diff.con commit Merge branch 'jk/rev-parse-symbolic-parents-fix' into maint (7b0490f)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "tempfile.h"
   6#include "quote.h"
   7#include "diff.h"
   8#include "diffcore.h"
   9#include "delta.h"
  10#include "xdiff-interface.h"
  11#include "color.h"
  12#include "attr.h"
  13#include "run-command.h"
  14#include "utf8.h"
  15#include "userdiff.h"
  16#include "submodule-config.h"
  17#include "submodule.h"
  18#include "ll-merge.h"
  19#include "string-list.h"
  20#include "argv-array.h"
  21#include "graph.h"
  22
  23#ifdef NO_FAST_WORKING_DIRECTORY
  24#define FAST_WORKING_DIRECTORY 0
  25#else
  26#define FAST_WORKING_DIRECTORY 1
  27#endif
  28
  29static int diff_detect_rename_default;
  30static int diff_indent_heuristic; /* experimental */
  31static int diff_compaction_heuristic; /* experimental */
  32static int diff_rename_limit_default = 400;
  33static int diff_suppress_blank_empty;
  34static int diff_use_color_default = -1;
  35static int diff_context_default = 3;
  36static const char *diff_word_regex_cfg;
  37static const char *external_diff_cmd_cfg;
  38static const char *diff_order_file_cfg;
  39int diff_auto_refresh_index = 1;
  40static int diff_mnemonic_prefix;
  41static int diff_no_prefix;
  42static int diff_stat_graph_width;
  43static int diff_dirstat_permille_default = 30;
  44static struct diff_options default_diff_options;
  45static long diff_algorithm;
  46static unsigned ws_error_highlight_default = WSEH_NEW;
  47
  48static char diff_colors[][COLOR_MAXLEN] = {
  49        GIT_COLOR_RESET,
  50        GIT_COLOR_NORMAL,       /* CONTEXT */
  51        GIT_COLOR_BOLD,         /* METAINFO */
  52        GIT_COLOR_CYAN,         /* FRAGINFO */
  53        GIT_COLOR_RED,          /* OLD */
  54        GIT_COLOR_GREEN,        /* NEW */
  55        GIT_COLOR_YELLOW,       /* COMMIT */
  56        GIT_COLOR_BG_RED,       /* WHITESPACE */
  57        GIT_COLOR_NORMAL,       /* FUNCINFO */
  58};
  59
  60static NORETURN void die_want_option(const char *option_name)
  61{
  62        die(_("option '%s' requires a value"), option_name);
  63}
  64
  65static int parse_diff_color_slot(const char *var)
  66{
  67        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  68                return DIFF_CONTEXT;
  69        if (!strcasecmp(var, "meta"))
  70                return DIFF_METAINFO;
  71        if (!strcasecmp(var, "frag"))
  72                return DIFF_FRAGINFO;
  73        if (!strcasecmp(var, "old"))
  74                return DIFF_FILE_OLD;
  75        if (!strcasecmp(var, "new"))
  76                return DIFF_FILE_NEW;
  77        if (!strcasecmp(var, "commit"))
  78                return DIFF_COMMIT;
  79        if (!strcasecmp(var, "whitespace"))
  80                return DIFF_WHITESPACE;
  81        if (!strcasecmp(var, "func"))
  82                return DIFF_FUNCINFO;
  83        return -1;
  84}
  85
  86static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  87                                struct strbuf *errmsg)
  88{
  89        char *params_copy = xstrdup(params_string);
  90        struct string_list params = STRING_LIST_INIT_NODUP;
  91        int ret = 0;
  92        int i;
  93
  94        if (*params_copy)
  95                string_list_split_in_place(&params, params_copy, ',', -1);
  96        for (i = 0; i < params.nr; i++) {
  97                const char *p = params.items[i].string;
  98                if (!strcmp(p, "changes")) {
  99                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 100                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 101                } else if (!strcmp(p, "lines")) {
 102                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
 103                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 104                } else if (!strcmp(p, "files")) {
 105                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 106                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 107                } else if (!strcmp(p, "noncumulative")) {
 108                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 109                } else if (!strcmp(p, "cumulative")) {
 110                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 111                } else if (isdigit(*p)) {
 112                        char *end;
 113                        int permille = strtoul(p, &end, 10) * 10;
 114                        if (*end == '.' && isdigit(*++end)) {
 115                                /* only use first digit */
 116                                permille += *end - '0';
 117                                /* .. and ignore any further digits */
 118                                while (isdigit(*++end))
 119                                        ; /* nothing */
 120                        }
 121                        if (!*end)
 122                                options->dirstat_permille = permille;
 123                        else {
 124                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 125                                            p);
 126                                ret++;
 127                        }
 128                } else {
 129                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 130                        ret++;
 131                }
 132
 133        }
 134        string_list_clear(&params, 0);
 135        free(params_copy);
 136        return ret;
 137}
 138
 139static int parse_submodule_params(struct diff_options *options, const char *value)
 140{
 141        if (!strcmp(value, "log"))
 142                options->submodule_format = DIFF_SUBMODULE_LOG;
 143        else if (!strcmp(value, "short"))
 144                options->submodule_format = DIFF_SUBMODULE_SHORT;
 145        else if (!strcmp(value, "diff"))
 146                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 147        else
 148                return -1;
 149        return 0;
 150}
 151
 152static int git_config_rename(const char *var, const char *value)
 153{
 154        if (!value)
 155                return DIFF_DETECT_RENAME;
 156        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 157                return  DIFF_DETECT_COPY;
 158        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 159}
 160
 161long parse_algorithm_value(const char *value)
 162{
 163        if (!value)
 164                return -1;
 165        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 166                return 0;
 167        else if (!strcasecmp(value, "minimal"))
 168                return XDF_NEED_MINIMAL;
 169        else if (!strcasecmp(value, "patience"))
 170                return XDF_PATIENCE_DIFF;
 171        else if (!strcasecmp(value, "histogram"))
 172                return XDF_HISTOGRAM_DIFF;
 173        return -1;
 174}
 175
 176static int parse_one_token(const char **arg, const char *token)
 177{
 178        const char *rest;
 179        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 180                *arg = rest;
 181                return 1;
 182        }
 183        return 0;
 184}
 185
 186static int parse_ws_error_highlight(const char *arg)
 187{
 188        const char *orig_arg = arg;
 189        unsigned val = 0;
 190
 191        while (*arg) {
 192                if (parse_one_token(&arg, "none"))
 193                        val = 0;
 194                else if (parse_one_token(&arg, "default"))
 195                        val = WSEH_NEW;
 196                else if (parse_one_token(&arg, "all"))
 197                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 198                else if (parse_one_token(&arg, "new"))
 199                        val |= WSEH_NEW;
 200                else if (parse_one_token(&arg, "old"))
 201                        val |= WSEH_OLD;
 202                else if (parse_one_token(&arg, "context"))
 203                        val |= WSEH_CONTEXT;
 204                else {
 205                        return -1 - (int)(arg - orig_arg);
 206                }
 207                if (*arg)
 208                        arg++;
 209        }
 210        return val;
 211}
 212
 213/*
 214 * These are to give UI layer defaults.
 215 * The core-level commands such as git-diff-files should
 216 * never be affected by the setting of diff.renames
 217 * the user happens to have in the configuration file.
 218 */
 219void init_diff_ui_defaults(void)
 220{
 221        diff_detect_rename_default = 1;
 222}
 223
 224int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 225{
 226        if (!strcmp(var, "diff.indentheuristic")) {
 227                diff_indent_heuristic = git_config_bool(var, value);
 228                if (diff_indent_heuristic)
 229                        diff_compaction_heuristic = 0;
 230        }
 231        if (!strcmp(var, "diff.compactionheuristic")) {
 232                diff_compaction_heuristic = git_config_bool(var, value);
 233                if (diff_compaction_heuristic)
 234                        diff_indent_heuristic = 0;
 235        }
 236        return 0;
 237}
 238
 239int git_diff_ui_config(const char *var, const char *value, void *cb)
 240{
 241        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 242                diff_use_color_default = git_config_colorbool(var, value);
 243                return 0;
 244        }
 245        if (!strcmp(var, "diff.context")) {
 246                diff_context_default = git_config_int(var, value);
 247                if (diff_context_default < 0)
 248                        return -1;
 249                return 0;
 250        }
 251        if (!strcmp(var, "diff.renames")) {
 252                diff_detect_rename_default = git_config_rename(var, value);
 253                return 0;
 254        }
 255        if (!strcmp(var, "diff.autorefreshindex")) {
 256                diff_auto_refresh_index = git_config_bool(var, value);
 257                return 0;
 258        }
 259        if (!strcmp(var, "diff.mnemonicprefix")) {
 260                diff_mnemonic_prefix = git_config_bool(var, value);
 261                return 0;
 262        }
 263        if (!strcmp(var, "diff.noprefix")) {
 264                diff_no_prefix = git_config_bool(var, value);
 265                return 0;
 266        }
 267        if (!strcmp(var, "diff.statgraphwidth")) {
 268                diff_stat_graph_width = git_config_int(var, value);
 269                return 0;
 270        }
 271        if (!strcmp(var, "diff.external"))
 272                return git_config_string(&external_diff_cmd_cfg, var, value);
 273        if (!strcmp(var, "diff.wordregex"))
 274                return git_config_string(&diff_word_regex_cfg, var, value);
 275        if (!strcmp(var, "diff.orderfile"))
 276                return git_config_pathname(&diff_order_file_cfg, var, value);
 277
 278        if (!strcmp(var, "diff.ignoresubmodules"))
 279                handle_ignore_submodules_arg(&default_diff_options, value);
 280
 281        if (!strcmp(var, "diff.submodule")) {
 282                if (parse_submodule_params(&default_diff_options, value))
 283                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 284                                value);
 285                return 0;
 286        }
 287
 288        if (!strcmp(var, "diff.algorithm")) {
 289                diff_algorithm = parse_algorithm_value(value);
 290                if (diff_algorithm < 0)
 291                        return -1;
 292                return 0;
 293        }
 294
 295        if (git_diff_heuristic_config(var, value, cb) < 0)
 296                return -1;
 297
 298        if (!strcmp(var, "diff.wserrorhighlight")) {
 299                int val = parse_ws_error_highlight(value);
 300                if (val < 0)
 301                        return -1;
 302                ws_error_highlight_default = val;
 303                return 0;
 304        }
 305
 306        if (git_color_config(var, value, cb) < 0)
 307                return -1;
 308
 309        return git_diff_basic_config(var, value, cb);
 310}
 311
 312int git_diff_basic_config(const char *var, const char *value, void *cb)
 313{
 314        const char *name;
 315
 316        if (!strcmp(var, "diff.renamelimit")) {
 317                diff_rename_limit_default = git_config_int(var, value);
 318                return 0;
 319        }
 320
 321        if (userdiff_config(var, value) < 0)
 322                return -1;
 323
 324        if (skip_prefix(var, "diff.color.", &name) ||
 325            skip_prefix(var, "color.diff.", &name)) {
 326                int slot = parse_diff_color_slot(name);
 327                if (slot < 0)
 328                        return 0;
 329                if (!value)
 330                        return config_error_nonbool(var);
 331                return color_parse(value, diff_colors[slot]);
 332        }
 333
 334        /* like GNU diff's --suppress-blank-empty option  */
 335        if (!strcmp(var, "diff.suppressblankempty") ||
 336                        /* for backwards compatibility */
 337                        !strcmp(var, "diff.suppress-blank-empty")) {
 338                diff_suppress_blank_empty = git_config_bool(var, value);
 339                return 0;
 340        }
 341
 342        if (!strcmp(var, "diff.dirstat")) {
 343                struct strbuf errmsg = STRBUF_INIT;
 344                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 345                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 346                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 347                                errmsg.buf);
 348                strbuf_release(&errmsg);
 349                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 350                return 0;
 351        }
 352
 353        if (starts_with(var, "submodule."))
 354                return parse_submodule_config_option(var, value);
 355
 356        return git_default_config(var, value, cb);
 357}
 358
 359static char *quote_two(const char *one, const char *two)
 360{
 361        int need_one = quote_c_style(one, NULL, NULL, 1);
 362        int need_two = quote_c_style(two, NULL, NULL, 1);
 363        struct strbuf res = STRBUF_INIT;
 364
 365        if (need_one + need_two) {
 366                strbuf_addch(&res, '"');
 367                quote_c_style(one, &res, NULL, 1);
 368                quote_c_style(two, &res, NULL, 1);
 369                strbuf_addch(&res, '"');
 370        } else {
 371                strbuf_addstr(&res, one);
 372                strbuf_addstr(&res, two);
 373        }
 374        return strbuf_detach(&res, NULL);
 375}
 376
 377static const char *external_diff(void)
 378{
 379        static const char *external_diff_cmd = NULL;
 380        static int done_preparing = 0;
 381
 382        if (done_preparing)
 383                return external_diff_cmd;
 384        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 385        if (!external_diff_cmd)
 386                external_diff_cmd = external_diff_cmd_cfg;
 387        done_preparing = 1;
 388        return external_diff_cmd;
 389}
 390
 391/*
 392 * Keep track of files used for diffing. Sometimes such an entry
 393 * refers to a temporary file, sometimes to an existing file, and
 394 * sometimes to "/dev/null".
 395 */
 396static struct diff_tempfile {
 397        /*
 398         * filename external diff should read from, or NULL if this
 399         * entry is currently not in use:
 400         */
 401        const char *name;
 402
 403        char hex[GIT_SHA1_HEXSZ + 1];
 404        char mode[10];
 405
 406        /*
 407         * If this diff_tempfile instance refers to a temporary file,
 408         * this tempfile object is used to manage its lifetime.
 409         */
 410        struct tempfile tempfile;
 411} diff_temp[2];
 412
 413typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 414
 415struct emit_callback {
 416        int color_diff;
 417        unsigned ws_rule;
 418        int blank_at_eof_in_preimage;
 419        int blank_at_eof_in_postimage;
 420        int lno_in_preimage;
 421        int lno_in_postimage;
 422        sane_truncate_fn truncate;
 423        const char **label_path;
 424        struct diff_words_data *diff_words;
 425        struct diff_options *opt;
 426        struct strbuf *header;
 427};
 428
 429static int count_lines(const char *data, int size)
 430{
 431        int count, ch, completely_empty = 1, nl_just_seen = 0;
 432        count = 0;
 433        while (0 < size--) {
 434                ch = *data++;
 435                if (ch == '\n') {
 436                        count++;
 437                        nl_just_seen = 1;
 438                        completely_empty = 0;
 439                }
 440                else {
 441                        nl_just_seen = 0;
 442                        completely_empty = 0;
 443                }
 444        }
 445        if (completely_empty)
 446                return 0;
 447        if (!nl_just_seen)
 448                count++; /* no trailing newline */
 449        return count;
 450}
 451
 452static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 453{
 454        if (!DIFF_FILE_VALID(one)) {
 455                mf->ptr = (char *)""; /* does not matter */
 456                mf->size = 0;
 457                return 0;
 458        }
 459        else if (diff_populate_filespec(one, 0))
 460                return -1;
 461
 462        mf->ptr = one->data;
 463        mf->size = one->size;
 464        return 0;
 465}
 466
 467/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 468static unsigned long diff_filespec_size(struct diff_filespec *one)
 469{
 470        if (!DIFF_FILE_VALID(one))
 471                return 0;
 472        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 473        return one->size;
 474}
 475
 476static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 477{
 478        char *ptr = mf->ptr;
 479        long size = mf->size;
 480        int cnt = 0;
 481
 482        if (!size)
 483                return cnt;
 484        ptr += size - 1; /* pointing at the very end */
 485        if (*ptr != '\n')
 486                ; /* incomplete line */
 487        else
 488                ptr--; /* skip the last LF */
 489        while (mf->ptr < ptr) {
 490                char *prev_eol;
 491                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 492                        if (*prev_eol == '\n')
 493                                break;
 494                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 495                        break;
 496                cnt++;
 497                ptr = prev_eol - 1;
 498        }
 499        return cnt;
 500}
 501
 502static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 503                               struct emit_callback *ecbdata)
 504{
 505        int l1, l2, at;
 506        unsigned ws_rule = ecbdata->ws_rule;
 507        l1 = count_trailing_blank(mf1, ws_rule);
 508        l2 = count_trailing_blank(mf2, ws_rule);
 509        if (l2 <= l1) {
 510                ecbdata->blank_at_eof_in_preimage = 0;
 511                ecbdata->blank_at_eof_in_postimage = 0;
 512                return;
 513        }
 514        at = count_lines(mf1->ptr, mf1->size);
 515        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 516
 517        at = count_lines(mf2->ptr, mf2->size);
 518        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 519}
 520
 521static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 522                        int first, const char *line, int len)
 523{
 524        int has_trailing_newline, has_trailing_carriage_return;
 525        int nofirst;
 526        FILE *file = o->file;
 527
 528        fputs(diff_line_prefix(o), file);
 529
 530        if (len == 0) {
 531                has_trailing_newline = (first == '\n');
 532                has_trailing_carriage_return = (!has_trailing_newline &&
 533                                                (first == '\r'));
 534                nofirst = has_trailing_newline || has_trailing_carriage_return;
 535        } else {
 536                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 537                if (has_trailing_newline)
 538                        len--;
 539                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 540                if (has_trailing_carriage_return)
 541                        len--;
 542                nofirst = 0;
 543        }
 544
 545        if (len || !nofirst) {
 546                fputs(set, file);
 547                if (!nofirst)
 548                        fputc(first, file);
 549                fwrite(line, len, 1, file);
 550                fputs(reset, file);
 551        }
 552        if (has_trailing_carriage_return)
 553                fputc('\r', file);
 554        if (has_trailing_newline)
 555                fputc('\n', file);
 556}
 557
 558static void emit_line(struct diff_options *o, const char *set, const char *reset,
 559                      const char *line, int len)
 560{
 561        emit_line_0(o, set, reset, line[0], line+1, len-1);
 562}
 563
 564static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 565{
 566        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 567              ecbdata->blank_at_eof_in_preimage &&
 568              ecbdata->blank_at_eof_in_postimage &&
 569              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 570              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 571                return 0;
 572        return ws_blank_line(line, len, ecbdata->ws_rule);
 573}
 574
 575static void emit_line_checked(const char *reset,
 576                              struct emit_callback *ecbdata,
 577                              const char *line, int len,
 578                              enum color_diff color,
 579                              unsigned ws_error_highlight,
 580                              char sign)
 581{
 582        const char *set = diff_get_color(ecbdata->color_diff, color);
 583        const char *ws = NULL;
 584
 585        if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
 586                ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 587                if (!*ws)
 588                        ws = NULL;
 589        }
 590
 591        if (!ws)
 592                emit_line_0(ecbdata->opt, set, reset, sign, line, len);
 593        else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 594                /* Blank line at EOF - paint '+' as well */
 595                emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 596        else {
 597                /* Emit just the prefix, then the rest. */
 598                emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 599                ws_check_emit(line, len, ecbdata->ws_rule,
 600                              ecbdata->opt->file, set, reset, ws);
 601        }
 602}
 603
 604static void emit_add_line(const char *reset,
 605                          struct emit_callback *ecbdata,
 606                          const char *line, int len)
 607{
 608        emit_line_checked(reset, ecbdata, line, len,
 609                          DIFF_FILE_NEW, WSEH_NEW, '+');
 610}
 611
 612static void emit_del_line(const char *reset,
 613                          struct emit_callback *ecbdata,
 614                          const char *line, int len)
 615{
 616        emit_line_checked(reset, ecbdata, line, len,
 617                          DIFF_FILE_OLD, WSEH_OLD, '-');
 618}
 619
 620static void emit_context_line(const char *reset,
 621                              struct emit_callback *ecbdata,
 622                              const char *line, int len)
 623{
 624        emit_line_checked(reset, ecbdata, line, len,
 625                          DIFF_CONTEXT, WSEH_CONTEXT, ' ');
 626}
 627
 628static void emit_hunk_header(struct emit_callback *ecbdata,
 629                             const char *line, int len)
 630{
 631        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 632        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 633        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 634        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 635        static const char atat[2] = { '@', '@' };
 636        const char *cp, *ep;
 637        struct strbuf msgbuf = STRBUF_INIT;
 638        int org_len = len;
 639        int i = 1;
 640
 641        /*
 642         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 643         * it always is at least 10 bytes long.
 644         */
 645        if (len < 10 ||
 646            memcmp(line, atat, 2) ||
 647            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 648                emit_line(ecbdata->opt, context, reset, line, len);
 649                return;
 650        }
 651        ep += 2; /* skip over @@ */
 652
 653        /* The hunk header in fraginfo color */
 654        strbuf_addstr(&msgbuf, frag);
 655        strbuf_add(&msgbuf, line, ep - line);
 656        strbuf_addstr(&msgbuf, reset);
 657
 658        /*
 659         * trailing "\r\n"
 660         */
 661        for ( ; i < 3; i++)
 662                if (line[len - i] == '\r' || line[len - i] == '\n')
 663                        len--;
 664
 665        /* blank before the func header */
 666        for (cp = ep; ep - line < len; ep++)
 667                if (*ep != ' ' && *ep != '\t')
 668                        break;
 669        if (ep != cp) {
 670                strbuf_addstr(&msgbuf, context);
 671                strbuf_add(&msgbuf, cp, ep - cp);
 672                strbuf_addstr(&msgbuf, reset);
 673        }
 674
 675        if (ep < line + len) {
 676                strbuf_addstr(&msgbuf, func);
 677                strbuf_add(&msgbuf, ep, line + len - ep);
 678                strbuf_addstr(&msgbuf, reset);
 679        }
 680
 681        strbuf_add(&msgbuf, line + len, org_len - len);
 682        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 683        strbuf_release(&msgbuf);
 684}
 685
 686static struct diff_tempfile *claim_diff_tempfile(void) {
 687        int i;
 688        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 689                if (!diff_temp[i].name)
 690                        return diff_temp + i;
 691        die("BUG: diff is failing to clean up its tempfiles");
 692}
 693
 694static void remove_tempfile(void)
 695{
 696        int i;
 697        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 698                if (is_tempfile_active(&diff_temp[i].tempfile))
 699                        delete_tempfile(&diff_temp[i].tempfile);
 700                diff_temp[i].name = NULL;
 701        }
 702}
 703
 704static void print_line_count(FILE *file, int count)
 705{
 706        switch (count) {
 707        case 0:
 708                fprintf(file, "0,0");
 709                break;
 710        case 1:
 711                fprintf(file, "1");
 712                break;
 713        default:
 714                fprintf(file, "1,%d", count);
 715                break;
 716        }
 717}
 718
 719static void emit_rewrite_lines(struct emit_callback *ecb,
 720                               int prefix, const char *data, int size)
 721{
 722        const char *endp = NULL;
 723        static const char *nneof = " No newline at end of file\n";
 724        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 725
 726        while (0 < size) {
 727                int len;
 728
 729                endp = memchr(data, '\n', size);
 730                len = endp ? (endp - data + 1) : size;
 731                if (prefix != '+') {
 732                        ecb->lno_in_preimage++;
 733                        emit_del_line(reset, ecb, data, len);
 734                } else {
 735                        ecb->lno_in_postimage++;
 736                        emit_add_line(reset, ecb, data, len);
 737                }
 738                size -= len;
 739                data += len;
 740        }
 741        if (!endp) {
 742                const char *context = diff_get_color(ecb->color_diff,
 743                                                     DIFF_CONTEXT);
 744                putc('\n', ecb->opt->file);
 745                emit_line_0(ecb->opt, context, reset, '\\',
 746                            nneof, strlen(nneof));
 747        }
 748}
 749
 750static void emit_rewrite_diff(const char *name_a,
 751                              const char *name_b,
 752                              struct diff_filespec *one,
 753                              struct diff_filespec *two,
 754                              struct userdiff_driver *textconv_one,
 755                              struct userdiff_driver *textconv_two,
 756                              struct diff_options *o)
 757{
 758        int lc_a, lc_b;
 759        const char *name_a_tab, *name_b_tab;
 760        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 761        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 762        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 763        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 764        const char *a_prefix, *b_prefix;
 765        char *data_one, *data_two;
 766        size_t size_one, size_two;
 767        struct emit_callback ecbdata;
 768        const char *line_prefix = diff_line_prefix(o);
 769
 770        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 771                a_prefix = o->b_prefix;
 772                b_prefix = o->a_prefix;
 773        } else {
 774                a_prefix = o->a_prefix;
 775                b_prefix = o->b_prefix;
 776        }
 777
 778        name_a += (*name_a == '/');
 779        name_b += (*name_b == '/');
 780        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 781        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 782
 783        strbuf_reset(&a_name);
 784        strbuf_reset(&b_name);
 785        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 786        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 787
 788        size_one = fill_textconv(textconv_one, one, &data_one);
 789        size_two = fill_textconv(textconv_two, two, &data_two);
 790
 791        memset(&ecbdata, 0, sizeof(ecbdata));
 792        ecbdata.color_diff = want_color(o->use_color);
 793        ecbdata.ws_rule = whitespace_rule(name_b);
 794        ecbdata.opt = o;
 795        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 796                mmfile_t mf1, mf2;
 797                mf1.ptr = (char *)data_one;
 798                mf2.ptr = (char *)data_two;
 799                mf1.size = size_one;
 800                mf2.size = size_two;
 801                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 802        }
 803        ecbdata.lno_in_preimage = 1;
 804        ecbdata.lno_in_postimage = 1;
 805
 806        lc_a = count_lines(data_one, size_one);
 807        lc_b = count_lines(data_two, size_two);
 808        fprintf(o->file,
 809                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 810                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 811                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 812                line_prefix, fraginfo);
 813        if (!o->irreversible_delete)
 814                print_line_count(o->file, lc_a);
 815        else
 816                fprintf(o->file, "?,?");
 817        fprintf(o->file, " +");
 818        print_line_count(o->file, lc_b);
 819        fprintf(o->file, " @@%s\n", reset);
 820        if (lc_a && !o->irreversible_delete)
 821                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 822        if (lc_b)
 823                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 824        if (textconv_one)
 825                free((char *)data_one);
 826        if (textconv_two)
 827                free((char *)data_two);
 828}
 829
 830struct diff_words_buffer {
 831        mmfile_t text;
 832        long alloc;
 833        struct diff_words_orig {
 834                const char *begin, *end;
 835        } *orig;
 836        int orig_nr, orig_alloc;
 837};
 838
 839static void diff_words_append(char *line, unsigned long len,
 840                struct diff_words_buffer *buffer)
 841{
 842        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 843        line++;
 844        len--;
 845        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 846        buffer->text.size += len;
 847        buffer->text.ptr[buffer->text.size] = '\0';
 848}
 849
 850struct diff_words_style_elem {
 851        const char *prefix;
 852        const char *suffix;
 853        const char *color; /* NULL; filled in by the setup code if
 854                            * color is enabled */
 855};
 856
 857struct diff_words_style {
 858        enum diff_words_type type;
 859        struct diff_words_style_elem new, old, ctx;
 860        const char *newline;
 861};
 862
 863static struct diff_words_style diff_words_styles[] = {
 864        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 865        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 866        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 867};
 868
 869struct diff_words_data {
 870        struct diff_words_buffer minus, plus;
 871        const char *current_plus;
 872        int last_minus;
 873        struct diff_options *opt;
 874        regex_t *word_regex;
 875        enum diff_words_type type;
 876        struct diff_words_style *style;
 877};
 878
 879static int fn_out_diff_words_write_helper(FILE *fp,
 880                                          struct diff_words_style_elem *st_el,
 881                                          const char *newline,
 882                                          size_t count, const char *buf,
 883                                          const char *line_prefix)
 884{
 885        int print = 0;
 886
 887        while (count) {
 888                char *p = memchr(buf, '\n', count);
 889                if (print)
 890                        fputs(line_prefix, fp);
 891                if (p != buf) {
 892                        if (st_el->color && fputs(st_el->color, fp) < 0)
 893                                return -1;
 894                        if (fputs(st_el->prefix, fp) < 0 ||
 895                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 896                            fputs(st_el->suffix, fp) < 0)
 897                                return -1;
 898                        if (st_el->color && *st_el->color
 899                            && fputs(GIT_COLOR_RESET, fp) < 0)
 900                                return -1;
 901                }
 902                if (!p)
 903                        return 0;
 904                if (fputs(newline, fp) < 0)
 905                        return -1;
 906                count -= p + 1 - buf;
 907                buf = p + 1;
 908                print = 1;
 909        }
 910        return 0;
 911}
 912
 913/*
 914 * '--color-words' algorithm can be described as:
 915 *
 916 *   1. collect a the minus/plus lines of a diff hunk, divided into
 917 *      minus-lines and plus-lines;
 918 *
 919 *   2. break both minus-lines and plus-lines into words and
 920 *      place them into two mmfile_t with one word for each line;
 921 *
 922 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 923 *
 924 * And for the common parts of the both file, we output the plus side text.
 925 * diff_words->current_plus is used to trace the current position of the plus file
 926 * which printed. diff_words->last_minus is used to trace the last minus word
 927 * printed.
 928 *
 929 * For '--graph' to work with '--color-words', we need to output the graph prefix
 930 * on each line of color words output. Generally, there are two conditions on
 931 * which we should output the prefix.
 932 *
 933 *   1. diff_words->last_minus == 0 &&
 934 *      diff_words->current_plus == diff_words->plus.text.ptr
 935 *
 936 *      that is: the plus text must start as a new line, and if there is no minus
 937 *      word printed, a graph prefix must be printed.
 938 *
 939 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 940 *      *(diff_words->current_plus - 1) == '\n'
 941 *
 942 *      that is: a graph prefix must be printed following a '\n'
 943 */
 944static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 945{
 946        if ((diff_words->last_minus == 0 &&
 947                diff_words->current_plus == diff_words->plus.text.ptr) ||
 948                (diff_words->current_plus > diff_words->plus.text.ptr &&
 949                *(diff_words->current_plus - 1) == '\n')) {
 950                return 1;
 951        } else {
 952                return 0;
 953        }
 954}
 955
 956static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 957{
 958        struct diff_words_data *diff_words = priv;
 959        struct diff_words_style *style = diff_words->style;
 960        int minus_first, minus_len, plus_first, plus_len;
 961        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 962        struct diff_options *opt = diff_words->opt;
 963        const char *line_prefix;
 964
 965        if (line[0] != '@' || parse_hunk_header(line, len,
 966                        &minus_first, &minus_len, &plus_first, &plus_len))
 967                return;
 968
 969        assert(opt);
 970        line_prefix = diff_line_prefix(opt);
 971
 972        /* POSIX requires that first be decremented by one if len == 0... */
 973        if (minus_len) {
 974                minus_begin = diff_words->minus.orig[minus_first].begin;
 975                minus_end =
 976                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 977        } else
 978                minus_begin = minus_end =
 979                        diff_words->minus.orig[minus_first].end;
 980
 981        if (plus_len) {
 982                plus_begin = diff_words->plus.orig[plus_first].begin;
 983                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 984        } else
 985                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 986
 987        if (color_words_output_graph_prefix(diff_words)) {
 988                fputs(line_prefix, diff_words->opt->file);
 989        }
 990        if (diff_words->current_plus != plus_begin) {
 991                fn_out_diff_words_write_helper(diff_words->opt->file,
 992                                &style->ctx, style->newline,
 993                                plus_begin - diff_words->current_plus,
 994                                diff_words->current_plus, line_prefix);
 995                if (*(plus_begin - 1) == '\n')
 996                        fputs(line_prefix, diff_words->opt->file);
 997        }
 998        if (minus_begin != minus_end) {
 999                fn_out_diff_words_write_helper(diff_words->opt->file,
1000                                &style->old, style->newline,
1001                                minus_end - minus_begin, minus_begin,
1002                                line_prefix);
1003        }
1004        if (plus_begin != plus_end) {
1005                fn_out_diff_words_write_helper(diff_words->opt->file,
1006                                &style->new, style->newline,
1007                                plus_end - plus_begin, plus_begin,
1008                                line_prefix);
1009        }
1010
1011        diff_words->current_plus = plus_end;
1012        diff_words->last_minus = minus_first;
1013}
1014
1015/* This function starts looking at *begin, and returns 0 iff a word was found. */
1016static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1017                int *begin, int *end)
1018{
1019        if (word_regex && *begin < buffer->size) {
1020                regmatch_t match[1];
1021                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1022                                 buffer->size - *begin, 1, match, 0)) {
1023                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1024                                        '\n', match[0].rm_eo - match[0].rm_so);
1025                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1026                        *begin += match[0].rm_so;
1027                        return *begin >= *end;
1028                }
1029                return -1;
1030        }
1031
1032        /* find the next word */
1033        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1034                (*begin)++;
1035        if (*begin >= buffer->size)
1036                return -1;
1037
1038        /* find the end of the word */
1039        *end = *begin + 1;
1040        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1041                (*end)++;
1042
1043        return 0;
1044}
1045
1046/*
1047 * This function splits the words in buffer->text, stores the list with
1048 * newline separator into out, and saves the offsets of the original words
1049 * in buffer->orig.
1050 */
1051static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1052                regex_t *word_regex)
1053{
1054        int i, j;
1055        long alloc = 0;
1056
1057        out->size = 0;
1058        out->ptr = NULL;
1059
1060        /* fake an empty "0th" word */
1061        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1062        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1063        buffer->orig_nr = 1;
1064
1065        for (i = 0; i < buffer->text.size; i++) {
1066                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1067                        return;
1068
1069                /* store original boundaries */
1070                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1071                                buffer->orig_alloc);
1072                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1073                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1074                buffer->orig_nr++;
1075
1076                /* store one word */
1077                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1078                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1079                out->ptr[out->size + j - i] = '\n';
1080                out->size += j - i + 1;
1081
1082                i = j - 1;
1083        }
1084}
1085
1086/* this executes the word diff on the accumulated buffers */
1087static void diff_words_show(struct diff_words_data *diff_words)
1088{
1089        xpparam_t xpp;
1090        xdemitconf_t xecfg;
1091        mmfile_t minus, plus;
1092        struct diff_words_style *style = diff_words->style;
1093
1094        struct diff_options *opt = diff_words->opt;
1095        const char *line_prefix;
1096
1097        assert(opt);
1098        line_prefix = diff_line_prefix(opt);
1099
1100        /* special case: only removal */
1101        if (!diff_words->plus.text.size) {
1102                fputs(line_prefix, diff_words->opt->file);
1103                fn_out_diff_words_write_helper(diff_words->opt->file,
1104                        &style->old, style->newline,
1105                        diff_words->minus.text.size,
1106                        diff_words->minus.text.ptr, line_prefix);
1107                diff_words->minus.text.size = 0;
1108                return;
1109        }
1110
1111        diff_words->current_plus = diff_words->plus.text.ptr;
1112        diff_words->last_minus = 0;
1113
1114        memset(&xpp, 0, sizeof(xpp));
1115        memset(&xecfg, 0, sizeof(xecfg));
1116        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1117        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1118        xpp.flags = 0;
1119        /* as only the hunk header will be parsed, we need a 0-context */
1120        xecfg.ctxlen = 0;
1121        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1122                          &xpp, &xecfg))
1123                die("unable to generate word diff");
1124        free(minus.ptr);
1125        free(plus.ptr);
1126        if (diff_words->current_plus != diff_words->plus.text.ptr +
1127                        diff_words->plus.text.size) {
1128                if (color_words_output_graph_prefix(diff_words))
1129                        fputs(line_prefix, diff_words->opt->file);
1130                fn_out_diff_words_write_helper(diff_words->opt->file,
1131                        &style->ctx, style->newline,
1132                        diff_words->plus.text.ptr + diff_words->plus.text.size
1133                        - diff_words->current_plus, diff_words->current_plus,
1134                        line_prefix);
1135        }
1136        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1137}
1138
1139/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1140static void diff_words_flush(struct emit_callback *ecbdata)
1141{
1142        if (ecbdata->diff_words->minus.text.size ||
1143            ecbdata->diff_words->plus.text.size)
1144                diff_words_show(ecbdata->diff_words);
1145}
1146
1147static void diff_filespec_load_driver(struct diff_filespec *one)
1148{
1149        /* Use already-loaded driver */
1150        if (one->driver)
1151                return;
1152
1153        if (S_ISREG(one->mode))
1154                one->driver = userdiff_find_by_path(one->path);
1155
1156        /* Fallback to default settings */
1157        if (!one->driver)
1158                one->driver = userdiff_find_by_name("default");
1159}
1160
1161static const char *userdiff_word_regex(struct diff_filespec *one)
1162{
1163        diff_filespec_load_driver(one);
1164        return one->driver->word_regex;
1165}
1166
1167static void init_diff_words_data(struct emit_callback *ecbdata,
1168                                 struct diff_options *orig_opts,
1169                                 struct diff_filespec *one,
1170                                 struct diff_filespec *two)
1171{
1172        int i;
1173        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1174        memcpy(o, orig_opts, sizeof(struct diff_options));
1175
1176        ecbdata->diff_words =
1177                xcalloc(1, sizeof(struct diff_words_data));
1178        ecbdata->diff_words->type = o->word_diff;
1179        ecbdata->diff_words->opt = o;
1180        if (!o->word_regex)
1181                o->word_regex = userdiff_word_regex(one);
1182        if (!o->word_regex)
1183                o->word_regex = userdiff_word_regex(two);
1184        if (!o->word_regex)
1185                o->word_regex = diff_word_regex_cfg;
1186        if (o->word_regex) {
1187                ecbdata->diff_words->word_regex = (regex_t *)
1188                        xmalloc(sizeof(regex_t));
1189                if (regcomp(ecbdata->diff_words->word_regex,
1190                            o->word_regex,
1191                            REG_EXTENDED | REG_NEWLINE))
1192                        die ("Invalid regular expression: %s",
1193                             o->word_regex);
1194        }
1195        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1196                if (o->word_diff == diff_words_styles[i].type) {
1197                        ecbdata->diff_words->style =
1198                                &diff_words_styles[i];
1199                        break;
1200                }
1201        }
1202        if (want_color(o->use_color)) {
1203                struct diff_words_style *st = ecbdata->diff_words->style;
1204                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1205                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1206                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1207        }
1208}
1209
1210static void free_diff_words_data(struct emit_callback *ecbdata)
1211{
1212        if (ecbdata->diff_words) {
1213                diff_words_flush(ecbdata);
1214                free (ecbdata->diff_words->opt);
1215                free (ecbdata->diff_words->minus.text.ptr);
1216                free (ecbdata->diff_words->minus.orig);
1217                free (ecbdata->diff_words->plus.text.ptr);
1218                free (ecbdata->diff_words->plus.orig);
1219                if (ecbdata->diff_words->word_regex) {
1220                        regfree(ecbdata->diff_words->word_regex);
1221                        free(ecbdata->diff_words->word_regex);
1222                }
1223                free(ecbdata->diff_words);
1224                ecbdata->diff_words = NULL;
1225        }
1226}
1227
1228const char *diff_get_color(int diff_use_color, enum color_diff ix)
1229{
1230        if (want_color(diff_use_color))
1231                return diff_colors[ix];
1232        return "";
1233}
1234
1235const char *diff_line_prefix(struct diff_options *opt)
1236{
1237        struct strbuf *msgbuf;
1238        if (!opt->output_prefix)
1239                return "";
1240
1241        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1242        return msgbuf->buf;
1243}
1244
1245static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1246{
1247        const char *cp;
1248        unsigned long allot;
1249        size_t l = len;
1250
1251        if (ecb->truncate)
1252                return ecb->truncate(line, len);
1253        cp = line;
1254        allot = l;
1255        while (0 < l) {
1256                (void) utf8_width(&cp, &l);
1257                if (!cp)
1258                        break; /* truncated in the middle? */
1259        }
1260        return allot - l;
1261}
1262
1263static void find_lno(const char *line, struct emit_callback *ecbdata)
1264{
1265        const char *p;
1266        ecbdata->lno_in_preimage = 0;
1267        ecbdata->lno_in_postimage = 0;
1268        p = strchr(line, '-');
1269        if (!p)
1270                return; /* cannot happen */
1271        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1272        p = strchr(p, '+');
1273        if (!p)
1274                return; /* cannot happen */
1275        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1276}
1277
1278static void fn_out_consume(void *priv, char *line, unsigned long len)
1279{
1280        struct emit_callback *ecbdata = priv;
1281        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1282        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1283        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1284        struct diff_options *o = ecbdata->opt;
1285        const char *line_prefix = diff_line_prefix(o);
1286
1287        o->found_changes = 1;
1288
1289        if (ecbdata->header) {
1290                fprintf(o->file, "%s", ecbdata->header->buf);
1291                strbuf_reset(ecbdata->header);
1292                ecbdata->header = NULL;
1293        }
1294
1295        if (ecbdata->label_path[0]) {
1296                const char *name_a_tab, *name_b_tab;
1297
1298                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1299                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1300
1301                fprintf(o->file, "%s%s--- %s%s%s\n",
1302                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1303                fprintf(o->file, "%s%s+++ %s%s%s\n",
1304                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1305                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1306        }
1307
1308        if (diff_suppress_blank_empty
1309            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1310                line[0] = '\n';
1311                len = 1;
1312        }
1313
1314        if (line[0] == '@') {
1315                if (ecbdata->diff_words)
1316                        diff_words_flush(ecbdata);
1317                len = sane_truncate_line(ecbdata, line, len);
1318                find_lno(line, ecbdata);
1319                emit_hunk_header(ecbdata, line, len);
1320                if (line[len-1] != '\n')
1321                        putc('\n', o->file);
1322                return;
1323        }
1324
1325        if (ecbdata->diff_words) {
1326                if (line[0] == '-') {
1327                        diff_words_append(line, len,
1328                                          &ecbdata->diff_words->minus);
1329                        return;
1330                } else if (line[0] == '+') {
1331                        diff_words_append(line, len,
1332                                          &ecbdata->diff_words->plus);
1333                        return;
1334                } else if (starts_with(line, "\\ ")) {
1335                        /*
1336                         * Eat the "no newline at eof" marker as if we
1337                         * saw a "+" or "-" line with nothing on it,
1338                         * and return without diff_words_flush() to
1339                         * defer processing. If this is the end of
1340                         * preimage, more "+" lines may come after it.
1341                         */
1342                        return;
1343                }
1344                diff_words_flush(ecbdata);
1345                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1346                        emit_line(o, context, reset, line, len);
1347                        fputs("~\n", o->file);
1348                } else {
1349                        /*
1350                         * Skip the prefix character, if any.  With
1351                         * diff_suppress_blank_empty, there may be
1352                         * none.
1353                         */
1354                        if (line[0] != '\n') {
1355                              line++;
1356                              len--;
1357                        }
1358                        emit_line(o, context, reset, line, len);
1359                }
1360                return;
1361        }
1362
1363        switch (line[0]) {
1364        case '+':
1365                ecbdata->lno_in_postimage++;
1366                emit_add_line(reset, ecbdata, line + 1, len - 1);
1367                break;
1368        case '-':
1369                ecbdata->lno_in_preimage++;
1370                emit_del_line(reset, ecbdata, line + 1, len - 1);
1371                break;
1372        case ' ':
1373                ecbdata->lno_in_postimage++;
1374                ecbdata->lno_in_preimage++;
1375                emit_context_line(reset, ecbdata, line + 1, len - 1);
1376                break;
1377        default:
1378                /* incomplete line at the end */
1379                ecbdata->lno_in_preimage++;
1380                emit_line(o, diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
1381                          reset, line, len);
1382                break;
1383        }
1384}
1385
1386static char *pprint_rename(const char *a, const char *b)
1387{
1388        const char *old = a;
1389        const char *new = b;
1390        struct strbuf name = STRBUF_INIT;
1391        int pfx_length, sfx_length;
1392        int pfx_adjust_for_slash;
1393        int len_a = strlen(a);
1394        int len_b = strlen(b);
1395        int a_midlen, b_midlen;
1396        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1397        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1398
1399        if (qlen_a || qlen_b) {
1400                quote_c_style(a, &name, NULL, 0);
1401                strbuf_addstr(&name, " => ");
1402                quote_c_style(b, &name, NULL, 0);
1403                return strbuf_detach(&name, NULL);
1404        }
1405
1406        /* Find common prefix */
1407        pfx_length = 0;
1408        while (*old && *new && *old == *new) {
1409                if (*old == '/')
1410                        pfx_length = old - a + 1;
1411                old++;
1412                new++;
1413        }
1414
1415        /* Find common suffix */
1416        old = a + len_a;
1417        new = b + len_b;
1418        sfx_length = 0;
1419        /*
1420         * If there is a common prefix, it must end in a slash.  In
1421         * that case we let this loop run 1 into the prefix to see the
1422         * same slash.
1423         *
1424         * If there is no common prefix, we cannot do this as it would
1425         * underrun the input strings.
1426         */
1427        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1428        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1429               b + pfx_length - pfx_adjust_for_slash <= new &&
1430               *old == *new) {
1431                if (*old == '/')
1432                        sfx_length = len_a - (old - a);
1433                old--;
1434                new--;
1435        }
1436
1437        /*
1438         * pfx{mid-a => mid-b}sfx
1439         * {pfx-a => pfx-b}sfx
1440         * pfx{sfx-a => sfx-b}
1441         * name-a => name-b
1442         */
1443        a_midlen = len_a - pfx_length - sfx_length;
1444        b_midlen = len_b - pfx_length - sfx_length;
1445        if (a_midlen < 0)
1446                a_midlen = 0;
1447        if (b_midlen < 0)
1448                b_midlen = 0;
1449
1450        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1451        if (pfx_length + sfx_length) {
1452                strbuf_add(&name, a, pfx_length);
1453                strbuf_addch(&name, '{');
1454        }
1455        strbuf_add(&name, a + pfx_length, a_midlen);
1456        strbuf_addstr(&name, " => ");
1457        strbuf_add(&name, b + pfx_length, b_midlen);
1458        if (pfx_length + sfx_length) {
1459                strbuf_addch(&name, '}');
1460                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1461        }
1462        return strbuf_detach(&name, NULL);
1463}
1464
1465struct diffstat_t {
1466        int nr;
1467        int alloc;
1468        struct diffstat_file {
1469                char *from_name;
1470                char *name;
1471                char *print_name;
1472                unsigned is_unmerged:1;
1473                unsigned is_binary:1;
1474                unsigned is_renamed:1;
1475                unsigned is_interesting:1;
1476                uintmax_t added, deleted;
1477        } **files;
1478};
1479
1480static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1481                                          const char *name_a,
1482                                          const char *name_b)
1483{
1484        struct diffstat_file *x;
1485        x = xcalloc(1, sizeof(*x));
1486        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1487        diffstat->files[diffstat->nr++] = x;
1488        if (name_b) {
1489                x->from_name = xstrdup(name_a);
1490                x->name = xstrdup(name_b);
1491                x->is_renamed = 1;
1492        }
1493        else {
1494                x->from_name = NULL;
1495                x->name = xstrdup(name_a);
1496        }
1497        return x;
1498}
1499
1500static void diffstat_consume(void *priv, char *line, unsigned long len)
1501{
1502        struct diffstat_t *diffstat = priv;
1503        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1504
1505        if (line[0] == '+')
1506                x->added++;
1507        else if (line[0] == '-')
1508                x->deleted++;
1509}
1510
1511const char mime_boundary_leader[] = "------------";
1512
1513static int scale_linear(int it, int width, int max_change)
1514{
1515        if (!it)
1516                return 0;
1517        /*
1518         * make sure that at least one '-' or '+' is printed if
1519         * there is any change to this path. The easiest way is to
1520         * scale linearly as if the alloted width is one column shorter
1521         * than it is, and then add 1 to the result.
1522         */
1523        return 1 + (it * (width - 1) / max_change);
1524}
1525
1526static void show_name(FILE *file,
1527                      const char *prefix, const char *name, int len)
1528{
1529        fprintf(file, " %s%-*s |", prefix, len, name);
1530}
1531
1532static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1533{
1534        if (cnt <= 0)
1535                return;
1536        fprintf(file, "%s", set);
1537        while (cnt--)
1538                putc(ch, file);
1539        fprintf(file, "%s", reset);
1540}
1541
1542static void fill_print_name(struct diffstat_file *file)
1543{
1544        char *pname;
1545
1546        if (file->print_name)
1547                return;
1548
1549        if (!file->is_renamed) {
1550                struct strbuf buf = STRBUF_INIT;
1551                if (quote_c_style(file->name, &buf, NULL, 0)) {
1552                        pname = strbuf_detach(&buf, NULL);
1553                } else {
1554                        pname = file->name;
1555                        strbuf_release(&buf);
1556                }
1557        } else {
1558                pname = pprint_rename(file->from_name, file->name);
1559        }
1560        file->print_name = pname;
1561}
1562
1563int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1564{
1565        struct strbuf sb = STRBUF_INIT;
1566        int ret;
1567
1568        if (!files) {
1569                assert(insertions == 0 && deletions == 0);
1570                return fprintf(fp, "%s\n", " 0 files changed");
1571        }
1572
1573        strbuf_addf(&sb,
1574                    (files == 1) ? " %d file changed" : " %d files changed",
1575                    files);
1576
1577        /*
1578         * For binary diff, the caller may want to print "x files
1579         * changed" with insertions == 0 && deletions == 0.
1580         *
1581         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1582         * is probably less confusing (i.e skip over "2 files changed
1583         * but nothing about added/removed lines? Is this a bug in Git?").
1584         */
1585        if (insertions || deletions == 0) {
1586                strbuf_addf(&sb,
1587                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1588                            insertions);
1589        }
1590
1591        if (deletions || insertions == 0) {
1592                strbuf_addf(&sb,
1593                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1594                            deletions);
1595        }
1596        strbuf_addch(&sb, '\n');
1597        ret = fputs(sb.buf, fp);
1598        strbuf_release(&sb);
1599        return ret;
1600}
1601
1602static void show_stats(struct diffstat_t *data, struct diff_options *options)
1603{
1604        int i, len, add, del, adds = 0, dels = 0;
1605        uintmax_t max_change = 0, max_len = 0;
1606        int total_files = data->nr, count;
1607        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1608        const char *reset, *add_c, *del_c;
1609        const char *line_prefix = "";
1610        int extra_shown = 0;
1611
1612        if (data->nr == 0)
1613                return;
1614
1615        line_prefix = diff_line_prefix(options);
1616        count = options->stat_count ? options->stat_count : data->nr;
1617
1618        reset = diff_get_color_opt(options, DIFF_RESET);
1619        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1620        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1621
1622        /*
1623         * Find the longest filename and max number of changes
1624         */
1625        for (i = 0; (i < count) && (i < data->nr); i++) {
1626                struct diffstat_file *file = data->files[i];
1627                uintmax_t change = file->added + file->deleted;
1628
1629                if (!file->is_interesting && (change == 0)) {
1630                        count++; /* not shown == room for one more */
1631                        continue;
1632                }
1633                fill_print_name(file);
1634                len = strlen(file->print_name);
1635                if (max_len < len)
1636                        max_len = len;
1637
1638                if (file->is_unmerged) {
1639                        /* "Unmerged" is 8 characters */
1640                        bin_width = bin_width < 8 ? 8 : bin_width;
1641                        continue;
1642                }
1643                if (file->is_binary) {
1644                        /* "Bin XXX -> YYY bytes" */
1645                        int w = 14 + decimal_width(file->added)
1646                                + decimal_width(file->deleted);
1647                        bin_width = bin_width < w ? w : bin_width;
1648                        /* Display change counts aligned with "Bin" */
1649                        number_width = 3;
1650                        continue;
1651                }
1652
1653                if (max_change < change)
1654                        max_change = change;
1655        }
1656        count = i; /* where we can stop scanning in data->files[] */
1657
1658        /*
1659         * We have width = stat_width or term_columns() columns total.
1660         * We want a maximum of min(max_len, stat_name_width) for the name part.
1661         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1662         * We also need 1 for " " and 4 + decimal_width(max_change)
1663         * for " | NNNN " and one the empty column at the end, altogether
1664         * 6 + decimal_width(max_change).
1665         *
1666         * If there's not enough space, we will use the smaller of
1667         * stat_name_width (if set) and 5/8*width for the filename,
1668         * and the rest for constant elements + graph part, but no more
1669         * than stat_graph_width for the graph part.
1670         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1671         * for the standard terminal size).
1672         *
1673         * In other words: stat_width limits the maximum width, and
1674         * stat_name_width fixes the maximum width of the filename,
1675         * and is also used to divide available columns if there
1676         * aren't enough.
1677         *
1678         * Binary files are displayed with "Bin XXX -> YYY bytes"
1679         * instead of the change count and graph. This part is treated
1680         * similarly to the graph part, except that it is not
1681         * "scaled". If total width is too small to accommodate the
1682         * guaranteed minimum width of the filename part and the
1683         * separators and this message, this message will "overflow"
1684         * making the line longer than the maximum width.
1685         */
1686
1687        if (options->stat_width == -1)
1688                width = term_columns() - strlen(line_prefix);
1689        else
1690                width = options->stat_width ? options->stat_width : 80;
1691        number_width = decimal_width(max_change) > number_width ?
1692                decimal_width(max_change) : number_width;
1693
1694        if (options->stat_graph_width == -1)
1695                options->stat_graph_width = diff_stat_graph_width;
1696
1697        /*
1698         * Guarantee 3/8*16==6 for the graph part
1699         * and 5/8*16==10 for the filename part
1700         */
1701        if (width < 16 + 6 + number_width)
1702                width = 16 + 6 + number_width;
1703
1704        /*
1705         * First assign sizes that are wanted, ignoring available width.
1706         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1707         * starting from "XXX" should fit in graph_width.
1708         */
1709        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1710        if (options->stat_graph_width &&
1711            options->stat_graph_width < graph_width)
1712                graph_width = options->stat_graph_width;
1713
1714        name_width = (options->stat_name_width > 0 &&
1715                      options->stat_name_width < max_len) ?
1716                options->stat_name_width : max_len;
1717
1718        /*
1719         * Adjust adjustable widths not to exceed maximum width
1720         */
1721        if (name_width + number_width + 6 + graph_width > width) {
1722                if (graph_width > width * 3/8 - number_width - 6) {
1723                        graph_width = width * 3/8 - number_width - 6;
1724                        if (graph_width < 6)
1725                                graph_width = 6;
1726                }
1727
1728                if (options->stat_graph_width &&
1729                    graph_width > options->stat_graph_width)
1730                        graph_width = options->stat_graph_width;
1731                if (name_width > width - number_width - 6 - graph_width)
1732                        name_width = width - number_width - 6 - graph_width;
1733                else
1734                        graph_width = width - number_width - 6 - name_width;
1735        }
1736
1737        /*
1738         * From here name_width is the width of the name area,
1739         * and graph_width is the width of the graph area.
1740         * max_change is used to scale graph properly.
1741         */
1742        for (i = 0; i < count; i++) {
1743                const char *prefix = "";
1744                struct diffstat_file *file = data->files[i];
1745                char *name = file->print_name;
1746                uintmax_t added = file->added;
1747                uintmax_t deleted = file->deleted;
1748                int name_len;
1749
1750                if (!file->is_interesting && (added + deleted == 0))
1751                        continue;
1752
1753                /*
1754                 * "scale" the filename
1755                 */
1756                len = name_width;
1757                name_len = strlen(name);
1758                if (name_width < name_len) {
1759                        char *slash;
1760                        prefix = "...";
1761                        len -= 3;
1762                        name += name_len - len;
1763                        slash = strchr(name, '/');
1764                        if (slash)
1765                                name = slash;
1766                }
1767
1768                if (file->is_binary) {
1769                        fprintf(options->file, "%s", line_prefix);
1770                        show_name(options->file, prefix, name, len);
1771                        fprintf(options->file, " %*s", number_width, "Bin");
1772                        if (!added && !deleted) {
1773                                putc('\n', options->file);
1774                                continue;
1775                        }
1776                        fprintf(options->file, " %s%"PRIuMAX"%s",
1777                                del_c, deleted, reset);
1778                        fprintf(options->file, " -> ");
1779                        fprintf(options->file, "%s%"PRIuMAX"%s",
1780                                add_c, added, reset);
1781                        fprintf(options->file, " bytes");
1782                        fprintf(options->file, "\n");
1783                        continue;
1784                }
1785                else if (file->is_unmerged) {
1786                        fprintf(options->file, "%s", line_prefix);
1787                        show_name(options->file, prefix, name, len);
1788                        fprintf(options->file, " Unmerged\n");
1789                        continue;
1790                }
1791
1792                /*
1793                 * scale the add/delete
1794                 */
1795                add = added;
1796                del = deleted;
1797
1798                if (graph_width <= max_change) {
1799                        int total = scale_linear(add + del, graph_width, max_change);
1800                        if (total < 2 && add && del)
1801                                /* width >= 2 due to the sanity check */
1802                                total = 2;
1803                        if (add < del) {
1804                                add = scale_linear(add, graph_width, max_change);
1805                                del = total - add;
1806                        } else {
1807                                del = scale_linear(del, graph_width, max_change);
1808                                add = total - del;
1809                        }
1810                }
1811                fprintf(options->file, "%s", line_prefix);
1812                show_name(options->file, prefix, name, len);
1813                fprintf(options->file, " %*"PRIuMAX"%s",
1814                        number_width, added + deleted,
1815                        added + deleted ? " " : "");
1816                show_graph(options->file, '+', add, add_c, reset);
1817                show_graph(options->file, '-', del, del_c, reset);
1818                fprintf(options->file, "\n");
1819        }
1820
1821        for (i = 0; i < data->nr; i++) {
1822                struct diffstat_file *file = data->files[i];
1823                uintmax_t added = file->added;
1824                uintmax_t deleted = file->deleted;
1825
1826                if (file->is_unmerged ||
1827                    (!file->is_interesting && (added + deleted == 0))) {
1828                        total_files--;
1829                        continue;
1830                }
1831
1832                if (!file->is_binary) {
1833                        adds += added;
1834                        dels += deleted;
1835                }
1836                if (i < count)
1837                        continue;
1838                if (!extra_shown)
1839                        fprintf(options->file, "%s ...\n", line_prefix);
1840                extra_shown = 1;
1841        }
1842        fprintf(options->file, "%s", line_prefix);
1843        print_stat_summary(options->file, total_files, adds, dels);
1844}
1845
1846static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1847{
1848        int i, adds = 0, dels = 0, total_files = data->nr;
1849
1850        if (data->nr == 0)
1851                return;
1852
1853        for (i = 0; i < data->nr; i++) {
1854                int added = data->files[i]->added;
1855                int deleted= data->files[i]->deleted;
1856
1857                if (data->files[i]->is_unmerged ||
1858                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1859                        total_files--;
1860                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1861                        adds += added;
1862                        dels += deleted;
1863                }
1864        }
1865        fprintf(options->file, "%s", diff_line_prefix(options));
1866        print_stat_summary(options->file, total_files, adds, dels);
1867}
1868
1869static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1870{
1871        int i;
1872
1873        if (data->nr == 0)
1874                return;
1875
1876        for (i = 0; i < data->nr; i++) {
1877                struct diffstat_file *file = data->files[i];
1878
1879                fprintf(options->file, "%s", diff_line_prefix(options));
1880
1881                if (file->is_binary)
1882                        fprintf(options->file, "-\t-\t");
1883                else
1884                        fprintf(options->file,
1885                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1886                                file->added, file->deleted);
1887                if (options->line_termination) {
1888                        fill_print_name(file);
1889                        if (!file->is_renamed)
1890                                write_name_quoted(file->name, options->file,
1891                                                  options->line_termination);
1892                        else {
1893                                fputs(file->print_name, options->file);
1894                                putc(options->line_termination, options->file);
1895                        }
1896                } else {
1897                        if (file->is_renamed) {
1898                                putc('\0', options->file);
1899                                write_name_quoted(file->from_name, options->file, '\0');
1900                        }
1901                        write_name_quoted(file->name, options->file, '\0');
1902                }
1903        }
1904}
1905
1906struct dirstat_file {
1907        const char *name;
1908        unsigned long changed;
1909};
1910
1911struct dirstat_dir {
1912        struct dirstat_file *files;
1913        int alloc, nr, permille, cumulative;
1914};
1915
1916static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1917                unsigned long changed, const char *base, int baselen)
1918{
1919        unsigned long this_dir = 0;
1920        unsigned int sources = 0;
1921        const char *line_prefix = diff_line_prefix(opt);
1922
1923        while (dir->nr) {
1924                struct dirstat_file *f = dir->files;
1925                int namelen = strlen(f->name);
1926                unsigned long this;
1927                char *slash;
1928
1929                if (namelen < baselen)
1930                        break;
1931                if (memcmp(f->name, base, baselen))
1932                        break;
1933                slash = strchr(f->name + baselen, '/');
1934                if (slash) {
1935                        int newbaselen = slash + 1 - f->name;
1936                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1937                        sources++;
1938                } else {
1939                        this = f->changed;
1940                        dir->files++;
1941                        dir->nr--;
1942                        sources += 2;
1943                }
1944                this_dir += this;
1945        }
1946
1947        /*
1948         * We don't report dirstat's for
1949         *  - the top level
1950         *  - or cases where everything came from a single directory
1951         *    under this directory (sources == 1).
1952         */
1953        if (baselen && sources != 1) {
1954                if (this_dir) {
1955                        int permille = this_dir * 1000 / changed;
1956                        if (permille >= dir->permille) {
1957                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1958                                        permille / 10, permille % 10, baselen, base);
1959                                if (!dir->cumulative)
1960                                        return 0;
1961                        }
1962                }
1963        }
1964        return this_dir;
1965}
1966
1967static int dirstat_compare(const void *_a, const void *_b)
1968{
1969        const struct dirstat_file *a = _a;
1970        const struct dirstat_file *b = _b;
1971        return strcmp(a->name, b->name);
1972}
1973
1974static void show_dirstat(struct diff_options *options)
1975{
1976        int i;
1977        unsigned long changed;
1978        struct dirstat_dir dir;
1979        struct diff_queue_struct *q = &diff_queued_diff;
1980
1981        dir.files = NULL;
1982        dir.alloc = 0;
1983        dir.nr = 0;
1984        dir.permille = options->dirstat_permille;
1985        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1986
1987        changed = 0;
1988        for (i = 0; i < q->nr; i++) {
1989                struct diff_filepair *p = q->queue[i];
1990                const char *name;
1991                unsigned long copied, added, damage;
1992                int content_changed;
1993
1994                name = p->two->path ? p->two->path : p->one->path;
1995
1996                if (p->one->oid_valid && p->two->oid_valid)
1997                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
1998                else
1999                        content_changed = 1;
2000
2001                if (!content_changed) {
2002                        /*
2003                         * The SHA1 has not changed, so pre-/post-content is
2004                         * identical. We can therefore skip looking at the
2005                         * file contents altogether.
2006                         */
2007                        damage = 0;
2008                        goto found_damage;
2009                }
2010
2011                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2012                        /*
2013                         * In --dirstat-by-file mode, we don't really need to
2014                         * look at the actual file contents at all.
2015                         * The fact that the SHA1 changed is enough for us to
2016                         * add this file to the list of results
2017                         * (with each file contributing equal damage).
2018                         */
2019                        damage = 1;
2020                        goto found_damage;
2021                }
2022
2023                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2024                        diff_populate_filespec(p->one, 0);
2025                        diff_populate_filespec(p->two, 0);
2026                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2027                                               &copied, &added);
2028                        diff_free_filespec_data(p->one);
2029                        diff_free_filespec_data(p->two);
2030                } else if (DIFF_FILE_VALID(p->one)) {
2031                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2032                        copied = added = 0;
2033                        diff_free_filespec_data(p->one);
2034                } else if (DIFF_FILE_VALID(p->two)) {
2035                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2036                        copied = 0;
2037                        added = p->two->size;
2038                        diff_free_filespec_data(p->two);
2039                } else
2040                        continue;
2041
2042                /*
2043                 * Original minus copied is the removed material,
2044                 * added is the new material.  They are both damages
2045                 * made to the preimage.
2046                 * If the resulting damage is zero, we know that
2047                 * diffcore_count_changes() considers the two entries to
2048                 * be identical, but since content_changed is true, we
2049                 * know that there must have been _some_ kind of change,
2050                 * so we force all entries to have damage > 0.
2051                 */
2052                damage = (p->one->size - copied) + added;
2053                if (!damage)
2054                        damage = 1;
2055
2056found_damage:
2057                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2058                dir.files[dir.nr].name = name;
2059                dir.files[dir.nr].changed = damage;
2060                changed += damage;
2061                dir.nr++;
2062        }
2063
2064        /* This can happen even with many files, if everything was renames */
2065        if (!changed)
2066                return;
2067
2068        /* Show all directories with more than x% of the changes */
2069        QSORT(dir.files, dir.nr, dirstat_compare);
2070        gather_dirstat(options, &dir, changed, "", 0);
2071}
2072
2073static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2074{
2075        int i;
2076        unsigned long changed;
2077        struct dirstat_dir dir;
2078
2079        if (data->nr == 0)
2080                return;
2081
2082        dir.files = NULL;
2083        dir.alloc = 0;
2084        dir.nr = 0;
2085        dir.permille = options->dirstat_permille;
2086        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2087
2088        changed = 0;
2089        for (i = 0; i < data->nr; i++) {
2090                struct diffstat_file *file = data->files[i];
2091                unsigned long damage = file->added + file->deleted;
2092                if (file->is_binary)
2093                        /*
2094                         * binary files counts bytes, not lines. Must find some
2095                         * way to normalize binary bytes vs. textual lines.
2096                         * The following heuristic assumes that there are 64
2097                         * bytes per "line".
2098                         * This is stupid and ugly, but very cheap...
2099                         */
2100                        damage = (damage + 63) / 64;
2101                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2102                dir.files[dir.nr].name = file->name;
2103                dir.files[dir.nr].changed = damage;
2104                changed += damage;
2105                dir.nr++;
2106        }
2107
2108        /* This can happen even with many files, if everything was renames */
2109        if (!changed)
2110                return;
2111
2112        /* Show all directories with more than x% of the changes */
2113        QSORT(dir.files, dir.nr, dirstat_compare);
2114        gather_dirstat(options, &dir, changed, "", 0);
2115}
2116
2117static void free_diffstat_info(struct diffstat_t *diffstat)
2118{
2119        int i;
2120        for (i = 0; i < diffstat->nr; i++) {
2121                struct diffstat_file *f = diffstat->files[i];
2122                if (f->name != f->print_name)
2123                        free(f->print_name);
2124                free(f->name);
2125                free(f->from_name);
2126                free(f);
2127        }
2128        free(diffstat->files);
2129}
2130
2131struct checkdiff_t {
2132        const char *filename;
2133        int lineno;
2134        int conflict_marker_size;
2135        struct diff_options *o;
2136        unsigned ws_rule;
2137        unsigned status;
2138};
2139
2140static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2141{
2142        char firstchar;
2143        int cnt;
2144
2145        if (len < marker_size + 1)
2146                return 0;
2147        firstchar = line[0];
2148        switch (firstchar) {
2149        case '=': case '>': case '<': case '|':
2150                break;
2151        default:
2152                return 0;
2153        }
2154        for (cnt = 1; cnt < marker_size; cnt++)
2155                if (line[cnt] != firstchar)
2156                        return 0;
2157        /* line[1] thru line[marker_size-1] are same as firstchar */
2158        if (len < marker_size + 1 || !isspace(line[marker_size]))
2159                return 0;
2160        return 1;
2161}
2162
2163static void checkdiff_consume(void *priv, char *line, unsigned long len)
2164{
2165        struct checkdiff_t *data = priv;
2166        int marker_size = data->conflict_marker_size;
2167        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2168        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2169        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2170        char *err;
2171        const char *line_prefix;
2172
2173        assert(data->o);
2174        line_prefix = diff_line_prefix(data->o);
2175
2176        if (line[0] == '+') {
2177                unsigned bad;
2178                data->lineno++;
2179                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2180                        data->status |= 1;
2181                        fprintf(data->o->file,
2182                                "%s%s:%d: leftover conflict marker\n",
2183                                line_prefix, data->filename, data->lineno);
2184                }
2185                bad = ws_check(line + 1, len - 1, data->ws_rule);
2186                if (!bad)
2187                        return;
2188                data->status |= bad;
2189                err = whitespace_error_string(bad);
2190                fprintf(data->o->file, "%s%s:%d: %s.\n",
2191                        line_prefix, data->filename, data->lineno, err);
2192                free(err);
2193                emit_line(data->o, set, reset, line, 1);
2194                ws_check_emit(line + 1, len - 1, data->ws_rule,
2195                              data->o->file, set, reset, ws);
2196        } else if (line[0] == ' ') {
2197                data->lineno++;
2198        } else if (line[0] == '@') {
2199                char *plus = strchr(line, '+');
2200                if (plus)
2201                        data->lineno = strtol(plus, NULL, 10) - 1;
2202                else
2203                        die("invalid diff");
2204        }
2205}
2206
2207static unsigned char *deflate_it(char *data,
2208                                 unsigned long size,
2209                                 unsigned long *result_size)
2210{
2211        int bound;
2212        unsigned char *deflated;
2213        git_zstream stream;
2214
2215        git_deflate_init(&stream, zlib_compression_level);
2216        bound = git_deflate_bound(&stream, size);
2217        deflated = xmalloc(bound);
2218        stream.next_out = deflated;
2219        stream.avail_out = bound;
2220
2221        stream.next_in = (unsigned char *)data;
2222        stream.avail_in = size;
2223        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2224                ; /* nothing */
2225        git_deflate_end(&stream);
2226        *result_size = stream.total_out;
2227        return deflated;
2228}
2229
2230static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2231                                  const char *prefix)
2232{
2233        void *cp;
2234        void *delta;
2235        void *deflated;
2236        void *data;
2237        unsigned long orig_size;
2238        unsigned long delta_size;
2239        unsigned long deflate_size;
2240        unsigned long data_size;
2241
2242        /* We could do deflated delta, or we could do just deflated two,
2243         * whichever is smaller.
2244         */
2245        delta = NULL;
2246        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2247        if (one->size && two->size) {
2248                delta = diff_delta(one->ptr, one->size,
2249                                   two->ptr, two->size,
2250                                   &delta_size, deflate_size);
2251                if (delta) {
2252                        void *to_free = delta;
2253                        orig_size = delta_size;
2254                        delta = deflate_it(delta, delta_size, &delta_size);
2255                        free(to_free);
2256                }
2257        }
2258
2259        if (delta && delta_size < deflate_size) {
2260                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2261                free(deflated);
2262                data = delta;
2263                data_size = delta_size;
2264        }
2265        else {
2266                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2267                free(delta);
2268                data = deflated;
2269                data_size = deflate_size;
2270        }
2271
2272        /* emit data encoded in base85 */
2273        cp = data;
2274        while (data_size) {
2275                int bytes = (52 < data_size) ? 52 : data_size;
2276                char line[70];
2277                data_size -= bytes;
2278                if (bytes <= 26)
2279                        line[0] = bytes + 'A' - 1;
2280                else
2281                        line[0] = bytes - 26 + 'a' - 1;
2282                encode_85(line + 1, cp, bytes);
2283                cp = (char *) cp + bytes;
2284                fprintf(file, "%s", prefix);
2285                fputs(line, file);
2286                fputc('\n', file);
2287        }
2288        fprintf(file, "%s\n", prefix);
2289        free(data);
2290}
2291
2292static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2293                             const char *prefix)
2294{
2295        fprintf(file, "%sGIT binary patch\n", prefix);
2296        emit_binary_diff_body(file, one, two, prefix);
2297        emit_binary_diff_body(file, two, one, prefix);
2298}
2299
2300int diff_filespec_is_binary(struct diff_filespec *one)
2301{
2302        if (one->is_binary == -1) {
2303                diff_filespec_load_driver(one);
2304                if (one->driver->binary != -1)
2305                        one->is_binary = one->driver->binary;
2306                else {
2307                        if (!one->data && DIFF_FILE_VALID(one))
2308                                diff_populate_filespec(one, CHECK_BINARY);
2309                        if (one->is_binary == -1 && one->data)
2310                                one->is_binary = buffer_is_binary(one->data,
2311                                                one->size);
2312                        if (one->is_binary == -1)
2313                                one->is_binary = 0;
2314                }
2315        }
2316        return one->is_binary;
2317}
2318
2319static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2320{
2321        diff_filespec_load_driver(one);
2322        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2323}
2324
2325void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2326{
2327        if (!options->a_prefix)
2328                options->a_prefix = a;
2329        if (!options->b_prefix)
2330                options->b_prefix = b;
2331}
2332
2333struct userdiff_driver *get_textconv(struct diff_filespec *one)
2334{
2335        if (!DIFF_FILE_VALID(one))
2336                return NULL;
2337
2338        diff_filespec_load_driver(one);
2339        return userdiff_get_textconv(one->driver);
2340}
2341
2342static void builtin_diff(const char *name_a,
2343                         const char *name_b,
2344                         struct diff_filespec *one,
2345                         struct diff_filespec *two,
2346                         const char *xfrm_msg,
2347                         int must_show_header,
2348                         struct diff_options *o,
2349                         int complete_rewrite)
2350{
2351        mmfile_t mf1, mf2;
2352        const char *lbl[2];
2353        char *a_one, *b_two;
2354        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2355        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2356        const char *a_prefix, *b_prefix;
2357        struct userdiff_driver *textconv_one = NULL;
2358        struct userdiff_driver *textconv_two = NULL;
2359        struct strbuf header = STRBUF_INIT;
2360        const char *line_prefix = diff_line_prefix(o);
2361
2362        diff_set_mnemonic_prefix(o, "a/", "b/");
2363        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2364                a_prefix = o->b_prefix;
2365                b_prefix = o->a_prefix;
2366        } else {
2367                a_prefix = o->a_prefix;
2368                b_prefix = o->b_prefix;
2369        }
2370
2371        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2372            (!one->mode || S_ISGITLINK(one->mode)) &&
2373            (!two->mode || S_ISGITLINK(two->mode))) {
2374                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2375                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2376                show_submodule_summary(o->file, one->path ? one->path : two->path,
2377                                line_prefix,
2378                                &one->oid, &two->oid,
2379                                two->dirty_submodule,
2380                                meta, del, add, reset);
2381                return;
2382        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2383                   (!one->mode || S_ISGITLINK(one->mode)) &&
2384                   (!two->mode || S_ISGITLINK(two->mode))) {
2385                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2386                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2387                show_submodule_inline_diff(o->file, one->path ? one->path : two->path,
2388                                line_prefix,
2389                                &one->oid, &two->oid,
2390                                two->dirty_submodule,
2391                                meta, del, add, reset, o);
2392                return;
2393        }
2394
2395        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2396                textconv_one = get_textconv(one);
2397                textconv_two = get_textconv(two);
2398        }
2399
2400        /* Never use a non-valid filename anywhere if at all possible */
2401        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2402        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2403
2404        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2405        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2406        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2407        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2408        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2409        if (lbl[0][0] == '/') {
2410                /* /dev/null */
2411                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2412                if (xfrm_msg)
2413                        strbuf_addstr(&header, xfrm_msg);
2414                must_show_header = 1;
2415        }
2416        else if (lbl[1][0] == '/') {
2417                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2418                if (xfrm_msg)
2419                        strbuf_addstr(&header, xfrm_msg);
2420                must_show_header = 1;
2421        }
2422        else {
2423                if (one->mode != two->mode) {
2424                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2425                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2426                        must_show_header = 1;
2427                }
2428                if (xfrm_msg)
2429                        strbuf_addstr(&header, xfrm_msg);
2430
2431                /*
2432                 * we do not run diff between different kind
2433                 * of objects.
2434                 */
2435                if ((one->mode ^ two->mode) & S_IFMT)
2436                        goto free_ab_and_return;
2437                if (complete_rewrite &&
2438                    (textconv_one || !diff_filespec_is_binary(one)) &&
2439                    (textconv_two || !diff_filespec_is_binary(two))) {
2440                        fprintf(o->file, "%s", header.buf);
2441                        strbuf_reset(&header);
2442                        emit_rewrite_diff(name_a, name_b, one, two,
2443                                                textconv_one, textconv_two, o);
2444                        o->found_changes = 1;
2445                        goto free_ab_and_return;
2446                }
2447        }
2448
2449        if (o->irreversible_delete && lbl[1][0] == '/') {
2450                fprintf(o->file, "%s", header.buf);
2451                strbuf_reset(&header);
2452                goto free_ab_and_return;
2453        } else if (!DIFF_OPT_TST(o, TEXT) &&
2454            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2455              (!textconv_two && diff_filespec_is_binary(two)) )) {
2456                if (!one->data && !two->data &&
2457                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2458                    !DIFF_OPT_TST(o, BINARY)) {
2459                        if (!oidcmp(&one->oid, &two->oid)) {
2460                                if (must_show_header)
2461                                        fprintf(o->file, "%s", header.buf);
2462                                goto free_ab_and_return;
2463                        }
2464                        fprintf(o->file, "%s", header.buf);
2465                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2466                                line_prefix, lbl[0], lbl[1]);
2467                        goto free_ab_and_return;
2468                }
2469                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2470                        die("unable to read files to diff");
2471                /* Quite common confusing case */
2472                if (mf1.size == mf2.size &&
2473                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2474                        if (must_show_header)
2475                                fprintf(o->file, "%s", header.buf);
2476                        goto free_ab_and_return;
2477                }
2478                fprintf(o->file, "%s", header.buf);
2479                strbuf_reset(&header);
2480                if (DIFF_OPT_TST(o, BINARY))
2481                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2482                else
2483                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2484                                line_prefix, lbl[0], lbl[1]);
2485                o->found_changes = 1;
2486        } else {
2487                /* Crazy xdl interfaces.. */
2488                const char *diffopts = getenv("GIT_DIFF_OPTS");
2489                const char *v;
2490                xpparam_t xpp;
2491                xdemitconf_t xecfg;
2492                struct emit_callback ecbdata;
2493                const struct userdiff_funcname *pe;
2494
2495                if (must_show_header) {
2496                        fprintf(o->file, "%s", header.buf);
2497                        strbuf_reset(&header);
2498                }
2499
2500                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2501                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2502
2503                pe = diff_funcname_pattern(one);
2504                if (!pe)
2505                        pe = diff_funcname_pattern(two);
2506
2507                memset(&xpp, 0, sizeof(xpp));
2508                memset(&xecfg, 0, sizeof(xecfg));
2509                memset(&ecbdata, 0, sizeof(ecbdata));
2510                ecbdata.label_path = lbl;
2511                ecbdata.color_diff = want_color(o->use_color);
2512                ecbdata.ws_rule = whitespace_rule(name_b);
2513                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2514                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2515                ecbdata.opt = o;
2516                ecbdata.header = header.len ? &header : NULL;
2517                xpp.flags = o->xdl_opts;
2518                xecfg.ctxlen = o->context;
2519                xecfg.interhunkctxlen = o->interhunkcontext;
2520                xecfg.flags = XDL_EMIT_FUNCNAMES;
2521                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2522                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2523                if (pe)
2524                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2525                if (!diffopts)
2526                        ;
2527                else if (skip_prefix(diffopts, "--unified=", &v))
2528                        xecfg.ctxlen = strtoul(v, NULL, 10);
2529                else if (skip_prefix(diffopts, "-u", &v))
2530                        xecfg.ctxlen = strtoul(v, NULL, 10);
2531                if (o->word_diff)
2532                        init_diff_words_data(&ecbdata, o, one, two);
2533                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2534                                  &xpp, &xecfg))
2535                        die("unable to generate diff for %s", one->path);
2536                if (o->word_diff)
2537                        free_diff_words_data(&ecbdata);
2538                if (textconv_one)
2539                        free(mf1.ptr);
2540                if (textconv_two)
2541                        free(mf2.ptr);
2542                xdiff_clear_find_func(&xecfg);
2543        }
2544
2545 free_ab_and_return:
2546        strbuf_release(&header);
2547        diff_free_filespec_data(one);
2548        diff_free_filespec_data(two);
2549        free(a_one);
2550        free(b_two);
2551        return;
2552}
2553
2554static void builtin_diffstat(const char *name_a, const char *name_b,
2555                             struct diff_filespec *one,
2556                             struct diff_filespec *two,
2557                             struct diffstat_t *diffstat,
2558                             struct diff_options *o,
2559                             struct diff_filepair *p)
2560{
2561        mmfile_t mf1, mf2;
2562        struct diffstat_file *data;
2563        int same_contents;
2564        int complete_rewrite = 0;
2565
2566        if (!DIFF_PAIR_UNMERGED(p)) {
2567                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2568                        complete_rewrite = 1;
2569        }
2570
2571        data = diffstat_add(diffstat, name_a, name_b);
2572        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2573
2574        if (!one || !two) {
2575                data->is_unmerged = 1;
2576                return;
2577        }
2578
2579        same_contents = !oidcmp(&one->oid, &two->oid);
2580
2581        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2582                data->is_binary = 1;
2583                if (same_contents) {
2584                        data->added = 0;
2585                        data->deleted = 0;
2586                } else {
2587                        data->added = diff_filespec_size(two);
2588                        data->deleted = diff_filespec_size(one);
2589                }
2590        }
2591
2592        else if (complete_rewrite) {
2593                diff_populate_filespec(one, 0);
2594                diff_populate_filespec(two, 0);
2595                data->deleted = count_lines(one->data, one->size);
2596                data->added = count_lines(two->data, two->size);
2597        }
2598
2599        else if (!same_contents) {
2600                /* Crazy xdl interfaces.. */
2601                xpparam_t xpp;
2602                xdemitconf_t xecfg;
2603
2604                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2605                        die("unable to read files to diff");
2606
2607                memset(&xpp, 0, sizeof(xpp));
2608                memset(&xecfg, 0, sizeof(xecfg));
2609                xpp.flags = o->xdl_opts;
2610                xecfg.ctxlen = o->context;
2611                xecfg.interhunkctxlen = o->interhunkcontext;
2612                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2613                                  &xpp, &xecfg))
2614                        die("unable to generate diffstat for %s", one->path);
2615        }
2616
2617        diff_free_filespec_data(one);
2618        diff_free_filespec_data(two);
2619}
2620
2621static void builtin_checkdiff(const char *name_a, const char *name_b,
2622                              const char *attr_path,
2623                              struct diff_filespec *one,
2624                              struct diff_filespec *two,
2625                              struct diff_options *o)
2626{
2627        mmfile_t mf1, mf2;
2628        struct checkdiff_t data;
2629
2630        if (!two)
2631                return;
2632
2633        memset(&data, 0, sizeof(data));
2634        data.filename = name_b ? name_b : name_a;
2635        data.lineno = 0;
2636        data.o = o;
2637        data.ws_rule = whitespace_rule(attr_path);
2638        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2639
2640        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2641                die("unable to read files to diff");
2642
2643        /*
2644         * All the other codepaths check both sides, but not checking
2645         * the "old" side here is deliberate.  We are checking the newly
2646         * introduced changes, and as long as the "new" side is text, we
2647         * can and should check what it introduces.
2648         */
2649        if (diff_filespec_is_binary(two))
2650                goto free_and_return;
2651        else {
2652                /* Crazy xdl interfaces.. */
2653                xpparam_t xpp;
2654                xdemitconf_t xecfg;
2655
2656                memset(&xpp, 0, sizeof(xpp));
2657                memset(&xecfg, 0, sizeof(xecfg));
2658                xecfg.ctxlen = 1; /* at least one context line */
2659                xpp.flags = 0;
2660                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2661                                  &xpp, &xecfg))
2662                        die("unable to generate checkdiff for %s", one->path);
2663
2664                if (data.ws_rule & WS_BLANK_AT_EOF) {
2665                        struct emit_callback ecbdata;
2666                        int blank_at_eof;
2667
2668                        ecbdata.ws_rule = data.ws_rule;
2669                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2670                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2671
2672                        if (blank_at_eof) {
2673                                static char *err;
2674                                if (!err)
2675                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2676                                fprintf(o->file, "%s:%d: %s.\n",
2677                                        data.filename, blank_at_eof, err);
2678                                data.status = 1; /* report errors */
2679                        }
2680                }
2681        }
2682 free_and_return:
2683        diff_free_filespec_data(one);
2684        diff_free_filespec_data(two);
2685        if (data.status)
2686                DIFF_OPT_SET(o, CHECK_FAILED);
2687}
2688
2689struct diff_filespec *alloc_filespec(const char *path)
2690{
2691        struct diff_filespec *spec;
2692
2693        FLEXPTR_ALLOC_STR(spec, path, path);
2694        spec->count = 1;
2695        spec->is_binary = -1;
2696        return spec;
2697}
2698
2699void free_filespec(struct diff_filespec *spec)
2700{
2701        if (!--spec->count) {
2702                diff_free_filespec_data(spec);
2703                free(spec);
2704        }
2705}
2706
2707void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2708                   int sha1_valid, unsigned short mode)
2709{
2710        if (mode) {
2711                spec->mode = canon_mode(mode);
2712                hashcpy(spec->oid.hash, sha1);
2713                spec->oid_valid = sha1_valid;
2714        }
2715}
2716
2717/*
2718 * Given a name and sha1 pair, if the index tells us the file in
2719 * the work tree has that object contents, return true, so that
2720 * prepare_temp_file() does not have to inflate and extract.
2721 */
2722static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2723{
2724        const struct cache_entry *ce;
2725        struct stat st;
2726        int pos, len;
2727
2728        /*
2729         * We do not read the cache ourselves here, because the
2730         * benchmark with my previous version that always reads cache
2731         * shows that it makes things worse for diff-tree comparing
2732         * two linux-2.6 kernel trees in an already checked out work
2733         * tree.  This is because most diff-tree comparisons deal with
2734         * only a small number of files, while reading the cache is
2735         * expensive for a large project, and its cost outweighs the
2736         * savings we get by not inflating the object to a temporary
2737         * file.  Practically, this code only helps when we are used
2738         * by diff-cache --cached, which does read the cache before
2739         * calling us.
2740         */
2741        if (!active_cache)
2742                return 0;
2743
2744        /* We want to avoid the working directory if our caller
2745         * doesn't need the data in a normal file, this system
2746         * is rather slow with its stat/open/mmap/close syscalls,
2747         * and the object is contained in a pack file.  The pack
2748         * is probably already open and will be faster to obtain
2749         * the data through than the working directory.  Loose
2750         * objects however would tend to be slower as they need
2751         * to be individually opened and inflated.
2752         */
2753        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2754                return 0;
2755
2756        /*
2757         * Similarly, if we'd have to convert the file contents anyway, that
2758         * makes the optimization not worthwhile.
2759         */
2760        if (!want_file && would_convert_to_git(name))
2761                return 0;
2762
2763        len = strlen(name);
2764        pos = cache_name_pos(name, len);
2765        if (pos < 0)
2766                return 0;
2767        ce = active_cache[pos];
2768
2769        /*
2770         * This is not the sha1 we are looking for, or
2771         * unreusable because it is not a regular file.
2772         */
2773        if (hashcmp(sha1, ce->oid.hash) || !S_ISREG(ce->ce_mode))
2774                return 0;
2775
2776        /*
2777         * If ce is marked as "assume unchanged", there is no
2778         * guarantee that work tree matches what we are looking for.
2779         */
2780        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2781                return 0;
2782
2783        /*
2784         * If ce matches the file in the work tree, we can reuse it.
2785         */
2786        if (ce_uptodate(ce) ||
2787            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2788                return 1;
2789
2790        return 0;
2791}
2792
2793static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2794{
2795        struct strbuf buf = STRBUF_INIT;
2796        char *dirty = "";
2797
2798        /* Are we looking at the work tree? */
2799        if (s->dirty_submodule)
2800                dirty = "-dirty";
2801
2802        strbuf_addf(&buf, "Subproject commit %s%s\n",
2803                    oid_to_hex(&s->oid), dirty);
2804        s->size = buf.len;
2805        if (size_only) {
2806                s->data = NULL;
2807                strbuf_release(&buf);
2808        } else {
2809                s->data = strbuf_detach(&buf, NULL);
2810                s->should_free = 1;
2811        }
2812        return 0;
2813}
2814
2815/*
2816 * While doing rename detection and pickaxe operation, we may need to
2817 * grab the data for the blob (or file) for our own in-core comparison.
2818 * diff_filespec has data and size fields for this purpose.
2819 */
2820int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2821{
2822        int size_only = flags & CHECK_SIZE_ONLY;
2823        int err = 0;
2824        /*
2825         * demote FAIL to WARN to allow inspecting the situation
2826         * instead of refusing.
2827         */
2828        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2829                                    ? SAFE_CRLF_WARN
2830                                    : safe_crlf);
2831
2832        if (!DIFF_FILE_VALID(s))
2833                die("internal error: asking to populate invalid file.");
2834        if (S_ISDIR(s->mode))
2835                return -1;
2836
2837        if (s->data)
2838                return 0;
2839
2840        if (size_only && 0 < s->size)
2841                return 0;
2842
2843        if (S_ISGITLINK(s->mode))
2844                return diff_populate_gitlink(s, size_only);
2845
2846        if (!s->oid_valid ||
2847            reuse_worktree_file(s->path, s->oid.hash, 0)) {
2848                struct strbuf buf = STRBUF_INIT;
2849                struct stat st;
2850                int fd;
2851
2852                if (lstat(s->path, &st) < 0) {
2853                        if (errno == ENOENT) {
2854                        err_empty:
2855                                err = -1;
2856                        empty:
2857                                s->data = (char *)"";
2858                                s->size = 0;
2859                                return err;
2860                        }
2861                }
2862                s->size = xsize_t(st.st_size);
2863                if (!s->size)
2864                        goto empty;
2865                if (S_ISLNK(st.st_mode)) {
2866                        struct strbuf sb = STRBUF_INIT;
2867
2868                        if (strbuf_readlink(&sb, s->path, s->size))
2869                                goto err_empty;
2870                        s->size = sb.len;
2871                        s->data = strbuf_detach(&sb, NULL);
2872                        s->should_free = 1;
2873                        return 0;
2874                }
2875                if (size_only)
2876                        return 0;
2877                if ((flags & CHECK_BINARY) &&
2878                    s->size > big_file_threshold && s->is_binary == -1) {
2879                        s->is_binary = 1;
2880                        return 0;
2881                }
2882                fd = open(s->path, O_RDONLY);
2883                if (fd < 0)
2884                        goto err_empty;
2885                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2886                close(fd);
2887                s->should_munmap = 1;
2888
2889                /*
2890                 * Convert from working tree format to canonical git format
2891                 */
2892                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2893                        size_t size = 0;
2894                        munmap(s->data, s->size);
2895                        s->should_munmap = 0;
2896                        s->data = strbuf_detach(&buf, &size);
2897                        s->size = size;
2898                        s->should_free = 1;
2899                }
2900        }
2901        else {
2902                enum object_type type;
2903                if (size_only || (flags & CHECK_BINARY)) {
2904                        type = sha1_object_info(s->oid.hash, &s->size);
2905                        if (type < 0)
2906                                die("unable to read %s",
2907                                    oid_to_hex(&s->oid));
2908                        if (size_only)
2909                                return 0;
2910                        if (s->size > big_file_threshold && s->is_binary == -1) {
2911                                s->is_binary = 1;
2912                                return 0;
2913                        }
2914                }
2915                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
2916                if (!s->data)
2917                        die("unable to read %s", oid_to_hex(&s->oid));
2918                s->should_free = 1;
2919        }
2920        return 0;
2921}
2922
2923void diff_free_filespec_blob(struct diff_filespec *s)
2924{
2925        if (s->should_free)
2926                free(s->data);
2927        else if (s->should_munmap)
2928                munmap(s->data, s->size);
2929
2930        if (s->should_free || s->should_munmap) {
2931                s->should_free = s->should_munmap = 0;
2932                s->data = NULL;
2933        }
2934}
2935
2936void diff_free_filespec_data(struct diff_filespec *s)
2937{
2938        diff_free_filespec_blob(s);
2939        free(s->cnt_data);
2940        s->cnt_data = NULL;
2941}
2942
2943static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2944                           void *blob,
2945                           unsigned long size,
2946                           const struct object_id *oid,
2947                           int mode)
2948{
2949        int fd;
2950        struct strbuf buf = STRBUF_INIT;
2951        struct strbuf template = STRBUF_INIT;
2952        char *path_dup = xstrdup(path);
2953        const char *base = basename(path_dup);
2954
2955        /* Generate "XXXXXX_basename.ext" */
2956        strbuf_addstr(&template, "XXXXXX_");
2957        strbuf_addstr(&template, base);
2958
2959        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
2960        if (fd < 0)
2961                die_errno("unable to create temp-file");
2962        if (convert_to_working_tree(path,
2963                        (const char *)blob, (size_t)size, &buf)) {
2964                blob = buf.buf;
2965                size = buf.len;
2966        }
2967        if (write_in_full(fd, blob, size) != size)
2968                die_errno("unable to write temp-file");
2969        close_tempfile(&temp->tempfile);
2970        temp->name = get_tempfile_path(&temp->tempfile);
2971        oid_to_hex_r(temp->hex, oid);
2972        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
2973        strbuf_release(&buf);
2974        strbuf_release(&template);
2975        free(path_dup);
2976}
2977
2978static struct diff_tempfile *prepare_temp_file(const char *name,
2979                struct diff_filespec *one)
2980{
2981        struct diff_tempfile *temp = claim_diff_tempfile();
2982
2983        if (!DIFF_FILE_VALID(one)) {
2984        not_a_valid_file:
2985                /* A '-' entry produces this for file-2, and
2986                 * a '+' entry produces this for file-1.
2987                 */
2988                temp->name = "/dev/null";
2989                xsnprintf(temp->hex, sizeof(temp->hex), ".");
2990                xsnprintf(temp->mode, sizeof(temp->mode), ".");
2991                return temp;
2992        }
2993
2994        if (!S_ISGITLINK(one->mode) &&
2995            (!one->oid_valid ||
2996             reuse_worktree_file(name, one->oid.hash, 1))) {
2997                struct stat st;
2998                if (lstat(name, &st) < 0) {
2999                        if (errno == ENOENT)
3000                                goto not_a_valid_file;
3001                        die_errno("stat(%s)", name);
3002                }
3003                if (S_ISLNK(st.st_mode)) {
3004                        struct strbuf sb = STRBUF_INIT;
3005                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3006                                die_errno("readlink(%s)", name);
3007                        prep_temp_blob(name, temp, sb.buf, sb.len,
3008                                       (one->oid_valid ?
3009                                        &one->oid : &null_oid),
3010                                       (one->oid_valid ?
3011                                        one->mode : S_IFLNK));
3012                        strbuf_release(&sb);
3013                }
3014                else {
3015                        /* we can borrow from the file in the work tree */
3016                        temp->name = name;
3017                        if (!one->oid_valid)
3018                                sha1_to_hex_r(temp->hex, null_sha1);
3019                        else
3020                                sha1_to_hex_r(temp->hex, one->oid.hash);
3021                        /* Even though we may sometimes borrow the
3022                         * contents from the work tree, we always want
3023                         * one->mode.  mode is trustworthy even when
3024                         * !(one->sha1_valid), as long as
3025                         * DIFF_FILE_VALID(one).
3026                         */
3027                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3028                }
3029                return temp;
3030        }
3031        else {
3032                if (diff_populate_filespec(one, 0))
3033                        die("cannot read data blob for %s", one->path);
3034                prep_temp_blob(name, temp, one->data, one->size,
3035                               &one->oid, one->mode);
3036        }
3037        return temp;
3038}
3039
3040static void add_external_diff_name(struct argv_array *argv,
3041                                   const char *name,
3042                                   struct diff_filespec *df)
3043{
3044        struct diff_tempfile *temp = prepare_temp_file(name, df);
3045        argv_array_push(argv, temp->name);
3046        argv_array_push(argv, temp->hex);
3047        argv_array_push(argv, temp->mode);
3048}
3049
3050/* An external diff command takes:
3051 *
3052 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3053 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3054 *
3055 */
3056static void run_external_diff(const char *pgm,
3057                              const char *name,
3058                              const char *other,
3059                              struct diff_filespec *one,
3060                              struct diff_filespec *two,
3061                              const char *xfrm_msg,
3062                              int complete_rewrite,
3063                              struct diff_options *o)
3064{
3065        struct argv_array argv = ARGV_ARRAY_INIT;
3066        struct argv_array env = ARGV_ARRAY_INIT;
3067        struct diff_queue_struct *q = &diff_queued_diff;
3068
3069        argv_array_push(&argv, pgm);
3070        argv_array_push(&argv, name);
3071
3072        if (one && two) {
3073                add_external_diff_name(&argv, name, one);
3074                if (!other)
3075                        add_external_diff_name(&argv, name, two);
3076                else {
3077                        add_external_diff_name(&argv, other, two);
3078                        argv_array_push(&argv, other);
3079                        argv_array_push(&argv, xfrm_msg);
3080                }
3081        }
3082
3083        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3084        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3085
3086        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3087                die(_("external diff died, stopping at %s"), name);
3088
3089        remove_tempfile();
3090        argv_array_clear(&argv);
3091        argv_array_clear(&env);
3092}
3093
3094static int similarity_index(struct diff_filepair *p)
3095{
3096        return p->score * 100 / MAX_SCORE;
3097}
3098
3099static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3100{
3101        if (startup_info->have_repository)
3102                return find_unique_abbrev(oid->hash, abbrev);
3103        else {
3104                char *hex = oid_to_hex(oid);
3105                if (abbrev < 0)
3106                        abbrev = FALLBACK_DEFAULT_ABBREV;
3107                if (abbrev > GIT_SHA1_HEXSZ)
3108                        die("BUG: oid abbreviation out of range: %d", abbrev);
3109                hex[abbrev] = '\0';
3110                return hex;
3111        }
3112}
3113
3114static void fill_metainfo(struct strbuf *msg,
3115                          const char *name,
3116                          const char *other,
3117                          struct diff_filespec *one,
3118                          struct diff_filespec *two,
3119                          struct diff_options *o,
3120                          struct diff_filepair *p,
3121                          int *must_show_header,
3122                          int use_color)
3123{
3124        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3125        const char *reset = diff_get_color(use_color, DIFF_RESET);
3126        const char *line_prefix = diff_line_prefix(o);
3127
3128        *must_show_header = 1;
3129        strbuf_init(msg, PATH_MAX * 2 + 300);
3130        switch (p->status) {
3131        case DIFF_STATUS_COPIED:
3132                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3133                            line_prefix, set, similarity_index(p));
3134                strbuf_addf(msg, "%s\n%s%scopy from ",
3135                            reset,  line_prefix, set);
3136                quote_c_style(name, msg, NULL, 0);
3137                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3138                quote_c_style(other, msg, NULL, 0);
3139                strbuf_addf(msg, "%s\n", reset);
3140                break;
3141        case DIFF_STATUS_RENAMED:
3142                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3143                            line_prefix, set, similarity_index(p));
3144                strbuf_addf(msg, "%s\n%s%srename from ",
3145                            reset, line_prefix, set);
3146                quote_c_style(name, msg, NULL, 0);
3147                strbuf_addf(msg, "%s\n%s%srename to ",
3148                            reset, line_prefix, set);
3149                quote_c_style(other, msg, NULL, 0);
3150                strbuf_addf(msg, "%s\n", reset);
3151                break;
3152        case DIFF_STATUS_MODIFIED:
3153                if (p->score) {
3154                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3155                                    line_prefix,
3156                                    set, similarity_index(p), reset);
3157                        break;
3158                }
3159                /* fallthru */
3160        default:
3161                *must_show_header = 0;
3162        }
3163        if (one && two && oidcmp(&one->oid, &two->oid)) {
3164                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3165
3166                if (DIFF_OPT_TST(o, BINARY)) {
3167                        mmfile_t mf;
3168                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3169                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3170                                abbrev = 40;
3171                }
3172                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3173                            diff_abbrev_oid(&one->oid, abbrev),
3174                            diff_abbrev_oid(&two->oid, abbrev));
3175                if (one->mode == two->mode)
3176                        strbuf_addf(msg, " %06o", one->mode);
3177                strbuf_addf(msg, "%s\n", reset);
3178        }
3179}
3180
3181static void run_diff_cmd(const char *pgm,
3182                         const char *name,
3183                         const char *other,
3184                         const char *attr_path,
3185                         struct diff_filespec *one,
3186                         struct diff_filespec *two,
3187                         struct strbuf *msg,
3188                         struct diff_options *o,
3189                         struct diff_filepair *p)
3190{
3191        const char *xfrm_msg = NULL;
3192        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3193        int must_show_header = 0;
3194
3195
3196        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3197                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3198                if (drv && drv->external)
3199                        pgm = drv->external;
3200        }
3201
3202        if (msg) {
3203                /*
3204                 * don't use colors when the header is intended for an
3205                 * external diff driver
3206                 */
3207                fill_metainfo(msg, name, other, one, two, o, p,
3208                              &must_show_header,
3209                              want_color(o->use_color) && !pgm);
3210                xfrm_msg = msg->len ? msg->buf : NULL;
3211        }
3212
3213        if (pgm) {
3214                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3215                                  complete_rewrite, o);
3216                return;
3217        }
3218        if (one && two)
3219                builtin_diff(name, other ? other : name,
3220                             one, two, xfrm_msg, must_show_header,
3221                             o, complete_rewrite);
3222        else
3223                fprintf(o->file, "* Unmerged path %s\n", name);
3224}
3225
3226static void diff_fill_sha1_info(struct diff_filespec *one)
3227{
3228        if (DIFF_FILE_VALID(one)) {
3229                if (!one->oid_valid) {
3230                        struct stat st;
3231                        if (one->is_stdin) {
3232                                oidclr(&one->oid);
3233                                return;
3234                        }
3235                        if (lstat(one->path, &st) < 0)
3236                                die_errno("stat '%s'", one->path);
3237                        if (index_path(one->oid.hash, one->path, &st, 0))
3238                                die("cannot hash %s", one->path);
3239                }
3240        }
3241        else
3242                oidclr(&one->oid);
3243}
3244
3245static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3246{
3247        /* Strip the prefix but do not molest /dev/null and absolute paths */
3248        if (*namep && **namep != '/') {
3249                *namep += prefix_length;
3250                if (**namep == '/')
3251                        ++*namep;
3252        }
3253        if (*otherp && **otherp != '/') {
3254                *otherp += prefix_length;
3255                if (**otherp == '/')
3256                        ++*otherp;
3257        }
3258}
3259
3260static void run_diff(struct diff_filepair *p, struct diff_options *o)
3261{
3262        const char *pgm = external_diff();
3263        struct strbuf msg;
3264        struct diff_filespec *one = p->one;
3265        struct diff_filespec *two = p->two;
3266        const char *name;
3267        const char *other;
3268        const char *attr_path;
3269
3270        name  = p->one->path;
3271        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3272        attr_path = name;
3273        if (o->prefix_length)
3274                strip_prefix(o->prefix_length, &name, &other);
3275
3276        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3277                pgm = NULL;
3278
3279        if (DIFF_PAIR_UNMERGED(p)) {
3280                run_diff_cmd(pgm, name, NULL, attr_path,
3281                             NULL, NULL, NULL, o, p);
3282                return;
3283        }
3284
3285        diff_fill_sha1_info(one);
3286        diff_fill_sha1_info(two);
3287
3288        if (!pgm &&
3289            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3290            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3291                /*
3292                 * a filepair that changes between file and symlink
3293                 * needs to be split into deletion and creation.
3294                 */
3295                struct diff_filespec *null = alloc_filespec(two->path);
3296                run_diff_cmd(NULL, name, other, attr_path,
3297                             one, null, &msg, o, p);
3298                free(null);
3299                strbuf_release(&msg);
3300
3301                null = alloc_filespec(one->path);
3302                run_diff_cmd(NULL, name, other, attr_path,
3303                             null, two, &msg, o, p);
3304                free(null);
3305        }
3306        else
3307                run_diff_cmd(pgm, name, other, attr_path,
3308                             one, two, &msg, o, p);
3309
3310        strbuf_release(&msg);
3311}
3312
3313static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3314                         struct diffstat_t *diffstat)
3315{
3316        const char *name;
3317        const char *other;
3318
3319        if (DIFF_PAIR_UNMERGED(p)) {
3320                /* unmerged */
3321                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3322                return;
3323        }
3324
3325        name = p->one->path;
3326        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3327
3328        if (o->prefix_length)
3329                strip_prefix(o->prefix_length, &name, &other);
3330
3331        diff_fill_sha1_info(p->one);
3332        diff_fill_sha1_info(p->two);
3333
3334        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3335}
3336
3337static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3338{
3339        const char *name;
3340        const char *other;
3341        const char *attr_path;
3342
3343        if (DIFF_PAIR_UNMERGED(p)) {
3344                /* unmerged */
3345                return;
3346        }
3347
3348        name = p->one->path;
3349        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3350        attr_path = other ? other : name;
3351
3352        if (o->prefix_length)
3353                strip_prefix(o->prefix_length, &name, &other);
3354
3355        diff_fill_sha1_info(p->one);
3356        diff_fill_sha1_info(p->two);
3357
3358        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3359}
3360
3361void diff_setup(struct diff_options *options)
3362{
3363        memcpy(options, &default_diff_options, sizeof(*options));
3364
3365        options->file = stdout;
3366
3367        options->line_termination = '\n';
3368        options->break_opt = -1;
3369        options->rename_limit = -1;
3370        options->dirstat_permille = diff_dirstat_permille_default;
3371        options->context = diff_context_default;
3372        options->ws_error_highlight = ws_error_highlight_default;
3373        DIFF_OPT_SET(options, RENAME_EMPTY);
3374
3375        /* pathchange left =NULL by default */
3376        options->change = diff_change;
3377        options->add_remove = diff_addremove;
3378        options->use_color = diff_use_color_default;
3379        options->detect_rename = diff_detect_rename_default;
3380        options->xdl_opts |= diff_algorithm;
3381        if (diff_indent_heuristic)
3382                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3383        else if (diff_compaction_heuristic)
3384                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3385
3386        options->orderfile = diff_order_file_cfg;
3387
3388        if (diff_no_prefix) {
3389                options->a_prefix = options->b_prefix = "";
3390        } else if (!diff_mnemonic_prefix) {
3391                options->a_prefix = "a/";
3392                options->b_prefix = "b/";
3393        }
3394}
3395
3396void diff_setup_done(struct diff_options *options)
3397{
3398        int count = 0;
3399
3400        if (options->set_default)
3401                options->set_default(options);
3402
3403        if (options->output_format & DIFF_FORMAT_NAME)
3404                count++;
3405        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3406                count++;
3407        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3408                count++;
3409        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3410                count++;
3411        if (count > 1)
3412                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
3413
3414        /*
3415         * Most of the time we can say "there are changes"
3416         * only by checking if there are changed paths, but
3417         * --ignore-whitespace* options force us to look
3418         * inside contents.
3419         */
3420
3421        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3422            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3423            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3424                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3425        else
3426                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3427
3428        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3429                options->detect_rename = DIFF_DETECT_COPY;
3430
3431        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3432                options->prefix = NULL;
3433        if (options->prefix)
3434                options->prefix_length = strlen(options->prefix);
3435        else
3436                options->prefix_length = 0;
3437
3438        if (options->output_format & (DIFF_FORMAT_NAME |
3439                                      DIFF_FORMAT_NAME_STATUS |
3440                                      DIFF_FORMAT_CHECKDIFF |
3441                                      DIFF_FORMAT_NO_OUTPUT))
3442                options->output_format &= ~(DIFF_FORMAT_RAW |
3443                                            DIFF_FORMAT_NUMSTAT |
3444                                            DIFF_FORMAT_DIFFSTAT |
3445                                            DIFF_FORMAT_SHORTSTAT |
3446                                            DIFF_FORMAT_DIRSTAT |
3447                                            DIFF_FORMAT_SUMMARY |
3448                                            DIFF_FORMAT_PATCH);
3449
3450        /*
3451         * These cases always need recursive; we do not drop caller-supplied
3452         * recursive bits for other formats here.
3453         */
3454        if (options->output_format & (DIFF_FORMAT_PATCH |
3455                                      DIFF_FORMAT_NUMSTAT |
3456                                      DIFF_FORMAT_DIFFSTAT |
3457                                      DIFF_FORMAT_SHORTSTAT |
3458                                      DIFF_FORMAT_DIRSTAT |
3459                                      DIFF_FORMAT_SUMMARY |
3460                                      DIFF_FORMAT_CHECKDIFF))
3461                DIFF_OPT_SET(options, RECURSIVE);
3462        /*
3463         * Also pickaxe would not work very well if you do not say recursive
3464         */
3465        if (options->pickaxe)
3466                DIFF_OPT_SET(options, RECURSIVE);
3467        /*
3468         * When patches are generated, submodules diffed against the work tree
3469         * must be checked for dirtiness too so it can be shown in the output
3470         */
3471        if (options->output_format & DIFF_FORMAT_PATCH)
3472                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3473
3474        if (options->detect_rename && options->rename_limit < 0)
3475                options->rename_limit = diff_rename_limit_default;
3476        if (options->setup & DIFF_SETUP_USE_CACHE) {
3477                if (!active_cache)
3478                        /* read-cache does not die even when it fails
3479                         * so it is safe for us to do this here.  Also
3480                         * it does not smudge active_cache or active_nr
3481                         * when it fails, so we do not have to worry about
3482                         * cleaning it up ourselves either.
3483                         */
3484                        read_cache();
3485        }
3486        if (40 < options->abbrev)
3487                options->abbrev = 40; /* full */
3488
3489        /*
3490         * It does not make sense to show the first hit we happened
3491         * to have found.  It does not make sense not to return with
3492         * exit code in such a case either.
3493         */
3494        if (DIFF_OPT_TST(options, QUICK)) {
3495                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3496                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3497        }
3498
3499        options->diff_path_counter = 0;
3500
3501        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3502                die(_("--follow requires exactly one pathspec"));
3503}
3504
3505static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3506{
3507        char c, *eq;
3508        int len;
3509
3510        if (*arg != '-')
3511                return 0;
3512        c = *++arg;
3513        if (!c)
3514                return 0;
3515        if (c == arg_short) {
3516                c = *++arg;
3517                if (!c)
3518                        return 1;
3519                if (val && isdigit(c)) {
3520                        char *end;
3521                        int n = strtoul(arg, &end, 10);
3522                        if (*end)
3523                                return 0;
3524                        *val = n;
3525                        return 1;
3526                }
3527                return 0;
3528        }
3529        if (c != '-')
3530                return 0;
3531        arg++;
3532        eq = strchrnul(arg, '=');
3533        len = eq - arg;
3534        if (!len || strncmp(arg, arg_long, len))
3535                return 0;
3536        if (*eq) {
3537                int n;
3538                char *end;
3539                if (!isdigit(*++eq))
3540                        return 0;
3541                n = strtoul(eq, &end, 10);
3542                if (*end)
3543                        return 0;
3544                *val = n;
3545        }
3546        return 1;
3547}
3548
3549static int diff_scoreopt_parse(const char *opt);
3550
3551static inline int short_opt(char opt, const char **argv,
3552                            const char **optarg)
3553{
3554        const char *arg = argv[0];
3555        if (arg[0] != '-' || arg[1] != opt)
3556                return 0;
3557        if (arg[2] != '\0') {
3558                *optarg = arg + 2;
3559                return 1;
3560        }
3561        if (!argv[1])
3562                die("Option '%c' requires a value", opt);
3563        *optarg = argv[1];
3564        return 2;
3565}
3566
3567int parse_long_opt(const char *opt, const char **argv,
3568                   const char **optarg)
3569{
3570        const char *arg = argv[0];
3571        if (!skip_prefix(arg, "--", &arg))
3572                return 0;
3573        if (!skip_prefix(arg, opt, &arg))
3574                return 0;
3575        if (*arg == '=') { /* stuck form: --option=value */
3576                *optarg = arg + 1;
3577                return 1;
3578        }
3579        if (*arg != '\0')
3580                return 0;
3581        /* separate form: --option value */
3582        if (!argv[1])
3583                die("Option '--%s' requires a value", opt);
3584        *optarg = argv[1];
3585        return 2;
3586}
3587
3588static int stat_opt(struct diff_options *options, const char **av)
3589{
3590        const char *arg = av[0];
3591        char *end;
3592        int width = options->stat_width;
3593        int name_width = options->stat_name_width;
3594        int graph_width = options->stat_graph_width;
3595        int count = options->stat_count;
3596        int argcount = 1;
3597
3598        if (!skip_prefix(arg, "--stat", &arg))
3599                die("BUG: stat option does not begin with --stat: %s", arg);
3600        end = (char *)arg;
3601
3602        switch (*arg) {
3603        case '-':
3604                if (skip_prefix(arg, "-width", &arg)) {
3605                        if (*arg == '=')
3606                                width = strtoul(arg + 1, &end, 10);
3607                        else if (!*arg && !av[1])
3608                                die_want_option("--stat-width");
3609                        else if (!*arg) {
3610                                width = strtoul(av[1], &end, 10);
3611                                argcount = 2;
3612                        }
3613                } else if (skip_prefix(arg, "-name-width", &arg)) {
3614                        if (*arg == '=')
3615                                name_width = strtoul(arg + 1, &end, 10);
3616                        else if (!*arg && !av[1])
3617                                die_want_option("--stat-name-width");
3618                        else if (!*arg) {
3619                                name_width = strtoul(av[1], &end, 10);
3620                                argcount = 2;
3621                        }
3622                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3623                        if (*arg == '=')
3624                                graph_width = strtoul(arg + 1, &end, 10);
3625                        else if (!*arg && !av[1])
3626                                die_want_option("--stat-graph-width");
3627                        else if (!*arg) {
3628                                graph_width = strtoul(av[1], &end, 10);
3629                                argcount = 2;
3630                        }
3631                } else if (skip_prefix(arg, "-count", &arg)) {
3632                        if (*arg == '=')
3633                                count = strtoul(arg + 1, &end, 10);
3634                        else if (!*arg && !av[1])
3635                                die_want_option("--stat-count");
3636                        else if (!*arg) {
3637                                count = strtoul(av[1], &end, 10);
3638                                argcount = 2;
3639                        }
3640                }
3641                break;
3642        case '=':
3643                width = strtoul(arg+1, &end, 10);
3644                if (*end == ',')
3645                        name_width = strtoul(end+1, &end, 10);
3646                if (*end == ',')
3647                        count = strtoul(end+1, &end, 10);
3648        }
3649
3650        /* Important! This checks all the error cases! */
3651        if (*end)
3652                return 0;
3653        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3654        options->stat_name_width = name_width;
3655        options->stat_graph_width = graph_width;
3656        options->stat_width = width;
3657        options->stat_count = count;
3658        return argcount;
3659}
3660
3661static int parse_dirstat_opt(struct diff_options *options, const char *params)
3662{
3663        struct strbuf errmsg = STRBUF_INIT;
3664        if (parse_dirstat_params(options, params, &errmsg))
3665                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3666                    errmsg.buf);
3667        strbuf_release(&errmsg);
3668        /*
3669         * The caller knows a dirstat-related option is given from the command
3670         * line; allow it to say "return this_function();"
3671         */
3672        options->output_format |= DIFF_FORMAT_DIRSTAT;
3673        return 1;
3674}
3675
3676static int parse_submodule_opt(struct diff_options *options, const char *value)
3677{
3678        if (parse_submodule_params(options, value))
3679                die(_("Failed to parse --submodule option parameter: '%s'"),
3680                        value);
3681        return 1;
3682}
3683
3684static const char diff_status_letters[] = {
3685        DIFF_STATUS_ADDED,
3686        DIFF_STATUS_COPIED,
3687        DIFF_STATUS_DELETED,
3688        DIFF_STATUS_MODIFIED,
3689        DIFF_STATUS_RENAMED,
3690        DIFF_STATUS_TYPE_CHANGED,
3691        DIFF_STATUS_UNKNOWN,
3692        DIFF_STATUS_UNMERGED,
3693        DIFF_STATUS_FILTER_AON,
3694        DIFF_STATUS_FILTER_BROKEN,
3695        '\0',
3696};
3697
3698static unsigned int filter_bit['Z' + 1];
3699
3700static void prepare_filter_bits(void)
3701{
3702        int i;
3703
3704        if (!filter_bit[DIFF_STATUS_ADDED]) {
3705                for (i = 0; diff_status_letters[i]; i++)
3706                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3707        }
3708}
3709
3710static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3711{
3712        return opt->filter & filter_bit[(int) status];
3713}
3714
3715static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3716{
3717        int i, optch;
3718
3719        prepare_filter_bits();
3720
3721        /*
3722         * If there is a negation e.g. 'd' in the input, and we haven't
3723         * initialized the filter field with another --diff-filter, start
3724         * from full set of bits, except for AON.
3725         */
3726        if (!opt->filter) {
3727                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3728                        if (optch < 'a' || 'z' < optch)
3729                                continue;
3730                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3731                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3732                        break;
3733                }
3734        }
3735
3736        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3737                unsigned int bit;
3738                int negate;
3739
3740                if ('a' <= optch && optch <= 'z') {
3741                        negate = 1;
3742                        optch = toupper(optch);
3743                } else {
3744                        negate = 0;
3745                }
3746
3747                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3748                if (!bit)
3749                        return optarg[i];
3750                if (negate)
3751                        opt->filter &= ~bit;
3752                else
3753                        opt->filter |= bit;
3754        }
3755        return 0;
3756}
3757
3758static void enable_patch_output(int *fmt) {
3759        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3760        *fmt |= DIFF_FORMAT_PATCH;
3761}
3762
3763static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
3764{
3765        int val = parse_ws_error_highlight(arg);
3766
3767        if (val < 0) {
3768                error("unknown value after ws-error-highlight=%.*s",
3769                      -1 - val, arg);
3770                return 0;
3771        }
3772        opt->ws_error_highlight = val;
3773        return 1;
3774}
3775
3776int diff_opt_parse(struct diff_options *options,
3777                   const char **av, int ac, const char *prefix)
3778{
3779        const char *arg = av[0];
3780        const char *optarg;
3781        int argcount;
3782
3783        if (!prefix)
3784                prefix = "";
3785
3786        /* Output format options */
3787        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3788            || opt_arg(arg, 'U', "unified", &options->context))
3789                enable_patch_output(&options->output_format);
3790        else if (!strcmp(arg, "--raw"))
3791                options->output_format |= DIFF_FORMAT_RAW;
3792        else if (!strcmp(arg, "--patch-with-raw")) {
3793                enable_patch_output(&options->output_format);
3794                options->output_format |= DIFF_FORMAT_RAW;
3795        } else if (!strcmp(arg, "--numstat"))
3796                options->output_format |= DIFF_FORMAT_NUMSTAT;
3797        else if (!strcmp(arg, "--shortstat"))
3798                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3799        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3800                return parse_dirstat_opt(options, "");
3801        else if (skip_prefix(arg, "-X", &arg))
3802                return parse_dirstat_opt(options, arg);
3803        else if (skip_prefix(arg, "--dirstat=", &arg))
3804                return parse_dirstat_opt(options, arg);
3805        else if (!strcmp(arg, "--cumulative"))
3806                return parse_dirstat_opt(options, "cumulative");
3807        else if (!strcmp(arg, "--dirstat-by-file"))
3808                return parse_dirstat_opt(options, "files");
3809        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3810                parse_dirstat_opt(options, "files");
3811                return parse_dirstat_opt(options, arg);
3812        }
3813        else if (!strcmp(arg, "--check"))
3814                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3815        else if (!strcmp(arg, "--summary"))
3816                options->output_format |= DIFF_FORMAT_SUMMARY;
3817        else if (!strcmp(arg, "--patch-with-stat")) {
3818                enable_patch_output(&options->output_format);
3819                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3820        } else if (!strcmp(arg, "--name-only"))
3821                options->output_format |= DIFF_FORMAT_NAME;
3822        else if (!strcmp(arg, "--name-status"))
3823                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3824        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3825                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3826        else if (starts_with(arg, "--stat"))
3827                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3828                return stat_opt(options, av);
3829
3830        /* renames options */
3831        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3832                 !strcmp(arg, "--break-rewrites")) {
3833                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3834                        return error("invalid argument to -B: %s", arg+2);
3835        }
3836        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3837                 !strcmp(arg, "--find-renames")) {
3838                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3839                        return error("invalid argument to -M: %s", arg+2);
3840                options->detect_rename = DIFF_DETECT_RENAME;
3841        }
3842        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3843                options->irreversible_delete = 1;
3844        }
3845        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3846                 !strcmp(arg, "--find-copies")) {
3847                if (options->detect_rename == DIFF_DETECT_COPY)
3848                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3849                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3850                        return error("invalid argument to -C: %s", arg+2);
3851                options->detect_rename = DIFF_DETECT_COPY;
3852        }
3853        else if (!strcmp(arg, "--no-renames"))
3854                options->detect_rename = 0;
3855        else if (!strcmp(arg, "--rename-empty"))
3856                DIFF_OPT_SET(options, RENAME_EMPTY);
3857        else if (!strcmp(arg, "--no-rename-empty"))
3858                DIFF_OPT_CLR(options, RENAME_EMPTY);
3859        else if (!strcmp(arg, "--relative"))
3860                DIFF_OPT_SET(options, RELATIVE_NAME);
3861        else if (skip_prefix(arg, "--relative=", &arg)) {
3862                DIFF_OPT_SET(options, RELATIVE_NAME);
3863                options->prefix = arg;
3864        }
3865
3866        /* xdiff options */
3867        else if (!strcmp(arg, "--minimal"))
3868                DIFF_XDL_SET(options, NEED_MINIMAL);
3869        else if (!strcmp(arg, "--no-minimal"))
3870                DIFF_XDL_CLR(options, NEED_MINIMAL);
3871        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3872                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3873        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3874                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3875        else if (!strcmp(arg, "--ignore-space-at-eol"))
3876                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3877        else if (!strcmp(arg, "--ignore-blank-lines"))
3878                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3879        else if (!strcmp(arg, "--indent-heuristic")) {
3880                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3881                DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
3882        } else if (!strcmp(arg, "--no-indent-heuristic"))
3883                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
3884        else if (!strcmp(arg, "--compaction-heuristic")) {
3885                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3886                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
3887        } else if (!strcmp(arg, "--no-compaction-heuristic"))
3888                DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
3889        else if (!strcmp(arg, "--patience"))
3890                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3891        else if (!strcmp(arg, "--histogram"))
3892                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3893        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3894                long value = parse_algorithm_value(optarg);
3895                if (value < 0)
3896                        return error("option diff-algorithm accepts \"myers\", "
3897                                     "\"minimal\", \"patience\" and \"histogram\"");
3898                /* clear out previous settings */
3899                DIFF_XDL_CLR(options, NEED_MINIMAL);
3900                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3901                options->xdl_opts |= value;
3902                return argcount;
3903        }
3904
3905        /* flags options */
3906        else if (!strcmp(arg, "--binary")) {
3907                enable_patch_output(&options->output_format);
3908                DIFF_OPT_SET(options, BINARY);
3909        }
3910        else if (!strcmp(arg, "--full-index"))
3911                DIFF_OPT_SET(options, FULL_INDEX);
3912        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3913                DIFF_OPT_SET(options, TEXT);
3914        else if (!strcmp(arg, "-R"))
3915                DIFF_OPT_SET(options, REVERSE_DIFF);
3916        else if (!strcmp(arg, "--find-copies-harder"))
3917                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3918        else if (!strcmp(arg, "--follow"))
3919                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3920        else if (!strcmp(arg, "--no-follow")) {
3921                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3922                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
3923        } else if (!strcmp(arg, "--color"))
3924                options->use_color = 1;
3925        else if (skip_prefix(arg, "--color=", &arg)) {
3926                int value = git_config_colorbool(NULL, arg);
3927                if (value < 0)
3928                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3929                options->use_color = value;
3930        }
3931        else if (!strcmp(arg, "--no-color"))
3932                options->use_color = 0;
3933        else if (!strcmp(arg, "--color-words")) {
3934                options->use_color = 1;
3935                options->word_diff = DIFF_WORDS_COLOR;
3936        }
3937        else if (skip_prefix(arg, "--color-words=", &arg)) {
3938                options->use_color = 1;
3939                options->word_diff = DIFF_WORDS_COLOR;
3940                options->word_regex = arg;
3941        }
3942        else if (!strcmp(arg, "--word-diff")) {
3943                if (options->word_diff == DIFF_WORDS_NONE)
3944                        options->word_diff = DIFF_WORDS_PLAIN;
3945        }
3946        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3947                if (!strcmp(arg, "plain"))
3948                        options->word_diff = DIFF_WORDS_PLAIN;
3949                else if (!strcmp(arg, "color")) {
3950                        options->use_color = 1;
3951                        options->word_diff = DIFF_WORDS_COLOR;
3952                }
3953                else if (!strcmp(arg, "porcelain"))
3954                        options->word_diff = DIFF_WORDS_PORCELAIN;
3955                else if (!strcmp(arg, "none"))
3956                        options->word_diff = DIFF_WORDS_NONE;
3957                else
3958                        die("bad --word-diff argument: %s", arg);
3959        }
3960        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3961                if (options->word_diff == DIFF_WORDS_NONE)
3962                        options->word_diff = DIFF_WORDS_PLAIN;
3963                options->word_regex = optarg;
3964                return argcount;
3965        }
3966        else if (!strcmp(arg, "--exit-code"))
3967                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3968        else if (!strcmp(arg, "--quiet"))
3969                DIFF_OPT_SET(options, QUICK);
3970        else if (!strcmp(arg, "--ext-diff"))
3971                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3972        else if (!strcmp(arg, "--no-ext-diff"))
3973                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3974        else if (!strcmp(arg, "--textconv"))
3975                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3976        else if (!strcmp(arg, "--no-textconv"))
3977                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3978        else if (!strcmp(arg, "--ignore-submodules")) {
3979                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3980                handle_ignore_submodules_arg(options, "all");
3981        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3982                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3983                handle_ignore_submodules_arg(options, arg);
3984        } else if (!strcmp(arg, "--submodule"))
3985                options->submodule_format = DIFF_SUBMODULE_LOG;
3986        else if (skip_prefix(arg, "--submodule=", &arg))
3987                return parse_submodule_opt(options, arg);
3988        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
3989                return parse_ws_error_highlight_opt(options, arg);
3990        else if (!strcmp(arg, "--ita-invisible-in-index"))
3991                options->ita_invisible_in_index = 1;
3992        else if (!strcmp(arg, "--ita-visible-in-index"))
3993                options->ita_invisible_in_index = 0;
3994
3995        /* misc options */
3996        else if (!strcmp(arg, "-z"))
3997                options->line_termination = 0;
3998        else if ((argcount = short_opt('l', av, &optarg))) {
3999                options->rename_limit = strtoul(optarg, NULL, 10);
4000                return argcount;
4001        }
4002        else if ((argcount = short_opt('S', av, &optarg))) {
4003                options->pickaxe = optarg;
4004                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4005                return argcount;
4006        } else if ((argcount = short_opt('G', av, &optarg))) {
4007                options->pickaxe = optarg;
4008                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4009                return argcount;
4010        }
4011        else if (!strcmp(arg, "--pickaxe-all"))
4012                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4013        else if (!strcmp(arg, "--pickaxe-regex"))
4014                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4015        else if ((argcount = short_opt('O', av, &optarg))) {
4016                const char *path = prefix_filename(prefix, strlen(prefix), optarg);
4017                options->orderfile = xstrdup(path);
4018                return argcount;
4019        }
4020        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4021                int offending = parse_diff_filter_opt(optarg, options);
4022                if (offending)
4023                        die("unknown change class '%c' in --diff-filter=%s",
4024                            offending, optarg);
4025                return argcount;
4026        }
4027        else if (!strcmp(arg, "--abbrev"))
4028                options->abbrev = DEFAULT_ABBREV;
4029        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4030                options->abbrev = strtoul(arg, NULL, 10);
4031                if (options->abbrev < MINIMUM_ABBREV)
4032                        options->abbrev = MINIMUM_ABBREV;
4033                else if (40 < options->abbrev)
4034                        options->abbrev = 40;
4035        }
4036        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4037                options->a_prefix = optarg;
4038                return argcount;
4039        }
4040        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4041                options->line_prefix = optarg;
4042                options->line_prefix_length = strlen(options->line_prefix);
4043                graph_setup_line_prefix(options);
4044                return argcount;
4045        }
4046        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4047                options->b_prefix = optarg;
4048                return argcount;
4049        }
4050        else if (!strcmp(arg, "--no-prefix"))
4051                options->a_prefix = options->b_prefix = "";
4052        else if (opt_arg(arg, '\0', "inter-hunk-context",
4053                         &options->interhunkcontext))
4054                ;
4055        else if (!strcmp(arg, "-W"))
4056                DIFF_OPT_SET(options, FUNCCONTEXT);
4057        else if (!strcmp(arg, "--function-context"))
4058                DIFF_OPT_SET(options, FUNCCONTEXT);
4059        else if (!strcmp(arg, "--no-function-context"))
4060                DIFF_OPT_CLR(options, FUNCCONTEXT);
4061        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4062                const char *path = prefix_filename(prefix, strlen(prefix), optarg);
4063                options->file = fopen(path, "w");
4064                if (!options->file)
4065                        die_errno("Could not open '%s'", path);
4066                options->close_file = 1;
4067                if (options->use_color != GIT_COLOR_ALWAYS)
4068                        options->use_color = GIT_COLOR_NEVER;
4069                return argcount;
4070        } else
4071                return 0;
4072        return 1;
4073}
4074
4075int parse_rename_score(const char **cp_p)
4076{
4077        unsigned long num, scale;
4078        int ch, dot;
4079        const char *cp = *cp_p;
4080
4081        num = 0;
4082        scale = 1;
4083        dot = 0;
4084        for (;;) {
4085                ch = *cp;
4086                if ( !dot && ch == '.' ) {
4087                        scale = 1;
4088                        dot = 1;
4089                } else if ( ch == '%' ) {
4090                        scale = dot ? scale*100 : 100;
4091                        cp++;   /* % is always at the end */
4092                        break;
4093                } else if ( ch >= '0' && ch <= '9' ) {
4094                        if ( scale < 100000 ) {
4095                                scale *= 10;
4096                                num = (num*10) + (ch-'0');
4097                        }
4098                } else {
4099                        break;
4100                }
4101                cp++;
4102        }
4103        *cp_p = cp;
4104
4105        /* user says num divided by scale and we say internally that
4106         * is MAX_SCORE * num / scale.
4107         */
4108        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4109}
4110
4111static int diff_scoreopt_parse(const char *opt)
4112{
4113        int opt1, opt2, cmd;
4114
4115        if (*opt++ != '-')
4116                return -1;
4117        cmd = *opt++;
4118        if (cmd == '-') {
4119                /* convert the long-form arguments into short-form versions */
4120                if (skip_prefix(opt, "break-rewrites", &opt)) {
4121                        if (*opt == 0 || *opt++ == '=')
4122                                cmd = 'B';
4123                } else if (skip_prefix(opt, "find-copies", &opt)) {
4124                        if (*opt == 0 || *opt++ == '=')
4125                                cmd = 'C';
4126                } else if (skip_prefix(opt, "find-renames", &opt)) {
4127                        if (*opt == 0 || *opt++ == '=')
4128                                cmd = 'M';
4129                }
4130        }
4131        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4132                return -1; /* that is not a -M, -C, or -B option */
4133
4134        opt1 = parse_rename_score(&opt);
4135        if (cmd != 'B')
4136                opt2 = 0;
4137        else {
4138                if (*opt == 0)
4139                        opt2 = 0;
4140                else if (*opt != '/')
4141                        return -1; /* we expect -B80/99 or -B80 */
4142                else {
4143                        opt++;
4144                        opt2 = parse_rename_score(&opt);
4145                }
4146        }
4147        if (*opt != 0)
4148                return -1;
4149        return opt1 | (opt2 << 16);
4150}
4151
4152struct diff_queue_struct diff_queued_diff;
4153
4154void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4155{
4156        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4157        queue->queue[queue->nr++] = dp;
4158}
4159
4160struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4161                                 struct diff_filespec *one,
4162                                 struct diff_filespec *two)
4163{
4164        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4165        dp->one = one;
4166        dp->two = two;
4167        if (queue)
4168                diff_q(queue, dp);
4169        return dp;
4170}
4171
4172void diff_free_filepair(struct diff_filepair *p)
4173{
4174        free_filespec(p->one);
4175        free_filespec(p->two);
4176        free(p);
4177}
4178
4179const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4180{
4181        int abblen;
4182        const char *abbrev;
4183
4184        if (len == GIT_SHA1_HEXSZ)
4185                return oid_to_hex(oid);
4186
4187        abbrev = diff_abbrev_oid(oid, len);
4188        abblen = strlen(abbrev);
4189
4190        /*
4191         * In well-behaved cases, where the abbbreviated result is the
4192         * same as the requested length, append three dots after the
4193         * abbreviation (hence the whole logic is limited to the case
4194         * where abblen < 37); when the actual abbreviated result is a
4195         * bit longer than the requested length, we reduce the number
4196         * of dots so that they match the well-behaved ones.  However,
4197         * if the actual abbreviation is longer than the requested
4198         * length by more than three, we give up on aligning, and add
4199         * three dots anyway, to indicate that the output is not the
4200         * full object name.  Yes, this may be suboptimal, but this
4201         * appears only in "diff --raw --abbrev" output and it is not
4202         * worth the effort to change it now.  Note that this would
4203         * likely to work fine when the automatic sizing of default
4204         * abbreviation length is used--we would be fed -1 in "len" in
4205         * that case, and will end up always appending three-dots, but
4206         * the automatic sizing is supposed to give abblen that ensures
4207         * uniqueness across all objects (statistically speaking).
4208         */
4209        if (abblen < GIT_SHA1_HEXSZ - 3) {
4210                static char hex[GIT_SHA1_HEXSZ + 1];
4211                if (len < abblen && abblen <= len + 2)
4212                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4213                else
4214                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4215                return hex;
4216        }
4217
4218        return oid_to_hex(oid);
4219}
4220
4221static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4222{
4223        int line_termination = opt->line_termination;
4224        int inter_name_termination = line_termination ? '\t' : '\0';
4225
4226        fprintf(opt->file, "%s", diff_line_prefix(opt));
4227        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4228                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4229                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4230                fprintf(opt->file, "%s ",
4231                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4232        }
4233        if (p->score) {
4234                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4235                        inter_name_termination);
4236        } else {
4237                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4238        }
4239
4240        if (p->status == DIFF_STATUS_COPIED ||
4241            p->status == DIFF_STATUS_RENAMED) {
4242                const char *name_a, *name_b;
4243                name_a = p->one->path;
4244                name_b = p->two->path;
4245                strip_prefix(opt->prefix_length, &name_a, &name_b);
4246                write_name_quoted(name_a, opt->file, inter_name_termination);
4247                write_name_quoted(name_b, opt->file, line_termination);
4248        } else {
4249                const char *name_a, *name_b;
4250                name_a = p->one->mode ? p->one->path : p->two->path;
4251                name_b = NULL;
4252                strip_prefix(opt->prefix_length, &name_a, &name_b);
4253                write_name_quoted(name_a, opt->file, line_termination);
4254        }
4255}
4256
4257int diff_unmodified_pair(struct diff_filepair *p)
4258{
4259        /* This function is written stricter than necessary to support
4260         * the currently implemented transformers, but the idea is to
4261         * let transformers to produce diff_filepairs any way they want,
4262         * and filter and clean them up here before producing the output.
4263         */
4264        struct diff_filespec *one = p->one, *two = p->two;
4265
4266        if (DIFF_PAIR_UNMERGED(p))
4267                return 0; /* unmerged is interesting */
4268
4269        /* deletion, addition, mode or type change
4270         * and rename are all interesting.
4271         */
4272        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4273            DIFF_PAIR_MODE_CHANGED(p) ||
4274            strcmp(one->path, two->path))
4275                return 0;
4276
4277        /* both are valid and point at the same path.  that is, we are
4278         * dealing with a change.
4279         */
4280        if (one->oid_valid && two->oid_valid &&
4281            !oidcmp(&one->oid, &two->oid) &&
4282            !one->dirty_submodule && !two->dirty_submodule)
4283                return 1; /* no change */
4284        if (!one->oid_valid && !two->oid_valid)
4285                return 1; /* both look at the same file on the filesystem. */
4286        return 0;
4287}
4288
4289static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4290{
4291        if (diff_unmodified_pair(p))
4292                return;
4293
4294        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4295            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4296                return; /* no tree diffs in patch format */
4297
4298        run_diff(p, o);
4299}
4300
4301static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4302                            struct diffstat_t *diffstat)
4303{
4304        if (diff_unmodified_pair(p))
4305                return;
4306
4307        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4308            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4309                return; /* no useful stat for tree diffs */
4310
4311        run_diffstat(p, o, diffstat);
4312}
4313
4314static void diff_flush_checkdiff(struct diff_filepair *p,
4315                struct diff_options *o)
4316{
4317        if (diff_unmodified_pair(p))
4318                return;
4319
4320        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4321            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4322                return; /* nothing to check in tree diffs */
4323
4324        run_checkdiff(p, o);
4325}
4326
4327int diff_queue_is_empty(void)
4328{
4329        struct diff_queue_struct *q = &diff_queued_diff;
4330        int i;
4331        for (i = 0; i < q->nr; i++)
4332                if (!diff_unmodified_pair(q->queue[i]))
4333                        return 0;
4334        return 1;
4335}
4336
4337#if DIFF_DEBUG
4338void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4339{
4340        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4341                x, one ? one : "",
4342                s->path,
4343                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4344                s->mode,
4345                s->oid_valid ? oid_to_hex(&s->oid) : "");
4346        fprintf(stderr, "queue[%d] %s size %lu\n",
4347                x, one ? one : "",
4348                s->size);
4349}
4350
4351void diff_debug_filepair(const struct diff_filepair *p, int i)
4352{
4353        diff_debug_filespec(p->one, i, "one");
4354        diff_debug_filespec(p->two, i, "two");
4355        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4356                p->score, p->status ? p->status : '?',
4357                p->one->rename_used, p->broken_pair);
4358}
4359
4360void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4361{
4362        int i;
4363        if (msg)
4364                fprintf(stderr, "%s\n", msg);
4365        fprintf(stderr, "q->nr = %d\n", q->nr);
4366        for (i = 0; i < q->nr; i++) {
4367                struct diff_filepair *p = q->queue[i];
4368                diff_debug_filepair(p, i);
4369        }
4370}
4371#endif
4372
4373static void diff_resolve_rename_copy(void)
4374{
4375        int i;
4376        struct diff_filepair *p;
4377        struct diff_queue_struct *q = &diff_queued_diff;
4378
4379        diff_debug_queue("resolve-rename-copy", q);
4380
4381        for (i = 0; i < q->nr; i++) {
4382                p = q->queue[i];
4383                p->status = 0; /* undecided */
4384                if (DIFF_PAIR_UNMERGED(p))
4385                        p->status = DIFF_STATUS_UNMERGED;
4386                else if (!DIFF_FILE_VALID(p->one))
4387                        p->status = DIFF_STATUS_ADDED;
4388                else if (!DIFF_FILE_VALID(p->two))
4389                        p->status = DIFF_STATUS_DELETED;
4390                else if (DIFF_PAIR_TYPE_CHANGED(p))
4391                        p->status = DIFF_STATUS_TYPE_CHANGED;
4392
4393                /* from this point on, we are dealing with a pair
4394                 * whose both sides are valid and of the same type, i.e.
4395                 * either in-place edit or rename/copy edit.
4396                 */
4397                else if (DIFF_PAIR_RENAME(p)) {
4398                        /*
4399                         * A rename might have re-connected a broken
4400                         * pair up, causing the pathnames to be the
4401                         * same again. If so, that's not a rename at
4402                         * all, just a modification..
4403                         *
4404                         * Otherwise, see if this source was used for
4405                         * multiple renames, in which case we decrement
4406                         * the count, and call it a copy.
4407                         */
4408                        if (!strcmp(p->one->path, p->two->path))
4409                                p->status = DIFF_STATUS_MODIFIED;
4410                        else if (--p->one->rename_used > 0)
4411                                p->status = DIFF_STATUS_COPIED;
4412                        else
4413                                p->status = DIFF_STATUS_RENAMED;
4414                }
4415                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4416                         p->one->mode != p->two->mode ||
4417                         p->one->dirty_submodule ||
4418                         p->two->dirty_submodule ||
4419                         is_null_oid(&p->one->oid))
4420                        p->status = DIFF_STATUS_MODIFIED;
4421                else {
4422                        /* This is a "no-change" entry and should not
4423                         * happen anymore, but prepare for broken callers.
4424                         */
4425                        error("feeding unmodified %s to diffcore",
4426                              p->one->path);
4427                        p->status = DIFF_STATUS_UNKNOWN;
4428                }
4429        }
4430        diff_debug_queue("resolve-rename-copy done", q);
4431}
4432
4433static int check_pair_status(struct diff_filepair *p)
4434{
4435        switch (p->status) {
4436        case DIFF_STATUS_UNKNOWN:
4437                return 0;
4438        case 0:
4439                die("internal error in diff-resolve-rename-copy");
4440        default:
4441                return 1;
4442        }
4443}
4444
4445static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4446{
4447        int fmt = opt->output_format;
4448
4449        if (fmt & DIFF_FORMAT_CHECKDIFF)
4450                diff_flush_checkdiff(p, opt);
4451        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4452                diff_flush_raw(p, opt);
4453        else if (fmt & DIFF_FORMAT_NAME) {
4454                const char *name_a, *name_b;
4455                name_a = p->two->path;
4456                name_b = NULL;
4457                strip_prefix(opt->prefix_length, &name_a, &name_b);
4458                write_name_quoted(name_a, opt->file, opt->line_termination);
4459        }
4460}
4461
4462static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4463{
4464        if (fs->mode)
4465                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4466        else
4467                fprintf(file, " %s ", newdelete);
4468        write_name_quoted(fs->path, file, '\n');
4469}
4470
4471
4472static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4473                const char *line_prefix)
4474{
4475        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4476                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4477                        p->two->mode, show_name ? ' ' : '\n');
4478                if (show_name) {
4479                        write_name_quoted(p->two->path, file, '\n');
4480                }
4481        }
4482}
4483
4484static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4485                        const char *line_prefix)
4486{
4487        char *names = pprint_rename(p->one->path, p->two->path);
4488
4489        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4490        free(names);
4491        show_mode_change(file, p, 0, line_prefix);
4492}
4493
4494static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4495{
4496        FILE *file = opt->file;
4497        const char *line_prefix = diff_line_prefix(opt);
4498
4499        switch(p->status) {
4500        case DIFF_STATUS_DELETED:
4501                fputs(line_prefix, file);
4502                show_file_mode_name(file, "delete", p->one);
4503                break;
4504        case DIFF_STATUS_ADDED:
4505                fputs(line_prefix, file);
4506                show_file_mode_name(file, "create", p->two);
4507                break;
4508        case DIFF_STATUS_COPIED:
4509                fputs(line_prefix, file);
4510                show_rename_copy(file, "copy", p, line_prefix);
4511                break;
4512        case DIFF_STATUS_RENAMED:
4513                fputs(line_prefix, file);
4514                show_rename_copy(file, "rename", p, line_prefix);
4515                break;
4516        default:
4517                if (p->score) {
4518                        fprintf(file, "%s rewrite ", line_prefix);
4519                        write_name_quoted(p->two->path, file, ' ');
4520                        fprintf(file, "(%d%%)\n", similarity_index(p));
4521                }
4522                show_mode_change(file, p, !p->score, line_prefix);
4523                break;
4524        }
4525}
4526
4527struct patch_id_t {
4528        git_SHA_CTX *ctx;
4529        int patchlen;
4530};
4531
4532static int remove_space(char *line, int len)
4533{
4534        int i;
4535        char *dst = line;
4536        unsigned char c;
4537
4538        for (i = 0; i < len; i++)
4539                if (!isspace((c = line[i])))
4540                        *dst++ = c;
4541
4542        return dst - line;
4543}
4544
4545static void patch_id_consume(void *priv, char *line, unsigned long len)
4546{
4547        struct patch_id_t *data = priv;
4548        int new_len;
4549
4550        /* Ignore line numbers when computing the SHA1 of the patch */
4551        if (starts_with(line, "@@ -"))
4552                return;
4553
4554        new_len = remove_space(line, len);
4555
4556        git_SHA1_Update(data->ctx, line, new_len);
4557        data->patchlen += new_len;
4558}
4559
4560/* returns 0 upon success, and writes result into sha1 */
4561static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
4562{
4563        struct diff_queue_struct *q = &diff_queued_diff;
4564        int i;
4565        git_SHA_CTX ctx;
4566        struct patch_id_t data;
4567        char buffer[PATH_MAX * 4 + 20];
4568
4569        git_SHA1_Init(&ctx);
4570        memset(&data, 0, sizeof(struct patch_id_t));
4571        data.ctx = &ctx;
4572
4573        for (i = 0; i < q->nr; i++) {
4574                xpparam_t xpp;
4575                xdemitconf_t xecfg;
4576                mmfile_t mf1, mf2;
4577                struct diff_filepair *p = q->queue[i];
4578                int len1, len2;
4579
4580                memset(&xpp, 0, sizeof(xpp));
4581                memset(&xecfg, 0, sizeof(xecfg));
4582                if (p->status == 0)
4583                        return error("internal diff status error");
4584                if (p->status == DIFF_STATUS_UNKNOWN)
4585                        continue;
4586                if (diff_unmodified_pair(p))
4587                        continue;
4588                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4589                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4590                        continue;
4591                if (DIFF_PAIR_UNMERGED(p))
4592                        continue;
4593
4594                diff_fill_sha1_info(p->one);
4595                diff_fill_sha1_info(p->two);
4596
4597                len1 = remove_space(p->one->path, strlen(p->one->path));
4598                len2 = remove_space(p->two->path, strlen(p->two->path));
4599                if (p->one->mode == 0)
4600                        len1 = snprintf(buffer, sizeof(buffer),
4601                                        "diff--gita/%.*sb/%.*s"
4602                                        "newfilemode%06o"
4603                                        "---/dev/null"
4604                                        "+++b/%.*s",
4605                                        len1, p->one->path,
4606                                        len2, p->two->path,
4607                                        p->two->mode,
4608                                        len2, p->two->path);
4609                else if (p->two->mode == 0)
4610                        len1 = snprintf(buffer, sizeof(buffer),
4611                                        "diff--gita/%.*sb/%.*s"
4612                                        "deletedfilemode%06o"
4613                                        "---a/%.*s"
4614                                        "+++/dev/null",
4615                                        len1, p->one->path,
4616                                        len2, p->two->path,
4617                                        p->one->mode,
4618                                        len1, p->one->path);
4619                else
4620                        len1 = snprintf(buffer, sizeof(buffer),
4621                                        "diff--gita/%.*sb/%.*s"
4622                                        "---a/%.*s"
4623                                        "+++b/%.*s",
4624                                        len1, p->one->path,
4625                                        len2, p->two->path,
4626                                        len1, p->one->path,
4627                                        len2, p->two->path);
4628                git_SHA1_Update(&ctx, buffer, len1);
4629
4630                if (diff_header_only)
4631                        continue;
4632
4633                if (fill_mmfile(&mf1, p->one) < 0 ||
4634                    fill_mmfile(&mf2, p->two) < 0)
4635                        return error("unable to read files to diff");
4636
4637                if (diff_filespec_is_binary(p->one) ||
4638                    diff_filespec_is_binary(p->two)) {
4639                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4640                                        40);
4641                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4642                                        40);
4643                        continue;
4644                }
4645
4646                xpp.flags = 0;
4647                xecfg.ctxlen = 3;
4648                xecfg.flags = 0;
4649                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4650                                  &xpp, &xecfg))
4651                        return error("unable to generate patch-id diff for %s",
4652                                     p->one->path);
4653        }
4654
4655        git_SHA1_Final(sha1, &ctx);
4656        return 0;
4657}
4658
4659int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
4660{
4661        struct diff_queue_struct *q = &diff_queued_diff;
4662        int i;
4663        int result = diff_get_patch_id(options, sha1, diff_header_only);
4664
4665        for (i = 0; i < q->nr; i++)
4666                diff_free_filepair(q->queue[i]);
4667
4668        free(q->queue);
4669        DIFF_QUEUE_CLEAR(q);
4670
4671        return result;
4672}
4673
4674static int is_summary_empty(const struct diff_queue_struct *q)
4675{
4676        int i;
4677
4678        for (i = 0; i < q->nr; i++) {
4679                const struct diff_filepair *p = q->queue[i];
4680
4681                switch (p->status) {
4682                case DIFF_STATUS_DELETED:
4683                case DIFF_STATUS_ADDED:
4684                case DIFF_STATUS_COPIED:
4685                case DIFF_STATUS_RENAMED:
4686                        return 0;
4687                default:
4688                        if (p->score)
4689                                return 0;
4690                        if (p->one->mode && p->two->mode &&
4691                            p->one->mode != p->two->mode)
4692                                return 0;
4693                        break;
4694                }
4695        }
4696        return 1;
4697}
4698
4699static const char rename_limit_warning[] =
4700N_("inexact rename detection was skipped due to too many files.");
4701
4702static const char degrade_cc_to_c_warning[] =
4703N_("only found copies from modified paths due to too many files.");
4704
4705static const char rename_limit_advice[] =
4706N_("you may want to set your %s variable to at least "
4707   "%d and retry the command.");
4708
4709void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4710{
4711        if (degraded_cc)
4712                warning(_(degrade_cc_to_c_warning));
4713        else if (needed)
4714                warning(_(rename_limit_warning));
4715        else
4716                return;
4717        if (0 < needed && needed < 32767)
4718                warning(_(rename_limit_advice), varname, needed);
4719}
4720
4721void diff_flush(struct diff_options *options)
4722{
4723        struct diff_queue_struct *q = &diff_queued_diff;
4724        int i, output_format = options->output_format;
4725        int separator = 0;
4726        int dirstat_by_line = 0;
4727
4728        /*
4729         * Order: raw, stat, summary, patch
4730         * or:    name/name-status/checkdiff (other bits clear)
4731         */
4732        if (!q->nr)
4733                goto free_queue;
4734
4735        if (output_format & (DIFF_FORMAT_RAW |
4736                             DIFF_FORMAT_NAME |
4737                             DIFF_FORMAT_NAME_STATUS |
4738                             DIFF_FORMAT_CHECKDIFF)) {
4739                for (i = 0; i < q->nr; i++) {
4740                        struct diff_filepair *p = q->queue[i];
4741                        if (check_pair_status(p))
4742                                flush_one_pair(p, options);
4743                }
4744                separator++;
4745        }
4746
4747        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4748                dirstat_by_line = 1;
4749
4750        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4751            dirstat_by_line) {
4752                struct diffstat_t diffstat;
4753
4754                memset(&diffstat, 0, sizeof(struct diffstat_t));
4755                for (i = 0; i < q->nr; i++) {
4756                        struct diff_filepair *p = q->queue[i];
4757                        if (check_pair_status(p))
4758                                diff_flush_stat(p, options, &diffstat);
4759                }
4760                if (output_format & DIFF_FORMAT_NUMSTAT)
4761                        show_numstat(&diffstat, options);
4762                if (output_format & DIFF_FORMAT_DIFFSTAT)
4763                        show_stats(&diffstat, options);
4764                if (output_format & DIFF_FORMAT_SHORTSTAT)
4765                        show_shortstats(&diffstat, options);
4766                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4767                        show_dirstat_by_line(&diffstat, options);
4768                free_diffstat_info(&diffstat);
4769                separator++;
4770        }
4771        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4772                show_dirstat(options);
4773
4774        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4775                for (i = 0; i < q->nr; i++) {
4776                        diff_summary(options, q->queue[i]);
4777                }
4778                separator++;
4779        }
4780
4781        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4782            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4783            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4784                /*
4785                 * run diff_flush_patch for the exit status. setting
4786                 * options->file to /dev/null should be safe, because we
4787                 * aren't supposed to produce any output anyway.
4788                 */
4789                if (options->close_file)
4790                        fclose(options->file);
4791                options->file = fopen("/dev/null", "w");
4792                if (!options->file)
4793                        die_errno("Could not open /dev/null");
4794                options->close_file = 1;
4795                for (i = 0; i < q->nr; i++) {
4796                        struct diff_filepair *p = q->queue[i];
4797                        if (check_pair_status(p))
4798                                diff_flush_patch(p, options);
4799                        if (options->found_changes)
4800                                break;
4801                }
4802        }
4803
4804        if (output_format & DIFF_FORMAT_PATCH) {
4805                if (separator) {
4806                        fprintf(options->file, "%s%c",
4807                                diff_line_prefix(options),
4808                                options->line_termination);
4809                        if (options->stat_sep) {
4810                                /* attach patch instead of inline */
4811                                fputs(options->stat_sep, options->file);
4812                        }
4813                }
4814
4815                for (i = 0; i < q->nr; i++) {
4816                        struct diff_filepair *p = q->queue[i];
4817                        if (check_pair_status(p))
4818                                diff_flush_patch(p, options);
4819                }
4820        }
4821
4822        if (output_format & DIFF_FORMAT_CALLBACK)
4823                options->format_callback(q, options, options->format_callback_data);
4824
4825        for (i = 0; i < q->nr; i++)
4826                diff_free_filepair(q->queue[i]);
4827free_queue:
4828        free(q->queue);
4829        DIFF_QUEUE_CLEAR(q);
4830        if (options->close_file)
4831                fclose(options->file);
4832
4833        /*
4834         * Report the content-level differences with HAS_CHANGES;
4835         * diff_addremove/diff_change does not set the bit when
4836         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4837         */
4838        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4839                if (options->found_changes)
4840                        DIFF_OPT_SET(options, HAS_CHANGES);
4841                else
4842                        DIFF_OPT_CLR(options, HAS_CHANGES);
4843        }
4844}
4845
4846static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4847{
4848        return (((p->status == DIFF_STATUS_MODIFIED) &&
4849                 ((p->score &&
4850                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4851                  (!p->score &&
4852                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4853                ((p->status != DIFF_STATUS_MODIFIED) &&
4854                 filter_bit_tst(p->status, options)));
4855}
4856
4857static void diffcore_apply_filter(struct diff_options *options)
4858{
4859        int i;
4860        struct diff_queue_struct *q = &diff_queued_diff;
4861        struct diff_queue_struct outq;
4862
4863        DIFF_QUEUE_CLEAR(&outq);
4864
4865        if (!options->filter)
4866                return;
4867
4868        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4869                int found;
4870                for (i = found = 0; !found && i < q->nr; i++) {
4871                        if (match_filter(options, q->queue[i]))
4872                                found++;
4873                }
4874                if (found)
4875                        return;
4876
4877                /* otherwise we will clear the whole queue
4878                 * by copying the empty outq at the end of this
4879                 * function, but first clear the current entries
4880                 * in the queue.
4881                 */
4882                for (i = 0; i < q->nr; i++)
4883                        diff_free_filepair(q->queue[i]);
4884        }
4885        else {
4886                /* Only the matching ones */
4887                for (i = 0; i < q->nr; i++) {
4888                        struct diff_filepair *p = q->queue[i];
4889                        if (match_filter(options, p))
4890                                diff_q(&outq, p);
4891                        else
4892                                diff_free_filepair(p);
4893                }
4894        }
4895        free(q->queue);
4896        *q = outq;
4897}
4898
4899/* Check whether two filespecs with the same mode and size are identical */
4900static int diff_filespec_is_identical(struct diff_filespec *one,
4901                                      struct diff_filespec *two)
4902{
4903        if (S_ISGITLINK(one->mode))
4904                return 0;
4905        if (diff_populate_filespec(one, 0))
4906                return 0;
4907        if (diff_populate_filespec(two, 0))
4908                return 0;
4909        return !memcmp(one->data, two->data, one->size);
4910}
4911
4912static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4913{
4914        if (p->done_skip_stat_unmatch)
4915                return p->skip_stat_unmatch_result;
4916
4917        p->done_skip_stat_unmatch = 1;
4918        p->skip_stat_unmatch_result = 0;
4919        /*
4920         * 1. Entries that come from stat info dirtiness
4921         *    always have both sides (iow, not create/delete),
4922         *    one side of the object name is unknown, with
4923         *    the same mode and size.  Keep the ones that
4924         *    do not match these criteria.  They have real
4925         *    differences.
4926         *
4927         * 2. At this point, the file is known to be modified,
4928         *    with the same mode and size, and the object
4929         *    name of one side is unknown.  Need to inspect
4930         *    the identical contents.
4931         */
4932        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4933            !DIFF_FILE_VALID(p->two) ||
4934            (p->one->oid_valid && p->two->oid_valid) ||
4935            (p->one->mode != p->two->mode) ||
4936            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4937            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4938            (p->one->size != p->two->size) ||
4939            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4940                p->skip_stat_unmatch_result = 1;
4941        return p->skip_stat_unmatch_result;
4942}
4943
4944static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4945{
4946        int i;
4947        struct diff_queue_struct *q = &diff_queued_diff;
4948        struct diff_queue_struct outq;
4949        DIFF_QUEUE_CLEAR(&outq);
4950
4951        for (i = 0; i < q->nr; i++) {
4952                struct diff_filepair *p = q->queue[i];
4953
4954                if (diff_filespec_check_stat_unmatch(p))
4955                        diff_q(&outq, p);
4956                else {
4957                        /*
4958                         * The caller can subtract 1 from skip_stat_unmatch
4959                         * to determine how many paths were dirty only
4960                         * due to stat info mismatch.
4961                         */
4962                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4963                                diffopt->skip_stat_unmatch++;
4964                        diff_free_filepair(p);
4965                }
4966        }
4967        free(q->queue);
4968        *q = outq;
4969}
4970
4971static int diffnamecmp(const void *a_, const void *b_)
4972{
4973        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4974        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4975        const char *name_a, *name_b;
4976
4977        name_a = a->one ? a->one->path : a->two->path;
4978        name_b = b->one ? b->one->path : b->two->path;
4979        return strcmp(name_a, name_b);
4980}
4981
4982void diffcore_fix_diff_index(struct diff_options *options)
4983{
4984        struct diff_queue_struct *q = &diff_queued_diff;
4985        QSORT(q->queue, q->nr, diffnamecmp);
4986}
4987
4988void diffcore_std(struct diff_options *options)
4989{
4990        /* NOTE please keep the following in sync with diff_tree_combined() */
4991        if (options->skip_stat_unmatch)
4992                diffcore_skip_stat_unmatch(options);
4993        if (!options->found_follow) {
4994                /* See try_to_follow_renames() in tree-diff.c */
4995                if (options->break_opt != -1)
4996                        diffcore_break(options->break_opt);
4997                if (options->detect_rename)
4998                        diffcore_rename(options);
4999                if (options->break_opt != -1)
5000                        diffcore_merge_broken();
5001        }
5002        if (options->pickaxe)
5003                diffcore_pickaxe(options);
5004        if (options->orderfile)
5005                diffcore_order(options->orderfile);
5006        if (!options->found_follow)
5007                /* See try_to_follow_renames() in tree-diff.c */
5008                diff_resolve_rename_copy();
5009        diffcore_apply_filter(options);
5010
5011        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5012                DIFF_OPT_SET(options, HAS_CHANGES);
5013        else
5014                DIFF_OPT_CLR(options, HAS_CHANGES);
5015
5016        options->found_follow = 0;
5017}
5018
5019int diff_result_code(struct diff_options *opt, int status)
5020{
5021        int result = 0;
5022
5023        diff_warn_rename_limit("diff.renameLimit",
5024                               opt->needed_rename_limit,
5025                               opt->degraded_cc_to_c);
5026        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5027            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5028                return status;
5029        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5030            DIFF_OPT_TST(opt, HAS_CHANGES))
5031                result |= 01;
5032        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5033            DIFF_OPT_TST(opt, CHECK_FAILED))
5034                result |= 02;
5035        return result;
5036}
5037
5038int diff_can_quit_early(struct diff_options *opt)
5039{
5040        return (DIFF_OPT_TST(opt, QUICK) &&
5041                !opt->filter &&
5042                DIFF_OPT_TST(opt, HAS_CHANGES));
5043}
5044
5045/*
5046 * Shall changes to this submodule be ignored?
5047 *
5048 * Submodule changes can be configured to be ignored separately for each path,
5049 * but that configuration can be overridden from the command line.
5050 */
5051static int is_submodule_ignored(const char *path, struct diff_options *options)
5052{
5053        int ignored = 0;
5054        unsigned orig_flags = options->flags;
5055        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5056                set_diffopt_flags_from_submodule_config(options, path);
5057        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5058                ignored = 1;
5059        options->flags = orig_flags;
5060        return ignored;
5061}
5062
5063void diff_addremove(struct diff_options *options,
5064                    int addremove, unsigned mode,
5065                    const unsigned char *sha1,
5066                    int sha1_valid,
5067                    const char *concatpath, unsigned dirty_submodule)
5068{
5069        struct diff_filespec *one, *two;
5070
5071        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5072                return;
5073
5074        /* This may look odd, but it is a preparation for
5075         * feeding "there are unchanged files which should
5076         * not produce diffs, but when you are doing copy
5077         * detection you would need them, so here they are"
5078         * entries to the diff-core.  They will be prefixed
5079         * with something like '=' or '*' (I haven't decided
5080         * which but should not make any difference).
5081         * Feeding the same new and old to diff_change()
5082         * also has the same effect.
5083         * Before the final output happens, they are pruned after
5084         * merged into rename/copy pairs as appropriate.
5085         */
5086        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5087                addremove = (addremove == '+' ? '-' :
5088                             addremove == '-' ? '+' : addremove);
5089
5090        if (options->prefix &&
5091            strncmp(concatpath, options->prefix, options->prefix_length))
5092                return;
5093
5094        one = alloc_filespec(concatpath);
5095        two = alloc_filespec(concatpath);
5096
5097        if (addremove != '+')
5098                fill_filespec(one, sha1, sha1_valid, mode);
5099        if (addremove != '-') {
5100                fill_filespec(two, sha1, sha1_valid, mode);
5101                two->dirty_submodule = dirty_submodule;
5102        }
5103
5104        diff_queue(&diff_queued_diff, one, two);
5105        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5106                DIFF_OPT_SET(options, HAS_CHANGES);
5107}
5108
5109void diff_change(struct diff_options *options,
5110                 unsigned old_mode, unsigned new_mode,
5111                 const unsigned char *old_sha1,
5112                 const unsigned char *new_sha1,
5113                 int old_sha1_valid, int new_sha1_valid,
5114                 const char *concatpath,
5115                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5116{
5117        struct diff_filespec *one, *two;
5118        struct diff_filepair *p;
5119
5120        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5121            is_submodule_ignored(concatpath, options))
5122                return;
5123
5124        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5125                unsigned tmp;
5126                const unsigned char *tmp_c;
5127                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
5128                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
5129                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
5130                        new_sha1_valid = tmp;
5131                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
5132                        new_dirty_submodule = tmp;
5133        }
5134
5135        if (options->prefix &&
5136            strncmp(concatpath, options->prefix, options->prefix_length))
5137                return;
5138
5139        one = alloc_filespec(concatpath);
5140        two = alloc_filespec(concatpath);
5141        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
5142        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
5143        one->dirty_submodule = old_dirty_submodule;
5144        two->dirty_submodule = new_dirty_submodule;
5145        p = diff_queue(&diff_queued_diff, one, two);
5146
5147        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5148                return;
5149
5150        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5151            !diff_filespec_check_stat_unmatch(p))
5152                return;
5153
5154        DIFF_OPT_SET(options, HAS_CHANGES);
5155}
5156
5157struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5158{
5159        struct diff_filepair *pair;
5160        struct diff_filespec *one, *two;
5161
5162        if (options->prefix &&
5163            strncmp(path, options->prefix, options->prefix_length))
5164                return NULL;
5165
5166        one = alloc_filespec(path);
5167        two = alloc_filespec(path);
5168        pair = diff_queue(&diff_queued_diff, one, two);
5169        pair->is_unmerged = 1;
5170        return pair;
5171}
5172
5173static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5174                size_t *outsize)
5175{
5176        struct diff_tempfile *temp;
5177        const char *argv[3];
5178        const char **arg = argv;
5179        struct child_process child = CHILD_PROCESS_INIT;
5180        struct strbuf buf = STRBUF_INIT;
5181        int err = 0;
5182
5183        temp = prepare_temp_file(spec->path, spec);
5184        *arg++ = pgm;
5185        *arg++ = temp->name;
5186        *arg = NULL;
5187
5188        child.use_shell = 1;
5189        child.argv = argv;
5190        child.out = -1;
5191        if (start_command(&child)) {
5192                remove_tempfile();
5193                return NULL;
5194        }
5195
5196        if (strbuf_read(&buf, child.out, 0) < 0)
5197                err = error("error reading from textconv command '%s'", pgm);
5198        close(child.out);
5199
5200        if (finish_command(&child) || err) {
5201                strbuf_release(&buf);
5202                remove_tempfile();
5203                return NULL;
5204        }
5205        remove_tempfile();
5206
5207        return strbuf_detach(&buf, outsize);
5208}
5209
5210size_t fill_textconv(struct userdiff_driver *driver,
5211                     struct diff_filespec *df,
5212                     char **outbuf)
5213{
5214        size_t size;
5215
5216        if (!driver) {
5217                if (!DIFF_FILE_VALID(df)) {
5218                        *outbuf = "";
5219                        return 0;
5220                }
5221                if (diff_populate_filespec(df, 0))
5222                        die("unable to read files to diff");
5223                *outbuf = df->data;
5224                return df->size;
5225        }
5226
5227        if (!driver->textconv)
5228                die("BUG: fill_textconv called with non-textconv driver");
5229
5230        if (driver->textconv_cache && df->oid_valid) {
5231                *outbuf = notes_cache_get(driver->textconv_cache,
5232                                          df->oid.hash,
5233                                          &size);
5234                if (*outbuf)
5235                        return size;
5236        }
5237
5238        *outbuf = run_textconv(driver->textconv, df, &size);
5239        if (!*outbuf)
5240                die("unable to read files to diff");
5241
5242        if (driver->textconv_cache && df->oid_valid) {
5243                /* ignore errors, as we might be in a readonly repository */
5244                notes_cache_put(driver->textconv_cache, df->oid.hash, *outbuf,
5245                                size);
5246                /*
5247                 * we could save up changes and flush them all at the end,
5248                 * but we would need an extra call after all diffing is done.
5249                 * Since generating a cache entry is the slow path anyway,
5250                 * this extra overhead probably isn't a big deal.
5251                 */
5252                notes_cache_write(driver->textconv_cache);
5253        }
5254
5255        return size;
5256}
5257
5258void setup_diff_pager(struct diff_options *opt)
5259{
5260        /*
5261         * If the user asked for our exit code, then either they want --quiet
5262         * or --exit-code. We should definitely not bother with a pager in the
5263         * former case, as we will generate no output. Since we still properly
5264         * report our exit code even when a pager is run, we _could_ run a
5265         * pager with --exit-code. But since we have not done so historically,
5266         * and because it is easy to find people oneline advising "git diff
5267         * --exit-code" in hooks and other scripts, we do not do so.
5268         */
5269        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5270            check_pager_config("diff") != 0)
5271                setup_pager();
5272}