1991        /* find the end of the word */
1992        *end = *begin + 1;
1993        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1994                (*end)++;
1995
1996        return 0;
1997}
1998
1999/*
2000 * This function splits the words in buffer->text, stores the list with
2001 * newline separator into out, and saves the offsets of the original words
2002 * in buffer->orig.
2003 */
2004static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2005                regex_t *word_regex)
2006{
2007        int i, j;
2008        long alloc = 0;
2009
2010        out->size = 0;
2011        out->ptr = NULL;
2012
2013        /* fake an empty "0th" word */
2014        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2015        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2016        buffer->orig_nr = 1;
2017
2018        for (i = 0; i < buffer->text.size; i++) {
2019                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2020                        return;
2021
2022                /* store original boundaries */
2023                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2024                                buffer->orig_alloc);
2025                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2026                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2027                buffer->orig_nr++;
2028
2029                /* store one word */
2030                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2031                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2032                out->ptr[out->size + j - i] = '\n';
2033                out->size += j - i + 1;
2034
2035                i = j - 1;
2036        }
2037}
2038
2039/* this executes the word diff on the accumulated buffers */
2040static void diff_words_show(struct diff_words_data *diff_words)
2041{
2042        xpparam_t xpp;
2043        xdemitconf_t xecfg;
2044        mmfile_t minus, plus;
2045        struct diff_words_style *style = diff_words->style;
2046
2047        struct diff_options *opt = diff_words->opt;
2048        const char *line_prefix;
2049
2050        assert(opt);
2051        line_prefix = diff_line_prefix(opt);
2052
2053        /* special case: only removal */
2054        if (!diff_words->plus.text.size) {
2055                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2056                                 line_prefix, strlen(line_prefix), 0);
2057                fn_out_diff_words_write_helper(diff_words->opt,
2058                        &style->old_word, style->newline,
2059                        diff_words->minus.text.size,
2060                        diff_words->minus.text.ptr);
2061                diff_words->minus.text.size = 0;
2062                return;
2063        }
2064
2065        diff_words->current_plus = diff_words->plus.text.ptr;
2066        diff_words->last_minus = 0;
2067
2068        memset(&xpp, 0, sizeof(xpp));
2069        memset(&xecfg, 0, sizeof(xecfg));
2070        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2071        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2072        xpp.flags = 0;
2073        /* as only the hunk header will be parsed, we need a 0-context */
2074        xecfg.ctxlen = 0;
2075        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2076                          diff_words, &xpp, &xecfg))
2077                die("unable to generate word diff");
2078        free(minus.ptr);
2079        free(plus.ptr);
2080        if (diff_words->current_plus != diff_words->plus.text.ptr +
2081                        diff_words->plus.text.size) {
2082                if (color_words_output_graph_prefix(diff_words))
2083                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2084                                         line_prefix, strlen(line_prefix), 0);
2085                fn_out_diff_words_write_helper(diff_words->opt,
2086                        &style->ctx, style->newline,
2087                        diff_words->plus.text.ptr + diff_words->plus.text.size
2088                        - diff_words->current_plus, diff_words->current_plus);
2089        }
2090        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2091}
2092
2093/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2094static void diff_words_flush(struct emit_callback *ecbdata)
2095{
2096        struct diff_options *wo = ecbdata->diff_words->opt;
2097
2098        if (ecbdata->diff_words->minus.text.size ||
2099            ecbdata->diff_words->plus.text.size)
2100                diff_words_show(ecbdata->diff_words);
2101
2102        if (wo->emitted_symbols) {
2103                struct diff_options *o = ecbdata->opt;
2104                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2105                int i;
2106
2107                /*
2108                 * NEEDSWORK:
2109                 * Instead of appending each, concat all words to a line?
2110                 */
2111                for (i = 0; i < wol->nr; i++)
2112                        append_emitted_diff_symbol(o, &wol->buf[i]);
2113
2114                for (i = 0; i < wol->nr; i++)
2115                        free((void *)wol->buf[i].line);
2116
2117                wol->nr = 0;
2118        }
2119}
2120
2121static void diff_filespec_load_driver(struct diff_filespec *one,
2122                                      struct index_state *istate)
2123{
2124        /* Use already-loaded driver */
2125        if (one->driver)
2126                return;
2127
2128        if (S_ISREG(one->mode))
2129                one->driver = userdiff_find_by_path(istate, one->path);
2130
2131        /* Fallback to default settings */
2132        if (!one->driver)
2133                one->driver = userdiff_find_by_name("default");
2134}
2135
2136static const char *userdiff_word_regex(struct diff_filespec *one,
2137                                       struct index_state *istate)
2138{
2139        diff_filespec_load_driver(one, istate);
2140        return one->driver->word_regex;
2141}
2142
2143static void init_diff_words_data(struct emit_callback *ecbdata,
2144                                 struct diff_options *orig_opts,
2145                                 struct diff_filespec *one,
2146                                 struct diff_filespec *two)
2147{
2148        int i;
2149        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2150        memcpy(o, orig_opts, sizeof(struct diff_options));
2151
2152        ecbdata->diff_words =
2153                xcalloc(1, sizeof(struct diff_words_data));
2154        ecbdata->diff_words->type = o->word_diff;
2155        ecbdata->diff_words->opt = o;
2156
2157        if (orig_opts->emitted_symbols)
2158                o->emitted_symbols =
2159                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2160
2161        if (!o->word_regex)
2162                o->word_regex = userdiff_word_regex(one, o->repo->index);
2163        if (!o->word_regex)
2164                o->word_regex = userdiff_word_regex(two, o->repo->index);
2165        if (!o->word_regex)
2166                o->word_regex = diff_word_regex_cfg;
2167        if (o->word_regex) {
2168                ecbdata->diff_words->word_regex = (regex_t *)
2169                        xmalloc(sizeof(regex_t));
2170                if (regcomp(ecbdata->diff_words->word_regex,
2171                            o->word_regex,
2172                            REG_EXTENDED | REG_NEWLINE))
2173                        die("invalid regular expression: %s",
2174                            o->word_regex);
2175        }
2176        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2177                if (o->word_diff == diff_words_styles[i].type) {
2178                        ecbdata->diff_words->style =
2179                                &diff_words_styles[i];
2180                        break;
2181                }
2182        }
2183        if (want_color(o->use_color)) {
2184                struct diff_words_style *st = ecbdata->diff_words->style;
2185                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2186                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2187                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2188        }
2189}
2190
2191static void free_diff_words_data(struct emit_callback *ecbdata)
2192{
2193        if (ecbdata->diff_words) {
2194                diff_words_flush(ecbdata);
2195                free (ecbdata->diff_words->opt->emitted_symbols);
2196                free (ecbdata->diff_words->opt);
2197                free (ecbdata->diff_words->minus.text.ptr);
2198                free (ecbdata->diff_words->minus.orig);
2199                free (ecbdata->diff_words->plus.text.ptr);
2200                free (ecbdata->diff_words->plus.orig);
2201                if (ecbdata->diff_words->word_regex) {
2202                        regfree(ecbdata->diff_words->word_regex);
2203                        free(ecbdata->diff_words->word_regex);
2204                }
2205                FREE_AND_NULL(ecbdata->diff_words);
2206        }
2207}
2208
2209const char *diff_get_color(int diff_use_color, enum color_diff ix)
2210{
2211        if (want_color(diff_use_color))
2212                return diff_colors[ix];
2213        return "";
2214}
2215
2216const char *diff_line_prefix(struct diff_options *opt)
2217{
2218        struct strbuf *msgbuf;
2219        if (!opt->output_prefix)
2220                return "";
2221
2222        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2223        return msgbuf->buf;
2224}
2225
2226static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2227{
2228        const char *cp;
2229        unsigned long allot;
2230        size_t l = len;
2231
2232        cp = line;
2233        allot = l;
2234        while (0 < l) {
2235                (void) utf8_width(&cp, &l);
2236                if (!cp)
2237                        break; /* truncated in the middle? */
2238        }
2239        return allot - l;
2240}
2241
2242static void find_lno(const char *line, struct emit_callback *ecbdata)
2243{
2244        const char *p;
2245        ecbdata->lno_in_preimage = 0;
2246        ecbdata->lno_in_postimage = 0;
2247        p = strchr(line, '-');
2248        if (!p)
2249                return; /* cannot happen */
2250        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2251        p = strchr(p, '+');
2252        if (!p)
2253                return; /* cannot happen */
2254        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2255}
2256
2257static void fn_out_consume(void *priv, char *line, unsigned long len)
2258{
2259        struct emit_callback *ecbdata = priv;
2260        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2261        struct diff_options *o = ecbdata->opt;
2262
2263        o->found_changes = 1;
2264
2265        if (ecbdata->header) {
2266                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2267                                 ecbdata->header->buf, ecbdata->header->len, 0);
2268                strbuf_reset(ecbdata->header);
2269                ecbdata->header = NULL;
2270        }
2271
2272        if (ecbdata->label_path[0]) {
2273                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2274                                 ecbdata->label_path[0],
2275                                 strlen(ecbdata->label_path[0]), 0);
2276                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2277                                 ecbdata->label_path[1],
2278                                 strlen(ecbdata->label_path[1]), 0);
2279                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2280        }
2281
2282        if (diff_suppress_blank_empty
2283            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2284                line[0] = '\n';
2285                len = 1;
2286        }
2287
2288        if (line[0] == '@') {
2289                if (ecbdata->diff_words)
2290                        diff_words_flush(ecbdata);
2291                len = sane_truncate_line(ecbdata, line, len);
2292                find_lno(line, ecbdata);
2293                emit_hunk_header(ecbdata, line, len);
2294                return;
2295        }
2296
2297        if (ecbdata->diff_words) {
2298                enum diff_symbol s =
2299                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2300                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2301                if (line[0] == '-') {
2302                        diff_words_append(line, len,
2303                                          &ecbdata->diff_words->minus);
2304                        return;
2305                } else if (line[0] == '+') {
2306                        diff_words_append(line, len,
2307                                          &ecbdata->diff_words->plus);
2308                        return;
2309                } else if (starts_with(line, "\\ ")) {
2310                        /*
2311                         * Eat the "no newline at eof" marker as if we
2312                         * saw a "+" or "-" line with nothing on it,
2313                         * and return without diff_words_flush() to
2314                         * defer processing. If this is the end of
2315                         * preimage, more "+" lines may come after it.
2316                         */
2317                        return;
2318                }
2319                diff_words_flush(ecbdata);
2320                emit_diff_symbol(o, s, line, len, 0);
2321                return;
2322        }
2323
2324        switch (line[0]) {
2325        case '+':
2326                ecbdata->lno_in_postimage++;
2327                emit_add_line(reset, ecbdata, line + 1, len - 1);
2328                break;
2329        case '-':
2330                ecbdata->lno_in_preimage++;
2331                emit_del_line(reset, ecbdata, line + 1, len - 1);
2332                break;
2333        case ' ':
2334                ecbdata->lno_in_postimage++;
2335                ecbdata->lno_in_preimage++;
2336                emit_context_line(reset, ecbdata, line + 1, len - 1);
2337                break;
2338        default:
2339                /* incomplete line at the end */
2340                ecbdata->lno_in_preimage++;
2341                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2342                                 line, len, 0);
2343                break;
2344        }
2345}
2346
2347static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2348{
2349        const char *old_name = a;
2350        const char *new_name = b;
2351        int pfx_length, sfx_length;
2352        int pfx_adjust_for_slash;
2353        int len_a = strlen(a);
2354        int len_b = strlen(b);
2355        int a_midlen, b_midlen;
2356        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2357        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2358
2359        if (qlen_a || qlen_b) {
2360                quote_c_style(a, name, NULL, 0);
2361                strbuf_addstr(name, " => ");
2362                quote_c_style(b, name, NULL, 0);
2363                return;
2364        }
2365
2366        /* Find common prefix */
2367        pfx_length = 0;
2368        while (*old_name && *new_name && *old_name == *new_name) {
2369                if (*old_name == '/')
2370                        pfx_length = old_name - a + 1;
2371                old_name++;
2372                new_name++;
2373        }
2374
2375        /* Find common suffix */
2376        old_name = a + len_a;
2377        new_name = b + len_b;
2378        sfx_length = 0;
2379        /*
2380         * If there is a common prefix, it must end in a slash.  In
2381         * that case we let this loop run 1 into the prefix to see the
2382         * same slash.
2383         *
2384         * If there is no common prefix, we cannot do this as it would
2385         * underrun the input strings.
2386         */
2387        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2388        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2389               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2390               *old_name == *new_name) {
2391                if (*old_name == '/')
2392                        sfx_length = len_a - (old_name - a);
2393                old_name--;
2394                new_name--;
2395        }
2396
2397        /*
2398         * pfx{mid-a => mid-b}sfx
2399         * {pfx-a => pfx-b}sfx
2400         * pfx{sfx-a => sfx-b}
2401         * name-a => name-b
2402         */
2403        a_midlen = len_a - pfx_length - sfx_length;
2404        b_midlen = len_b - pfx_length - sfx_length;
2405        if (a_midlen < 0)
2406                a_midlen = 0;
2407        if (b_midlen < 0)
2408                b_midlen = 0;
2409
2410        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2411        if (pfx_length + sfx_length) {
2412                strbuf_add(name, a, pfx_length);
2413                strbuf_addch(name, '{');
2414        }
2415        strbuf_add(name, a + pfx_length, a_midlen);
2416        strbuf_addstr(name, " => ");
2417        strbuf_add(name, b + pfx_length, b_midlen);
2418        if (pfx_length + sfx_length) {
2419                strbuf_addch(name, '}');
2420                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2421        }
2422}
2423
2424struct diffstat_t {
2425        int nr;
2426        int alloc;
2427        struct diffstat_file {
2428                char *from_name;
2429                char *name;
2430                char *print_name;
2431                const char *comments;
2432                unsigned is_unmerged:1;
2433                unsigned is_binary:1;
2434                unsigned is_renamed:1;
2435                unsigned is_interesting:1;
2436                uintmax_t added, deleted;
2437        } **files;
2438};
2439
2440static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2441                                          const char *name_a,
2442                                          const char *name_b)
2443{
2444        struct diffstat_file *x;
2445        x = xcalloc(1, sizeof(*x));
2446        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2447        diffstat->files[diffstat->nr++] = x;
2448        if (name_b) {
2449                x->from_name = xstrdup(name_a);
2450                x->name = xstrdup(name_b);
2451                x->is_renamed = 1;
2452        }
2453        else {
2454                x->from_name = NULL;
2455                x->name = xstrdup(name_a);
2456        }
2457        return x;
2458}
2459
2460static void diffstat_consume(void *priv, char *line, unsigned long len)
2461{
2462        struct diffstat_t *diffstat = priv;
2463        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2464
2465        if (line[0] == '+')
2466                x->added++;
2467        else if (line[0] == '-')
2468                x->deleted++;
2469}
2470
2471const char mime_boundary_leader[] = "------------";
2472
2473static int scale_linear(int it, int width, int max_change)
2474{
2475        if (!it)
2476                return 0;
2477        /*
2478         * make sure that at least one '-' or '+' is printed if
2479         * there is any change to this path. The easiest way is to
2480         * scale linearly as if the alloted width is one column shorter
2481         * than it is, and then add 1 to the result.
2482         */
2483        return 1 + (it * (width - 1) / max_change);
2484}
2485
2486static void show_graph(struct strbuf *out, char ch, int cnt,
2487                       const char *set, const char *reset)
2488{
2489        if (cnt <= 0)
2490                return;
2491        strbuf_addstr(out, set);
2492        strbuf_addchars(out, ch, cnt);
2493        strbuf_addstr(out, reset);
2494}
2495
2496static void fill_print_name(struct diffstat_file *file)
2497{
2498        struct strbuf pname = STRBUF_INIT;
2499
2500        if (file->print_name)
2501                return;
2502
2503        if (file->is_renamed)
2504                pprint_rename(&pname, file->from_name, file->name);
2505        else
2506                quote_c_style(file->name, &pname, NULL, 0);
2507
2508        if (file->comments)
2509                strbuf_addf(&pname, " (%s)", file->comments);
2510
2511        file->print_name = strbuf_detach(&pname, NULL);
2512}
2513
2514static void print_stat_summary_inserts_deletes(struct diff_options *options,
2515                int files, int insertions, int deletions)
2516{
2517        struct strbuf sb = STRBUF_INIT;
2518
2519        if (!files) {
2520                assert(insertions == 0 && deletions == 0);
2521                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2522                                 NULL, 0, 0);
2523                return;
2524        }
2525
2526        strbuf_addf(&sb,
2527                    (files == 1) ? " %d file changed" : " %d files changed",
2528                    files);
2529
2530        /*
2531         * For binary diff, the caller may want to print "x files
2532         * changed" with insertions == 0 && deletions == 0.
2533         *
2534         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2535         * is probably less confusing (i.e skip over "2 files changed
2536         * but nothing about added/removed lines? Is this a bug in Git?").
2537         */
2538        if (insertions || deletions == 0) {
2539                strbuf_addf(&sb,
2540                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2541                            insertions);
2542        }
2543
2544        if (deletions || insertions == 0) {
2545                strbuf_addf(&sb,
2546                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2547                            deletions);
2548        }
2549        strbuf_addch(&sb, '\n');
2550        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2551                         sb.buf, sb.len, 0);
2552        strbuf_release(&sb);
2553}
2554
2555void print_stat_summary(FILE *fp, int files,
2556                        int insertions, int deletions)
2557{
2558        struct diff_options o;
2559        memset(&o, 0, sizeof(o));
2560        o.file = fp;
2561
2562        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2563}
2564
2565static void show_stats(struct diffstat_t *data, struct diff_options *options)
2566{
2567        int i, len, add, del, adds = 0, dels = 0;
2568        uintmax_t max_change = 0, max_len = 0;
2569        int total_files = data->nr, count;
2570        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2571        const char *reset, *add_c, *del_c;
2572        int extra_shown = 0;
2573        const char *line_prefix = diff_line_prefix(options);
2574        struct strbuf out = STRBUF_INIT;
2575
2576        if (data->nr == 0)
2577                return;
2578
2579        count = options->stat_count ? options->stat_count : data->nr;
2580
2581        reset = diff_get_color_opt(options, DIFF_RESET);
2582        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2583        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2584
2585        /*
2586         * Find the longest filename and max number of changes
2587         */
2588        for (i = 0; (i < count) && (i < data->nr); i++) {
2589                struct diffstat_file *file = data->files[i];
2590                uintmax_t change = file->added + file->deleted;
2591
2592                if (!file->is_interesting && (change == 0)) {
2593                        count++; /* not shown == room for one more */
2594                        continue;
2595                }
2596                fill_print_name(file);
2597                len = strlen(file->print_name);
2598                if (max_len < len)
2599                        max_len = len;
2600
2601                if (file->is_unmerged) {
2602                        /* "Unmerged" is 8 characters */
2603                        bin_width = bin_width < 8 ? 8 : bin_width;
2604                        continue;
2605                }
2606                if (file->is_binary) {
2607                        /* "Bin XXX -> YYY bytes" */
2608                        int w = 14 + decimal_width(file->added)
2609                                + decimal_width(file->deleted);
2610                        bin_width = bin_width < w ? w : bin_width;
2611                        /* Display change counts aligned with "Bin" */
2612                        number_width = 3;
2613                        continue;
2614                }
2615
2616                if (max_change < change)
2617                        max_change = change;
2618        }
2619        count = i; /* where we can stop scanning in data->files[] */
2620
2621        /*
2622         * We have width = stat_width or term_columns() columns total.
2623         * We want a maximum of min(max_len, stat_name_width) for the name part.
2624         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2625         * We also need 1 for " " and 4 + decimal_width(max_change)
2626         * for " | NNNN " and one the empty column at the end, altogether
2627         * 6 + decimal_width(max_change).
2628         *
2629         * If there's not enough space, we will use the smaller of
2630         * stat_name_width (if set) and 5/8*width for the filename,
2631         * and the rest for constant elements + graph part, but no more
2632         * than stat_graph_width for the graph part.
2633         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2634         * for the standard terminal size).
2635         *
2636         * In other words: stat_width limits the maximum width, and
2637         * stat_name_width fixes the maximum width of the filename,
2638         * and is also used to divide available columns if there
2639         * aren't enough.
2640         *
2641         * Binary files are displayed with "Bin XXX -> YYY bytes"
2642         * instead of the change count and graph. This part is treated
2643         * similarly to the graph part, except that it is not
2644         * "scaled". If total width is too small to accommodate the
2645         * guaranteed minimum width of the filename part and the
2646         * separators and this message, this message will "overflow"
2647         * making the line longer than the maximum width.
2648         */
2649
2650        if (options->stat_width == -1)
2651                width = term_columns() - strlen(line_prefix);
2652        else
2653                width = options->stat_width ? options->stat_width : 80;
2654        number_width = decimal_width(max_change) > number_width ?
2655                decimal_width(max_change) : number_width;
2656
2657        if (options->stat_graph_width == -1)
2658                options->stat_graph_width = diff_stat_graph_width;
2659
2660        /*
2661         * Guarantee 3/8*16==6 for the graph part
2662         * and 5/8*16==10 for the filename part
2663         */
2664        if (width < 16 + 6 + number_width)
2665                width = 16 + 6 + number_width;
2666
2667        /*
2668         * First assign sizes that are wanted, ignoring available width.
2669         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2670         * starting from "XXX" should fit in graph_width.
2671         */
2672        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2673        if (options->stat_graph_width &&
2674            options->stat_graph_width < graph_width)
2675                graph_width = options->stat_graph_width;
2676
2677        name_width = (options->stat_name_width > 0 &&
2678                      options->stat_name_width < max_len) ?
2679                options->stat_name_width : max_len;
2680
2681        /*
2682         * Adjust adjustable widths not to exceed maximum width
2683         */
2684        if (name_width + number_width + 6 + graph_width > width) {
2685                if (graph_width > width * 3/8 - number_width - 6) {
2686                        graph_width = width * 3/8 - number_width - 6;
2687                        if (graph_width < 6)
2688                                graph_width = 6;
2689                }
2690
2691                if (options->stat_graph_width &&
2692                    graph_width > options->stat_graph_width)
2693                        graph_width = options->stat_graph_width;
2694                if (name_width > width - number_width - 6 - graph_width)
2695                        name_width = width - number_width - 6 - graph_width;
2696                else
2697                        graph_width = width - number_width - 6 - name_width;
2698        }
2699
2700        /*
2701         * From here name_width is the width of the name area,
2702         * and graph_width is the width of the graph area.
2703         * max_change is used to scale graph properly.
2704         */
2705        for (i = 0; i < count; i++) {
2706                const char *prefix = "";
2707                struct diffstat_file *file = data->files[i];
2708                char *name = file->print_name;
2709                uintmax_t added = file->added;
2710                uintmax_t deleted = file->deleted;
2711                int name_len;
2712
2713                if (!file->is_interesting && (added + deleted == 0))
2714                        continue;
2715
2716                /*
2717                 * "scale" the filename
2718                 */
2719                len = name_width;
2720                name_len = strlen(name);
2721                if (name_width < name_len) {
2722                        char *slash;
2723                        prefix = "...";
2724                        len -= 3;
2725                        name += name_len - len;
2726                        slash = strchr(name, '/');
2727                        if (slash)
2728                                name = slash;
2729                }
2730
2731                if (file->is_binary) {
2732                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2733                        strbuf_addf(&out, " %*s", number_width, "Bin");
2734                        if (!added && !deleted) {
2735                                strbuf_addch(&out, '\n');
2736                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2737                                                 out.buf, out.len, 0);
2738                                strbuf_reset(&out);
2739                                continue;
2740                        }
2741                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2742                                del_c, deleted, reset);
2743                        strbuf_addstr(&out, " -> ");
2744                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2745                                add_c, added, reset);
2746                        strbuf_addstr(&out, " bytes\n");
2747                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2748                                         out.buf, out.len, 0);
2749                        strbuf_reset(&out);
2750                        continue;
2751                }
2752                else if (file->is_unmerged) {
2753                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2754                        strbuf_addstr(&out, " Unmerged\n");
2755                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2756                                         out.buf, out.len, 0);
2757                        strbuf_reset(&out);
2758                        continue;
2759                }
2760
2761                /*
2762                 * scale the add/delete
2763                 */
2764                add = added;
2765                del = deleted;
2766
2767                if (graph_width <= max_change) {
2768                        int total = scale_linear(add + del, graph_width, max_change);
2769                        if (total < 2 && add && del)
2770                                /* width >= 2 due to the sanity check */
2771                                total = 2;
2772                        if (add < del) {
2773                                add = scale_linear(add, graph_width, max_change);
2774                                del = total - add;
2775                        } else {
2776                                del = scale_linear(del, graph_width, max_change);
2777                                add = total - del;
2778                        }
2779                }
2780                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2781                strbuf_addf(&out, " %*"PRIuMAX"%s",
2782                        number_width, added + deleted,
2783                        added + deleted ? " " : "");
2784                show_graph(&out, '+', add, add_c, reset);
2785                show_graph(&out, '-', del, del_c, reset);
2786                strbuf_addch(&out, '\n');
2787                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2788                                 out.buf, out.len, 0);
2789                strbuf_reset(&out);
2790        }
2791
2792        for (i = 0; i < data->nr; i++) {
2793                struct diffstat_file *file = data->files[i];
2794                uintmax_t added = file->added;
2795                uintmax_t deleted = file->deleted;
2796
2797                if (file->is_unmerged ||
2798                    (!file->is_interesting && (added + deleted == 0))) {
2799                        total_files--;
2800                        continue;
2801                }
2802
2803                if (!file->is_binary) {
2804                        adds += added;
2805                        dels += deleted;
2806                }
2807                if (i < count)
2808                        continue;
2809                if (!extra_shown)
2810                        emit_diff_symbol(options,
2811                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2812                                         NULL, 0, 0);
2813                extra_shown = 1;
2814        }
2815
2816        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2817        strbuf_release(&out);
2818}
2819
2820static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2821{
2822        int i, adds = 0, dels = 0, total_files = data->nr;
2823
2824        if (data->nr == 0)
2825                return;
2826
2827        for (i = 0; i < data->nr; i++) {
2828                int added = data->files[i]->added;
2829                int deleted = data->files[i]->deleted;
2830
2831                if (data->files[i]->is_unmerged ||
2832                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2833                        total_files--;
2834                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2835                        adds += added;
2836                        dels += deleted;
2837                }
2838        }
2839        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2840}
2841
2842static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2843{
2844        int i;
2845
2846        if (data->nr == 0)
2847                return;
2848
2849        for (i = 0; i < data->nr; i++) {
2850                struct diffstat_file *file = data->files[i];
2851
2852                fprintf(options->file, "%s", diff_line_prefix(options));
2853
2854                if (file->is_binary)
2855                        fprintf(options->file, "-\t-\t");
2856                else
2857                        fprintf(options->file,
2858                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2859                                file->added, file->deleted);
2860                if (options->line_termination) {
2861                        fill_print_name(file);
2862                        if (!file->is_renamed)
2863                                write_name_quoted(file->name, options->file,
2864                                                  options->line_termination);
2865                        else {
2866                                fputs(file->print_name, options->file);
2867                                putc(options->line_termination, options->file);
2868                        }
2869                } else {
2870                        if (file->is_renamed) {
2871                                putc('\0', options->file);
2872                                write_name_quoted(file->from_name, options->file, '\0');
2873                        }
2874                        write_name_quoted(file->name, options->file, '\0');
2875                }
2876        }
2877}
2878
2879struct dirstat_file {
2880        const char *name;
2881        unsigned long changed;
2882};
2883
2884struct dirstat_dir {
2885        struct dirstat_file *files;
2886        int alloc, nr, permille, cumulative;
2887};
2888
2889static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2890                unsigned long changed, const char *base, int baselen)
2891{
2892        unsigned long sum_changes = 0;
2893        unsigned int sources = 0;
2894        const char *line_prefix = diff_line_prefix(opt);
2895
2896        while (dir->nr) {
2897                struct dirstat_file *f = dir->files;
2898                int namelen = strlen(f->name);
2899                unsigned long changes;
2900                char *slash;
2901
2902                if (namelen < baselen)
2903                        break;
2904                if (memcmp(f->name, base, baselen))
2905                        break;
2906                slash = strchr(f->name + baselen, '/');
2907                if (slash) {
2908                        int newbaselen = slash + 1 - f->name;
2909                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2910                        sources++;
2911                } else {
2912                        changes = f->changed;
2913                        dir->files++;
2914                        dir->nr--;
2915                        sources += 2;
2916                }
2917                sum_changes += changes;
2918        }
2919
2920        /*
2921         * We don't report dirstat's for
2922         *  - the top level
2923         *  - or cases where everything came from a single directory
2924         *    under this directory (sources == 1).
2925         */
2926        if (baselen && sources != 1) {
2927                if (sum_changes) {
2928                        int permille = sum_changes * 1000 / changed;
2929                        if (permille >= dir->permille) {
2930                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2931                                        permille / 10, permille % 10, baselen, base);
2932                                if (!dir->cumulative)
2933                                        return 0;
2934                        }
2935                }
2936        }
2937        return sum_changes;
2938}
2939
2940static int dirstat_compare(const void *_a, const void *_b)
2941{
2942        const struct dirstat_file *a = _a;
2943        const struct dirstat_file *b = _b;
2944        return strcmp(a->name, b->name);
2945}
2946
2947static void show_dirstat(struct diff_options *options)
2948{
2949        int i;
2950        unsigned long changed;
2951        struct dirstat_dir dir;
2952        struct diff_queue_struct *q = &diff_queued_diff;
2953
2954        dir.files = NULL;
2955        dir.alloc = 0;
2956        dir.nr = 0;
2957        dir.permille = options->dirstat_permille;
2958        dir.cumulative = options->flags.dirstat_cumulative;
2959
2960        changed = 0;
2961        for (i = 0; i < q->nr; i++) {
2962                struct diff_filepair *p = q->queue[i];
2963                const char *name;
2964                unsigned long copied, added, damage;
2965
2966                name = p->two->path ? p->two->path : p->one->path;
2967
2968                if (p->one->oid_valid && p->two->oid_valid &&
2969                    oideq(&p->one->oid, &p->two->oid)) {
2970                        /*
2971                         * The SHA1 has not changed, so pre-/post-content is
2972                         * identical. We can therefore skip looking at the
2973                         * file contents altogether.
2974                         */
2975                        damage = 0;
2976                        goto found_damage;
2977                }
2978
2979                if (options->flags.dirstat_by_file) {
2980                        /*
2981                         * In --dirstat-by-file mode, we don't really need to
2982                         * look at the actual file contents at all.
2983                         * The fact that the SHA1 changed is enough for us to
2984                         * add this file to the list of results
2985                         * (with each file contributing equal damage).
2986                         */
2987                        damage = 1;
2988                        goto found_damage;
2989                }
2990
2991                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2992                        diff_populate_filespec(options->repo, p->one, 0);
2993                        diff_populate_filespec(options->repo, p->two, 0);
2994                        diffcore_count_changes(options->repo,
2995                                               p->one, p->two, NULL, NULL,
2996                                               &copied, &added);
2997                        diff_free_filespec_data(p->one);
2998                        diff_free_filespec_data(p->two);
2999                } else if (DIFF_FILE_VALID(p->one)) {
3000                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3001                        copied = added = 0;
3002                        diff_free_filespec_data(p->one);
3003                } else if (DIFF_FILE_VALID(p->two)) {
3004                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3005                        copied = 0;
3006                        added = p->two->size;
3007                        diff_free_filespec_data(p->two);
3008                } else
3009                        continue;
3010
3011                /*
3012                 * Original minus copied is the removed material,
3013                 * added is the new material.  They are both damages
3014                 * made to the preimage.
3015                 * If the resulting damage is zero, we know that
3016                 * diffcore_count_changes() considers the two entries to
3017                 * be identical, but since the oid changed, we
3018                 * know that there must have been _some_ kind of change,
3019                 * so we force all entries to have damage > 0.
3020                 */
3021                damage = (p->one->size - copied) + added;
3022                if (!damage)
3023                        damage = 1;
3024
3025found_damage:
3026                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3027                dir.files[dir.nr].name = name;
3028                dir.files[dir.nr].changed = damage;
3029                changed += damage;
3030                dir.nr++;
3031        }
3032
3033        /* This can happen even with many files, if everything was renames */
3034        if (!changed)
3035                return;
3036
3037        /* Show all directories with more than x% of the changes */
3038        QSORT(dir.files, dir.nr, dirstat_compare);
3039        gather_dirstat(options, &dir, changed, "", 0);
3040}
3041
3042static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3043{
3044        int i;
3045        unsigned long changed;
3046        struct dirstat_dir dir;
3047
3048        if (data->nr == 0)
3049                return;
3050
3051        dir.files = NULL;
3052        dir.alloc = 0;
3053        dir.nr = 0;
3054        dir.permille = options->dirstat_permille;
3055        dir.cumulative = options->flags.dirstat_cumulative;
3056
3057        changed = 0;
3058        for (i = 0; i < data->nr; i++) {
3059                struct diffstat_file *file = data->files[i];
3060                unsigned long damage = file->added + file->deleted;
3061                if (file->is_binary)
3062                        /*
3063                         * binary files counts bytes, not lines. Must find some
3064                         * way to normalize binary bytes vs. textual lines.
3065                         * The following heuristic assumes that there are 64
3066                         * bytes per "line".
3067                         * This is stupid and ugly, but very cheap...
3068                         */
3069                        damage = DIV_ROUND_UP(damage, 64);
3070                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3071                dir.files[dir.nr].name = file->name;
3072                dir.files[dir.nr].changed = damage;
3073                changed += damage;
3074                dir.nr++;
3075        }
3076
3077        /* This can happen even with many files, if everything was renames */
3078        if (!changed)
3079                return;
3080
3081        /* Show all directories with more than x% of the changes */
3082        QSORT(dir.files, dir.nr, dirstat_compare);
3083        gather_dirstat(options, &dir, changed, "", 0);
3084}
3085
3086static void free_diffstat_info(struct diffstat_t *diffstat)
3087{
3088        int i;
3089        for (i = 0; i < diffstat->nr; i++) {
3090                struct diffstat_file *f = diffstat->files[i];
3091                free(f->print_name);
3092                free(f->name);
3093                free(f->from_name);
3094                free(f);
3095        }
3096        free(diffstat->files);
3097}
3098
3099struct checkdiff_t {
3100        const char *filename;
3101        int lineno;
3102        int conflict_marker_size;
3103        struct diff_options *o;
3104        unsigned ws_rule;
3105        unsigned status;
3106};
3107
3108static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3109{
3110        char firstchar;
3111        int cnt;
3112
3113        if (len < marker_size + 1)
3114                return 0;
3115        firstchar = line[0];
3116        switch (firstchar) {
3117        case '=': case '>': case '<': case '|':
3118                break;
3119        default:
3120                return 0;
3121        }
3122        for (cnt = 1; cnt < marker_size; cnt++)
3123                if (line[cnt] != firstchar)
3124                        return 0;
3125        /* line[1] thru line[marker_size-1] are same as firstchar */
3126        if (len < marker_size + 1 || !isspace(line[marker_size]))
3127                return 0;
3128        return 1;
3129}
3130
3131static void checkdiff_consume_hunk(void *priv,
3132                                   long ob, long on, long nb, long nn,
3133                                   const char *func, long funclen)
3134
3135{
3136        struct checkdiff_t *data = priv;
3137        data->lineno = nb - 1;
3138}
3139
3140static void checkdiff_consume(void *priv, char *line, unsigned long len)
3141{
3142        struct checkdiff_t *data = priv;
3143        int marker_size = data->conflict_marker_size;
3144        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3145        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3146        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3147        char *err;
3148        const char *line_prefix;
3149
3150        assert(data->o);
3151        line_prefix = diff_line_prefix(data->o);
3152
3153        if (line[0] == '+') {
3154                unsigned bad;
3155                data->lineno++;
3156                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3157                        data->status |= 1;
3158                        fprintf(data->o->file,
3159                                "%s%s:%d: leftover conflict marker\n",
3160                                line_prefix, data->filename, data->lineno);
3161                }
3162                bad = ws_check(line + 1, len - 1, data->ws_rule);
3163                if (!bad)
3164                        return;
3165                data->status |= bad;
3166                err = whitespace_error_string(bad);
3167                fprintf(data->o->file, "%s%s:%d: %s.\n",
3168                        line_prefix, data->filename, data->lineno, err);
3169                free(err);
3170                emit_line(data->o, set, reset, line, 1);
3171                ws_check_emit(line + 1, len - 1, data->ws_rule,
3172                              data->o->file, set, reset, ws);
3173        } else if (line[0] == ' ') {
3174                data->lineno++;
3175        }
3176}
3177
3178static unsigned char *deflate_it(char *data,
3179                                 unsigned long size,
3180                                 unsigned long *result_size)
3181{
3182        int bound;
3183        unsigned char *deflated;
3184        git_zstream stream;
3185
3186        git_deflate_init(&stream, zlib_compression_level);
3187        bound = git_deflate_bound(&stream, size);
3188        deflated = xmalloc(bound);
3189        stream.next_out = deflated;
3190        stream.avail_out = bound;
3191
3192        stream.next_in = (unsigned char *)data;
3193        stream.avail_in = size;
3194        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3195                ; /* nothing */
3196        git_deflate_end(&stream);
3197        *result_size = stream.total_out;
3198        return deflated;
3199}
3200
3201static void emit_binary_diff_body(struct diff_options *o,
3202                                  mmfile_t *one, mmfile_t *two)
3203{
3204        void *cp;
3205        void *delta;
3206        void *deflated;
3207        void *data;
3208        unsigned long orig_size;
3209        unsigned long delta_size;
3210        unsigned long deflate_size;
3211        unsigned long data_size;
3212
3213        /* We could do deflated delta, or we could do just deflated two,
3214         * whichever is smaller.
3215         */
3216        delta = NULL;
3217        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3218        if (one->size && two->size) {
3219                delta = diff_delta(one->ptr, one->size,
3220                                   two->ptr, two->size,
3221                                   &delta_size, deflate_size);
3222                if (delta) {
3223                        void *to_free = delta;
3224                        orig_size = delta_size;
3225                        delta = deflate_it(delta, delta_size, &delta_size);
3226                        free(to_free);
3227                }
3228        }
3229
3230        if (delta && delta_size < deflate_size) {
3231                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3232                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3233                                 s, strlen(s), 0);
3234                free(s);
3235                free(deflated);
3236                data = delta;
3237                data_size = delta_size;
3238        } else {
3239                char *s = xstrfmt("%lu", two->size);
3240                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3241                                 s, strlen(s), 0);
3242                free(s);
3243                free(delta);
3244                data = deflated;
3245                data_size = deflate_size;
3246        }
3247
3248        /* emit data encoded in base85 */
3249        cp = data;
3250        while (data_size) {
3251                int len;
3252                int bytes = (52 < data_size) ? 52 : data_size;
3253                char line[71];
3254                data_size -= bytes;
3255                if (bytes <= 26)
3256                        line[0] = bytes + 'A' - 1;
3257                else
3258                        line[0] = bytes - 26 + 'a' - 1;
3259                encode_85(line + 1, cp, bytes);
3260                cp = (char *) cp + bytes;
3261
3262                len = strlen(line);
3263                line[len++] = '\n';
3264                line[len] = '\0';
3265
3266                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3267                                 line, len, 0);
3268        }
3269        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3270        free(data);
3271}
3272
3273static void emit_binary_diff(struct diff_options *o,
3274                             mmfile_t *one, mmfile_t *two)
3275{
3276        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3277        emit_binary_diff_body(o, one, two);
3278        emit_binary_diff_body(o, two, one);
3279}
3280
3281int diff_filespec_is_binary(struct repository *r,
3282                            struct diff_filespec *one)
3283{
3284        if (one->is_binary == -1) {
3285                diff_filespec_load_driver(one, r->index);
3286                if (one->driver->binary != -1)
3287                        one->is_binary = one->driver->binary;
3288                else {
3289                        if (!one->data && DIFF_FILE_VALID(one))
3290                                diff_populate_filespec(r, one, CHECK_BINARY);
3291                        if (one->is_binary == -1 && one->data)
3292                                one->is_binary = buffer_is_binary(one->data,
3293                                                one->size);
3294                        if (one->is_binary == -1)
3295                                one->is_binary = 0;
3296                }
3297        }
3298        return one->is_binary;
3299}
3300
3301static const struct userdiff_funcname *
3302diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3303{
3304        diff_filespec_load_driver(one, o->repo->index);
3305        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3306}
3307
3308void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3309{
3310        if (!options->a_prefix)
3311                options->a_prefix = a;
3312        if (!options->b_prefix)
3313                options->b_prefix = b;
3314}
3315
3316struct userdiff_driver *get_textconv(struct repository *r,
3317                                     struct diff_filespec *one)
3318{
3319        if (!DIFF_FILE_VALID(one))
3320                return NULL;
3321
3322        diff_filespec_load_driver(one, r->index);
3323        return userdiff_get_textconv(r, one->driver);
3324}
3325
3326static void builtin_diff(const char *name_a,
3327                         const char *name_b,
3328                         struct diff_filespec *one,
3329                         struct diff_filespec *two,
3330                         const char *xfrm_msg,
3331                         int must_show_header,
3332                         struct diff_options *o,
3333                         int complete_rewrite)
3334{
3335        mmfile_t mf1, mf2;
3336        const char *lbl[2];
3337        char *a_one, *b_two;
3338        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3339        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3340        const char *a_prefix, *b_prefix;
3341        struct userdiff_driver *textconv_one = NULL;
3342        struct userdiff_driver *textconv_two = NULL;
3343        struct strbuf header = STRBUF_INIT;
3344        const char *line_prefix = diff_line_prefix(o);
3345
3346        diff_set_mnemonic_prefix(o, "a/", "b/");
3347        if (o->flags.reverse_diff) {
3348                a_prefix = o->b_prefix;
3349                b_prefix = o->a_prefix;
3350        } else {
3351                a_prefix = o->a_prefix;
3352                b_prefix = o->b_prefix;
3353        }
3354
3355        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3356            (!one->mode || S_ISGITLINK(one->mode)) &&
3357            (!two->mode || S_ISGITLINK(two->mode))) {
3358                show_submodule_summary(o, one->path ? one->path : two->path,
3359                                &one->oid, &two->oid,
3360                                two->dirty_submodule);
3361                return;
3362        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3363                   (!one->mode || S_ISGITLINK(one->mode)) &&
3364                   (!two->mode || S_ISGITLINK(two->mode))) {
3365                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3366                                &one->oid, &two->oid,
3367                                two->dirty_submodule);
3368                return;
3369        }
3370
3371        if (o->flags.allow_textconv) {
3372                textconv_one = get_textconv(o->repo, one);
3373                textconv_two = get_textconv(o->repo, two);
3374        }
3375
3376        /* Never use a non-valid filename anywhere if at all possible */
3377        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3378        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3379
3380        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3381        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3382        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3383        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3384        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3385        if (lbl[0][0] == '/') {
3386                /* /dev/null */
3387                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3388                if (xfrm_msg)
3389                        strbuf_addstr(&header, xfrm_msg);
3390                must_show_header = 1;
3391        }
3392        else if (lbl[1][0] == '/') {
3393                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3394                if (xfrm_msg)
3395                        strbuf_addstr(&header, xfrm_msg);
3396                must_show_header = 1;
3397        }
3398        else {
3399                if (one->mode != two->mode) {
3400                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3401                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3402                        must_show_header = 1;
3403                }
3404                if (xfrm_msg)
3405                        strbuf_addstr(&header, xfrm_msg);
3406
3407                /*
3408                 * we do not run diff between different kind
3409                 * of objects.
3410                 */
3411                if ((one->mode ^ two->mode) & S_IFMT)
3412                        goto free_ab_and_return;
3413                if (complete_rewrite &&
3414                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3415                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3416                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3417                                         header.buf, header.len, 0);
3418                        strbuf_reset(&header);
3419                        emit_rewrite_diff(name_a, name_b, one, two,
3420                                          textconv_one, textconv_two, o);
3421                        o->found_changes = 1;
3422                        goto free_ab_and_return;
3423                }
3424        }
3425
3426        if (o->irreversible_delete && lbl[1][0] == '/') {
3427                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3428                                 header.len, 0);
3429                strbuf_reset(&header);
3430                goto free_ab_and_return;
3431        } else if (!o->flags.text &&
3432                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3433                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3434                struct strbuf sb = STRBUF_INIT;
3435                if (!one->data && !two->data &&
3436                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3437                    !o->flags.binary) {
3438                        if (oideq(&one->oid, &two->oid)) {
3439                                if (must_show_header)
3440                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3441                                                         header.buf, header.len,
3442                                                         0);
3443                                goto free_ab_and_return;
3444                        }
3445                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3446                                         header.buf, header.len, 0);
3447                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3448                                    diff_line_prefix(o), lbl[0], lbl[1]);
3449                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3450                                         sb.buf, sb.len, 0);
3451                        strbuf_release(&sb);
3452                        goto free_ab_and_return;
3453                }
3454                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3455                    fill_mmfile(o->repo, &mf2, two) < 0)
3456                        die("unable to read files to diff");
3457                /* Quite common confusing case */
3458                if (mf1.size == mf2.size &&
3459                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3460                        if (must_show_header)
3461                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3462                                                 header.buf, header.len, 0);
3463                        goto free_ab_and_return;
3464                }
3465                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3466                strbuf_reset(&header);
3467                if (o->flags.binary)
3468                        emit_binary_diff(o, &mf1, &mf2);
3469                else {
3470                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3471                                    diff_line_prefix(o), lbl[0], lbl[1]);
3472                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3473                                         sb.buf, sb.len, 0);
3474                        strbuf_release(&sb);
3475                }
3476                o->found_changes = 1;
3477        } else {
3478                /* Crazy xdl interfaces.. */
3479                const char *diffopts = getenv("GIT_DIFF_OPTS");
3480                const char *v;
3481                xpparam_t xpp;
3482                xdemitconf_t xecfg;
3483                struct emit_callback ecbdata;
3484                const struct userdiff_funcname *pe;
3485
3486                if (must_show_header) {
3487                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3488                                         header.buf, header.len, 0);
3489                        strbuf_reset(&header);
3490                }
3491
3492                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3493                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3494
3495                pe = diff_funcname_pattern(o, one);
3496                if (!pe)
3497                        pe = diff_funcname_pattern(o, two);
3498
3499                memset(&xpp, 0, sizeof(xpp));
3500                memset(&xecfg, 0, sizeof(xecfg));
3501                memset(&ecbdata, 0, sizeof(ecbdata));
3502                if (o->flags.suppress_diff_headers)
3503                        lbl[0] = NULL;
3504                ecbdata.label_path = lbl;
3505                ecbdata.color_diff = want_color(o->use_color);
3506                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3507                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3508                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3509                ecbdata.opt = o;
3510                if (header.len && !o->flags.suppress_diff_headers)
3511                        ecbdata.header = &header;
3512                xpp.flags = o->xdl_opts;
3513                xpp.anchors = o->anchors;
3514                xpp.anchors_nr = o->anchors_nr;
3515                xecfg.ctxlen = o->context;
3516                xecfg.interhunkctxlen = o->interhunkcontext;
3517                xecfg.flags = XDL_EMIT_FUNCNAMES;
3518                if (o->flags.funccontext)
3519                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3520                if (pe)
3521                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3522                if (!diffopts)
3523                        ;
3524                else if (skip_prefix(diffopts, "--unified=", &v))
3525                        xecfg.ctxlen = strtoul(v, NULL, 10);
3526                else if (skip_prefix(diffopts, "-u", &v))
3527                        xecfg.ctxlen = strtoul(v, NULL, 10);
3528                if (o->word_diff)
3529                        init_diff_words_data(&ecbdata, o, one, two);
3530                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3531                                  &ecbdata, &xpp, &xecfg))
3532                        die("unable to generate diff for %s", one->path);
3533                if (o->word_diff)
3534                        free_diff_words_data(&ecbdata);
3535                if (textconv_one)
3536                        free(mf1.ptr);
3537                if (textconv_two)
3538                        free(mf2.ptr);
3539                xdiff_clear_find_func(&xecfg);
3540        }
3541
3542 free_ab_and_return:
3543        strbuf_release(&header);
3544        diff_free_filespec_data(one);
3545        diff_free_filespec_data(two);
3546        free(a_one);
3547        free(b_two);
3548        return;
3549}
3550
3551static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3552{
3553        if (!is_renamed) {
3554                if (p->status == DIFF_STATUS_ADDED) {
3555                        if (S_ISLNK(p->two->mode))
3556                                return "new +l";
3557                        else if ((p->two->mode & 0777) == 0755)
3558                                return "new +x";
3559                        else
3560                                return "new";
3561                } else if (p->status == DIFF_STATUS_DELETED)
3562                        return "gone";
3563        }
3564        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3565                return "mode -l";
3566        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3567                return "mode +l";
3568        else if ((p->one->mode & 0777) == 0644 &&
3569                 (p->two->mode & 0777) == 0755)
3570                return "mode +x";
3571        else if ((p->one->mode & 0777) == 0755 &&
3572                 (p->two->mode & 0777) == 0644)
3573                return "mode -x";
3574        return NULL;
3575}
3576
3577static void builtin_diffstat(const char *name_a, const char *name_b,
3578                             struct diff_filespec *one,
3579                             struct diff_filespec *two,
3580                             struct diffstat_t *diffstat,
3581                             struct diff_options *o,
3582                             struct diff_filepair *p)
3583{
3584        mmfile_t mf1, mf2;
3585        struct diffstat_file *data;
3586        int same_contents;
3587        int complete_rewrite = 0;
3588
3589        if (!DIFF_PAIR_UNMERGED(p)) {
3590                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3591                        complete_rewrite = 1;
3592        }
3593
3594        data = diffstat_add(diffstat, name_a, name_b);
3595        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3596        if (o->flags.stat_with_summary)
3597                data->comments = get_compact_summary(p, data->is_renamed);
3598
3599        if (!one || !two) {
3600                data->is_unmerged = 1;
3601                return;
3602        }
3603
3604        same_contents = oideq(&one->oid, &two->oid);
3605
3606        if (diff_filespec_is_binary(o->repo, one) ||
3607            diff_filespec_is_binary(o->repo, two)) {
3608                data->is_binary = 1;
3609                if (same_contents) {
3610                        data->added = 0;
3611                        data->deleted = 0;
3612                } else {
3613                        data->added = diff_filespec_size(o->repo, two);
3614                        data->deleted = diff_filespec_size(o->repo, one);
3615                }
3616        }
3617
3618        else if (complete_rewrite) {
3619                diff_populate_filespec(o->repo, one, 0);
3620                diff_populate_filespec(o->repo, two, 0);
3621                data->deleted = count_lines(one->data, one->size);
3622                data->added = count_lines(two->data, two->size);
3623        }
3624
3625        else if (!same_contents) {
3626                /* Crazy xdl interfaces.. */
3627                xpparam_t xpp;
3628                xdemitconf_t xecfg;
3629
3630                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3631                    fill_mmfile(o->repo, &mf2, two) < 0)
3632                        die("unable to read files to diff");
3633
3634                memset(&xpp, 0, sizeof(xpp));
3635                memset(&xecfg, 0, sizeof(xecfg));
3636                xpp.flags = o->xdl_opts;
3637                xpp.anchors = o->anchors;
3638                xpp.anchors_nr = o->anchors_nr;
3639                xecfg.ctxlen = o->context;
3640                xecfg.interhunkctxlen = o->interhunkcontext;
3641                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3642                                  diffstat_consume, diffstat, &xpp, &xecfg))
3643                        die("unable to generate diffstat for %s", one->path);
3644        }
3645
3646        diff_free_filespec_data(one);
3647        diff_free_filespec_data(two);
3648}
3649
3650static void builtin_checkdiff(const char *name_a, const char *name_b,
3651                              const char *attr_path,
3652                              struct diff_filespec *one,
3653                              struct diff_filespec *two,
3654                              struct diff_options *o)
3655{
3656        mmfile_t mf1, mf2;
3657        struct checkdiff_t data;
3658
3659        if (!two)
3660                return;
3661
3662        memset(&data, 0, sizeof(data));
3663        data.filename = name_b ? name_b : name_a;
3664        data.lineno = 0;
3665        data.o = o;
3666        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3667        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3668
3669        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3670            fill_mmfile(o->repo, &mf2, two) < 0)
3671                die("unable to read files to diff");
3672
3673        /*
3674         * All the other codepaths check both sides, but not checking
3675         * the "old" side here is deliberate.  We are checking the newly
3676         * introduced changes, and as long as the "new" side is text, we
3677         * can and should check what it introduces.
3678         */
3679        if (diff_filespec_is_binary(o->repo, two))
3680                goto free_and_return;
3681        else {
3682                /* Crazy xdl interfaces.. */
3683                xpparam_t xpp;
3684                xdemitconf_t xecfg;
3685
3686                memset(&xpp, 0, sizeof(xpp));
3687                memset(&xecfg, 0, sizeof(xecfg));
3688                xecfg.ctxlen = 1; /* at least one context line */
3689                xpp.flags = 0;
3690                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3691                                  checkdiff_consume, &data,
3692                                  &xpp, &xecfg))
3693                        die("unable to generate checkdiff for %s", one->path);
3694
3695                if (data.ws_rule & WS_BLANK_AT_EOF) {
3696                        struct emit_callback ecbdata;
3697                        int blank_at_eof;
3698
3699                        ecbdata.ws_rule = data.ws_rule;
3700                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3701                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3702
3703                        if (blank_at_eof) {
3704                                static char *err;
3705                                if (!err)
3706                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3707                                fprintf(o->file, "%s:%d: %s.\n",
3708                                        data.filename, blank_at_eof, err);
3709                                data.status = 1; /* report errors */
3710                        }
3711                }
3712        }
3713 free_and_return:
3714        diff_free_filespec_data(one);
3715        diff_free_filespec_data(two);
3716        if (data.status)
3717                o->flags.check_failed = 1;
3718}
3719
3720struct diff_filespec *alloc_filespec(const char *path)
3721{
3722        struct diff_filespec *spec;
3723
3724        FLEXPTR_ALLOC_STR(spec, path, path);
3725        spec->count = 1;
3726        spec->is_binary = -1;
3727        return spec;
3728}
3729
3730void free_filespec(struct diff_filespec *spec)
3731{
3732        if (!--spec->count) {
3733                diff_free_filespec_data(spec);
3734                free(spec);
3735        }
3736}
3737
3738void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3739                   int oid_valid, unsigned short mode)
3740{
3741        if (mode) {
3742                spec->mode = canon_mode(mode);
3743                oidcpy(&spec->oid, oid);
3744                spec->oid_valid = oid_valid;
3745        }
3746}
3747
3748/*
3749 * Given a name and sha1 pair, if the index tells us the file in
3750 * the work tree has that object contents, return true, so that
3751 * prepare_temp_file() does not have to inflate and extract.
3752 */
3753static int reuse_worktree_file(struct index_state *istate,
3754                               const char *name,
3755                               const struct object_id *oid,
3756                               int want_file)
3757{
3758        const struct cache_entry *ce;
3759        struct stat st;
3760        int pos, len;
3761
3762        /*
3763         * We do not read the cache ourselves here, because the
3764         * benchmark with my previous version that always reads cache
3765         * shows that it makes things worse for diff-tree comparing
3766         * two linux-2.6 kernel trees in an already checked out work
3767         * tree.  This is because most diff-tree comparisons deal with
3768         * only a small number of files, while reading the cache is
3769         * expensive for a large project, and its cost outweighs the
3770         * savings we get by not inflating the object to a temporary
3771         * file.  Practically, this code only helps when we are used
3772         * by diff-cache --cached, which does read the cache before
3773         * calling us.
3774         */
3775        if (!istate->cache)
3776                return 0;
3777
3778        /* We want to avoid the working directory if our caller
3779         * doesn't need the data in a normal file, this system
3780         * is rather slow with its stat/open/mmap/close syscalls,
3781         * and the object is contained in a pack file.  The pack
3782         * is probably already open and will be faster to obtain
3783         * the data through than the working directory.  Loose
3784         * objects however would tend to be slower as they need
3785         * to be individually opened and inflated.
3786         */
3787        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3788                return 0;
3789
3790        /*
3791         * Similarly, if we'd have to convert the file contents anyway, that
3792         * makes the optimization not worthwhile.
3793         */
3794        if (!want_file && would_convert_to_git(istate, name))
3795                return 0;
3796
3797        len = strlen(name);
3798        pos = index_name_pos(istate, name, len);
3799        if (pos < 0)
3800                return 0;
3801        ce = istate->cache[pos];
3802
3803        /*
3804         * This is not the sha1 we are looking for, or
3805         * unreusable because it is not a regular file.
3806         */
3807        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3808                return 0;
3809
3810        /*
3811         * If ce is marked as "assume unchanged", there is no
3812         * guarantee that work tree matches what we are looking for.
3813         */
3814        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3815                return 0;
3816
3817        /*
3818         * If ce matches the file in the work tree, we can reuse it.
3819         */
3820        if (ce_uptodate(ce) ||
3821            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3822                return 1;
3823
3824        return 0;
3825}
3826
3827static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3828{
3829        struct strbuf buf = STRBUF_INIT;
3830        char *dirty = "";
3831
3832        /* Are we looking at the work tree? */
3833        if (s->dirty_submodule)
3834                dirty = "-dirty";
3835
3836        strbuf_addf(&buf, "Subproject commit %s%s\n",
3837                    oid_to_hex(&s->oid), dirty);
3838        s->size = buf.len;
3839        if (size_only) {
3840                s->data = NULL;
3841                strbuf_release(&buf);
3842        } else {
3843                s->data = strbuf_detach(&buf, NULL);
3844                s->should_free = 1;
3845        }
3846        return 0;
3847}
3848
3849/*
3850 * While doing rename detection and pickaxe operation, we may need to
3851 * grab the data for the blob (or file) for our own in-core comparison.
3852 * diff_filespec has data and size fields for this purpose.
3853 */
3854int diff_populate_filespec(struct repository *r,
3855                           struct diff_filespec *s,
3856                           unsigned int flags)
3857{
3858        int size_only = flags & CHECK_SIZE_ONLY;
3859        int err = 0;
3860        int conv_flags = global_conv_flags_eol;
3861        /*
3862         * demote FAIL to WARN to allow inspecting the situation
3863         * instead of refusing.
3864         */
3865        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3866                conv_flags = CONV_EOL_RNDTRP_WARN;
3867
3868        if (!DIFF_FILE_VALID(s))
3869                die("internal error: asking to populate invalid file.");
3870        if (S_ISDIR(s->mode))
3871                return -1;
3872
3873        if (s->data)
3874                return 0;
3875
3876        if (size_only && 0 < s->size)
3877                return 0;
3878
3879        if (S_ISGITLINK(s->mode))
3880                return diff_populate_gitlink(s, size_only);
3881
3882        if (!s->oid_valid ||
3883            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3884                struct strbuf buf = STRBUF_INIT;
3885                struct stat st;
3886                int fd;
3887
3888                if (lstat(s->path, &st) < 0) {
3889                err_empty:
3890                        err = -1;
3891                empty:
3892                        s->data = (char *)"";
3893                        s->size = 0;
3894                        return err;
3895                }
3896                s->size = xsize_t(st.st_size);
3897                if (!s->size)
3898                        goto empty;
3899                if (S_ISLNK(st.st_mode)) {
3900                        struct strbuf sb = STRBUF_INIT;
3901
3902                        if (strbuf_readlink(&sb, s->path, s->size))
3903                                goto err_empty;
3904                        s->size = sb.len;
3905                        s->data = strbuf_detach(&sb, NULL);
3906                        s->should_free = 1;
3907                        return 0;
3908                }
3909
3910                /*
3911                 * Even if the caller would be happy with getting
3912                 * only the size, we cannot return early at this
3913                 * point if the path requires us to run the content
3914                 * conversion.
3915                 */
3916                if (size_only && !would_convert_to_git(r->index, s->path))
3917                        return 0;
3918
3919                /*
3920                 * Note: this check uses xsize_t(st.st_size) that may
3921                 * not be the true size of the blob after it goes
3922                 * through convert_to_git().  This may not strictly be
3923                 * correct, but the whole point of big_file_threshold
3924                 * and is_binary check being that we want to avoid
3925                 * opening the file and inspecting the contents, this
3926                 * is probably fine.
3927                 */
3928                if ((flags & CHECK_BINARY) &&
3929                    s->size > big_file_threshold && s->is_binary == -1) {
3930                        s->is_binary = 1;
3931                        return 0;
3932                }
3933                fd = open(s->path, O_RDONLY);
3934                if (fd < 0)
3935                        goto err_empty;
3936                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3937                close(fd);
3938                s->should_munmap = 1;
3939
3940                /*
3941                 * Convert from working tree format to canonical git format
3942                 */
3943                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
3944                        size_t size = 0;
3945                        munmap(s->data, s->size);
3946                        s->should_munmap = 0;
3947                        s->data = strbuf_detach(&buf, &size);
3948                        s->size = size;
3949                        s->should_free = 1;
3950                }
3951        }
3952        else {
3953                enum object_type type;
3954                if (size_only || (flags & CHECK_BINARY)) {
3955                        type = oid_object_info(r, &s->oid, &s->size);
3956                        if (type < 0)
3957                                die("unable to read %s",
3958                                    oid_to_hex(&s->oid));
3959                        if (size_only)
3960                                return 0;
3961                        if (s->size > big_file_threshold && s->is_binary == -1) {
3962                                s->is_binary = 1;
3963                                return 0;
3964                        }
3965                }
3966                s->data = read_object_file(&s->oid, &type, &s->size);
3967                if (!s->data)
3968                        die("unable to read %s", oid_to_hex(&s->oid));
3969                s->should_free = 1;
3970        }
3971        return 0;
3972}
3973
3974void diff_free_filespec_blob(struct diff_filespec *s)
3975{
3976        if (s->should_free)
3977                free(s->data);
3978        else if (s->should_munmap)
3979                munmap(s->data, s->size);
3980
3981        if (s->should_free || s->should_munmap) {
3982                s->should_free = s->should_munmap = 0;
3983                s->data = NULL;
3984        }
3985}
3986
3987void diff_free_filespec_data(struct diff_filespec *s)
3988{
3989        diff_free_filespec_blob(s);
3990        FREE_AND_NULL(s->cnt_data);
3991}
3992
3993static void prep_temp_blob(struct index_state *istate,
3994                           const char *path, struct diff_tempfile *temp,
3995                           void *blob,
3996                           unsigned long size,
3997                           const struct object_id *oid,
3998                           int mode)
3999{
4000        struct strbuf buf = STRBUF_INIT;
4001        struct strbuf tempfile = STRBUF_INIT;
4002        char *path_dup = xstrdup(path);
4003        const char *base = basename(path_dup);
4004
4005        /* Generate "XXXXXX_basename.ext" */
4006        strbuf_addstr(&tempfile, "XXXXXX_");
4007        strbuf_addstr(&tempfile, base);
4008
4009        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4010        if (!temp->tempfile)
4011                die_errno("unable to create temp-file");
4012        if (convert_to_working_tree(istate, path,
4013                        (const char *)blob, (size_t)size, &buf)) {
4014                blob = buf.buf;
4015                size = buf.len;
4016        }
4017        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4018            close_tempfile_gently(temp->tempfile))
4019                die_errno("unable to write temp-file");
4020        temp->name = get_tempfile_path(temp->tempfile);
4021        oid_to_hex_r(temp->hex, oid);
4022        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4023        strbuf_release(&buf);
4024        strbuf_release(&tempfile);
4025        free(path_dup);
4026}
4027
4028static struct diff_tempfile *prepare_temp_file(struct repository *r,
4029                                               const char *name,
4030                                               struct diff_filespec *one)
4031{
4032        struct diff_tempfile *temp = claim_diff_tempfile();
4033
4034        if (!DIFF_FILE_VALID(one)) {
4035        not_a_valid_file:
4036                /* A '-' entry produces this for file-2, and
4037                 * a '+' entry produces this for file-1.
4038                 */
4039                temp->name = "/dev/null";
4040                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4041                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4042                return temp;
4043        }
4044
4045        if (!S_ISGITLINK(one->mode) &&
4046            (!one->oid_valid ||
4047             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4048                struct stat st;
4049                if (lstat(name, &st) < 0) {
4050                        if (errno == ENOENT)
4051                                goto not_a_valid_file;
4052                        die_errno("stat(%s)", name);
4053                }
4054                if (S_ISLNK(st.st_mode)) {
4055                        struct strbuf sb = STRBUF_INIT;
4056                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4057                                die_errno("readlink(%s)", name);
4058                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4059                                       (one->oid_valid ?
4060                                        &one->oid : &null_oid),
4061                                       (one->oid_valid ?
4062                                        one->mode : S_IFLNK));
4063                        strbuf_release(&sb);
4064                }
4065                else {
4066                        /* we can borrow from the file in the work tree */
4067                        temp->name = name;
4068                        if (!one->oid_valid)
4069                                oid_to_hex_r(temp->hex, &null_oid);
4070                        else
4071                                oid_to_hex_r(temp->hex, &one->oid);
4072                        /* Even though we may sometimes borrow the
4073                         * contents from the work tree, we always want
4074                         * one->mode.  mode is trustworthy even when
4075                         * !(one->oid_valid), as long as
4076                         * DIFF_FILE_VALID(one).
4077                         */
4078                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4079                }
4080                return temp;
4081        }
4082        else {
4083                if (diff_populate_filespec(r, one, 0))
4084                        die("cannot read data blob for %s", one->path);
4085                prep_temp_blob(r->index, name, temp,
4086                               one->data, one->size,
4087                               &one->oid, one->mode);
4088        }
4089        return temp;
4090}
4091
4092static void add_external_diff_name(struct repository *r,
4093                                   struct argv_array *argv,
4094                                   const char *name,
4095                                   struct diff_filespec *df)
4096{
4097        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4098        argv_array_push(argv, temp->name);
4099        argv_array_push(argv, temp->hex);
4100        argv_array_push(argv, temp->mode);
4101}
4102
4103/* An external diff command takes:
4104 *
4105 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4106 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4107 *
4108 */
4109static void run_external_diff(const char *pgm,
4110                              const char *name,
4111                              const char *other,
4112                              struct diff_filespec *one,
4113                              struct diff_filespec *two,
4114                              const char *xfrm_msg,
4115                              int complete_rewrite,
4116                              struct diff_options *o)
4117{
4118        struct argv_array argv = ARGV_ARRAY_INIT;
4119        struct argv_array env = ARGV_ARRAY_INIT;
4120        struct diff_queue_struct *q = &diff_queued_diff;
4121
4122        argv_array_push(&argv, pgm);
4123        argv_array_push(&argv, name);
4124
4125        if (one && two) {
4126                add_external_diff_name(o->repo, &argv, name, one);
4127                if (!other)
4128                        add_external_diff_name(o->repo, &argv, name, two);
4129                else {
4130                        add_external_diff_name(o->repo, &argv, other, two);
4131                        argv_array_push(&argv, other);
4132                        argv_array_push(&argv, xfrm_msg);
4133                }
4134        }
4135
4136        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4137        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4138
4139        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4140                die(_("external diff died, stopping at %s"), name);
4141
4142        remove_tempfile();
4143        argv_array_clear(&argv);
4144        argv_array_clear(&env);
4145}
4146
4147static int similarity_index(struct diff_filepair *p)
4148{
4149        return p->score * 100 / MAX_SCORE;
4150}
4151
4152static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4153{
4154        if (startup_info->have_repository)
4155                return find_unique_abbrev(oid, abbrev);
4156        else {
4157                char *hex = oid_to_hex(oid);
4158                if (abbrev < 0)
4159                        abbrev = FALLBACK_DEFAULT_ABBREV;
4160                if (abbrev > the_hash_algo->hexsz)
4161                        BUG("oid abbreviation out of range: %d", abbrev);
4162                if (abbrev)
4163                        hex[abbrev] = '\0';
4164                return hex;
4165        }
4166}
4167
4168static void fill_metainfo(struct strbuf *msg,
4169                          const char *name,
4170                          const char *other,
4171                          struct diff_filespec *one,
4172                          struct diff_filespec *two,
4173                          struct diff_options *o,
4174                          struct diff_filepair *p,
4175                          int *must_show_header,
4176                          int use_color)
4177{
4178        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4179        const char *reset = diff_get_color(use_color, DIFF_RESET);
4180        const char *line_prefix = diff_line_prefix(o);
4181
4182        *must_show_header = 1;
4183        strbuf_init(msg, PATH_MAX * 2 + 300);
4184        switch (p->status) {
4185        case DIFF_STATUS_COPIED:
4186                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4187                            line_prefix, set, similarity_index(p));
4188                strbuf_addf(msg, "%s\n%s%scopy from ",
4189                            reset,  line_prefix, set);
4190                quote_c_style(name, msg, NULL, 0);
4191                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4192                quote_c_style(other, msg, NULL, 0);
4193                strbuf_addf(msg, "%s\n", reset);
4194                break;
4195        case DIFF_STATUS_RENAMED:
4196                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4197                            line_prefix, set, similarity_index(p));
4198                strbuf_addf(msg, "%s\n%s%srename from ",
4199                            reset, line_prefix, set);
4200                quote_c_style(name, msg, NULL, 0);
4201                strbuf_addf(msg, "%s\n%s%srename to ",
4202                            reset, line_prefix, set);
4203                quote_c_style(other, msg, NULL, 0);
4204                strbuf_addf(msg, "%s\n", reset);
4205                break;
4206        case DIFF_STATUS_MODIFIED:
4207                if (p->score) {
4208                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4209                                    line_prefix,
4210                                    set, similarity_index(p), reset);
4211                        break;
4212                }
4213                /* fallthru */
4214        default:
4215                *must_show_header = 0;
4216        }
4217        if (one && two && !oideq(&one->oid, &two->oid)) {
4218                const unsigned hexsz = the_hash_algo->hexsz;
4219                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4220
4221                if (o->flags.binary) {
4222                        mmfile_t mf;
4223                        if ((!fill_mmfile(o->repo, &mf, one) &&
4224                             diff_filespec_is_binary(o->repo, one)) ||
4225                            (!fill_mmfile(o->repo, &mf, two) &&
4226                             diff_filespec_is_binary(o->repo, two)))
4227                                abbrev = hexsz;
4228                }
4229                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4230                            diff_abbrev_oid(&one->oid, abbrev),
4231                            diff_abbrev_oid(&two->oid, abbrev));
4232                if (one->mode == two->mode)
4233                        strbuf_addf(msg, " %06o", one->mode);
4234                strbuf_addf(msg, "%s\n", reset);
4235        }
4236}
4237
4238static void run_diff_cmd(const char *pgm,
4239                         const char *name,
4240                         const char *other,
4241                         const char *attr_path,
4242                         struct diff_filespec *one,
4243                         struct diff_filespec *two,
4244                         struct strbuf *msg,
4245                         struct diff_options *o,
4246                         struct diff_filepair *p)
4247{
4248        const char *xfrm_msg = NULL;
4249        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4250        int must_show_header = 0;
4251
4252
4253        if (o->flags.allow_external) {
4254                struct userdiff_driver *drv;
4255
4256                drv = userdiff_find_by_path(o->repo->index, attr_path);
4257                if (drv && drv->external)
4258                        pgm = drv->external;
4259        }
4260
4261        if (msg) {
4262                /*
4263                 * don't use colors when the header is intended for an
4264                 * external diff driver
4265                 */
4266                fill_metainfo(msg, name, other, one, two, o, p,
4267                              &must_show_header,
4268                              want_color(o->use_color) && !pgm);
4269                xfrm_msg = msg->len ? msg->buf : NULL;
4270        }
4271
4272        if (pgm) {
4273                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4274                                  complete_rewrite, o);
4275                return;
4276        }
4277        if (one && two)
4278                builtin_diff(name, other ? other : name,
4279                             one, two, xfrm_msg, must_show_header,
4280                             o, complete_rewrite);
4281        else
4282                fprintf(o->file, "* Unmerged path %s\n", name);
4283}
4284
4285static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4286{
4287        if (DIFF_FILE_VALID(one)) {
4288                if (!one->oid_valid) {
4289                        struct stat st;
4290                        if (one->is_stdin) {
4291                                oidclr(&one->oid);
4292                                return;
4293                        }
4294                        if (lstat(one->path, &st) < 0)
4295                                die_errno("stat '%s'", one->path);
4296                        if (index_path(istate, &one->oid, one->path, &st, 0))
4297                                die("cannot hash %s", one->path);
4298                }
4299        }
4300        else
4301                oidclr(&one->oid);
4302}
4303
4304static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4305{
4306        /* Strip the prefix but do not molest /dev/null and absolute paths */
4307        if (*namep && !is_absolute_path(*namep)) {
4308                *namep += prefix_length;
4309                if (**namep == '/')
4310                        ++*namep;
4311        }
4312        if (*otherp && !is_absolute_path(*otherp)) {
4313                *otherp += prefix_length;
4314                if (**otherp == '/')
4315                        ++*otherp;
4316        }
4317}
4318
4319static void run_diff(struct diff_filepair *p, struct diff_options *o)
4320{
4321        const char *pgm = external_diff();
4322        struct strbuf msg;
4323        struct diff_filespec *one = p->one;
4324        struct diff_filespec *two = p->two;
4325        const char *name;
4326        const char *other;
4327        const char *attr_path;
4328
4329        name  = one->path;
4330        other = (strcmp(name, two->path) ? two->path : NULL);
4331        attr_path = name;
4332        if (o->prefix_length)
4333                strip_prefix(o->prefix_length, &name, &other);
4334
4335        if (!o->flags.allow_external)
4336                pgm = NULL;
4337
4338        if (DIFF_PAIR_UNMERGED(p)) {
4339                run_diff_cmd(pgm, name, NULL, attr_path,
4340                             NULL, NULL, NULL, o, p);
4341                return;
4342        }
4343
4344        diff_fill_oid_info(one, o->repo->index);
4345        diff_fill_oid_info(two, o->repo->index);
4346
4347        if (!pgm &&
4348            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4349            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4350                /*
4351                 * a filepair that changes between file and symlink
4352                 * needs to be split into deletion and creation.
4353                 */
4354                struct diff_filespec *null = alloc_filespec(two->path);
4355                run_diff_cmd(NULL, name, other, attr_path,
4356                             one, null, &msg,
4357                             o, p);
4358                free(null);
4359                strbuf_release(&msg);
4360
4361                null = alloc_filespec(one->path);
4362                run_diff_cmd(NULL, name, other, attr_path,
4363                             null, two, &msg, o, p);
4364                free(null);
4365        }
4366        else
4367                run_diff_cmd(pgm, name, other, attr_path,
4368                             one, two, &msg, o, p);
4369
4370        strbuf_release(&msg);
4371}
4372
4373static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4374                         struct diffstat_t *diffstat)
4375{
4376        const char *name;
4377        const char *other;
4378
4379        if (DIFF_PAIR_UNMERGED(p)) {
4380                /* unmerged */
4381                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4382                                 diffstat, o, p);
4383                return;
4384        }
4385
4386        name = p->one->path;
4387        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4388
4389        if (o->prefix_length)
4390                strip_prefix(o->prefix_length, &name, &other);
4391
4392        diff_fill_oid_info(p->one, o->repo->index);
4393        diff_fill_oid_info(p->two, o->repo->index);
4394
4395        builtin_diffstat(name, other, p->one, p->two,
4396                         diffstat, o, p);
4397}
4398
4399static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4400{
4401        const char *name;
4402        const char *other;
4403        const char *attr_path;
4404
4405        if (DIFF_PAIR_UNMERGED(p)) {
4406                /* unmerged */
4407                return;
4408        }
4409
4410        name = p->one->path;
4411        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4412        attr_path = other ? other : name;
4413
4414        if (o->prefix_length)
4415                strip_prefix(o->prefix_length, &name, &other);
4416
4417        diff_fill_oid_info(p->one, o->repo->index);
4418        diff_fill_oid_info(p->two, o->repo->index);
4419
4420        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4421}
4422
4423void repo_diff_setup(struct repository *r, struct diff_options *options)
4424{
4425        memcpy(options, &default_diff_options, sizeof(*options));
4426
4427        options->file = stdout;
4428        options->repo = r;
4429
4430        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4431        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4432        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4433        options->abbrev = DEFAULT_ABBREV;
4434        options->line_termination = '\n';
4435        options->break_opt = -1;
4436        options->rename_limit = -1;
4437        options->dirstat_permille = diff_dirstat_permille_default;
4438        options->context = diff_context_default;
4439        options->interhunkcontext = diff_interhunk_context_default;
4440        options->ws_error_highlight = ws_error_highlight_default;
4441        options->flags.rename_empty = 1;
4442        options->objfind = NULL;
4443
4444        /* pathchange left =NULL by default */
4445        options->change = diff_change;
4446        options->add_remove = diff_addremove;
4447        options->use_color = diff_use_color_default;
4448        options->detect_rename = diff_detect_rename_default;
4449        options->xdl_opts |= diff_algorithm;
4450        if (diff_indent_heuristic)
4451                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4452
4453        options->orderfile = diff_order_file_cfg;
4454
4455        if (diff_no_prefix) {
4456                options->a_prefix = options->b_prefix = "";
4457        } else if (!diff_mnemonic_prefix) {
4458                options->a_prefix = "a/";
4459                options->b_prefix = "b/";
4460        }
4461
4462        options->color_moved = diff_color_moved_default;
4463        options->color_moved_ws_handling = diff_color_moved_ws_default;
4464}
4465
4466void diff_setup_done(struct diff_options *options)
4467{
4468        unsigned check_mask = DIFF_FORMAT_NAME |
4469                              DIFF_FORMAT_NAME_STATUS |
4470                              DIFF_FORMAT_CHECKDIFF |
4471                              DIFF_FORMAT_NO_OUTPUT;
4472        /*
4473         * This must be signed because we're comparing against a potentially
4474         * negative value.
4475         */
4476        const int hexsz = the_hash_algo->hexsz;
4477
4478        if (options->set_default)
4479                options->set_default(options);
4480
4481        if (HAS_MULTI_BITS(options->output_format & check_mask))
4482                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4483
4484        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4485                die(_("-G, -S and --find-object are mutually exclusive"));
4486
4487        /*
4488         * Most of the time we can say "there are changes"
4489         * only by checking if there are changed paths, but
4490         * --ignore-whitespace* options force us to look
4491         * inside contents.
4492         */
4493
4494        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4495                options->flags.diff_from_contents = 1;
4496        else
4497                options->flags.diff_from_contents = 0;
4498
4499        if (options->flags.find_copies_harder)
4500                options->detect_rename = DIFF_DETECT_COPY;
4501
4502        if (!options->flags.relative_name)
4503                options->prefix = NULL;
4504        if (options->prefix)
4505                options->prefix_length = strlen(options->prefix);
4506        else
4507                options->prefix_length = 0;
4508
4509        if (options->output_format & (DIFF_FORMAT_NAME |
4510                                      DIFF_FORMAT_NAME_STATUS |
4511                                      DIFF_FORMAT_CHECKDIFF |
4512                                      DIFF_FORMAT_NO_OUTPUT))
4513                options->output_format &= ~(DIFF_FORMAT_RAW |
4514                                            DIFF_FORMAT_NUMSTAT |
4515                                            DIFF_FORMAT_DIFFSTAT |
4516                                            DIFF_FORMAT_SHORTSTAT |
4517                                            DIFF_FORMAT_DIRSTAT |
4518                                            DIFF_FORMAT_SUMMARY |
4519                                            DIFF_FORMAT_PATCH);
4520
4521        /*
4522         * These cases always need recursive; we do not drop caller-supplied
4523         * recursive bits for other formats here.
4524         */
4525        if (options->output_format & (DIFF_FORMAT_PATCH |
4526                                      DIFF_FORMAT_NUMSTAT |
4527                                      DIFF_FORMAT_DIFFSTAT |
4528                                      DIFF_FORMAT_SHORTSTAT |
4529                                      DIFF_FORMAT_DIRSTAT |
4530                                      DIFF_FORMAT_SUMMARY |
4531                                      DIFF_FORMAT_CHECKDIFF))
4532                options->flags.recursive = 1;
4533        /*
4534         * Also pickaxe would not work very well if you do not say recursive
4535         */
4536        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4537                options->flags.recursive = 1;
4538        /*
4539         * When patches are generated, submodules diffed against the work tree
4540         * must be checked for dirtiness too so it can be shown in the output
4541         */
4542        if (options->output_format & DIFF_FORMAT_PATCH)
4543                options->flags.dirty_submodules = 1;
4544
4545        if (options->detect_rename && options->rename_limit < 0)
4546                options->rename_limit = diff_rename_limit_default;
4547        if (hexsz < options->abbrev)
4548                options->abbrev = hexsz; /* full */
4549
4550        /*
4551         * It does not make sense to show the first hit we happened
4552         * to have found.  It does not make sense not to return with
4553         * exit code in such a case either.
4554         */
4555        if (options->flags.quick) {
4556                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4557                options->flags.exit_with_status = 1;
4558        }
4559
4560        options->diff_path_counter = 0;
4561
4562        if (options->flags.follow_renames && options->pathspec.nr != 1)
4563                die(_("--follow requires exactly one pathspec"));
4564
4565        if (!options->use_color || external_diff())
4566                options->color_moved = 0;
4567}
4568
4569static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4570{
4571        char c, *eq;
4572        int len;
4573
4574        if (*arg != '-')
4575                return 0;
4576        c = *++arg;
4577        if (!c)
4578                return 0;
4579        if (c == arg_short) {
4580                c = *++arg;
4581                if (!c)
4582                        return 1;
4583                if (val && isdigit(c)) {
4584                        char *end;
4585                        int n = strtoul(arg, &end, 10);
4586                        if (*end)
4587                                return 0;
4588                        *val = n;
4589                        return 1;
4590                }
4591                return 0;
4592        }
4593        if (c != '-')
4594                return 0;
4595        arg++;
4596        eq = strchrnul(arg, '=');
4597        len = eq - arg;
4598        if (!len || strncmp(arg, arg_long, len))
4599                return 0;
4600        if (*eq) {
4601                int n;
4602                char *end;
4603                if (!isdigit(*++eq))
4604                        return 0;
4605                n = strtoul(eq, &end, 10);
4606                if (*end)
4607                        return 0;
4608                *val = n;
4609        }
4610        return 1;
4611}
4612
4613static int diff_scoreopt_parse(const char *opt);
4614
4615static inline int short_opt(char opt, const char **argv,
4616                            const char **optarg)
4617{
4618        const char *arg = argv[0];
4619        if (arg[0] != '-' || arg[1] != opt)
4620                return 0;
4621        if (arg[2] != '\0') {
4622                *optarg = arg + 2;
4623                return 1;
4624        }
4625        if (!argv[1])
4626                die("Option '%c' requires a value", opt);
4627        *optarg = argv[1];
4628        return 2;
4629}
4630
4631int parse_long_opt(const char *opt, const char **argv,
4632                   const char **optarg)
4633{
4634        const char *arg = argv[0];
4635        if (!skip_prefix(arg, "--", &arg))
4636                return 0;
4637        if (!skip_prefix(arg, opt, &arg))
4638                return 0;
4639        if (*arg == '=') { /* stuck form: --option=value */
4640                *optarg = arg + 1;
4641                return 1;
4642        }
4643        if (*arg != '\0')
4644                return 0;
4645        /* separate form: --option value */
4646        if (!argv[1])
4647                die("Option '--%s' requires a value", opt);
4648        *optarg = argv[1];
4649        return 2;
4650}
4651
4652static int stat_opt(struct diff_options *options, const char **av)
4653{
4654        const char *arg = av[0];
4655        char *end;
4656        int width = options->stat_width;
4657        int name_width = options->stat_name_width;
4658        int graph_width = options->stat_graph_width;
4659        int count = options->stat_count;
4660        int argcount = 1;
4661
4662        if (!skip_prefix(arg, "--stat", &arg))
4663                BUG("stat option does not begin with --stat: %s", arg);
4664        end = (char *)arg;
4665
4666        switch (*arg) {
4667        case '-':
4668                if (skip_prefix(arg, "-width", &arg)) {
4669                        if (*arg == '=')
4670                                width = strtoul(arg + 1, &end, 10);
4671                        else if (!*arg && !av[1])
4672                                die_want_option("--stat-width");
4673                        else if (!*arg) {
4674                                width = strtoul(av[1], &end, 10);
4675                                argcount = 2;
4676                        }
4677                } else if (skip_prefix(arg, "-name-width", &arg)) {
4678                        if (*arg == '=')
4679                                name_width = strtoul(arg + 1, &end, 10);
4680                        else if (!*arg && !av[1])
4681                                die_want_option("--stat-name-width");
4682                        else if (!*arg) {
4683                                name_width = strtoul(av[1], &end, 10);
4684                                argcount = 2;
4685                        }
4686                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4687                        if (*arg == '=')
4688                                graph_width = strtoul(arg + 1, &end, 10);
4689                        else if (!*arg && !av[1])
4690                                die_want_option("--stat-graph-width");
4691                        else if (!*arg) {
4692                                graph_width = strtoul(av[1], &end, 10);
4693                                argcount = 2;
4694                        }
4695                } else if (skip_prefix(arg, "-count", &arg)) {
4696                        if (*arg == '=')
4697                                count = strtoul(arg + 1, &end, 10);
4698                        else if (!*arg && !av[1])
4699                                die_want_option("--stat-count");
4700                        else if (!*arg) {
4701                                count = strtoul(av[1], &end, 10);
4702                                argcount = 2;
4703                        }
4704                }
4705                break;
4706        case '=':
4707                width = strtoul(arg+1, &end, 10);
4708                if (*end == ',')
4709                        name_width = strtoul(end+1, &end, 10);
4710                if (*end == ',')
4711                        count = strtoul(end+1, &end, 10);
4712        }
4713
4714        /* Important! This checks all the error cases! */
4715        if (*end)
4716                return 0;
4717        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4718        options->stat_name_width = name_width;
4719        options->stat_graph_width = graph_width;
4720        options->stat_width = width;
4721        options->stat_count = count;
4722        return argcount;
4723}
4724
4725static int parse_dirstat_opt(struct diff_options *options, const char *params)
4726{
4727        struct strbuf errmsg = STRBUF_INIT;
4728        if (parse_dirstat_params(options, params, &errmsg))
4729                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4730                    errmsg.buf);
4731        strbuf_release(&errmsg);
4732        /*
4733         * The caller knows a dirstat-related option is given from the command
4734         * line; allow it to say "return this_function();"
4735         */
4736        options->output_format |= DIFF_FORMAT_DIRSTAT;
4737        return 1;
4738}
4739
4740static int parse_submodule_opt(struct diff_options *options, const char *value)
4741{
4742        if (parse_submodule_params(options, value))
4743                die(_("Failed to parse --submodule option parameter: '%s'"),
4744                        value);
4745        return 1;
4746}
4747
4748static const char diff_status_letters[] = {
4749        DIFF_STATUS_ADDED,
4750        DIFF_STATUS_COPIED,
4751        DIFF_STATUS_DELETED,
4752        DIFF_STATUS_MODIFIED,
4753        DIFF_STATUS_RENAMED,
4754        DIFF_STATUS_TYPE_CHANGED,
4755        DIFF_STATUS_UNKNOWN,
4756        DIFF_STATUS_UNMERGED,
4757        DIFF_STATUS_FILTER_AON,
4758        DIFF_STATUS_FILTER_BROKEN,
4759        '\0',
4760};
4761
4762static unsigned int filter_bit['Z' + 1];
4763
4764static void prepare_filter_bits(void)
4765{
4766        int i;
4767
4768        if (!filter_bit[DIFF_STATUS_ADDED]) {
4769                for (i = 0; diff_status_letters[i]; i++)
4770                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4771        }
4772}
4773
4774static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4775{
4776        return opt->filter & filter_bit[(int) status];
4777}
4778
4779static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4780{
4781        int i, optch;
4782
4783        prepare_filter_bits();
4784
4785        /*
4786         * If there is a negation e.g. 'd' in the input, and we haven't
4787         * initialized the filter field with another --diff-filter, start
4788         * from full set of bits, except for AON.
4789         */
4790        if (!opt->filter) {
4791                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4792                        if (optch < 'a' || 'z' < optch)
4793                                continue;
4794                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4795                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4796                        break;
4797                }
4798        }
4799
4800        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4801                unsigned int bit;
4802                int negate;
4803
4804                if ('a' <= optch && optch <= 'z') {
4805                        negate = 1;
4806                        optch = toupper(optch);
4807                } else {
4808                        negate = 0;
4809                }
4810
4811                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4812                if (!bit)
4813                        return optarg[i];
4814                if (negate)
4815                        opt->filter &= ~bit;
4816                else
4817                        opt->filter |= bit;
4818        }
4819        return 0;
4820}
4821
4822static void enable_patch_output(int *fmt) {
4823        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4824        *fmt |= DIFF_FORMAT_PATCH;
4825}
4826
4827static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4828{
4829        int val = parse_ws_error_highlight(arg);
4830
4831        if (val < 0) {
4832                error("unknown value after ws-error-highlight=%.*s",
4833                      -1 - val, arg);
4834                return 0;
4835        }
4836        opt->ws_error_highlight = val;
4837        return 1;
4838}
4839
4840static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4841{
4842        struct object_id oid;
4843
4844        if (get_oid(arg, &oid))
4845                return error("unable to resolve '%s'", arg);
4846
4847        if (!opt->objfind)
4848                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4849
4850        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4851        opt->flags.recursive = 1;
4852        opt->flags.tree_in_recursive = 1;
4853        oidset_insert(opt->objfind, &oid);
4854        return 1;
4855}
4856
4857int diff_opt_parse(struct diff_options *options,
4858                   const char **av, int ac, const char *prefix)
4859{
4860        const char *arg = av[0];
4861        const char *optarg;
4862        int argcount;
4863
4864        if (!prefix)
4865                prefix = "";
4866
4867        /* Output format options */
4868        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4869            || opt_arg(arg, 'U', "unified", &options->context))
4870                enable_patch_output(&options->output_format);
4871        else if (!strcmp(arg, "--raw"))
4872                options->output_format |= DIFF_FORMAT_RAW;
4873        else if (!strcmp(arg, "--patch-with-raw")) {
4874                enable_patch_output(&options->output_format);
4875                options->output_format |= DIFF_FORMAT_RAW;
4876        } else if (!strcmp(arg, "--numstat"))
4877                options->output_format |= DIFF_FORMAT_NUMSTAT;
4878        else if (!strcmp(arg, "--shortstat"))
4879                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4880        else if (skip_prefix(arg, "-X", &arg) ||
4881                 skip_to_optional_arg(arg, "--dirstat", &arg))
4882                return parse_dirstat_opt(options, arg);
4883        else if (!strcmp(arg, "--cumulative"))
4884                return parse_dirstat_opt(options, "cumulative");
4885        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4886                parse_dirstat_opt(options, "files");
4887                return parse_dirstat_opt(options, arg);
4888        }
4889        else if (!strcmp(arg, "--check"))
4890                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4891        else if (!strcmp(arg, "--summary"))
4892                options->output_format |= DIFF_FORMAT_SUMMARY;
4893        else if (!strcmp(arg, "--patch-with-stat")) {
4894                enable_patch_output(&options->output_format);
4895                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4896        } else if (!strcmp(arg, "--name-only"))
4897                options->output_format |= DIFF_FORMAT_NAME;
4898        else if (!strcmp(arg, "--name-status"))
4899                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4900        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4901                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4902        else if (starts_with(arg, "--stat"))
4903                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4904                return stat_opt(options, av);
4905        else if (!strcmp(arg, "--compact-summary")) {
4906                 options->flags.stat_with_summary = 1;
4907                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4908        } else if (!strcmp(arg, "--no-compact-summary"))
4909                 options->flags.stat_with_summary = 0;
4910        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4911                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4912        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4913                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4914        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4915                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4916
4917        /* renames options */
4918        else if (starts_with(arg, "-B") ||
4919                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4920                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4921                        return error("invalid argument to -B: %s", arg+2);
4922        }
4923        else if (starts_with(arg, "-M") ||
4924                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4925                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4926                        return error("invalid argument to -M: %s", arg+2);
4927                options->detect_rename = DIFF_DETECT_RENAME;
4928        }
4929        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4930                options->irreversible_delete = 1;
4931        }
4932        else if (starts_with(arg, "-C") ||
4933                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4934                if (options->detect_rename == DIFF_DETECT_COPY)
4935                        options->flags.find_copies_harder = 1;
4936                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4937                        return error("invalid argument to -C: %s", arg+2);
4938                options->detect_rename = DIFF_DETECT_COPY;
4939        }
4940        else if (!strcmp(arg, "--no-renames"))
4941                options->detect_rename = 0;
4942        else if (!strcmp(arg, "--rename-empty"))
4943                options->flags.rename_empty = 1;
4944        else if (!strcmp(arg, "--no-rename-empty"))
4945                options->flags.rename_empty = 0;
4946        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4947                options->flags.relative_name = 1;
4948                if (arg)
4949                        options->prefix = arg;
4950        }
4951
4952        /* xdiff options */
4953        else if (!strcmp(arg, "--minimal"))
4954                DIFF_XDL_SET(options, NEED_MINIMAL);
4955        else if (!strcmp(arg, "--no-minimal"))
4956                DIFF_XDL_CLR(options, NEED_MINIMAL);
4957        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4958                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4959        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4960                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4961        else if (!strcmp(arg, "--ignore-space-at-eol"))
4962                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4963        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4964                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4965        else if (!strcmp(arg, "--ignore-blank-lines"))
4966                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4967        else if (!strcmp(arg, "--indent-heuristic"))
4968                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4969        else if (!strcmp(arg, "--no-indent-heuristic"))
4970                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4971        else if (!strcmp(arg, "--patience")) {
4972                int i;
4973                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4974                /*
4975                 * Both --patience and --anchored use PATIENCE_DIFF
4976                 * internally, so remove any anchors previously
4977                 * specified.
4978                 */
4979                for (i = 0; i < options->anchors_nr; i++)
4980                        free(options->anchors[i]);
4981                options->anchors_nr = 0;
4982        } else if (!strcmp(arg, "--histogram"))
4983                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4984        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4985                long value = parse_algorithm_value(optarg);
4986                if (value < 0)
4987                        return error("option diff-algorithm accepts \"myers\", "
4988                                     "\"minimal\", \"patience\" and \"histogram\"");
4989                /* clear out previous settings */
4990                DIFF_XDL_CLR(options, NEED_MINIMAL);
4991                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4992                options->xdl_opts |= value;
4993                return argcount;
4994        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4995                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4996                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4997                           options->anchors_alloc);
4998                options->anchors[options->anchors_nr++] = xstrdup(arg);
4999        }
5000
5001        /* flags options */
5002        else if (!strcmp(arg, "--binary")) {
5003                enable_patch_output(&options->output_format);
5004                options->flags.binary = 1;
5005        }
5006        else if (!strcmp(arg, "--full-index"))
5007                options->flags.full_index = 1;
5008        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5009                options->flags.text = 1;
5010        else if (!strcmp(arg, "-R"))
5011                options->flags.reverse_diff = 1;
5012        else if (!strcmp(arg, "--find-copies-harder"))
5013                options->flags.find_copies_harder = 1;
5014        else if (!strcmp(arg, "--follow"))
5015                options->flags.follow_renames = 1;
5016        else if (!strcmp(arg, "--no-follow")) {
5017                options->flags.follow_renames = 0;
5018                options->flags.default_follow_renames = 0;
5019        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5020                int value = git_config_colorbool(NULL, arg);
5021                if (value < 0)
5022                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5023                options->use_color = value;
5024        }
5025        else if (!strcmp(arg, "--no-color"))
5026                options->use_color = 0;
5027        else if (!strcmp(arg, "--color-moved")) {
5028                if (diff_color_moved_default)
5029                        options->color_moved = diff_color_moved_default;
5030                if (options->color_moved == COLOR_MOVED_NO)
5031                        options->color_moved = COLOR_MOVED_DEFAULT;
5032        } else if (!strcmp(arg, "--no-color-moved"))
5033                options->color_moved = COLOR_MOVED_NO;
5034        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5035                int cm = parse_color_moved(arg);
5036                if (cm < 0)
5037                        die("bad --color-moved argument: %s", arg);
5038                options->color_moved = cm;
5039        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5040                options->color_moved_ws_handling = parse_color_moved_ws(arg);
5041        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5042                options->use_color = 1;
5043                options->word_diff = DIFF_WORDS_COLOR;
5044        }
5045        else if (!strcmp(arg, "--word-diff")) {
5046                if (options->word_diff == DIFF_WORDS_NONE)
5047                        options->word_diff = DIFF_WORDS_PLAIN;
5048        }
5049        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5050                if (!strcmp(arg, "plain"))
5051                        options->word_diff = DIFF_WORDS_PLAIN;
5052                else if (!strcmp(arg, "color")) {
5053                        options->use_color = 1;
5054                        options->word_diff = DIFF_WORDS_COLOR;
5055                }
5056                else if (!strcmp(arg, "porcelain"))
5057                        options->word_diff = DIFF_WORDS_PORCELAIN;
5058                else if (!strcmp(arg, "none"))
5059                        options->word_diff = DIFF_WORDS_NONE;
5060                else
5061                        die("bad --word-diff argument: %s", arg);
5062        }
5063        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5064                if (options->word_diff == DIFF_WORDS_NONE)
5065                        options->word_diff = DIFF_WORDS_PLAIN;
5066                options->word_regex = optarg;
5067                return argcount;
5068        }
5069        else if (!strcmp(arg, "--exit-code"))
5070                options->flags.exit_with_status = 1;
5071        else if (!strcmp(arg, "--quiet"))
5072                options->flags.quick = 1;
5073        else if (!strcmp(arg, "--ext-diff"))
5074                options->flags.allow_external = 1;
5075        else if (!strcmp(arg, "--no-ext-diff"))
5076                options->flags.allow_external = 0;
5077        else if (!strcmp(arg, "--textconv")) {
5078                options->flags.allow_textconv = 1;
5079                options->flags.textconv_set_via_cmdline = 1;
5080        } else if (!strcmp(arg, "--no-textconv"))
5081                options->flags.allow_textconv = 0;
5082        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5083                options->flags.override_submodule_config = 1;
5084                handle_ignore_submodules_arg(options, arg);
5085        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5086                return parse_submodule_opt(options, arg);
5087        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5088                return parse_ws_error_highlight_opt(options, arg);
5089        else if (!strcmp(arg, "--ita-invisible-in-index"))
5090                options->ita_invisible_in_index = 1;
5091        else if (!strcmp(arg, "--ita-visible-in-index"))
5092                options->ita_invisible_in_index = 0;
5093
5094        /* misc options */
5095        else if (!strcmp(arg, "-z"))
5096                options->line_termination = 0;
5097        else if ((argcount = short_opt('l', av, &optarg))) {
5098                options->rename_limit = strtoul(optarg, NULL, 10);
5099                return argcount;
5100        }
5101        else if ((argcount = short_opt('S', av, &optarg))) {
5102                options->pickaxe = optarg;
5103                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5104                return argcount;
5105        } else if ((argcount = short_opt('G', av, &optarg))) {
5106                options->pickaxe = optarg;
5107                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5108                return argcount;
5109        }
5110        else if (!strcmp(arg, "--pickaxe-all"))
5111                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5112        else if (!strcmp(arg, "--pickaxe-regex"))
5113                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5114        else if ((argcount = short_opt('O', av, &optarg))) {
5115                options->orderfile = prefix_filename(prefix, optarg);
5116                return argcount;
5117        } else if (skip_prefix(arg, "--find-object=", &arg))
5118                return parse_objfind_opt(options, arg);
5119        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5120                int offending = parse_diff_filter_opt(optarg, options);
5121                if (offending)
5122                        die("unknown change class '%c' in --diff-filter=%s",
5123                            offending, optarg);
5124                return argcount;
5125        }
5126        else if (!strcmp(arg, "--no-abbrev"))
5127                options->abbrev = 0;
5128        else if (!strcmp(arg, "--abbrev"))
5129                options->abbrev = DEFAULT_ABBREV;
5130        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5131                options->abbrev = strtoul(arg, NULL, 10);
5132                if (options->abbrev < MINIMUM_ABBREV)
5133                        options->abbrev = MINIMUM_ABBREV;
5134                else if (the_hash_algo->hexsz < options->abbrev)
5135                        options->abbrev = the_hash_algo->hexsz;
5136        }
5137        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5138                options->a_prefix = optarg;
5139                return argcount;
5140        }
5141        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5142                options->line_prefix = optarg;
5143                options->line_prefix_length = strlen(options->line_prefix);
5144                graph_setup_line_prefix(options);
5145                return argcount;
5146        }
5147        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5148                options->b_prefix = optarg;
5149                return argcount;
5150        }
5151        else if (!strcmp(arg, "--no-prefix"))
5152                options->a_prefix = options->b_prefix = "";
5153        else if (opt_arg(arg, '\0', "inter-hunk-context",
5154                         &options->interhunkcontext))
5155                ;
5156        else if (!strcmp(arg, "-W"))
5157                options->flags.funccontext = 1;
5158        else if (!strcmp(arg, "--function-context"))
5159                options->flags.funccontext = 1;
5160        else if (!strcmp(arg, "--no-function-context"))
5161                options->flags.funccontext = 0;
5162        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5163                char *path = prefix_filename(prefix, optarg);
5164                options->file = xfopen(path, "w");
5165                options->close_file = 1;
5166                if (options->use_color != GIT_COLOR_ALWAYS)
5167                        options->use_color = GIT_COLOR_NEVER;
5168                free(path);
5169                return argcount;
5170        } else
5171                return 0;
5172        return 1;
5173}
5174
5175int parse_rename_score(const char **cp_p)
5176{
5177        unsigned long num, scale;
5178        int ch, dot;
5179        const char *cp = *cp_p;
5180
5181        num = 0;
5182        scale = 1;
5183        dot = 0;
5184        for (;;) {
5185                ch = *cp;
5186                if ( !dot && ch == '.' ) {
5187                        scale = 1;
5188                        dot = 1;
5189                } else if ( ch == '%' ) {
5190                        scale = dot ? scale*100 : 100;
5191                        cp++;   /* % is always at the end */
5192                        break;
5193                } else if ( ch >= '0' && ch <= '9' ) {
5194                        if ( scale < 100000 ) {
5195                                scale *= 10;
5196                                num = (num*10) + (ch-'0');
5197                        }
5198                } else {
5199                        break;
5200                }
5201                cp++;
5202        }
5203        *cp_p = cp;
5204
5205        /* user says num divided by scale and we say internally that
5206         * is MAX_SCORE * num / scale.
5207         */
5208        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5209}
5210
5211static int diff_scoreopt_parse(const char *opt)
5212{
5213        int opt1, opt2, cmd;
5214
5215        if (*opt++ != '-')
5216                return -1;
5217        cmd = *opt++;
5218        if (cmd == '-') {
5219                /* convert the long-form arguments into short-form versions */
5220                if (skip_prefix(opt, "break-rewrites", &opt)) {
5221                        if (*opt == 0 || *opt++ == '=')
5222                                cmd = 'B';
5223                } else if (skip_prefix(opt, "find-copies", &opt)) {
5224                        if (*opt == 0 || *opt++ == '=')
5225                                cmd = 'C';
5226                } else if (skip_prefix(opt, "find-renames", &opt)) {
5227                        if (*opt == 0 || *opt++ == '=')
5228                                cmd = 'M';
5229                }
5230        }
5231        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5232                return -1; /* that is not a -M, -C, or -B option */
5233
5234        opt1 = parse_rename_score(&opt);
5235        if (cmd != 'B')
5236                opt2 = 0;
5237        else {
5238                if (*opt == 0)
5239                        opt2 = 0;
5240                else if (*opt != '/')
5241                        return -1; /* we expect -B80/99 or -B80 */
5242                else {
5243                        opt++;
5244                        opt2 = parse_rename_score(&opt);
5245                }
5246        }
5247        if (*opt != 0)
5248                return -1;
5249        return opt1 | (opt2 << 16);
5250}
5251
5252struct diff_queue_struct diff_queued_diff;
5253
5254void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5255{
5256        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5257        queue->queue[queue->nr++] = dp;
5258}
5259
5260struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5261                                 struct diff_filespec *one,
5262                                 struct diff_filespec *two)
5263{
5264        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5265        dp->one = one;
5266        dp->two = two;
5267        if (queue)
5268                diff_q(queue, dp);
5269        return dp;
5270}
5271
5272void diff_free_filepair(struct diff_filepair *p)
5273{
5274        free_filespec(p->one);
5275        free_filespec(p->two);
5276        free(p);
5277}
5278
5279const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5280{
5281        int abblen;
5282        const char *abbrev;
5283
5284        /* Do we want all 40 hex characters? */
5285        if (len == the_hash_algo->hexsz)
5286                return oid_to_hex(oid);
5287
5288        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5289        abbrev = diff_abbrev_oid(oid, len);
5290
5291        if (!print_sha1_ellipsis())
5292                return abbrev;
5293
5294        abblen = strlen(abbrev);
5295
5296        /*
5297         * In well-behaved cases, where the abbreviated result is the
5298         * same as the requested length, append three dots after the
5299         * abbreviation (hence the whole logic is limited to the case
5300         * where abblen < 37); when the actual abbreviated result is a
5301         * bit longer than the requested length, we reduce the number
5302         * of dots so that they match the well-behaved ones.  However,
5303         * if the actual abbreviation is longer than the requested
5304         * length by more than three, we give up on aligning, and add
5305         * three dots anyway, to indicate that the output is not the
5306         * full object name.  Yes, this may be suboptimal, but this
5307         * appears only in "diff --raw --abbrev" output and it is not
5308         * worth the effort to change it now.  Note that this would
5309         * likely to work fine when the automatic sizing of default
5310         * abbreviation length is used--we would be fed -1 in "len" in
5311         * that case, and will end up always appending three-dots, but
5312         * the automatic sizing is supposed to give abblen that ensures
5313         * uniqueness across all objects (statistically speaking).
5314         */
5315        if (abblen < the_hash_algo->hexsz - 3) {
5316                static char hex[GIT_MAX_HEXSZ + 1];
5317                if (len < abblen && abblen <= len + 2)
5318                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5319                else
5320                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5321                return hex;
5322        }
5323
5324        return oid_to_hex(oid);
5325}
5326
5327static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5328{
5329        int line_termination = opt->line_termination;
5330        int inter_name_termination = line_termination ? '\t' : '\0';
5331
5332        fprintf(opt->file, "%s", diff_line_prefix(opt));
5333        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5334                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5335                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5336                fprintf(opt->file, "%s ",
5337                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5338        }
5339        if (p->score) {
5340                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5341                        inter_name_termination);
5342        } else {
5343                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5344        }
5345
5346        if (p->status == DIFF_STATUS_COPIED ||
5347            p->status == DIFF_STATUS_RENAMED) {
5348                const char *name_a, *name_b;
5349                name_a = p->one->path;
5350                name_b = p->two->path;
5351                strip_prefix(opt->prefix_length, &name_a, &name_b);
5352                write_name_quoted(name_a, opt->file, inter_name_termination);
5353                write_name_quoted(name_b, opt->file, line_termination);
5354        } else {
5355                const char *name_a, *name_b;
5356                name_a = p->one->mode ? p->one->path : p->two->path;
5357                name_b = NULL;
5358                strip_prefix(opt->prefix_length, &name_a, &name_b);
5359                write_name_quoted(name_a, opt->file, line_termination);
5360        }
5361}
5362
5363int diff_unmodified_pair(struct diff_filepair *p)
5364{
5365        /* This function is written stricter than necessary to support
5366         * the currently implemented transformers, but the idea is to
5367         * let transformers to produce diff_filepairs any way they want,
5368         * and filter and clean them up here before producing the output.
5369         */
5370        struct diff_filespec *one = p->one, *two = p->two;
5371
5372        if (DIFF_PAIR_UNMERGED(p))
5373                return 0; /* unmerged is interesting */
5374
5375        /* deletion, addition, mode or type change
5376         * and rename are all interesting.
5377         */
5378        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5379            DIFF_PAIR_MODE_CHANGED(p) ||
5380            strcmp(one->path, two->path))
5381                return 0;
5382
5383        /* both are valid and point at the same path.  that is, we are
5384         * dealing with a change.
5385         */
5386        if (one->oid_valid && two->oid_valid &&
5387            oideq(&one->oid, &two->oid) &&
5388            !one->dirty_submodule && !two->dirty_submodule)
5389                return 1; /* no change */
5390        if (!one->oid_valid && !two->oid_valid)
5391                return 1; /* both look at the same file on the filesystem. */
5392        return 0;
5393}
5394
5395static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5396{
5397        if (diff_unmodified_pair(p))
5398                return;
5399
5400        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5401            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5402                return; /* no tree diffs in patch format */
5403
5404        run_diff(p, o);
5405}
5406
5407static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5408                            struct diffstat_t *diffstat)
5409{
5410        if (diff_unmodified_pair(p))
5411                return;
5412
5413        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5414            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5415                return; /* no useful stat for tree diffs */
5416
5417        run_diffstat(p, o, diffstat);
5418}
5419
5420static void diff_flush_checkdiff(struct diff_filepair *p,
5421                struct diff_options *o)
5422{
5423        if (diff_unmodified_pair(p))
5424                return;
5425
5426        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5427            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5428                return; /* nothing to check in tree diffs */
5429
5430        run_checkdiff(p, o);
5431}
5432
5433int diff_queue_is_empty(void)
5434{
5435        struct diff_queue_struct *q = &diff_queued_diff;
5436        int i;
5437        for (i = 0; i < q->nr; i++)
5438                if (!diff_unmodified_pair(q->queue[i]))
5439                        return 0;
5440        return 1;
5441}
5442
5443#if DIFF_DEBUG
5444void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5445{
5446        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5447                x, one ? one : "",
5448                s->path,
5449                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5450                s->mode,
5451                s->oid_valid ? oid_to_hex(&s->oid) : "");
5452        fprintf(stderr, "queue[%d] %s size %lu\n",
5453                x, one ? one : "",
5454                s->size);
5455}
5456
5457void diff_debug_filepair(const struct diff_filepair *p, int i)
5458{
5459        diff_debug_filespec(p->one, i, "one");
5460        diff_debug_filespec(p->two, i, "two");
5461        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5462                p->score, p->status ? p->status : '?',
5463                p->one->rename_used, p->broken_pair);
5464}
5465
5466void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5467{
5468        int i;
5469        if (msg)
5470                fprintf(stderr, "%s\n", msg);
5471        fprintf(stderr, "q->nr = %d\n", q->nr);
5472        for (i = 0; i < q->nr; i++) {
5473                struct diff_filepair *p = q->queue[i];
5474                diff_debug_filepair(p, i);
5475        }
5476}
5477#endif
5478
5479static void diff_resolve_rename_copy(void)
5480{
5481        int i;
5482        struct diff_filepair *p;
5483        struct diff_queue_struct *q = &diff_queued_diff;
5484
5485        diff_debug_queue("resolve-rename-copy", q);
5486
5487        for (i = 0; i < q->nr; i++) {
5488                p = q->queue[i];
5489                p->status = 0; /* undecided */
5490                if (DIFF_PAIR_UNMERGED(p))
5491                        p->status = DIFF_STATUS_UNMERGED;
5492                else if (!DIFF_FILE_VALID(p->one))
5493                        p->status = DIFF_STATUS_ADDED;
5494                else if (!DIFF_FILE_VALID(p->two))
5495                        p->status = DIFF_STATUS_DELETED;
5496                else if (DIFF_PAIR_TYPE_CHANGED(p))
5497                        p->status = DIFF_STATUS_TYPE_CHANGED;
5498
5499                /* from this point on, we are dealing with a pair
5500                 * whose both sides are valid and of the same type, i.e.
5501                 * either in-place edit or rename/copy edit.
5502                 */
5503                else if (DIFF_PAIR_RENAME(p)) {
5504                        /*
5505                         * A rename might have re-connected a broken
5506                         * pair up, causing the pathnames to be the
5507                         * same again. If so, that's not a rename at
5508                         * all, just a modification..
5509                         *
5510                         * Otherwise, see if this source was used for
5511                         * multiple renames, in which case we decrement
5512                         * the count, and call it a copy.
5513                         */
5514                        if (!strcmp(p->one->path, p->two->path))
5515                                p->status = DIFF_STATUS_MODIFIED;
5516                        else if (--p->one->rename_used > 0)
5517                                p->status = DIFF_STATUS_COPIED;
5518                        else
5519                                p->status = DIFF_STATUS_RENAMED;
5520                }
5521                else if (!oideq(&p->one->oid, &p->two->oid) ||
5522                         p->one->mode != p->two->mode ||
5523                         p->one->dirty_submodule ||
5524                         p->two->dirty_submodule ||
5525                         is_null_oid(&p->one->oid))
5526                        p->status = DIFF_STATUS_MODIFIED;
5527                else {
5528                        /* This is a "no-change" entry and should not
5529                         * happen anymore, but prepare for broken callers.
5530                         */
5531                        error("feeding unmodified %s to diffcore",
5532                              p->one->path);
5533                        p->status = DIFF_STATUS_UNKNOWN;
5534                }
5535        }
5536        diff_debug_queue("resolve-rename-copy done", q);
5537}
5538
5539static int check_pair_status(struct diff_filepair *p)
5540{
5541        switch (p->status) {
5542        case DIFF_STATUS_UNKNOWN:
5543                return 0;
5544        case 0:
5545                die("internal error in diff-resolve-rename-copy");
5546        default:
5547                return 1;
5548        }
5549}
5550
5551static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5552{
5553        int fmt = opt->output_format;
5554
5555        if (fmt & DIFF_FORMAT_CHECKDIFF)
5556                diff_flush_checkdiff(p, opt);
5557        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5558                diff_flush_raw(p, opt);
5559        else if (fmt & DIFF_FORMAT_NAME) {
5560                const char *name_a, *name_b;
5561                name_a = p->two->path;
5562                name_b = NULL;
5563                strip_prefix(opt->prefix_length, &name_a, &name_b);
5564                fprintf(opt->file, "%s", diff_line_prefix(opt));
5565                write_name_quoted(name_a, opt->file, opt->line_termination);
5566        }
5567}
5568
5569static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5570{
5571        struct strbuf sb = STRBUF_INIT;
5572        if (fs->mode)
5573                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5574        else
5575                strbuf_addf(&sb, " %s ", newdelete);
5576
5577        quote_c_style(fs->path, &sb, NULL, 0);
5578        strbuf_addch(&sb, '\n');
5579        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5580                         sb.buf, sb.len, 0);
5581        strbuf_release(&sb);
5582}
5583
5584static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5585                int show_name)
5586{
5587        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5588                struct strbuf sb = STRBUF_INIT;
5589                strbuf_addf(&sb, " mode change %06o => %06o",
5590                            p->one->mode, p->two->mode);
5591                if (show_name) {
5592                        strbuf_addch(&sb, ' ');
5593                        quote_c_style(p->two->path, &sb, NULL, 0);
5594                }
5595                strbuf_addch(&sb, '\n');
5596                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5597                                 sb.buf, sb.len, 0);
5598                strbuf_release(&sb);
5599        }
5600}
5601
5602static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5603                struct diff_filepair *p)
5604{
5605        struct strbuf sb = STRBUF_INIT;
5606        struct strbuf names = STRBUF_INIT;
5607
5608        pprint_rename(&names, p->one->path, p->two->path);
5609        strbuf_addf(&sb, " %s %s (%d%%)\n",
5610                    renamecopy, names.buf, similarity_index(p));
5611        strbuf_release(&names);
5612        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5613                                 sb.buf, sb.len, 0);
5614        show_mode_change(opt, p, 0);
5615        strbuf_release(&sb);
5616}
5617
5618static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5619{
5620        switch(p->status) {
5621        case DIFF_STATUS_DELETED:
5622                show_file_mode_name(opt, "delete", p->one);
5623                break;
5624        case DIFF_STATUS_ADDED:
5625                show_file_mode_name(opt, "create", p->two);
5626                break;
5627        case DIFF_STATUS_COPIED:
5628                show_rename_copy(opt, "copy", p);
5629                break;
5630        case DIFF_STATUS_RENAMED:
5631                show_rename_copy(opt, "rename", p);
5632                break;
5633        default:
5634                if (p->score) {
5635                        struct strbuf sb = STRBUF_INIT;
5636                        strbuf_addstr(&sb, " rewrite ");
5637                        quote_c_style(p->two->path, &sb, NULL, 0);
5638                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5639                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5640                                         sb.buf, sb.len, 0);
5641                        strbuf_release(&sb);
5642                }
5643                show_mode_change(opt, p, !p->score);
5644                break;
5645        }
5646}
5647
5648struct patch_id_t {
5649        git_SHA_CTX *ctx;
5650        int patchlen;
5651};
5652
5653static int remove_space(char *line, int len)
5654{
5655        int i;
5656        char *dst = line;
5657        unsigned char c;
5658
5659        for (i = 0; i < len; i++)
5660                if (!isspace((c = line[i])))
5661                        *dst++ = c;
5662
5663        return dst - line;
5664}
5665
5666static void patch_id_consume(void *priv, char *line, unsigned long len)
5667{
5668        struct patch_id_t *data = priv;
5669        int new_len;
5670
5671        new_len = remove_space(line, len);
5672
5673        git_SHA1_Update(data->ctx, line, new_len);
5674        data->patchlen += new_len;
5675}
5676
5677static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5678{
5679        git_SHA1_Update(ctx, str, strlen(str));
5680}
5681
5682static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5683{
5684        /* large enough for 2^32 in octal */
5685        char buf[12];
5686        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5687        git_SHA1_Update(ctx, buf, len);
5688}
5689
5690/* returns 0 upon success, and writes result into sha1 */
5691static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5692{
5693        struct diff_queue_struct *q = &diff_queued_diff;
5694        int i;
5695        git_SHA_CTX ctx;
5696        struct patch_id_t data;
5697
5698        git_SHA1_Init(&ctx);
5699        memset(&data, 0, sizeof(struct patch_id_t));
5700        data.ctx = &ctx;
5701
5702        for (i = 0; i < q->nr; i++) {
5703                xpparam_t xpp;
5704                xdemitconf_t xecfg;
5705                mmfile_t mf1, mf2;
5706                struct diff_filepair *p = q->queue[i];
5707                int len1, len2;
5708
5709                memset(&xpp, 0, sizeof(xpp));
5710                memset(&xecfg, 0, sizeof(xecfg));
5711                if (p->status == 0)
5712                        return error("internal diff status error");
5713                if (p->status == DIFF_STATUS_UNKNOWN)
5714                        continue;
5715                if (diff_unmodified_pair(p))
5716                        continue;
5717                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5718                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5719                        continue;
5720                if (DIFF_PAIR_UNMERGED(p))
5721                        continue;
5722
5723                diff_fill_oid_info(p->one, options->repo->index);
5724                diff_fill_oid_info(p->two, options->repo->index);
5725
5726                len1 = remove_space(p->one->path, strlen(p->one->path));
5727                len2 = remove_space(p->two->path, strlen(p->two->path));
5728                patch_id_add_string(&ctx, "diff--git");
5729                patch_id_add_string(&ctx, "a/");
5730                git_SHA1_Update(&ctx, p->one->path, len1);
5731                patch_id_add_string(&ctx, "b/");
5732                git_SHA1_Update(&ctx, p->two->path, len2);
5733
5734                if (p->one->mode == 0) {
5735                        patch_id_add_string(&ctx, "newfilemode");
5736                        patch_id_add_mode(&ctx, p->two->mode);
5737                        patch_id_add_string(&ctx, "---/dev/null");
5738                        patch_id_add_string(&ctx, "+++b/");
5739                        git_SHA1_Update(&ctx, p->two->path, len2);
5740                } else if (p->two->mode == 0) {
5741                        patch_id_add_string(&ctx, "deletedfilemode");
5742                        patch_id_add_mode(&ctx, p->one->mode);
5743                        patch_id_add_string(&ctx, "---a/");
5744                        git_SHA1_Update(&ctx, p->one->path, len1);
5745                        patch_id_add_string(&ctx, "+++/dev/null");
5746                } else {
5747                        patch_id_add_string(&ctx, "---a/");
5748                        git_SHA1_Update(&ctx, p->one->path, len1);
5749                        patch_id_add_string(&ctx, "+++b/");
5750                        git_SHA1_Update(&ctx, p->two->path, len2);
5751                }
5752
5753                if (diff_header_only)
5754                        continue;
5755
5756                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5757                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5758                        return error("unable to read files to diff");
5759
5760                if (diff_filespec_is_binary(options->repo, p->one) ||
5761                    diff_filespec_is_binary(options->repo, p->two)) {
5762                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5763                                        GIT_SHA1_HEXSZ);
5764                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5765                                        GIT_SHA1_HEXSZ);
5766                        continue;
5767                }
5768
5769                xpp.flags = 0;
5770                xecfg.ctxlen = 3;
5771                xecfg.flags = 0;
5772                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5773                                  patch_id_consume, &data, &xpp, &xecfg))
5774                        return error("unable to generate patch-id diff for %s",
5775                                     p->one->path);
5776        }
5777
5778        git_SHA1_Final(oid->hash, &ctx);
5779        return 0;
5780}
5781
5782int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5783{
5784        struct diff_queue_struct *q = &diff_queued_diff;
5785        int i;
5786        int result = diff_get_patch_id(options, oid, diff_header_only);
5787
5788        for (i = 0; i < q->nr; i++)
5789                diff_free_filepair(q->queue[i]);
5790
5791        free(q->queue);
5792        DIFF_QUEUE_CLEAR(q);
5793
5794        return result;
5795}
5796
5797static int is_summary_empty(const struct diff_queue_struct *q)
5798{
5799        int i;
5800
5801        for (i = 0; i < q->nr; i++) {
5802                const struct diff_filepair *p = q->queue[i];
5803
5804                switch (p->status) {
5805                case DIFF_STATUS_DELETED:
5806                case DIFF_STATUS_ADDED:
5807                case DIFF_STATUS_COPIED:
5808                case DIFF_STATUS_RENAMED:
5809                        return 0;
5810                default:
5811                        if (p->score)
5812                                return 0;
5813                        if (p->one->mode && p->two->mode &&
5814                            p->one->mode != p->two->mode)
5815                                return 0;
5816                        break;
5817                }
5818        }
5819        return 1;
5820}
5821
5822static const char rename_limit_warning[] =
5823N_("inexact rename detection was skipped due to too many files.");
5824
5825static const char degrade_cc_to_c_warning[] =
5826N_("only found copies from modified paths due to too many files.");
5827
5828static const char rename_limit_advice[] =
5829N_("you may want to set your %s variable to at least "
5830   "%d and retry the command.");
5831
5832void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5833{
5834        fflush(stdout);
5835        if (degraded_cc)
5836                warning(_(degrade_cc_to_c_warning));
5837        else if (needed)
5838                warning(_(rename_limit_warning));
5839        else
5840                return;
5841        if (0 < needed)
5842                warning(_(rename_limit_advice), varname, needed);
5843}
5844
5845static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5846{
5847        int i;
5848        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5849        struct diff_queue_struct *q = &diff_queued_diff;
5850
5851        if (WSEH_NEW & WS_RULE_MASK)
5852                BUG("WS rules bit mask overlaps with diff symbol flags");
5853
5854        if (o->color_moved)
5855                o->emitted_symbols = &esm;
5856
5857        for (i = 0; i < q->nr; i++) {
5858                struct diff_filepair *p = q->queue[i];
5859                if (check_pair_status(p))
5860                        diff_flush_patch(p, o);
5861        }
5862
5863        if (o->emitted_symbols) {
5864                if (o->color_moved) {
5865                        struct hashmap add_lines, del_lines;
5866
5867                        if (o->color_moved_ws_handling &
5868                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5869                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5870
5871                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5872                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5873
5874                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5875                        mark_color_as_moved(o, &add_lines, &del_lines);
5876                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5877                                dim_moved_lines(o);
5878
5879                        hashmap_free(&add_lines, 1);
5880                        hashmap_free(&del_lines, 1);
5881                }
5882
5883                for (i = 0; i < esm.nr; i++)
5884                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5885
5886                for (i = 0; i < esm.nr; i++)
5887                        free((void *)esm.buf[i].line);
5888        }
5889        esm.nr = 0;
5890}
5891
5892void diff_flush(struct diff_options *options)
5893{
5894        struct diff_queue_struct *q = &diff_queued_diff;
5895        int i, output_format = options->output_format;
5896        int separator = 0;
5897        int dirstat_by_line = 0;
5898
5899        /*
5900         * Order: raw, stat, summary, patch
5901         * or:    name/name-status/checkdiff (other bits clear)
5902         */
5903        if (!q->nr)
5904                goto free_queue;
5905
5906        if (output_format & (DIFF_FORMAT_RAW |
5907                             DIFF_FORMAT_NAME |
5908                             DIFF_FORMAT_NAME_STATUS |
5909                             DIFF_FORMAT_CHECKDIFF)) {
5910                for (i = 0; i < q->nr; i++) {
5911                        struct diff_filepair *p = q->queue[i];
5912                        if (check_pair_status(p))
5913                                flush_one_pair(p, options);
5914                }
5915                separator++;
5916        }
5917
5918        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5919                dirstat_by_line = 1;
5920
5921        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5922            dirstat_by_line) {
5923                struct diffstat_t diffstat;
5924
5925                memset(&diffstat, 0, sizeof(struct diffstat_t));
5926                for (i = 0; i < q->nr; i++) {
5927                        struct diff_filepair *p = q->queue[i];
5928                        if (check_pair_status(p))
5929                                diff_flush_stat(p, options, &diffstat);
5930                }
5931                if (output_format & DIFF_FORMAT_NUMSTAT)
5932                        show_numstat(&diffstat, options);
5933                if (output_format & DIFF_FORMAT_DIFFSTAT)
5934                        show_stats(&diffstat, options);
5935                if (output_format & DIFF_FORMAT_SHORTSTAT)
5936                        show_shortstats(&diffstat, options);
5937                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5938                        show_dirstat_by_line(&diffstat, options);
5939                free_diffstat_info(&diffstat);
5940                separator++;
5941        }
5942        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5943                show_dirstat(options);
5944
5945        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5946                for (i = 0; i < q->nr; i++) {
5947                        diff_summary(options, q->queue[i]);
5948                }
5949                separator++;
5950        }
5951
5952        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5953            options->flags.exit_with_status &&
5954            options->flags.diff_from_contents) {
5955                /*
5956                 * run diff_flush_patch for the exit status. setting
5957                 * options->file to /dev/null should be safe, because we
5958                 * aren't supposed to produce any output anyway.
5959                 */
5960                if (options->close_file)
5961                        fclose(options->file);
5962                options->file = xfopen("/dev/null", "w");
5963                options->close_file = 1;
5964                options->color_moved = 0;
5965                for (i = 0; i < q->nr; i++) {
5966                        struct diff_filepair *p = q->queue[i];
5967                        if (check_pair_status(p))
5968                                diff_flush_patch(p, options);
5969                        if (options->found_changes)
5970                                break;
5971                }
5972        }
5973
5974        if (output_format & DIFF_FORMAT_PATCH) {
5975                if (separator) {
5976                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5977                        if (options->stat_sep)
5978                                /* attach patch instead of inline */
5979                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5980                                                 NULL, 0, 0);
5981                }
5982
5983                diff_flush_patch_all_file_pairs(options);
5984        }
5985
5986        if (output_format & DIFF_FORMAT_CALLBACK)
5987                options->format_callback(q, options, options->format_callback_data);
5988
5989        for (i = 0; i < q->nr; i++)
5990                diff_free_filepair(q->queue[i]);
5991free_queue:
5992        free(q->queue);
5993        DIFF_QUEUE_CLEAR(q);
5994        if (options->close_file)
5995                fclose(options->file);
5996
5997        /*
5998         * Report the content-level differences with HAS_CHANGES;
5999         * diff_addremove/diff_change does not set the bit when
6000         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6001         */
6002        if (options->flags.diff_from_contents) {
6003                if (options->found_changes)
6004                        options->flags.has_changes = 1;
6005                else
6006                        options->flags.has_changes = 0;
6007        }
6008}
6009
6010static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6011{
6012        return (((p->status == DIFF_STATUS_MODIFIED) &&
6013                 ((p->score &&
6014                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6015                  (!p->score &&
6016                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6017                ((p->status != DIFF_STATUS_MODIFIED) &&
6018                 filter_bit_tst(p->status, options)));
6019}
6020
6021static void diffcore_apply_filter(struct diff_options *options)
6022{
6023        int i;
6024        struct diff_queue_struct *q = &diff_queued_diff;
6025        struct diff_queue_struct outq;
6026
6027        DIFF_QUEUE_CLEAR(&outq);
6028
6029        if (!options->filter)
6030                return;
6031
6032        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6033                int found;
6034                for (i = found = 0; !found && i < q->nr; i++) {
6035                        if (match_filter(options, q->queue[i]))
6036                                found++;
6037                }
6038                if (found)
6039                        return;
6040
6041                /* otherwise we will clear the whole queue
6042                 * by copying the empty outq at the end of this
6043                 * function, but first clear the current entries
6044                 * in the queue.
6045                 */
6046                for (i = 0; i < q->nr; i++)
6047                        diff_free_filepair(q->queue[i]);
6048        }
6049        else {
6050                /* Only the matching ones */
6051                for (i = 0; i < q->nr; i++) {
6052                        struct diff_filepair *p = q->queue[i];
6053                        if (match_filter(options, p))
6054                                diff_q(&outq, p);
6055                        else
6056                                diff_free_filepair(p);
6057                }
6058        }
6059        free(q->queue);
6060        *q = outq;
6061}
6062
6063/* Check whether two filespecs with the same mode and size are identical */
6064static int diff_filespec_is_identical(struct repository *r,
6065                                      struct diff_filespec *one,
6066                                      struct diff_filespec *two)
6067{
6068        if (S_ISGITLINK(one->mode))
6069                return 0;
6070        if (diff_populate_filespec(r, one, 0))
6071                return 0;
6072        if (diff_populate_filespec(r, two, 0))
6073                return 0;
6074        return !memcmp(one->data, two->data, one->size);
6075}
6076
6077static int diff_filespec_check_stat_unmatch(struct repository *r,
6078                                            struct diff_filepair *p)
6079{
6080        if (p->done_skip_stat_unmatch)
6081                return p->skip_stat_unmatch_result;
6082
6083        p->done_skip_stat_unmatch = 1;
6084        p->skip_stat_unmatch_result = 0;
6085        /*
6086         * 1. Entries that come from stat info dirtiness
6087         *    always have both sides (iow, not create/delete),
6088         *    one side of the object name is unknown, with
6089         *    the same mode and size.  Keep the ones that
6090         *    do not match these criteria.  They have real
6091         *    differences.
6092         *
6093         * 2. At this point, the file is known to be modified,
6094         *    with the same mode and size, and the object
6095         *    name of one side is unknown.  Need to inspect
6096         *    the identical contents.
6097         */
6098        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6099            !DIFF_FILE_VALID(p->two) ||
6100            (p->one->oid_valid && p->two->oid_valid) ||
6101            (p->one->mode != p->two->mode) ||
6102            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6103            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6104            (p->one->size != p->two->size) ||
6105            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6106                p->skip_stat_unmatch_result = 1;
6107        return p->skip_stat_unmatch_result;
6108}
6109
6110static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6111{
6112        int i;
6113        struct diff_queue_struct *q = &diff_queued_diff;
6114        struct diff_queue_struct outq;
6115        DIFF_QUEUE_CLEAR(&outq);
6116
6117        for (i = 0; i < q->nr; i++) {
6118                struct diff_filepair *p = q->queue[i];
6119
6120                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6121                        diff_q(&outq, p);
6122                else {
6123                        /*
6124                         * The caller can subtract 1 from skip_stat_unmatch
6125                         * to determine how many paths were dirty only
6126                         * due to stat info mismatch.
6127                         */
6128                        if (!diffopt->flags.no_index)
6129                                diffopt->skip_stat_unmatch++;
6130                        diff_free_filepair(p);
6131                }
6132        }
6133        free(q->queue);
6134        *q = outq;
6135}
6136
6137static int diffnamecmp(const void *a_, const void *b_)
6138{
6139        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6140        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6141        const char *name_a, *name_b;
6142
6143        name_a = a->one ? a->one->path : a->two->path;
6144        name_b = b->one ? b->one->path : b->two->path;
6145        return strcmp(name_a, name_b);
6146}
6147
6148void diffcore_fix_diff_index(struct diff_options *options)
6149{
6150        struct diff_queue_struct *q = &diff_queued_diff;
6151        QSORT(q->queue, q->nr, diffnamecmp);
6152}
6153
6154void diffcore_std(struct diff_options *options)
6155{
6156        /* NOTE please keep the following in sync with diff_tree_combined() */
6157        if (options->skip_stat_unmatch)
6158                diffcore_skip_stat_unmatch(options);
6159        if (!options->found_follow) {
6160                /* See try_to_follow_renames() in tree-diff.c */
6161                if (options->break_opt != -1)
6162                        diffcore_break(options->repo,
6163                                       options->break_opt);
6164                if (options->detect_rename)
6165                        diffcore_rename(options);
6166                if (options->break_opt != -1)
6167                        diffcore_merge_broken();
6168        }
6169        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6170                diffcore_pickaxe(options);
6171        if (options->orderfile)
6172                diffcore_order(options->orderfile);
6173        if (!options->found_follow)
6174                /* See try_to_follow_renames() in tree-diff.c */
6175                diff_resolve_rename_copy();
6176        diffcore_apply_filter(options);
6177
6178        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6179                options->flags.has_changes = 1;
6180        else
6181                options->flags.has_changes = 0;
6182
6183        options->found_follow = 0;
6184}
6185
6186int diff_result_code(struct diff_options *opt, int status)
6187{
6188        int result = 0;
6189
6190        diff_warn_rename_limit("diff.renameLimit",
6191                               opt->needed_rename_limit,
6192                               opt->degraded_cc_to_c);
6193        if (!opt->flags.exit_with_status &&
6194            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6195                return status;
6196        if (opt->flags.exit_with_status &&
6197            opt->flags.has_changes)
6198                result |= 01;
6199        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6200            opt->flags.check_failed)
6201                result |= 02;
6202        return result;
6203}
6204
6205int diff_can_quit_early(struct diff_options *opt)
6206{
6207        return (opt->flags.quick &&
6208                !opt->filter &&
6209                opt->flags.has_changes);
6210}
6211
6212/*
6213 * Shall changes to this submodule be ignored?
6214 *
6215 * Submodule changes can be configured to be ignored separately for each path,
6216 * but that configuration can be overridden from the command line.
6217 */
6218static int is_submodule_ignored(const char *path, struct diff_options *options)
6219{
6220        int ignored = 0;
6221        struct diff_flags orig_flags = options->flags;
6222        if (!options->flags.override_submodule_config)
6223                set_diffopt_flags_from_submodule_config(options, path);
6224        if (options->flags.ignore_submodules)
6225                ignored = 1;
6226        options->flags = orig_flags;
6227        return ignored;
6228}
6229
6230void diff_addremove(struct diff_options *options,
6231                    int addremove, unsigned mode,
6232                    const struct object_id *oid,
6233                    int oid_valid,
6234                    const char *concatpath, unsigned dirty_submodule)
6235{
6236        struct diff_filespec *one, *two;
6237
6238        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6239                return;
6240
6241        /* This may look odd, but it is a preparation for
6242         * feeding "there are unchanged files which should
6243         * not produce diffs, but when you are doing copy
6244         * detection you would need them, so here they are"
6245         * entries to the diff-core.  They will be prefixed
6246         * with something like '=' or '*' (I haven't decided
6247         * which but should not make any difference).
6248         * Feeding the same new and old to diff_change()
6249         * also has the same effect.
6250         * Before the final output happens, they are pruned after
6251         * merged into rename/copy pairs as appropriate.
6252         */
6253        if (options->flags.reverse_diff)
6254                addremove = (addremove == '+' ? '-' :
6255                             addremove == '-' ? '+' : addremove);
6256
6257        if (options->prefix &&
6258            strncmp(concatpath, options->prefix, options->prefix_length))
6259                return;
6260
6261        one = alloc_filespec(concatpath);
6262        two = alloc_filespec(concatpath);
6263
6264        if (addremove != '+')
6265                fill_filespec(one, oid, oid_valid, mode);
6266        if (addremove != '-') {
6267                fill_filespec(two, oid, oid_valid, mode);
6268                two->dirty_submodule = dirty_submodule;
6269        }
6270
6271        diff_queue(&diff_queued_diff, one, two);
6272        if (!options->flags.diff_from_contents)
6273                options->flags.has_changes = 1;
6274}
6275
6276void diff_change(struct diff_options *options,
6277                 unsigned old_mode, unsigned new_mode,
6278                 const struct object_id *old_oid,
6279                 const struct object_id *new_oid,
6280                 int old_oid_valid, int new_oid_valid,
6281                 const char *concatpath,
6282                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6283{
6284        struct diff_filespec *one, *two;
6285        struct diff_filepair *p;
6286
6287        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6288            is_submodule_ignored(concatpath, options))
6289                return;
6290
6291        if (options->flags.reverse_diff) {
6292                SWAP(old_mode, new_mode);
6293                SWAP(old_oid, new_oid);
6294                SWAP(old_oid_valid, new_oid_valid);
6295                SWAP(old_dirty_submodule, new_dirty_submodule);
6296        }
6297
6298        if (options->prefix &&
6299            strncmp(concatpath, options->prefix, options->prefix_length))
6300                return;
6301
6302        one = alloc_filespec(concatpath);
6303        two = alloc_filespec(concatpath);
6304        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6305        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6306        one->dirty_submodule = old_dirty_submodule;
6307        two->dirty_submodule = new_dirty_submodule;
6308        p = diff_queue(&diff_queued_diff, one, two);
6309
6310        if (options->flags.diff_from_contents)
6311                return;
6312
6313        if (options->flags.quick && options->skip_stat_unmatch &&
6314            !diff_filespec_check_stat_unmatch(options->repo, p))
6315                return;
6316
6317        options->flags.has_changes = 1;
6318}
6319
6320struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6321{
6322        struct diff_filepair *pair;
6323        struct diff_filespec *one, *two;
6324
6325        if (options->prefix &&
6326            strncmp(path, options->prefix, options->prefix_length))
6327                return NULL;
6328
6329        one = alloc_filespec(path);
6330        two = alloc_filespec(path);
6331        pair = diff_queue(&diff_queued_diff, one, two);
6332        pair->is_unmerged = 1;
6333        return pair;
6334}
6335
6336static char *run_textconv(struct repository *r,
6337                          const char *pgm,
6338                          struct diff_filespec *spec,
6339                          size_t *outsize)
6340{
6341        struct diff_tempfile *temp;
6342        const char *argv[3];
6343        const char **arg = argv;
6344        struct child_process child = CHILD_PROCESS_INIT;
6345        struct strbuf buf = STRBUF_INIT;
6346        int err = 0;
6347
6348        temp = prepare_temp_file(r, spec->path, spec);
6349        *arg++ = pgm;
6350        *arg++ = temp->name;
6351        *arg = NULL;
6352
6353        child.use_shell = 1;
6354        child.argv = argv;
6355        child.out = -1;
6356        if (start_command(&child)) {
6357                remove_tempfile();
6358                return NULL;
6359        }
6360
6361        if (strbuf_read(&buf, child.out, 0) < 0)
6362                err = error("error reading from textconv command '%s'", pgm);
6363        close(child.out);
6364
6365        if (finish_command(&child) || err) {
6366                strbuf_release(&buf);
6367                remove_tempfile();
6368                return NULL;
6369        }
6370        remove_tempfile();
6371
6372        return strbuf_detach(&buf, outsize);
6373}
6374
6375size_t fill_textconv(struct repository *r,
6376                     struct userdiff_driver *driver,
6377                     struct diff_filespec *df,
6378                     char **outbuf)
6379{
6380        size_t size;
6381
6382        if (!driver) {
6383                if (!DIFF_FILE_VALID(df)) {
6384                        *outbuf = "";
6385                        return 0;
6386                }
6387                if (diff_populate_filespec(r, df, 0))
6388                        die("unable to read files to diff");
6389                *outbuf = df->data;
6390                return df->size;
6391        }
6392
6393        if (!driver->textconv)
6394                BUG("fill_textconv called with non-textconv driver");
6395
6396        if (driver->textconv_cache && df->oid_valid) {
6397                *outbuf = notes_cache_get(driver->textconv_cache,
6398                                          &df->oid,
6399                                          &size);
6400                if (*outbuf)
6401                        return size;
6402        }
6403
6404        *outbuf = run_textconv(r, driver->textconv, df, &size);
6405        if (!*outbuf)
6406                die("unable to read files to diff");
6407
6408        if (driver->textconv_cache && df->oid_valid) {
6409                /* ignore errors, as we might be in a readonly repository */
6410                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6411                                size);
6412                /*
6413                 * we could save up changes and flush them all at the end,
6414                 * but we would need an extra call after all diffing is done.
6415                 * Since generating a cache entry is the slow path anyway,
6416                 * this extra overhead probably isn't a big deal.
6417                 */
6418                notes_cache_write(driver->textconv_cache);
6419        }
6420
6421        return size;
6422}
6423
6424int textconv_object(struct repository *r,
6425                    const char *path,
6426                    unsigned mode,
6427                    const struct object_id *oid,
6428                    int oid_valid,
6429                    char **buf,
6430                    unsigned long *buf_size)
6431{
6432        struct diff_filespec *df;
6433        struct userdiff_driver *textconv;
6434
6435        df = alloc_filespec(path);
6436        fill_filespec(df, oid, oid_valid, mode);
6437        textconv = get_textconv(r, df);
6438        if (!textconv) {
6439                free_filespec(df);
6440                return 0;
6441        }
6442
6443        *buf_size = fill_textconv(r, textconv, df, buf);
6444        free_filespec(df);
6445        return 1;
6446}
6447
6448void setup_diff_pager(struct diff_options *opt)
6449{
6450        /*
6451         * If the user asked for our exit code, then either they want --quiet
6452         * or --exit-code. We should definitely not bother with a pager in the
6453         * former case, as we will generate no output. Since we still properly
6454         * report our exit code even when a pager is run, we _could_ run a
6455         * pager with --exit-code. But since we have not done so historically,
6456         * and because it is easy to find people oneline advising "git diff
6457         * --exit-code" in hooks and other scripts, we do not do so.
6458         */
6459        if (!opt->flags.exit_with_status &&
6460            check_pager_config("diff") != 0)
6461                setup_pager();
6462}