diff.con commit remote-curl: rename shadowed options variable (fcaa6e6)
   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
  22#ifdef NO_FAST_WORKING_DIRECTORY
  23#define FAST_WORKING_DIRECTORY 0
  24#else
  25#define FAST_WORKING_DIRECTORY 1
  26#endif
  27
  28static int diff_detect_rename_default;
  29static int diff_compaction_heuristic; /* experimental */
  30static int diff_rename_limit_default = 400;
  31static int diff_suppress_blank_empty;
  32static int diff_use_color_default = -1;
  33static int diff_context_default = 3;
  34static const char *diff_word_regex_cfg;
  35static const char *external_diff_cmd_cfg;
  36static const char *diff_order_file_cfg;
  37int diff_auto_refresh_index = 1;
  38static int diff_mnemonic_prefix;
  39static int diff_no_prefix;
  40static int diff_stat_graph_width;
  41static int diff_dirstat_permille_default = 30;
  42static struct diff_options default_diff_options;
  43static long diff_algorithm;
  44
  45static char diff_colors[][COLOR_MAXLEN] = {
  46        GIT_COLOR_RESET,
  47        GIT_COLOR_NORMAL,       /* CONTEXT */
  48        GIT_COLOR_BOLD,         /* METAINFO */
  49        GIT_COLOR_CYAN,         /* FRAGINFO */
  50        GIT_COLOR_RED,          /* OLD */
  51        GIT_COLOR_GREEN,        /* NEW */
  52        GIT_COLOR_YELLOW,       /* COMMIT */
  53        GIT_COLOR_BG_RED,       /* WHITESPACE */
  54        GIT_COLOR_NORMAL,       /* FUNCINFO */
  55};
  56
  57static int parse_diff_color_slot(const char *var)
  58{
  59        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  60                return DIFF_CONTEXT;
  61        if (!strcasecmp(var, "meta"))
  62                return DIFF_METAINFO;
  63        if (!strcasecmp(var, "frag"))
  64                return DIFF_FRAGINFO;
  65        if (!strcasecmp(var, "old"))
  66                return DIFF_FILE_OLD;
  67        if (!strcasecmp(var, "new"))
  68                return DIFF_FILE_NEW;
  69        if (!strcasecmp(var, "commit"))
  70                return DIFF_COMMIT;
  71        if (!strcasecmp(var, "whitespace"))
  72                return DIFF_WHITESPACE;
  73        if (!strcasecmp(var, "func"))
  74                return DIFF_FUNCINFO;
  75        return -1;
  76}
  77
  78static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  79                                struct strbuf *errmsg)
  80{
  81        char *params_copy = xstrdup(params_string);
  82        struct string_list params = STRING_LIST_INIT_NODUP;
  83        int ret = 0;
  84        int i;
  85
  86        if (*params_copy)
  87                string_list_split_in_place(&params, params_copy, ',', -1);
  88        for (i = 0; i < params.nr; i++) {
  89                const char *p = params.items[i].string;
  90                if (!strcmp(p, "changes")) {
  91                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  92                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  93                } else if (!strcmp(p, "lines")) {
  94                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  95                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  96                } else if (!strcmp(p, "files")) {
  97                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  98                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  99                } else if (!strcmp(p, "noncumulative")) {
 100                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 101                } else if (!strcmp(p, "cumulative")) {
 102                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 103                } else if (isdigit(*p)) {
 104                        char *end;
 105                        int permille = strtoul(p, &end, 10) * 10;
 106                        if (*end == '.' && isdigit(*++end)) {
 107                                /* only use first digit */
 108                                permille += *end - '0';
 109                                /* .. and ignore any further digits */
 110                                while (isdigit(*++end))
 111                                        ; /* nothing */
 112                        }
 113                        if (!*end)
 114                                options->dirstat_permille = permille;
 115                        else {
 116                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 117                                            p);
 118                                ret++;
 119                        }
 120                } else {
 121                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 122                        ret++;
 123                }
 124
 125        }
 126        string_list_clear(&params, 0);
 127        free(params_copy);
 128        return ret;
 129}
 130
 131static int parse_submodule_params(struct diff_options *options, const char *value)
 132{
 133        if (!strcmp(value, "log"))
 134                DIFF_OPT_SET(options, SUBMODULE_LOG);
 135        else if (!strcmp(value, "short"))
 136                DIFF_OPT_CLR(options, SUBMODULE_LOG);
 137        else
 138                return -1;
 139        return 0;
 140}
 141
 142static int git_config_rename(const char *var, const char *value)
 143{
 144        if (!value)
 145                return DIFF_DETECT_RENAME;
 146        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 147                return  DIFF_DETECT_COPY;
 148        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 149}
 150
 151long parse_algorithm_value(const char *value)
 152{
 153        if (!value)
 154                return -1;
 155        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 156                return 0;
 157        else if (!strcasecmp(value, "minimal"))
 158                return XDF_NEED_MINIMAL;
 159        else if (!strcasecmp(value, "patience"))
 160                return XDF_PATIENCE_DIFF;
 161        else if (!strcasecmp(value, "histogram"))
 162                return XDF_HISTOGRAM_DIFF;
 163        return -1;
 164}
 165
 166/*
 167 * These are to give UI layer defaults.
 168 * The core-level commands such as git-diff-files should
 169 * never be affected by the setting of diff.renames
 170 * the user happens to have in the configuration file.
 171 */
 172void init_diff_ui_defaults(void)
 173{
 174        diff_detect_rename_default = 1;
 175}
 176
 177int git_diff_ui_config(const char *var, const char *value, void *cb)
 178{
 179        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 180                diff_use_color_default = git_config_colorbool(var, value);
 181                return 0;
 182        }
 183        if (!strcmp(var, "diff.context")) {
 184                diff_context_default = git_config_int(var, value);
 185                if (diff_context_default < 0)
 186                        return -1;
 187                return 0;
 188        }
 189        if (!strcmp(var, "diff.renames")) {
 190                diff_detect_rename_default = git_config_rename(var, value);
 191                return 0;
 192        }
 193        if (!strcmp(var, "diff.compactionheuristic")) {
 194                diff_compaction_heuristic = git_config_bool(var, value);
 195                return 0;
 196        }
 197        if (!strcmp(var, "diff.autorefreshindex")) {
 198                diff_auto_refresh_index = git_config_bool(var, value);
 199                return 0;
 200        }
 201        if (!strcmp(var, "diff.mnemonicprefix")) {
 202                diff_mnemonic_prefix = git_config_bool(var, value);
 203                return 0;
 204        }
 205        if (!strcmp(var, "diff.noprefix")) {
 206                diff_no_prefix = git_config_bool(var, value);
 207                return 0;
 208        }
 209        if (!strcmp(var, "diff.statgraphwidth")) {
 210                diff_stat_graph_width = git_config_int(var, value);
 211                return 0;
 212        }
 213        if (!strcmp(var, "diff.external"))
 214                return git_config_string(&external_diff_cmd_cfg, var, value);
 215        if (!strcmp(var, "diff.wordregex"))
 216                return git_config_string(&diff_word_regex_cfg, var, value);
 217        if (!strcmp(var, "diff.orderfile"))
 218                return git_config_pathname(&diff_order_file_cfg, var, value);
 219
 220        if (!strcmp(var, "diff.ignoresubmodules"))
 221                handle_ignore_submodules_arg(&default_diff_options, value);
 222
 223        if (!strcmp(var, "diff.submodule")) {
 224                if (parse_submodule_params(&default_diff_options, value))
 225                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 226                                value);
 227                return 0;
 228        }
 229
 230        if (!strcmp(var, "diff.algorithm")) {
 231                diff_algorithm = parse_algorithm_value(value);
 232                if (diff_algorithm < 0)
 233                        return -1;
 234                return 0;
 235        }
 236
 237        if (git_color_config(var, value, cb) < 0)
 238                return -1;
 239
 240        return git_diff_basic_config(var, value, cb);
 241}
 242
 243int git_diff_basic_config(const char *var, const char *value, void *cb)
 244{
 245        const char *name;
 246
 247        if (!strcmp(var, "diff.renamelimit")) {
 248                diff_rename_limit_default = git_config_int(var, value);
 249                return 0;
 250        }
 251
 252        if (userdiff_config(var, value) < 0)
 253                return -1;
 254
 255        if (skip_prefix(var, "diff.color.", &name) ||
 256            skip_prefix(var, "color.diff.", &name)) {
 257                int slot = parse_diff_color_slot(name);
 258                if (slot < 0)
 259                        return 0;
 260                if (!value)
 261                        return config_error_nonbool(var);
 262                return color_parse(value, diff_colors[slot]);
 263        }
 264
 265        /* like GNU diff's --suppress-blank-empty option  */
 266        if (!strcmp(var, "diff.suppressblankempty") ||
 267                        /* for backwards compatibility */
 268                        !strcmp(var, "diff.suppress-blank-empty")) {
 269                diff_suppress_blank_empty = git_config_bool(var, value);
 270                return 0;
 271        }
 272
 273        if (!strcmp(var, "diff.dirstat")) {
 274                struct strbuf errmsg = STRBUF_INIT;
 275                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 276                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 277                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 278                                errmsg.buf);
 279                strbuf_release(&errmsg);
 280                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 281                return 0;
 282        }
 283
 284        if (starts_with(var, "submodule."))
 285                return parse_submodule_config_option(var, value);
 286
 287        return git_default_config(var, value, cb);
 288}
 289
 290static char *quote_two(const char *one, const char *two)
 291{
 292        int need_one = quote_c_style(one, NULL, NULL, 1);
 293        int need_two = quote_c_style(two, NULL, NULL, 1);
 294        struct strbuf res = STRBUF_INIT;
 295
 296        if (need_one + need_two) {
 297                strbuf_addch(&res, '"');
 298                quote_c_style(one, &res, NULL, 1);
 299                quote_c_style(two, &res, NULL, 1);
 300                strbuf_addch(&res, '"');
 301        } else {
 302                strbuf_addstr(&res, one);
 303                strbuf_addstr(&res, two);
 304        }
 305        return strbuf_detach(&res, NULL);
 306}
 307
 308static const char *external_diff(void)
 309{
 310        static const char *external_diff_cmd = NULL;
 311        static int done_preparing = 0;
 312
 313        if (done_preparing)
 314                return external_diff_cmd;
 315        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 316        if (!external_diff_cmd)
 317                external_diff_cmd = external_diff_cmd_cfg;
 318        done_preparing = 1;
 319        return external_diff_cmd;
 320}
 321
 322/*
 323 * Keep track of files used for diffing. Sometimes such an entry
 324 * refers to a temporary file, sometimes to an existing file, and
 325 * sometimes to "/dev/null".
 326 */
 327static struct diff_tempfile {
 328        /*
 329         * filename external diff should read from, or NULL if this
 330         * entry is currently not in use:
 331         */
 332        const char *name;
 333
 334        char hex[GIT_SHA1_HEXSZ + 1];
 335        char mode[10];
 336
 337        /*
 338         * If this diff_tempfile instance refers to a temporary file,
 339         * this tempfile object is used to manage its lifetime.
 340         */
 341        struct tempfile tempfile;
 342} diff_temp[2];
 343
 344typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 345
 346struct emit_callback {
 347        int color_diff;
 348        unsigned ws_rule;
 349        int blank_at_eof_in_preimage;
 350        int blank_at_eof_in_postimage;
 351        int lno_in_preimage;
 352        int lno_in_postimage;
 353        sane_truncate_fn truncate;
 354        const char **label_path;
 355        struct diff_words_data *diff_words;
 356        struct diff_options *opt;
 357        int *found_changesp;
 358        struct strbuf *header;
 359};
 360
 361static int count_lines(const char *data, int size)
 362{
 363        int count, ch, completely_empty = 1, nl_just_seen = 0;
 364        count = 0;
 365        while (0 < size--) {
 366                ch = *data++;
 367                if (ch == '\n') {
 368                        count++;
 369                        nl_just_seen = 1;
 370                        completely_empty = 0;
 371                }
 372                else {
 373                        nl_just_seen = 0;
 374                        completely_empty = 0;
 375                }
 376        }
 377        if (completely_empty)
 378                return 0;
 379        if (!nl_just_seen)
 380                count++; /* no trailing newline */
 381        return count;
 382}
 383
 384static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 385{
 386        if (!DIFF_FILE_VALID(one)) {
 387                mf->ptr = (char *)""; /* does not matter */
 388                mf->size = 0;
 389                return 0;
 390        }
 391        else if (diff_populate_filespec(one, 0))
 392                return -1;
 393
 394        mf->ptr = one->data;
 395        mf->size = one->size;
 396        return 0;
 397}
 398
 399/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 400static unsigned long diff_filespec_size(struct diff_filespec *one)
 401{
 402        if (!DIFF_FILE_VALID(one))
 403                return 0;
 404        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 405        return one->size;
 406}
 407
 408static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 409{
 410        char *ptr = mf->ptr;
 411        long size = mf->size;
 412        int cnt = 0;
 413
 414        if (!size)
 415                return cnt;
 416        ptr += size - 1; /* pointing at the very end */
 417        if (*ptr != '\n')
 418                ; /* incomplete line */
 419        else
 420                ptr--; /* skip the last LF */
 421        while (mf->ptr < ptr) {
 422                char *prev_eol;
 423                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 424                        if (*prev_eol == '\n')
 425                                break;
 426                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 427                        break;
 428                cnt++;
 429                ptr = prev_eol - 1;
 430        }
 431        return cnt;
 432}
 433
 434static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 435                               struct emit_callback *ecbdata)
 436{
 437        int l1, l2, at;
 438        unsigned ws_rule = ecbdata->ws_rule;
 439        l1 = count_trailing_blank(mf1, ws_rule);
 440        l2 = count_trailing_blank(mf2, ws_rule);
 441        if (l2 <= l1) {
 442                ecbdata->blank_at_eof_in_preimage = 0;
 443                ecbdata->blank_at_eof_in_postimage = 0;
 444                return;
 445        }
 446        at = count_lines(mf1->ptr, mf1->size);
 447        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 448
 449        at = count_lines(mf2->ptr, mf2->size);
 450        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 451}
 452
 453static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 454                        int first, const char *line, int len)
 455{
 456        int has_trailing_newline, has_trailing_carriage_return;
 457        int nofirst;
 458        FILE *file = o->file;
 459
 460        fputs(diff_line_prefix(o), file);
 461
 462        if (len == 0) {
 463                has_trailing_newline = (first == '\n');
 464                has_trailing_carriage_return = (!has_trailing_newline &&
 465                                                (first == '\r'));
 466                nofirst = has_trailing_newline || has_trailing_carriage_return;
 467        } else {
 468                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 469                if (has_trailing_newline)
 470                        len--;
 471                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 472                if (has_trailing_carriage_return)
 473                        len--;
 474                nofirst = 0;
 475        }
 476
 477        if (len || !nofirst) {
 478                fputs(set, file);
 479                if (!nofirst)
 480                        fputc(first, file);
 481                fwrite(line, len, 1, file);
 482                fputs(reset, file);
 483        }
 484        if (has_trailing_carriage_return)
 485                fputc('\r', file);
 486        if (has_trailing_newline)
 487                fputc('\n', file);
 488}
 489
 490static void emit_line(struct diff_options *o, const char *set, const char *reset,
 491                      const char *line, int len)
 492{
 493        emit_line_0(o, set, reset, line[0], line+1, len-1);
 494}
 495
 496static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 497{
 498        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 499              ecbdata->blank_at_eof_in_preimage &&
 500              ecbdata->blank_at_eof_in_postimage &&
 501              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 502              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 503                return 0;
 504        return ws_blank_line(line, len, ecbdata->ws_rule);
 505}
 506
 507static void emit_line_checked(const char *reset,
 508                              struct emit_callback *ecbdata,
 509                              const char *line, int len,
 510                              enum color_diff color,
 511                              unsigned ws_error_highlight,
 512                              char sign)
 513{
 514        const char *set = diff_get_color(ecbdata->color_diff, color);
 515        const char *ws = NULL;
 516
 517        if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
 518                ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 519                if (!*ws)
 520                        ws = NULL;
 521        }
 522
 523        if (!ws)
 524                emit_line_0(ecbdata->opt, set, reset, sign, line, len);
 525        else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 526                /* Blank line at EOF - paint '+' as well */
 527                emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 528        else {
 529                /* Emit just the prefix, then the rest. */
 530                emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 531                ws_check_emit(line, len, ecbdata->ws_rule,
 532                              ecbdata->opt->file, set, reset, ws);
 533        }
 534}
 535
 536static void emit_add_line(const char *reset,
 537                          struct emit_callback *ecbdata,
 538                          const char *line, int len)
 539{
 540        emit_line_checked(reset, ecbdata, line, len,
 541                          DIFF_FILE_NEW, WSEH_NEW, '+');
 542}
 543
 544static void emit_del_line(const char *reset,
 545                          struct emit_callback *ecbdata,
 546                          const char *line, int len)
 547{
 548        emit_line_checked(reset, ecbdata, line, len,
 549                          DIFF_FILE_OLD, WSEH_OLD, '-');
 550}
 551
 552static void emit_context_line(const char *reset,
 553                              struct emit_callback *ecbdata,
 554                              const char *line, int len)
 555{
 556        emit_line_checked(reset, ecbdata, line, len,
 557                          DIFF_CONTEXT, WSEH_CONTEXT, ' ');
 558}
 559
 560static void emit_hunk_header(struct emit_callback *ecbdata,
 561                             const char *line, int len)
 562{
 563        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 564        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 565        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 566        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 567        static const char atat[2] = { '@', '@' };
 568        const char *cp, *ep;
 569        struct strbuf msgbuf = STRBUF_INIT;
 570        int org_len = len;
 571        int i = 1;
 572
 573        /*
 574         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 575         * it always is at least 10 bytes long.
 576         */
 577        if (len < 10 ||
 578            memcmp(line, atat, 2) ||
 579            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 580                emit_line(ecbdata->opt, context, reset, line, len);
 581                return;
 582        }
 583        ep += 2; /* skip over @@ */
 584
 585        /* The hunk header in fraginfo color */
 586        strbuf_addstr(&msgbuf, frag);
 587        strbuf_add(&msgbuf, line, ep - line);
 588        strbuf_addstr(&msgbuf, reset);
 589
 590        /*
 591         * trailing "\r\n"
 592         */
 593        for ( ; i < 3; i++)
 594                if (line[len - i] == '\r' || line[len - i] == '\n')
 595                        len--;
 596
 597        /* blank before the func header */
 598        for (cp = ep; ep - line < len; ep++)
 599                if (*ep != ' ' && *ep != '\t')
 600                        break;
 601        if (ep != cp) {
 602                strbuf_addstr(&msgbuf, context);
 603                strbuf_add(&msgbuf, cp, ep - cp);
 604                strbuf_addstr(&msgbuf, reset);
 605        }
 606
 607        if (ep < line + len) {
 608                strbuf_addstr(&msgbuf, func);
 609                strbuf_add(&msgbuf, ep, line + len - ep);
 610                strbuf_addstr(&msgbuf, reset);
 611        }
 612
 613        strbuf_add(&msgbuf, line + len, org_len - len);
 614        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 615        strbuf_release(&msgbuf);
 616}
 617
 618static struct diff_tempfile *claim_diff_tempfile(void) {
 619        int i;
 620        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 621                if (!diff_temp[i].name)
 622                        return diff_temp + i;
 623        die("BUG: diff is failing to clean up its tempfiles");
 624}
 625
 626static void remove_tempfile(void)
 627{
 628        int i;
 629        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 630                if (is_tempfile_active(&diff_temp[i].tempfile))
 631                        delete_tempfile(&diff_temp[i].tempfile);
 632                diff_temp[i].name = NULL;
 633        }
 634}
 635
 636static void print_line_count(FILE *file, int count)
 637{
 638        switch (count) {
 639        case 0:
 640                fprintf(file, "0,0");
 641                break;
 642        case 1:
 643                fprintf(file, "1");
 644                break;
 645        default:
 646                fprintf(file, "1,%d", count);
 647                break;
 648        }
 649}
 650
 651static void emit_rewrite_lines(struct emit_callback *ecb,
 652                               int prefix, const char *data, int size)
 653{
 654        const char *endp = NULL;
 655        static const char *nneof = " No newline at end of file\n";
 656        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 657
 658        while (0 < size) {
 659                int len;
 660
 661                endp = memchr(data, '\n', size);
 662                len = endp ? (endp - data + 1) : size;
 663                if (prefix != '+') {
 664                        ecb->lno_in_preimage++;
 665                        emit_del_line(reset, ecb, data, len);
 666                } else {
 667                        ecb->lno_in_postimage++;
 668                        emit_add_line(reset, ecb, data, len);
 669                }
 670                size -= len;
 671                data += len;
 672        }
 673        if (!endp) {
 674                const char *context = diff_get_color(ecb->color_diff,
 675                                                     DIFF_CONTEXT);
 676                putc('\n', ecb->opt->file);
 677                emit_line_0(ecb->opt, context, reset, '\\',
 678                            nneof, strlen(nneof));
 679        }
 680}
 681
 682static void emit_rewrite_diff(const char *name_a,
 683                              const char *name_b,
 684                              struct diff_filespec *one,
 685                              struct diff_filespec *two,
 686                              struct userdiff_driver *textconv_one,
 687                              struct userdiff_driver *textconv_two,
 688                              struct diff_options *o)
 689{
 690        int lc_a, lc_b;
 691        const char *name_a_tab, *name_b_tab;
 692        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 693        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 694        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 695        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 696        const char *a_prefix, *b_prefix;
 697        char *data_one, *data_two;
 698        size_t size_one, size_two;
 699        struct emit_callback ecbdata;
 700        const char *line_prefix = diff_line_prefix(o);
 701
 702        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 703                a_prefix = o->b_prefix;
 704                b_prefix = o->a_prefix;
 705        } else {
 706                a_prefix = o->a_prefix;
 707                b_prefix = o->b_prefix;
 708        }
 709
 710        name_a += (*name_a == '/');
 711        name_b += (*name_b == '/');
 712        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 713        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 714
 715        strbuf_reset(&a_name);
 716        strbuf_reset(&b_name);
 717        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 718        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 719
 720        size_one = fill_textconv(textconv_one, one, &data_one);
 721        size_two = fill_textconv(textconv_two, two, &data_two);
 722
 723        memset(&ecbdata, 0, sizeof(ecbdata));
 724        ecbdata.color_diff = want_color(o->use_color);
 725        ecbdata.found_changesp = &o->found_changes;
 726        ecbdata.ws_rule = whitespace_rule(name_b);
 727        ecbdata.opt = o;
 728        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 729                mmfile_t mf1, mf2;
 730                mf1.ptr = (char *)data_one;
 731                mf2.ptr = (char *)data_two;
 732                mf1.size = size_one;
 733                mf2.size = size_two;
 734                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 735        }
 736        ecbdata.lno_in_preimage = 1;
 737        ecbdata.lno_in_postimage = 1;
 738
 739        lc_a = count_lines(data_one, size_one);
 740        lc_b = count_lines(data_two, size_two);
 741        fprintf(o->file,
 742                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 743                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 744                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 745                line_prefix, fraginfo);
 746        if (!o->irreversible_delete)
 747                print_line_count(o->file, lc_a);
 748        else
 749                fprintf(o->file, "?,?");
 750        fprintf(o->file, " +");
 751        print_line_count(o->file, lc_b);
 752        fprintf(o->file, " @@%s\n", reset);
 753        if (lc_a && !o->irreversible_delete)
 754                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 755        if (lc_b)
 756                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 757        if (textconv_one)
 758                free((char *)data_one);
 759        if (textconv_two)
 760                free((char *)data_two);
 761}
 762
 763struct diff_words_buffer {
 764        mmfile_t text;
 765        long alloc;
 766        struct diff_words_orig {
 767                const char *begin, *end;
 768        } *orig;
 769        int orig_nr, orig_alloc;
 770};
 771
 772static void diff_words_append(char *line, unsigned long len,
 773                struct diff_words_buffer *buffer)
 774{
 775        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 776        line++;
 777        len--;
 778        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 779        buffer->text.size += len;
 780        buffer->text.ptr[buffer->text.size] = '\0';
 781}
 782
 783struct diff_words_style_elem {
 784        const char *prefix;
 785        const char *suffix;
 786        const char *color; /* NULL; filled in by the setup code if
 787                            * color is enabled */
 788};
 789
 790struct diff_words_style {
 791        enum diff_words_type type;
 792        struct diff_words_style_elem new, old, ctx;
 793        const char *newline;
 794};
 795
 796static struct diff_words_style diff_words_styles[] = {
 797        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 798        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 799        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 800};
 801
 802struct diff_words_data {
 803        struct diff_words_buffer minus, plus;
 804        const char *current_plus;
 805        int last_minus;
 806        struct diff_options *opt;
 807        regex_t *word_regex;
 808        enum diff_words_type type;
 809        struct diff_words_style *style;
 810};
 811
 812static int fn_out_diff_words_write_helper(FILE *fp,
 813                                          struct diff_words_style_elem *st_el,
 814                                          const char *newline,
 815                                          size_t count, const char *buf,
 816                                          const char *line_prefix)
 817{
 818        int print = 0;
 819
 820        while (count) {
 821                char *p = memchr(buf, '\n', count);
 822                if (print)
 823                        fputs(line_prefix, fp);
 824                if (p != buf) {
 825                        if (st_el->color && fputs(st_el->color, fp) < 0)
 826                                return -1;
 827                        if (fputs(st_el->prefix, fp) < 0 ||
 828                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 829                            fputs(st_el->suffix, fp) < 0)
 830                                return -1;
 831                        if (st_el->color && *st_el->color
 832                            && fputs(GIT_COLOR_RESET, fp) < 0)
 833                                return -1;
 834                }
 835                if (!p)
 836                        return 0;
 837                if (fputs(newline, fp) < 0)
 838                        return -1;
 839                count -= p + 1 - buf;
 840                buf = p + 1;
 841                print = 1;
 842        }
 843        return 0;
 844}
 845
 846/*
 847 * '--color-words' algorithm can be described as:
 848 *
 849 *   1. collect a the minus/plus lines of a diff hunk, divided into
 850 *      minus-lines and plus-lines;
 851 *
 852 *   2. break both minus-lines and plus-lines into words and
 853 *      place them into two mmfile_t with one word for each line;
 854 *
 855 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 856 *
 857 * And for the common parts of the both file, we output the plus side text.
 858 * diff_words->current_plus is used to trace the current position of the plus file
 859 * which printed. diff_words->last_minus is used to trace the last minus word
 860 * printed.
 861 *
 862 * For '--graph' to work with '--color-words', we need to output the graph prefix
 863 * on each line of color words output. Generally, there are two conditions on
 864 * which we should output the prefix.
 865 *
 866 *   1. diff_words->last_minus == 0 &&
 867 *      diff_words->current_plus == diff_words->plus.text.ptr
 868 *
 869 *      that is: the plus text must start as a new line, and if there is no minus
 870 *      word printed, a graph prefix must be printed.
 871 *
 872 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 873 *      *(diff_words->current_plus - 1) == '\n'
 874 *
 875 *      that is: a graph prefix must be printed following a '\n'
 876 */
 877static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 878{
 879        if ((diff_words->last_minus == 0 &&
 880                diff_words->current_plus == diff_words->plus.text.ptr) ||
 881                (diff_words->current_plus > diff_words->plus.text.ptr &&
 882                *(diff_words->current_plus - 1) == '\n')) {
 883                return 1;
 884        } else {
 885                return 0;
 886        }
 887}
 888
 889static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 890{
 891        struct diff_words_data *diff_words = priv;
 892        struct diff_words_style *style = diff_words->style;
 893        int minus_first, minus_len, plus_first, plus_len;
 894        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 895        struct diff_options *opt = diff_words->opt;
 896        const char *line_prefix;
 897
 898        if (line[0] != '@' || parse_hunk_header(line, len,
 899                        &minus_first, &minus_len, &plus_first, &plus_len))
 900                return;
 901
 902        assert(opt);
 903        line_prefix = diff_line_prefix(opt);
 904
 905        /* POSIX requires that first be decremented by one if len == 0... */
 906        if (minus_len) {
 907                minus_begin = diff_words->minus.orig[minus_first].begin;
 908                minus_end =
 909                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 910        } else
 911                minus_begin = minus_end =
 912                        diff_words->minus.orig[minus_first].end;
 913
 914        if (plus_len) {
 915                plus_begin = diff_words->plus.orig[plus_first].begin;
 916                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 917        } else
 918                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 919
 920        if (color_words_output_graph_prefix(diff_words)) {
 921                fputs(line_prefix, diff_words->opt->file);
 922        }
 923        if (diff_words->current_plus != plus_begin) {
 924                fn_out_diff_words_write_helper(diff_words->opt->file,
 925                                &style->ctx, style->newline,
 926                                plus_begin - diff_words->current_plus,
 927                                diff_words->current_plus, line_prefix);
 928                if (*(plus_begin - 1) == '\n')
 929                        fputs(line_prefix, diff_words->opt->file);
 930        }
 931        if (minus_begin != minus_end) {
 932                fn_out_diff_words_write_helper(diff_words->opt->file,
 933                                &style->old, style->newline,
 934                                minus_end - minus_begin, minus_begin,
 935                                line_prefix);
 936        }
 937        if (plus_begin != plus_end) {
 938                fn_out_diff_words_write_helper(diff_words->opt->file,
 939                                &style->new, style->newline,
 940                                plus_end - plus_begin, plus_begin,
 941                                line_prefix);
 942        }
 943
 944        diff_words->current_plus = plus_end;
 945        diff_words->last_minus = minus_first;
 946}
 947
 948/* This function starts looking at *begin, and returns 0 iff a word was found. */
 949static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 950                int *begin, int *end)
 951{
 952        if (word_regex && *begin < buffer->size) {
 953                regmatch_t match[1];
 954                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 955                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 956                                        '\n', match[0].rm_eo - match[0].rm_so);
 957                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 958                        *begin += match[0].rm_so;
 959                        return *begin >= *end;
 960                }
 961                return -1;
 962        }
 963
 964        /* find the next word */
 965        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 966                (*begin)++;
 967        if (*begin >= buffer->size)
 968                return -1;
 969
 970        /* find the end of the word */
 971        *end = *begin + 1;
 972        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 973                (*end)++;
 974
 975        return 0;
 976}
 977
 978/*
 979 * This function splits the words in buffer->text, stores the list with
 980 * newline separator into out, and saves the offsets of the original words
 981 * in buffer->orig.
 982 */
 983static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 984                regex_t *word_regex)
 985{
 986        int i, j;
 987        long alloc = 0;
 988
 989        out->size = 0;
 990        out->ptr = NULL;
 991
 992        /* fake an empty "0th" word */
 993        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 994        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 995        buffer->orig_nr = 1;
 996
 997        for (i = 0; i < buffer->text.size; i++) {
 998                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 999                        return;
1000
1001                /* store original boundaries */
1002                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1003                                buffer->orig_alloc);
1004                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1005                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1006                buffer->orig_nr++;
1007
1008                /* store one word */
1009                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1010                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1011                out->ptr[out->size + j - i] = '\n';
1012                out->size += j - i + 1;
1013
1014                i = j - 1;
1015        }
1016}
1017
1018/* this executes the word diff on the accumulated buffers */
1019static void diff_words_show(struct diff_words_data *diff_words)
1020{
1021        xpparam_t xpp;
1022        xdemitconf_t xecfg;
1023        mmfile_t minus, plus;
1024        struct diff_words_style *style = diff_words->style;
1025
1026        struct diff_options *opt = diff_words->opt;
1027        const char *line_prefix;
1028
1029        assert(opt);
1030        line_prefix = diff_line_prefix(opt);
1031
1032        /* special case: only removal */
1033        if (!diff_words->plus.text.size) {
1034                fputs(line_prefix, diff_words->opt->file);
1035                fn_out_diff_words_write_helper(diff_words->opt->file,
1036                        &style->old, style->newline,
1037                        diff_words->minus.text.size,
1038                        diff_words->minus.text.ptr, line_prefix);
1039                diff_words->minus.text.size = 0;
1040                return;
1041        }
1042
1043        diff_words->current_plus = diff_words->plus.text.ptr;
1044        diff_words->last_minus = 0;
1045
1046        memset(&xpp, 0, sizeof(xpp));
1047        memset(&xecfg, 0, sizeof(xecfg));
1048        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1049        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1050        xpp.flags = 0;
1051        /* as only the hunk header will be parsed, we need a 0-context */
1052        xecfg.ctxlen = 0;
1053        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1054                          &xpp, &xecfg))
1055                die("unable to generate word diff");
1056        free(minus.ptr);
1057        free(plus.ptr);
1058        if (diff_words->current_plus != diff_words->plus.text.ptr +
1059                        diff_words->plus.text.size) {
1060                if (color_words_output_graph_prefix(diff_words))
1061                        fputs(line_prefix, diff_words->opt->file);
1062                fn_out_diff_words_write_helper(diff_words->opt->file,
1063                        &style->ctx, style->newline,
1064                        diff_words->plus.text.ptr + diff_words->plus.text.size
1065                        - diff_words->current_plus, diff_words->current_plus,
1066                        line_prefix);
1067        }
1068        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1069}
1070
1071/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1072static void diff_words_flush(struct emit_callback *ecbdata)
1073{
1074        if (ecbdata->diff_words->minus.text.size ||
1075            ecbdata->diff_words->plus.text.size)
1076                diff_words_show(ecbdata->diff_words);
1077}
1078
1079static void diff_filespec_load_driver(struct diff_filespec *one)
1080{
1081        /* Use already-loaded driver */
1082        if (one->driver)
1083                return;
1084
1085        if (S_ISREG(one->mode))
1086                one->driver = userdiff_find_by_path(one->path);
1087
1088        /* Fallback to default settings */
1089        if (!one->driver)
1090                one->driver = userdiff_find_by_name("default");
1091}
1092
1093static const char *userdiff_word_regex(struct diff_filespec *one)
1094{
1095        diff_filespec_load_driver(one);
1096        return one->driver->word_regex;
1097}
1098
1099static void init_diff_words_data(struct emit_callback *ecbdata,
1100                                 struct diff_options *orig_opts,
1101                                 struct diff_filespec *one,
1102                                 struct diff_filespec *two)
1103{
1104        int i;
1105        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1106        memcpy(o, orig_opts, sizeof(struct diff_options));
1107
1108        ecbdata->diff_words =
1109                xcalloc(1, sizeof(struct diff_words_data));
1110        ecbdata->diff_words->type = o->word_diff;
1111        ecbdata->diff_words->opt = o;
1112        if (!o->word_regex)
1113                o->word_regex = userdiff_word_regex(one);
1114        if (!o->word_regex)
1115                o->word_regex = userdiff_word_regex(two);
1116        if (!o->word_regex)
1117                o->word_regex = diff_word_regex_cfg;
1118        if (o->word_regex) {
1119                ecbdata->diff_words->word_regex = (regex_t *)
1120                        xmalloc(sizeof(regex_t));
1121                if (regcomp(ecbdata->diff_words->word_regex,
1122                            o->word_regex,
1123                            REG_EXTENDED | REG_NEWLINE))
1124                        die ("Invalid regular expression: %s",
1125                             o->word_regex);
1126        }
1127        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1128                if (o->word_diff == diff_words_styles[i].type) {
1129                        ecbdata->diff_words->style =
1130                                &diff_words_styles[i];
1131                        break;
1132                }
1133        }
1134        if (want_color(o->use_color)) {
1135                struct diff_words_style *st = ecbdata->diff_words->style;
1136                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1137                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1138                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1139        }
1140}
1141
1142static void free_diff_words_data(struct emit_callback *ecbdata)
1143{
1144        if (ecbdata->diff_words) {
1145                diff_words_flush(ecbdata);
1146                free (ecbdata->diff_words->opt);
1147                free (ecbdata->diff_words->minus.text.ptr);
1148                free (ecbdata->diff_words->minus.orig);
1149                free (ecbdata->diff_words->plus.text.ptr);
1150                free (ecbdata->diff_words->plus.orig);
1151                if (ecbdata->diff_words->word_regex) {
1152                        regfree(ecbdata->diff_words->word_regex);
1153                        free(ecbdata->diff_words->word_regex);
1154                }
1155                free(ecbdata->diff_words);
1156                ecbdata->diff_words = NULL;
1157        }
1158}
1159
1160const char *diff_get_color(int diff_use_color, enum color_diff ix)
1161{
1162        if (want_color(diff_use_color))
1163                return diff_colors[ix];
1164        return "";
1165}
1166
1167const char *diff_line_prefix(struct diff_options *opt)
1168{
1169        struct strbuf *msgbuf;
1170        if (!opt->output_prefix)
1171                return "";
1172
1173        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1174        return msgbuf->buf;
1175}
1176
1177static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1178{
1179        const char *cp;
1180        unsigned long allot;
1181        size_t l = len;
1182
1183        if (ecb->truncate)
1184                return ecb->truncate(line, len);
1185        cp = line;
1186        allot = l;
1187        while (0 < l) {
1188                (void) utf8_width(&cp, &l);
1189                if (!cp)
1190                        break; /* truncated in the middle? */
1191        }
1192        return allot - l;
1193}
1194
1195static void find_lno(const char *line, struct emit_callback *ecbdata)
1196{
1197        const char *p;
1198        ecbdata->lno_in_preimage = 0;
1199        ecbdata->lno_in_postimage = 0;
1200        p = strchr(line, '-');
1201        if (!p)
1202                return; /* cannot happen */
1203        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1204        p = strchr(p, '+');
1205        if (!p)
1206                return; /* cannot happen */
1207        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1208}
1209
1210static void fn_out_consume(void *priv, char *line, unsigned long len)
1211{
1212        struct emit_callback *ecbdata = priv;
1213        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1214        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1215        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1216        struct diff_options *o = ecbdata->opt;
1217        const char *line_prefix = diff_line_prefix(o);
1218
1219        if (ecbdata->header) {
1220                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1221                strbuf_reset(ecbdata->header);
1222                ecbdata->header = NULL;
1223        }
1224        *(ecbdata->found_changesp) = 1;
1225
1226        if (ecbdata->label_path[0]) {
1227                const char *name_a_tab, *name_b_tab;
1228
1229                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1230                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1231
1232                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1233                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1234                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1235                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1236                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1237        }
1238
1239        if (diff_suppress_blank_empty
1240            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1241                line[0] = '\n';
1242                len = 1;
1243        }
1244
1245        if (line[0] == '@') {
1246                if (ecbdata->diff_words)
1247                        diff_words_flush(ecbdata);
1248                len = sane_truncate_line(ecbdata, line, len);
1249                find_lno(line, ecbdata);
1250                emit_hunk_header(ecbdata, line, len);
1251                if (line[len-1] != '\n')
1252                        putc('\n', ecbdata->opt->file);
1253                return;
1254        }
1255
1256        if (len < 1) {
1257                emit_line(ecbdata->opt, reset, reset, line, len);
1258                if (ecbdata->diff_words
1259                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1260                        fputs("~\n", ecbdata->opt->file);
1261                return;
1262        }
1263
1264        if (ecbdata->diff_words) {
1265                if (line[0] == '-') {
1266                        diff_words_append(line, len,
1267                                          &ecbdata->diff_words->minus);
1268                        return;
1269                } else if (line[0] == '+') {
1270                        diff_words_append(line, len,
1271                                          &ecbdata->diff_words->plus);
1272                        return;
1273                } else if (starts_with(line, "\\ ")) {
1274                        /*
1275                         * Eat the "no newline at eof" marker as if we
1276                         * saw a "+" or "-" line with nothing on it,
1277                         * and return without diff_words_flush() to
1278                         * defer processing. If this is the end of
1279                         * preimage, more "+" lines may come after it.
1280                         */
1281                        return;
1282                }
1283                diff_words_flush(ecbdata);
1284                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1285                        emit_line(ecbdata->opt, context, reset, line, len);
1286                        fputs("~\n", ecbdata->opt->file);
1287                } else {
1288                        /*
1289                         * Skip the prefix character, if any.  With
1290                         * diff_suppress_blank_empty, there may be
1291                         * none.
1292                         */
1293                        if (line[0] != '\n') {
1294                              line++;
1295                              len--;
1296                        }
1297                        emit_line(ecbdata->opt, context, reset, line, len);
1298                }
1299                return;
1300        }
1301
1302        switch (line[0]) {
1303        case '+':
1304                ecbdata->lno_in_postimage++;
1305                emit_add_line(reset, ecbdata, line + 1, len - 1);
1306                break;
1307        case '-':
1308                ecbdata->lno_in_preimage++;
1309                emit_del_line(reset, ecbdata, line + 1, len - 1);
1310                break;
1311        case ' ':
1312                ecbdata->lno_in_postimage++;
1313                ecbdata->lno_in_preimage++;
1314                emit_context_line(reset, ecbdata, line + 1, len - 1);
1315                break;
1316        default:
1317                /* incomplete line at the end */
1318                ecbdata->lno_in_preimage++;
1319                emit_line(ecbdata->opt,
1320                          diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
1321                          reset, line, len);
1322                break;
1323        }
1324}
1325
1326static char *pprint_rename(const char *a, const char *b)
1327{
1328        const char *old = a;
1329        const char *new = b;
1330        struct strbuf name = STRBUF_INIT;
1331        int pfx_length, sfx_length;
1332        int pfx_adjust_for_slash;
1333        int len_a = strlen(a);
1334        int len_b = strlen(b);
1335        int a_midlen, b_midlen;
1336        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1337        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1338
1339        if (qlen_a || qlen_b) {
1340                quote_c_style(a, &name, NULL, 0);
1341                strbuf_addstr(&name, " => ");
1342                quote_c_style(b, &name, NULL, 0);
1343                return strbuf_detach(&name, NULL);
1344        }
1345
1346        /* Find common prefix */
1347        pfx_length = 0;
1348        while (*old && *new && *old == *new) {
1349                if (*old == '/')
1350                        pfx_length = old - a + 1;
1351                old++;
1352                new++;
1353        }
1354
1355        /* Find common suffix */
1356        old = a + len_a;
1357        new = b + len_b;
1358        sfx_length = 0;
1359        /*
1360         * If there is a common prefix, it must end in a slash.  In
1361         * that case we let this loop run 1 into the prefix to see the
1362         * same slash.
1363         *
1364         * If there is no common prefix, we cannot do this as it would
1365         * underrun the input strings.
1366         */
1367        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1368        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1369               b + pfx_length - pfx_adjust_for_slash <= new &&
1370               *old == *new) {
1371                if (*old == '/')
1372                        sfx_length = len_a - (old - a);
1373                old--;
1374                new--;
1375        }
1376
1377        /*
1378         * pfx{mid-a => mid-b}sfx
1379         * {pfx-a => pfx-b}sfx
1380         * pfx{sfx-a => sfx-b}
1381         * name-a => name-b
1382         */
1383        a_midlen = len_a - pfx_length - sfx_length;
1384        b_midlen = len_b - pfx_length - sfx_length;
1385        if (a_midlen < 0)
1386                a_midlen = 0;
1387        if (b_midlen < 0)
1388                b_midlen = 0;
1389
1390        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1391        if (pfx_length + sfx_length) {
1392                strbuf_add(&name, a, pfx_length);
1393                strbuf_addch(&name, '{');
1394        }
1395        strbuf_add(&name, a + pfx_length, a_midlen);
1396        strbuf_addstr(&name, " => ");
1397        strbuf_add(&name, b + pfx_length, b_midlen);
1398        if (pfx_length + sfx_length) {
1399                strbuf_addch(&name, '}');
1400                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1401        }
1402        return strbuf_detach(&name, NULL);
1403}
1404
1405struct diffstat_t {
1406        int nr;
1407        int alloc;
1408        struct diffstat_file {
1409                char *from_name;
1410                char *name;
1411                char *print_name;
1412                unsigned is_unmerged:1;
1413                unsigned is_binary:1;
1414                unsigned is_renamed:1;
1415                unsigned is_interesting:1;
1416                uintmax_t added, deleted;
1417        } **files;
1418};
1419
1420static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1421                                          const char *name_a,
1422                                          const char *name_b)
1423{
1424        struct diffstat_file *x;
1425        x = xcalloc(1, sizeof(*x));
1426        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1427        diffstat->files[diffstat->nr++] = x;
1428        if (name_b) {
1429                x->from_name = xstrdup(name_a);
1430                x->name = xstrdup(name_b);
1431                x->is_renamed = 1;
1432        }
1433        else {
1434                x->from_name = NULL;
1435                x->name = xstrdup(name_a);
1436        }
1437        return x;
1438}
1439
1440static void diffstat_consume(void *priv, char *line, unsigned long len)
1441{
1442        struct diffstat_t *diffstat = priv;
1443        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1444
1445        if (line[0] == '+')
1446                x->added++;
1447        else if (line[0] == '-')
1448                x->deleted++;
1449}
1450
1451const char mime_boundary_leader[] = "------------";
1452
1453static int scale_linear(int it, int width, int max_change)
1454{
1455        if (!it)
1456                return 0;
1457        /*
1458         * make sure that at least one '-' or '+' is printed if
1459         * there is any change to this path. The easiest way is to
1460         * scale linearly as if the alloted width is one column shorter
1461         * than it is, and then add 1 to the result.
1462         */
1463        return 1 + (it * (width - 1) / max_change);
1464}
1465
1466static void show_name(FILE *file,
1467                      const char *prefix, const char *name, int len)
1468{
1469        fprintf(file, " %s%-*s |", prefix, len, name);
1470}
1471
1472static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1473{
1474        if (cnt <= 0)
1475                return;
1476        fprintf(file, "%s", set);
1477        while (cnt--)
1478                putc(ch, file);
1479        fprintf(file, "%s", reset);
1480}
1481
1482static void fill_print_name(struct diffstat_file *file)
1483{
1484        char *pname;
1485
1486        if (file->print_name)
1487                return;
1488
1489        if (!file->is_renamed) {
1490                struct strbuf buf = STRBUF_INIT;
1491                if (quote_c_style(file->name, &buf, NULL, 0)) {
1492                        pname = strbuf_detach(&buf, NULL);
1493                } else {
1494                        pname = file->name;
1495                        strbuf_release(&buf);
1496                }
1497        } else {
1498                pname = pprint_rename(file->from_name, file->name);
1499        }
1500        file->print_name = pname;
1501}
1502
1503int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1504{
1505        struct strbuf sb = STRBUF_INIT;
1506        int ret;
1507
1508        if (!files) {
1509                assert(insertions == 0 && deletions == 0);
1510                return fprintf(fp, "%s\n", " 0 files changed");
1511        }
1512
1513        strbuf_addf(&sb,
1514                    (files == 1) ? " %d file changed" : " %d files changed",
1515                    files);
1516
1517        /*
1518         * For binary diff, the caller may want to print "x files
1519         * changed" with insertions == 0 && deletions == 0.
1520         *
1521         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1522         * is probably less confusing (i.e skip over "2 files changed
1523         * but nothing about added/removed lines? Is this a bug in Git?").
1524         */
1525        if (insertions || deletions == 0) {
1526                strbuf_addf(&sb,
1527                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1528                            insertions);
1529        }
1530
1531        if (deletions || insertions == 0) {
1532                strbuf_addf(&sb,
1533                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1534                            deletions);
1535        }
1536        strbuf_addch(&sb, '\n');
1537        ret = fputs(sb.buf, fp);
1538        strbuf_release(&sb);
1539        return ret;
1540}
1541
1542static void show_stats(struct diffstat_t *data, struct diff_options *options)
1543{
1544        int i, len, add, del, adds = 0, dels = 0;
1545        uintmax_t max_change = 0, max_len = 0;
1546        int total_files = data->nr, count;
1547        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1548        const char *reset, *add_c, *del_c;
1549        const char *line_prefix = "";
1550        int extra_shown = 0;
1551
1552        if (data->nr == 0)
1553                return;
1554
1555        line_prefix = diff_line_prefix(options);
1556        count = options->stat_count ? options->stat_count : data->nr;
1557
1558        reset = diff_get_color_opt(options, DIFF_RESET);
1559        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1560        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1561
1562        /*
1563         * Find the longest filename and max number of changes
1564         */
1565        for (i = 0; (i < count) && (i < data->nr); i++) {
1566                struct diffstat_file *file = data->files[i];
1567                uintmax_t change = file->added + file->deleted;
1568
1569                if (!file->is_interesting && (change == 0)) {
1570                        count++; /* not shown == room for one more */
1571                        continue;
1572                }
1573                fill_print_name(file);
1574                len = strlen(file->print_name);
1575                if (max_len < len)
1576                        max_len = len;
1577
1578                if (file->is_unmerged) {
1579                        /* "Unmerged" is 8 characters */
1580                        bin_width = bin_width < 8 ? 8 : bin_width;
1581                        continue;
1582                }
1583                if (file->is_binary) {
1584                        /* "Bin XXX -> YYY bytes" */
1585                        int w = 14 + decimal_width(file->added)
1586                                + decimal_width(file->deleted);
1587                        bin_width = bin_width < w ? w : bin_width;
1588                        /* Display change counts aligned with "Bin" */
1589                        number_width = 3;
1590                        continue;
1591                }
1592
1593                if (max_change < change)
1594                        max_change = change;
1595        }
1596        count = i; /* where we can stop scanning in data->files[] */
1597
1598        /*
1599         * We have width = stat_width or term_columns() columns total.
1600         * We want a maximum of min(max_len, stat_name_width) for the name part.
1601         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1602         * We also need 1 for " " and 4 + decimal_width(max_change)
1603         * for " | NNNN " and one the empty column at the end, altogether
1604         * 6 + decimal_width(max_change).
1605         *
1606         * If there's not enough space, we will use the smaller of
1607         * stat_name_width (if set) and 5/8*width for the filename,
1608         * and the rest for constant elements + graph part, but no more
1609         * than stat_graph_width for the graph part.
1610         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1611         * for the standard terminal size).
1612         *
1613         * In other words: stat_width limits the maximum width, and
1614         * stat_name_width fixes the maximum width of the filename,
1615         * and is also used to divide available columns if there
1616         * aren't enough.
1617         *
1618         * Binary files are displayed with "Bin XXX -> YYY bytes"
1619         * instead of the change count and graph. This part is treated
1620         * similarly to the graph part, except that it is not
1621         * "scaled". If total width is too small to accommodate the
1622         * guaranteed minimum width of the filename part and the
1623         * separators and this message, this message will "overflow"
1624         * making the line longer than the maximum width.
1625         */
1626
1627        if (options->stat_width == -1)
1628                width = term_columns() - options->output_prefix_length;
1629        else
1630                width = options->stat_width ? options->stat_width : 80;
1631        number_width = decimal_width(max_change) > number_width ?
1632                decimal_width(max_change) : number_width;
1633
1634        if (options->stat_graph_width == -1)
1635                options->stat_graph_width = diff_stat_graph_width;
1636
1637        /*
1638         * Guarantee 3/8*16==6 for the graph part
1639         * and 5/8*16==10 for the filename part
1640         */
1641        if (width < 16 + 6 + number_width)
1642                width = 16 + 6 + number_width;
1643
1644        /*
1645         * First assign sizes that are wanted, ignoring available width.
1646         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1647         * starting from "XXX" should fit in graph_width.
1648         */
1649        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1650        if (options->stat_graph_width &&
1651            options->stat_graph_width < graph_width)
1652                graph_width = options->stat_graph_width;
1653
1654        name_width = (options->stat_name_width > 0 &&
1655                      options->stat_name_width < max_len) ?
1656                options->stat_name_width : max_len;
1657
1658        /*
1659         * Adjust adjustable widths not to exceed maximum width
1660         */
1661        if (name_width + number_width + 6 + graph_width > width) {
1662                if (graph_width > width * 3/8 - number_width - 6) {
1663                        graph_width = width * 3/8 - number_width - 6;
1664                        if (graph_width < 6)
1665                                graph_width = 6;
1666                }
1667
1668                if (options->stat_graph_width &&
1669                    graph_width > options->stat_graph_width)
1670                        graph_width = options->stat_graph_width;
1671                if (name_width > width - number_width - 6 - graph_width)
1672                        name_width = width - number_width - 6 - graph_width;
1673                else
1674                        graph_width = width - number_width - 6 - name_width;
1675        }
1676
1677        /*
1678         * From here name_width is the width of the name area,
1679         * and graph_width is the width of the graph area.
1680         * max_change is used to scale graph properly.
1681         */
1682        for (i = 0; i < count; i++) {
1683                const char *prefix = "";
1684                struct diffstat_file *file = data->files[i];
1685                char *name = file->print_name;
1686                uintmax_t added = file->added;
1687                uintmax_t deleted = file->deleted;
1688                int name_len;
1689
1690                if (!file->is_interesting && (added + deleted == 0))
1691                        continue;
1692
1693                /*
1694                 * "scale" the filename
1695                 */
1696                len = name_width;
1697                name_len = strlen(name);
1698                if (name_width < name_len) {
1699                        char *slash;
1700                        prefix = "...";
1701                        len -= 3;
1702                        name += name_len - len;
1703                        slash = strchr(name, '/');
1704                        if (slash)
1705                                name = slash;
1706                }
1707
1708                if (file->is_binary) {
1709                        fprintf(options->file, "%s", line_prefix);
1710                        show_name(options->file, prefix, name, len);
1711                        fprintf(options->file, " %*s", number_width, "Bin");
1712                        if (!added && !deleted) {
1713                                putc('\n', options->file);
1714                                continue;
1715                        }
1716                        fprintf(options->file, " %s%"PRIuMAX"%s",
1717                                del_c, deleted, reset);
1718                        fprintf(options->file, " -> ");
1719                        fprintf(options->file, "%s%"PRIuMAX"%s",
1720                                add_c, added, reset);
1721                        fprintf(options->file, " bytes");
1722                        fprintf(options->file, "\n");
1723                        continue;
1724                }
1725                else if (file->is_unmerged) {
1726                        fprintf(options->file, "%s", line_prefix);
1727                        show_name(options->file, prefix, name, len);
1728                        fprintf(options->file, " Unmerged\n");
1729                        continue;
1730                }
1731
1732                /*
1733                 * scale the add/delete
1734                 */
1735                add = added;
1736                del = deleted;
1737
1738                if (graph_width <= max_change) {
1739                        int total = scale_linear(add + del, graph_width, max_change);
1740                        if (total < 2 && add && del)
1741                                /* width >= 2 due to the sanity check */
1742                                total = 2;
1743                        if (add < del) {
1744                                add = scale_linear(add, graph_width, max_change);
1745                                del = total - add;
1746                        } else {
1747                                del = scale_linear(del, graph_width, max_change);
1748                                add = total - del;
1749                        }
1750                }
1751                fprintf(options->file, "%s", line_prefix);
1752                show_name(options->file, prefix, name, len);
1753                fprintf(options->file, " %*"PRIuMAX"%s",
1754                        number_width, added + deleted,
1755                        added + deleted ? " " : "");
1756                show_graph(options->file, '+', add, add_c, reset);
1757                show_graph(options->file, '-', del, del_c, reset);
1758                fprintf(options->file, "\n");
1759        }
1760
1761        for (i = 0; i < data->nr; i++) {
1762                struct diffstat_file *file = data->files[i];
1763                uintmax_t added = file->added;
1764                uintmax_t deleted = file->deleted;
1765
1766                if (file->is_unmerged ||
1767                    (!file->is_interesting && (added + deleted == 0))) {
1768                        total_files--;
1769                        continue;
1770                }
1771
1772                if (!file->is_binary) {
1773                        adds += added;
1774                        dels += deleted;
1775                }
1776                if (i < count)
1777                        continue;
1778                if (!extra_shown)
1779                        fprintf(options->file, "%s ...\n", line_prefix);
1780                extra_shown = 1;
1781        }
1782        fprintf(options->file, "%s", line_prefix);
1783        print_stat_summary(options->file, total_files, adds, dels);
1784}
1785
1786static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1787{
1788        int i, adds = 0, dels = 0, total_files = data->nr;
1789
1790        if (data->nr == 0)
1791                return;
1792
1793        for (i = 0; i < data->nr; i++) {
1794                int added = data->files[i]->added;
1795                int deleted= data->files[i]->deleted;
1796
1797                if (data->files[i]->is_unmerged ||
1798                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1799                        total_files--;
1800                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1801                        adds += added;
1802                        dels += deleted;
1803                }
1804        }
1805        fprintf(options->file, "%s", diff_line_prefix(options));
1806        print_stat_summary(options->file, total_files, adds, dels);
1807}
1808
1809static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1810{
1811        int i;
1812
1813        if (data->nr == 0)
1814                return;
1815
1816        for (i = 0; i < data->nr; i++) {
1817                struct diffstat_file *file = data->files[i];
1818
1819                fprintf(options->file, "%s", diff_line_prefix(options));
1820
1821                if (file->is_binary)
1822                        fprintf(options->file, "-\t-\t");
1823                else
1824                        fprintf(options->file,
1825                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1826                                file->added, file->deleted);
1827                if (options->line_termination) {
1828                        fill_print_name(file);
1829                        if (!file->is_renamed)
1830                                write_name_quoted(file->name, options->file,
1831                                                  options->line_termination);
1832                        else {
1833                                fputs(file->print_name, options->file);
1834                                putc(options->line_termination, options->file);
1835                        }
1836                } else {
1837                        if (file->is_renamed) {
1838                                putc('\0', options->file);
1839                                write_name_quoted(file->from_name, options->file, '\0');
1840                        }
1841                        write_name_quoted(file->name, options->file, '\0');
1842                }
1843        }
1844}
1845
1846struct dirstat_file {
1847        const char *name;
1848        unsigned long changed;
1849};
1850
1851struct dirstat_dir {
1852        struct dirstat_file *files;
1853        int alloc, nr, permille, cumulative;
1854};
1855
1856static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1857                unsigned long changed, const char *base, int baselen)
1858{
1859        unsigned long this_dir = 0;
1860        unsigned int sources = 0;
1861        const char *line_prefix = diff_line_prefix(opt);
1862
1863        while (dir->nr) {
1864                struct dirstat_file *f = dir->files;
1865                int namelen = strlen(f->name);
1866                unsigned long this;
1867                char *slash;
1868
1869                if (namelen < baselen)
1870                        break;
1871                if (memcmp(f->name, base, baselen))
1872                        break;
1873                slash = strchr(f->name + baselen, '/');
1874                if (slash) {
1875                        int newbaselen = slash + 1 - f->name;
1876                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1877                        sources++;
1878                } else {
1879                        this = f->changed;
1880                        dir->files++;
1881                        dir->nr--;
1882                        sources += 2;
1883                }
1884                this_dir += this;
1885        }
1886
1887        /*
1888         * We don't report dirstat's for
1889         *  - the top level
1890         *  - or cases where everything came from a single directory
1891         *    under this directory (sources == 1).
1892         */
1893        if (baselen && sources != 1) {
1894                if (this_dir) {
1895                        int permille = this_dir * 1000 / changed;
1896                        if (permille >= dir->permille) {
1897                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1898                                        permille / 10, permille % 10, baselen, base);
1899                                if (!dir->cumulative)
1900                                        return 0;
1901                        }
1902                }
1903        }
1904        return this_dir;
1905}
1906
1907static int dirstat_compare(const void *_a, const void *_b)
1908{
1909        const struct dirstat_file *a = _a;
1910        const struct dirstat_file *b = _b;
1911        return strcmp(a->name, b->name);
1912}
1913
1914static void show_dirstat(struct diff_options *options)
1915{
1916        int i;
1917        unsigned long changed;
1918        struct dirstat_dir dir;
1919        struct diff_queue_struct *q = &diff_queued_diff;
1920
1921        dir.files = NULL;
1922        dir.alloc = 0;
1923        dir.nr = 0;
1924        dir.permille = options->dirstat_permille;
1925        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1926
1927        changed = 0;
1928        for (i = 0; i < q->nr; i++) {
1929                struct diff_filepair *p = q->queue[i];
1930                const char *name;
1931                unsigned long copied, added, damage;
1932                int content_changed;
1933
1934                name = p->two->path ? p->two->path : p->one->path;
1935
1936                if (p->one->sha1_valid && p->two->sha1_valid)
1937                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1938                else
1939                        content_changed = 1;
1940
1941                if (!content_changed) {
1942                        /*
1943                         * The SHA1 has not changed, so pre-/post-content is
1944                         * identical. We can therefore skip looking at the
1945                         * file contents altogether.
1946                         */
1947                        damage = 0;
1948                        goto found_damage;
1949                }
1950
1951                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1952                        /*
1953                         * In --dirstat-by-file mode, we don't really need to
1954                         * look at the actual file contents at all.
1955                         * The fact that the SHA1 changed is enough for us to
1956                         * add this file to the list of results
1957                         * (with each file contributing equal damage).
1958                         */
1959                        damage = 1;
1960                        goto found_damage;
1961                }
1962
1963                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1964                        diff_populate_filespec(p->one, 0);
1965                        diff_populate_filespec(p->two, 0);
1966                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1967                                               &copied, &added);
1968                        diff_free_filespec_data(p->one);
1969                        diff_free_filespec_data(p->two);
1970                } else if (DIFF_FILE_VALID(p->one)) {
1971                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
1972                        copied = added = 0;
1973                        diff_free_filespec_data(p->one);
1974                } else if (DIFF_FILE_VALID(p->two)) {
1975                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
1976                        copied = 0;
1977                        added = p->two->size;
1978                        diff_free_filespec_data(p->two);
1979                } else
1980                        continue;
1981
1982                /*
1983                 * Original minus copied is the removed material,
1984                 * added is the new material.  They are both damages
1985                 * made to the preimage.
1986                 * If the resulting damage is zero, we know that
1987                 * diffcore_count_changes() considers the two entries to
1988                 * be identical, but since content_changed is true, we
1989                 * know that there must have been _some_ kind of change,
1990                 * so we force all entries to have damage > 0.
1991                 */
1992                damage = (p->one->size - copied) + added;
1993                if (!damage)
1994                        damage = 1;
1995
1996found_damage:
1997                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1998                dir.files[dir.nr].name = name;
1999                dir.files[dir.nr].changed = damage;
2000                changed += damage;
2001                dir.nr++;
2002        }
2003
2004        /* This can happen even with many files, if everything was renames */
2005        if (!changed)
2006                return;
2007
2008        /* Show all directories with more than x% of the changes */
2009        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2010        gather_dirstat(options, &dir, changed, "", 0);
2011}
2012
2013static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2014{
2015        int i;
2016        unsigned long changed;
2017        struct dirstat_dir dir;
2018
2019        if (data->nr == 0)
2020                return;
2021
2022        dir.files = NULL;
2023        dir.alloc = 0;
2024        dir.nr = 0;
2025        dir.permille = options->dirstat_permille;
2026        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2027
2028        changed = 0;
2029        for (i = 0; i < data->nr; i++) {
2030                struct diffstat_file *file = data->files[i];
2031                unsigned long damage = file->added + file->deleted;
2032                if (file->is_binary)
2033                        /*
2034                         * binary files counts bytes, not lines. Must find some
2035                         * way to normalize binary bytes vs. textual lines.
2036                         * The following heuristic assumes that there are 64
2037                         * bytes per "line".
2038                         * This is stupid and ugly, but very cheap...
2039                         */
2040                        damage = (damage + 63) / 64;
2041                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2042                dir.files[dir.nr].name = file->name;
2043                dir.files[dir.nr].changed = damage;
2044                changed += damage;
2045                dir.nr++;
2046        }
2047
2048        /* This can happen even with many files, if everything was renames */
2049        if (!changed)
2050                return;
2051
2052        /* Show all directories with more than x% of the changes */
2053        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2054        gather_dirstat(options, &dir, changed, "", 0);
2055}
2056
2057static void free_diffstat_info(struct diffstat_t *diffstat)
2058{
2059        int i;
2060        for (i = 0; i < diffstat->nr; i++) {
2061                struct diffstat_file *f = diffstat->files[i];
2062                if (f->name != f->print_name)
2063                        free(f->print_name);
2064                free(f->name);
2065                free(f->from_name);
2066                free(f);
2067        }
2068        free(diffstat->files);
2069}
2070
2071struct checkdiff_t {
2072        const char *filename;
2073        int lineno;
2074        int conflict_marker_size;
2075        struct diff_options *o;
2076        unsigned ws_rule;
2077        unsigned status;
2078};
2079
2080static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2081{
2082        char firstchar;
2083        int cnt;
2084
2085        if (len < marker_size + 1)
2086                return 0;
2087        firstchar = line[0];
2088        switch (firstchar) {
2089        case '=': case '>': case '<': case '|':
2090                break;
2091        default:
2092                return 0;
2093        }
2094        for (cnt = 1; cnt < marker_size; cnt++)
2095                if (line[cnt] != firstchar)
2096                        return 0;
2097        /* line[1] thru line[marker_size-1] are same as firstchar */
2098        if (len < marker_size + 1 || !isspace(line[marker_size]))
2099                return 0;
2100        return 1;
2101}
2102
2103static void checkdiff_consume(void *priv, char *line, unsigned long len)
2104{
2105        struct checkdiff_t *data = priv;
2106        int marker_size = data->conflict_marker_size;
2107        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2108        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2109        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2110        char *err;
2111        const char *line_prefix;
2112
2113        assert(data->o);
2114        line_prefix = diff_line_prefix(data->o);
2115
2116        if (line[0] == '+') {
2117                unsigned bad;
2118                data->lineno++;
2119                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2120                        data->status |= 1;
2121                        fprintf(data->o->file,
2122                                "%s%s:%d: leftover conflict marker\n",
2123                                line_prefix, data->filename, data->lineno);
2124                }
2125                bad = ws_check(line + 1, len - 1, data->ws_rule);
2126                if (!bad)
2127                        return;
2128                data->status |= bad;
2129                err = whitespace_error_string(bad);
2130                fprintf(data->o->file, "%s%s:%d: %s.\n",
2131                        line_prefix, data->filename, data->lineno, err);
2132                free(err);
2133                emit_line(data->o, set, reset, line, 1);
2134                ws_check_emit(line + 1, len - 1, data->ws_rule,
2135                              data->o->file, set, reset, ws);
2136        } else if (line[0] == ' ') {
2137                data->lineno++;
2138        } else if (line[0] == '@') {
2139                char *plus = strchr(line, '+');
2140                if (plus)
2141                        data->lineno = strtol(plus, NULL, 10) - 1;
2142                else
2143                        die("invalid diff");
2144        }
2145}
2146
2147static unsigned char *deflate_it(char *data,
2148                                 unsigned long size,
2149                                 unsigned long *result_size)
2150{
2151        int bound;
2152        unsigned char *deflated;
2153        git_zstream stream;
2154
2155        git_deflate_init(&stream, zlib_compression_level);
2156        bound = git_deflate_bound(&stream, size);
2157        deflated = xmalloc(bound);
2158        stream.next_out = deflated;
2159        stream.avail_out = bound;
2160
2161        stream.next_in = (unsigned char *)data;
2162        stream.avail_in = size;
2163        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2164                ; /* nothing */
2165        git_deflate_end(&stream);
2166        *result_size = stream.total_out;
2167        return deflated;
2168}
2169
2170static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2171                                  const char *prefix)
2172{
2173        void *cp;
2174        void *delta;
2175        void *deflated;
2176        void *data;
2177        unsigned long orig_size;
2178        unsigned long delta_size;
2179        unsigned long deflate_size;
2180        unsigned long data_size;
2181
2182        /* We could do deflated delta, or we could do just deflated two,
2183         * whichever is smaller.
2184         */
2185        delta = NULL;
2186        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2187        if (one->size && two->size) {
2188                delta = diff_delta(one->ptr, one->size,
2189                                   two->ptr, two->size,
2190                                   &delta_size, deflate_size);
2191                if (delta) {
2192                        void *to_free = delta;
2193                        orig_size = delta_size;
2194                        delta = deflate_it(delta, delta_size, &delta_size);
2195                        free(to_free);
2196                }
2197        }
2198
2199        if (delta && delta_size < deflate_size) {
2200                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2201                free(deflated);
2202                data = delta;
2203                data_size = delta_size;
2204        }
2205        else {
2206                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2207                free(delta);
2208                data = deflated;
2209                data_size = deflate_size;
2210        }
2211
2212        /* emit data encoded in base85 */
2213        cp = data;
2214        while (data_size) {
2215                int bytes = (52 < data_size) ? 52 : data_size;
2216                char line[70];
2217                data_size -= bytes;
2218                if (bytes <= 26)
2219                        line[0] = bytes + 'A' - 1;
2220                else
2221                        line[0] = bytes - 26 + 'a' - 1;
2222                encode_85(line + 1, cp, bytes);
2223                cp = (char *) cp + bytes;
2224                fprintf(file, "%s", prefix);
2225                fputs(line, file);
2226                fputc('\n', file);
2227        }
2228        fprintf(file, "%s\n", prefix);
2229        free(data);
2230}
2231
2232static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2233                             const char *prefix)
2234{
2235        fprintf(file, "%sGIT binary patch\n", prefix);
2236        emit_binary_diff_body(file, one, two, prefix);
2237        emit_binary_diff_body(file, two, one, prefix);
2238}
2239
2240int diff_filespec_is_binary(struct diff_filespec *one)
2241{
2242        if (one->is_binary == -1) {
2243                diff_filespec_load_driver(one);
2244                if (one->driver->binary != -1)
2245                        one->is_binary = one->driver->binary;
2246                else {
2247                        if (!one->data && DIFF_FILE_VALID(one))
2248                                diff_populate_filespec(one, CHECK_BINARY);
2249                        if (one->is_binary == -1 && one->data)
2250                                one->is_binary = buffer_is_binary(one->data,
2251                                                one->size);
2252                        if (one->is_binary == -1)
2253                                one->is_binary = 0;
2254                }
2255        }
2256        return one->is_binary;
2257}
2258
2259static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2260{
2261        diff_filespec_load_driver(one);
2262        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2263}
2264
2265void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2266{
2267        if (!options->a_prefix)
2268                options->a_prefix = a;
2269        if (!options->b_prefix)
2270                options->b_prefix = b;
2271}
2272
2273struct userdiff_driver *get_textconv(struct diff_filespec *one)
2274{
2275        if (!DIFF_FILE_VALID(one))
2276                return NULL;
2277
2278        diff_filespec_load_driver(one);
2279        return userdiff_get_textconv(one->driver);
2280}
2281
2282static void builtin_diff(const char *name_a,
2283                         const char *name_b,
2284                         struct diff_filespec *one,
2285                         struct diff_filespec *two,
2286                         const char *xfrm_msg,
2287                         int must_show_header,
2288                         struct diff_options *o,
2289                         int complete_rewrite)
2290{
2291        mmfile_t mf1, mf2;
2292        const char *lbl[2];
2293        char *a_one, *b_two;
2294        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2295        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2296        const char *a_prefix, *b_prefix;
2297        struct userdiff_driver *textconv_one = NULL;
2298        struct userdiff_driver *textconv_two = NULL;
2299        struct strbuf header = STRBUF_INIT;
2300        const char *line_prefix = diff_line_prefix(o);
2301
2302        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2303                        (!one->mode || S_ISGITLINK(one->mode)) &&
2304                        (!two->mode || S_ISGITLINK(two->mode))) {
2305                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2306                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2307                show_submodule_summary(o->file, one->path ? one->path : two->path,
2308                                line_prefix,
2309                                one->sha1, two->sha1, two->dirty_submodule,
2310                                meta, del, add, reset);
2311                return;
2312        }
2313
2314        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2315                textconv_one = get_textconv(one);
2316                textconv_two = get_textconv(two);
2317        }
2318
2319        diff_set_mnemonic_prefix(o, "a/", "b/");
2320        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2321                a_prefix = o->b_prefix;
2322                b_prefix = o->a_prefix;
2323        } else {
2324                a_prefix = o->a_prefix;
2325                b_prefix = o->b_prefix;
2326        }
2327
2328        /* Never use a non-valid filename anywhere if at all possible */
2329        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2330        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2331
2332        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2333        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2334        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2335        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2336        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2337        if (lbl[0][0] == '/') {
2338                /* /dev/null */
2339                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2340                if (xfrm_msg)
2341                        strbuf_addstr(&header, xfrm_msg);
2342                must_show_header = 1;
2343        }
2344        else if (lbl[1][0] == '/') {
2345                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2346                if (xfrm_msg)
2347                        strbuf_addstr(&header, xfrm_msg);
2348                must_show_header = 1;
2349        }
2350        else {
2351                if (one->mode != two->mode) {
2352                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2353                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2354                        must_show_header = 1;
2355                }
2356                if (xfrm_msg)
2357                        strbuf_addstr(&header, xfrm_msg);
2358
2359                /*
2360                 * we do not run diff between different kind
2361                 * of objects.
2362                 */
2363                if ((one->mode ^ two->mode) & S_IFMT)
2364                        goto free_ab_and_return;
2365                if (complete_rewrite &&
2366                    (textconv_one || !diff_filespec_is_binary(one)) &&
2367                    (textconv_two || !diff_filespec_is_binary(two))) {
2368                        fprintf(o->file, "%s", header.buf);
2369                        strbuf_reset(&header);
2370                        emit_rewrite_diff(name_a, name_b, one, two,
2371                                                textconv_one, textconv_two, o);
2372                        o->found_changes = 1;
2373                        goto free_ab_and_return;
2374                }
2375        }
2376
2377        if (o->irreversible_delete && lbl[1][0] == '/') {
2378                fprintf(o->file, "%s", header.buf);
2379                strbuf_reset(&header);
2380                goto free_ab_and_return;
2381        } else if (!DIFF_OPT_TST(o, TEXT) &&
2382            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2383              (!textconv_two && diff_filespec_is_binary(two)) )) {
2384                if (!one->data && !two->data &&
2385                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2386                    !DIFF_OPT_TST(o, BINARY)) {
2387                        if (!hashcmp(one->sha1, two->sha1)) {
2388                                if (must_show_header)
2389                                        fprintf(o->file, "%s", header.buf);
2390                                goto free_ab_and_return;
2391                        }
2392                        fprintf(o->file, "%s", header.buf);
2393                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2394                                line_prefix, lbl[0], lbl[1]);
2395                        goto free_ab_and_return;
2396                }
2397                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2398                        die("unable to read files to diff");
2399                /* Quite common confusing case */
2400                if (mf1.size == mf2.size &&
2401                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2402                        if (must_show_header)
2403                                fprintf(o->file, "%s", header.buf);
2404                        goto free_ab_and_return;
2405                }
2406                fprintf(o->file, "%s", header.buf);
2407                strbuf_reset(&header);
2408                if (DIFF_OPT_TST(o, BINARY))
2409                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2410                else
2411                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2412                                line_prefix, lbl[0], lbl[1]);
2413                o->found_changes = 1;
2414        } else {
2415                /* Crazy xdl interfaces.. */
2416                const char *diffopts = getenv("GIT_DIFF_OPTS");
2417                const char *v;
2418                xpparam_t xpp;
2419                xdemitconf_t xecfg;
2420                struct emit_callback ecbdata;
2421                const struct userdiff_funcname *pe;
2422
2423                if (must_show_header) {
2424                        fprintf(o->file, "%s", header.buf);
2425                        strbuf_reset(&header);
2426                }
2427
2428                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2429                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2430
2431                pe = diff_funcname_pattern(one);
2432                if (!pe)
2433                        pe = diff_funcname_pattern(two);
2434
2435                memset(&xpp, 0, sizeof(xpp));
2436                memset(&xecfg, 0, sizeof(xecfg));
2437                memset(&ecbdata, 0, sizeof(ecbdata));
2438                ecbdata.label_path = lbl;
2439                ecbdata.color_diff = want_color(o->use_color);
2440                ecbdata.found_changesp = &o->found_changes;
2441                ecbdata.ws_rule = whitespace_rule(name_b);
2442                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2443                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2444                ecbdata.opt = o;
2445                ecbdata.header = header.len ? &header : NULL;
2446                xpp.flags = o->xdl_opts;
2447                xecfg.ctxlen = o->context;
2448                xecfg.interhunkctxlen = o->interhunkcontext;
2449                xecfg.flags = XDL_EMIT_FUNCNAMES;
2450                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2451                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2452                if (pe)
2453                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2454                if (!diffopts)
2455                        ;
2456                else if (skip_prefix(diffopts, "--unified=", &v))
2457                        xecfg.ctxlen = strtoul(v, NULL, 10);
2458                else if (skip_prefix(diffopts, "-u", &v))
2459                        xecfg.ctxlen = strtoul(v, NULL, 10);
2460                if (o->word_diff)
2461                        init_diff_words_data(&ecbdata, o, one, two);
2462                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2463                                  &xpp, &xecfg))
2464                        die("unable to generate diff for %s", one->path);
2465                if (o->word_diff)
2466                        free_diff_words_data(&ecbdata);
2467                if (textconv_one)
2468                        free(mf1.ptr);
2469                if (textconv_two)
2470                        free(mf2.ptr);
2471                xdiff_clear_find_func(&xecfg);
2472        }
2473
2474 free_ab_and_return:
2475        strbuf_release(&header);
2476        diff_free_filespec_data(one);
2477        diff_free_filespec_data(two);
2478        free(a_one);
2479        free(b_two);
2480        return;
2481}
2482
2483static void builtin_diffstat(const char *name_a, const char *name_b,
2484                             struct diff_filespec *one,
2485                             struct diff_filespec *two,
2486                             struct diffstat_t *diffstat,
2487                             struct diff_options *o,
2488                             struct diff_filepair *p)
2489{
2490        mmfile_t mf1, mf2;
2491        struct diffstat_file *data;
2492        int same_contents;
2493        int complete_rewrite = 0;
2494
2495        if (!DIFF_PAIR_UNMERGED(p)) {
2496                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2497                        complete_rewrite = 1;
2498        }
2499
2500        data = diffstat_add(diffstat, name_a, name_b);
2501        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2502
2503        if (!one || !two) {
2504                data->is_unmerged = 1;
2505                return;
2506        }
2507
2508        same_contents = !hashcmp(one->sha1, two->sha1);
2509
2510        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2511                data->is_binary = 1;
2512                if (same_contents) {
2513                        data->added = 0;
2514                        data->deleted = 0;
2515                } else {
2516                        data->added = diff_filespec_size(two);
2517                        data->deleted = diff_filespec_size(one);
2518                }
2519        }
2520
2521        else if (complete_rewrite) {
2522                diff_populate_filespec(one, 0);
2523                diff_populate_filespec(two, 0);
2524                data->deleted = count_lines(one->data, one->size);
2525                data->added = count_lines(two->data, two->size);
2526        }
2527
2528        else if (!same_contents) {
2529                /* Crazy xdl interfaces.. */
2530                xpparam_t xpp;
2531                xdemitconf_t xecfg;
2532
2533                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2534                        die("unable to read files to diff");
2535
2536                memset(&xpp, 0, sizeof(xpp));
2537                memset(&xecfg, 0, sizeof(xecfg));
2538                xpp.flags = o->xdl_opts;
2539                xecfg.ctxlen = o->context;
2540                xecfg.interhunkctxlen = o->interhunkcontext;
2541                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2542                                  &xpp, &xecfg))
2543                        die("unable to generate diffstat for %s", one->path);
2544        }
2545
2546        diff_free_filespec_data(one);
2547        diff_free_filespec_data(two);
2548}
2549
2550static void builtin_checkdiff(const char *name_a, const char *name_b,
2551                              const char *attr_path,
2552                              struct diff_filespec *one,
2553                              struct diff_filespec *two,
2554                              struct diff_options *o)
2555{
2556        mmfile_t mf1, mf2;
2557        struct checkdiff_t data;
2558
2559        if (!two)
2560                return;
2561
2562        memset(&data, 0, sizeof(data));
2563        data.filename = name_b ? name_b : name_a;
2564        data.lineno = 0;
2565        data.o = o;
2566        data.ws_rule = whitespace_rule(attr_path);
2567        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2568
2569        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2570                die("unable to read files to diff");
2571
2572        /*
2573         * All the other codepaths check both sides, but not checking
2574         * the "old" side here is deliberate.  We are checking the newly
2575         * introduced changes, and as long as the "new" side is text, we
2576         * can and should check what it introduces.
2577         */
2578        if (diff_filespec_is_binary(two))
2579                goto free_and_return;
2580        else {
2581                /* Crazy xdl interfaces.. */
2582                xpparam_t xpp;
2583                xdemitconf_t xecfg;
2584
2585                memset(&xpp, 0, sizeof(xpp));
2586                memset(&xecfg, 0, sizeof(xecfg));
2587                xecfg.ctxlen = 1; /* at least one context line */
2588                xpp.flags = 0;
2589                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2590                                  &xpp, &xecfg))
2591                        die("unable to generate checkdiff for %s", one->path);
2592
2593                if (data.ws_rule & WS_BLANK_AT_EOF) {
2594                        struct emit_callback ecbdata;
2595                        int blank_at_eof;
2596
2597                        ecbdata.ws_rule = data.ws_rule;
2598                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2599                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2600
2601                        if (blank_at_eof) {
2602                                static char *err;
2603                                if (!err)
2604                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2605                                fprintf(o->file, "%s:%d: %s.\n",
2606                                        data.filename, blank_at_eof, err);
2607                                data.status = 1; /* report errors */
2608                        }
2609                }
2610        }
2611 free_and_return:
2612        diff_free_filespec_data(one);
2613        diff_free_filespec_data(two);
2614        if (data.status)
2615                DIFF_OPT_SET(o, CHECK_FAILED);
2616}
2617
2618struct diff_filespec *alloc_filespec(const char *path)
2619{
2620        struct diff_filespec *spec;
2621
2622        FLEXPTR_ALLOC_STR(spec, path, path);
2623        spec->count = 1;
2624        spec->is_binary = -1;
2625        return spec;
2626}
2627
2628void free_filespec(struct diff_filespec *spec)
2629{
2630        if (!--spec->count) {
2631                diff_free_filespec_data(spec);
2632                free(spec);
2633        }
2634}
2635
2636void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2637                   int sha1_valid, unsigned short mode)
2638{
2639        if (mode) {
2640                spec->mode = canon_mode(mode);
2641                hashcpy(spec->sha1, sha1);
2642                spec->sha1_valid = sha1_valid;
2643        }
2644}
2645
2646/*
2647 * Given a name and sha1 pair, if the index tells us the file in
2648 * the work tree has that object contents, return true, so that
2649 * prepare_temp_file() does not have to inflate and extract.
2650 */
2651static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2652{
2653        const struct cache_entry *ce;
2654        struct stat st;
2655        int pos, len;
2656
2657        /*
2658         * We do not read the cache ourselves here, because the
2659         * benchmark with my previous version that always reads cache
2660         * shows that it makes things worse for diff-tree comparing
2661         * two linux-2.6 kernel trees in an already checked out work
2662         * tree.  This is because most diff-tree comparisons deal with
2663         * only a small number of files, while reading the cache is
2664         * expensive for a large project, and its cost outweighs the
2665         * savings we get by not inflating the object to a temporary
2666         * file.  Practically, this code only helps when we are used
2667         * by diff-cache --cached, which does read the cache before
2668         * calling us.
2669         */
2670        if (!active_cache)
2671                return 0;
2672
2673        /* We want to avoid the working directory if our caller
2674         * doesn't need the data in a normal file, this system
2675         * is rather slow with its stat/open/mmap/close syscalls,
2676         * and the object is contained in a pack file.  The pack
2677         * is probably already open and will be faster to obtain
2678         * the data through than the working directory.  Loose
2679         * objects however would tend to be slower as they need
2680         * to be individually opened and inflated.
2681         */
2682        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2683                return 0;
2684
2685        /*
2686         * Similarly, if we'd have to convert the file contents anyway, that
2687         * makes the optimization not worthwhile.
2688         */
2689        if (!want_file && would_convert_to_git(name))
2690                return 0;
2691
2692        len = strlen(name);
2693        pos = cache_name_pos(name, len);
2694        if (pos < 0)
2695                return 0;
2696        ce = active_cache[pos];
2697
2698        /*
2699         * This is not the sha1 we are looking for, or
2700         * unreusable because it is not a regular file.
2701         */
2702        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2703                return 0;
2704
2705        /*
2706         * If ce is marked as "assume unchanged", there is no
2707         * guarantee that work tree matches what we are looking for.
2708         */
2709        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2710                return 0;
2711
2712        /*
2713         * If ce matches the file in the work tree, we can reuse it.
2714         */
2715        if (ce_uptodate(ce) ||
2716            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2717                return 1;
2718
2719        return 0;
2720}
2721
2722static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2723{
2724        struct strbuf buf = STRBUF_INIT;
2725        char *dirty = "";
2726
2727        /* Are we looking at the work tree? */
2728        if (s->dirty_submodule)
2729                dirty = "-dirty";
2730
2731        strbuf_addf(&buf, "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2732        s->size = buf.len;
2733        if (size_only) {
2734                s->data = NULL;
2735                strbuf_release(&buf);
2736        } else {
2737                s->data = strbuf_detach(&buf, NULL);
2738                s->should_free = 1;
2739        }
2740        return 0;
2741}
2742
2743/*
2744 * While doing rename detection and pickaxe operation, we may need to
2745 * grab the data for the blob (or file) for our own in-core comparison.
2746 * diff_filespec has data and size fields for this purpose.
2747 */
2748int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2749{
2750        int size_only = flags & CHECK_SIZE_ONLY;
2751        int err = 0;
2752        /*
2753         * demote FAIL to WARN to allow inspecting the situation
2754         * instead of refusing.
2755         */
2756        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2757                                    ? SAFE_CRLF_WARN
2758                                    : safe_crlf);
2759
2760        if (!DIFF_FILE_VALID(s))
2761                die("internal error: asking to populate invalid file.");
2762        if (S_ISDIR(s->mode))
2763                return -1;
2764
2765        if (s->data)
2766                return 0;
2767
2768        if (size_only && 0 < s->size)
2769                return 0;
2770
2771        if (S_ISGITLINK(s->mode))
2772                return diff_populate_gitlink(s, size_only);
2773
2774        if (!s->sha1_valid ||
2775            reuse_worktree_file(s->path, s->sha1, 0)) {
2776                struct strbuf buf = STRBUF_INIT;
2777                struct stat st;
2778                int fd;
2779
2780                if (lstat(s->path, &st) < 0) {
2781                        if (errno == ENOENT) {
2782                        err_empty:
2783                                err = -1;
2784                        empty:
2785                                s->data = (char *)"";
2786                                s->size = 0;
2787                                return err;
2788                        }
2789                }
2790                s->size = xsize_t(st.st_size);
2791                if (!s->size)
2792                        goto empty;
2793                if (S_ISLNK(st.st_mode)) {
2794                        struct strbuf sb = STRBUF_INIT;
2795
2796                        if (strbuf_readlink(&sb, s->path, s->size))
2797                                goto err_empty;
2798                        s->size = sb.len;
2799                        s->data = strbuf_detach(&sb, NULL);
2800                        s->should_free = 1;
2801                        return 0;
2802                }
2803                if (size_only)
2804                        return 0;
2805                if ((flags & CHECK_BINARY) &&
2806                    s->size > big_file_threshold && s->is_binary == -1) {
2807                        s->is_binary = 1;
2808                        return 0;
2809                }
2810                fd = open(s->path, O_RDONLY);
2811                if (fd < 0)
2812                        goto err_empty;
2813                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2814                close(fd);
2815                s->should_munmap = 1;
2816
2817                /*
2818                 * Convert from working tree format to canonical git format
2819                 */
2820                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2821                        size_t size = 0;
2822                        munmap(s->data, s->size);
2823                        s->should_munmap = 0;
2824                        s->data = strbuf_detach(&buf, &size);
2825                        s->size = size;
2826                        s->should_free = 1;
2827                }
2828        }
2829        else {
2830                enum object_type type;
2831                if (size_only || (flags & CHECK_BINARY)) {
2832                        type = sha1_object_info(s->sha1, &s->size);
2833                        if (type < 0)
2834                                die("unable to read %s", sha1_to_hex(s->sha1));
2835                        if (size_only)
2836                                return 0;
2837                        if (s->size > big_file_threshold && s->is_binary == -1) {
2838                                s->is_binary = 1;
2839                                return 0;
2840                        }
2841                }
2842                s->data = read_sha1_file(s->sha1, &type, &s->size);
2843                if (!s->data)
2844                        die("unable to read %s", sha1_to_hex(s->sha1));
2845                s->should_free = 1;
2846        }
2847        return 0;
2848}
2849
2850void diff_free_filespec_blob(struct diff_filespec *s)
2851{
2852        if (s->should_free)
2853                free(s->data);
2854        else if (s->should_munmap)
2855                munmap(s->data, s->size);
2856
2857        if (s->should_free || s->should_munmap) {
2858                s->should_free = s->should_munmap = 0;
2859                s->data = NULL;
2860        }
2861}
2862
2863void diff_free_filespec_data(struct diff_filespec *s)
2864{
2865        diff_free_filespec_blob(s);
2866        free(s->cnt_data);
2867        s->cnt_data = NULL;
2868}
2869
2870static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2871                           void *blob,
2872                           unsigned long size,
2873                           const unsigned char *sha1,
2874                           int mode)
2875{
2876        int fd;
2877        struct strbuf buf = STRBUF_INIT;
2878        struct strbuf template = STRBUF_INIT;
2879        char *path_dup = xstrdup(path);
2880        const char *base = basename(path_dup);
2881
2882        /* Generate "XXXXXX_basename.ext" */
2883        strbuf_addstr(&template, "XXXXXX_");
2884        strbuf_addstr(&template, base);
2885
2886        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
2887        if (fd < 0)
2888                die_errno("unable to create temp-file");
2889        if (convert_to_working_tree(path,
2890                        (const char *)blob, (size_t)size, &buf)) {
2891                blob = buf.buf;
2892                size = buf.len;
2893        }
2894        if (write_in_full(fd, blob, size) != size)
2895                die_errno("unable to write temp-file");
2896        close_tempfile(&temp->tempfile);
2897        temp->name = get_tempfile_path(&temp->tempfile);
2898        sha1_to_hex_r(temp->hex, sha1);
2899        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
2900        strbuf_release(&buf);
2901        strbuf_release(&template);
2902        free(path_dup);
2903}
2904
2905static struct diff_tempfile *prepare_temp_file(const char *name,
2906                struct diff_filespec *one)
2907{
2908        struct diff_tempfile *temp = claim_diff_tempfile();
2909
2910        if (!DIFF_FILE_VALID(one)) {
2911        not_a_valid_file:
2912                /* A '-' entry produces this for file-2, and
2913                 * a '+' entry produces this for file-1.
2914                 */
2915                temp->name = "/dev/null";
2916                xsnprintf(temp->hex, sizeof(temp->hex), ".");
2917                xsnprintf(temp->mode, sizeof(temp->mode), ".");
2918                return temp;
2919        }
2920
2921        if (!S_ISGITLINK(one->mode) &&
2922            (!one->sha1_valid ||
2923             reuse_worktree_file(name, one->sha1, 1))) {
2924                struct stat st;
2925                if (lstat(name, &st) < 0) {
2926                        if (errno == ENOENT)
2927                                goto not_a_valid_file;
2928                        die_errno("stat(%s)", name);
2929                }
2930                if (S_ISLNK(st.st_mode)) {
2931                        struct strbuf sb = STRBUF_INIT;
2932                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2933                                die_errno("readlink(%s)", name);
2934                        prep_temp_blob(name, temp, sb.buf, sb.len,
2935                                       (one->sha1_valid ?
2936                                        one->sha1 : null_sha1),
2937                                       (one->sha1_valid ?
2938                                        one->mode : S_IFLNK));
2939                        strbuf_release(&sb);
2940                }
2941                else {
2942                        /* we can borrow from the file in the work tree */
2943                        temp->name = name;
2944                        if (!one->sha1_valid)
2945                                sha1_to_hex_r(temp->hex, null_sha1);
2946                        else
2947                                sha1_to_hex_r(temp->hex, one->sha1);
2948                        /* Even though we may sometimes borrow the
2949                         * contents from the work tree, we always want
2950                         * one->mode.  mode is trustworthy even when
2951                         * !(one->sha1_valid), as long as
2952                         * DIFF_FILE_VALID(one).
2953                         */
2954                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
2955                }
2956                return temp;
2957        }
2958        else {
2959                if (diff_populate_filespec(one, 0))
2960                        die("cannot read data blob for %s", one->path);
2961                prep_temp_blob(name, temp, one->data, one->size,
2962                               one->sha1, one->mode);
2963        }
2964        return temp;
2965}
2966
2967static void add_external_diff_name(struct argv_array *argv,
2968                                   const char *name,
2969                                   struct diff_filespec *df)
2970{
2971        struct diff_tempfile *temp = prepare_temp_file(name, df);
2972        argv_array_push(argv, temp->name);
2973        argv_array_push(argv, temp->hex);
2974        argv_array_push(argv, temp->mode);
2975}
2976
2977/* An external diff command takes:
2978 *
2979 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2980 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2981 *
2982 */
2983static void run_external_diff(const char *pgm,
2984                              const char *name,
2985                              const char *other,
2986                              struct diff_filespec *one,
2987                              struct diff_filespec *two,
2988                              const char *xfrm_msg,
2989                              int complete_rewrite,
2990                              struct diff_options *o)
2991{
2992        struct argv_array argv = ARGV_ARRAY_INIT;
2993        struct argv_array env = ARGV_ARRAY_INIT;
2994        struct diff_queue_struct *q = &diff_queued_diff;
2995
2996        argv_array_push(&argv, pgm);
2997        argv_array_push(&argv, name);
2998
2999        if (one && two) {
3000                add_external_diff_name(&argv, name, one);
3001                if (!other)
3002                        add_external_diff_name(&argv, name, two);
3003                else {
3004                        add_external_diff_name(&argv, other, two);
3005                        argv_array_push(&argv, other);
3006                        argv_array_push(&argv, xfrm_msg);
3007                }
3008        }
3009
3010        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3011        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3012
3013        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3014                die(_("external diff died, stopping at %s"), name);
3015
3016        remove_tempfile();
3017        argv_array_clear(&argv);
3018        argv_array_clear(&env);
3019}
3020
3021static int similarity_index(struct diff_filepair *p)
3022{
3023        return p->score * 100 / MAX_SCORE;
3024}
3025
3026static void fill_metainfo(struct strbuf *msg,
3027                          const char *name,
3028                          const char *other,
3029                          struct diff_filespec *one,
3030                          struct diff_filespec *two,
3031                          struct diff_options *o,
3032                          struct diff_filepair *p,
3033                          int *must_show_header,
3034                          int use_color)
3035{
3036        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3037        const char *reset = diff_get_color(use_color, DIFF_RESET);
3038        const char *line_prefix = diff_line_prefix(o);
3039
3040        *must_show_header = 1;
3041        strbuf_init(msg, PATH_MAX * 2 + 300);
3042        switch (p->status) {
3043        case DIFF_STATUS_COPIED:
3044                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3045                            line_prefix, set, similarity_index(p));
3046                strbuf_addf(msg, "%s\n%s%scopy from ",
3047                            reset,  line_prefix, set);
3048                quote_c_style(name, msg, NULL, 0);
3049                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3050                quote_c_style(other, msg, NULL, 0);
3051                strbuf_addf(msg, "%s\n", reset);
3052                break;
3053        case DIFF_STATUS_RENAMED:
3054                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3055                            line_prefix, set, similarity_index(p));
3056                strbuf_addf(msg, "%s\n%s%srename from ",
3057                            reset, line_prefix, set);
3058                quote_c_style(name, msg, NULL, 0);
3059                strbuf_addf(msg, "%s\n%s%srename to ",
3060                            reset, line_prefix, set);
3061                quote_c_style(other, msg, NULL, 0);
3062                strbuf_addf(msg, "%s\n", reset);
3063                break;
3064        case DIFF_STATUS_MODIFIED:
3065                if (p->score) {
3066                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3067                                    line_prefix,
3068                                    set, similarity_index(p), reset);
3069                        break;
3070                }
3071                /* fallthru */
3072        default:
3073                *must_show_header = 0;
3074        }
3075        if (one && two && hashcmp(one->sha1, two->sha1)) {
3076                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3077
3078                if (DIFF_OPT_TST(o, BINARY)) {
3079                        mmfile_t mf;
3080                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3081                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3082                                abbrev = 40;
3083                }
3084                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3085                            find_unique_abbrev(one->sha1, abbrev));
3086                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
3087                if (one->mode == two->mode)
3088                        strbuf_addf(msg, " %06o", one->mode);
3089                strbuf_addf(msg, "%s\n", reset);
3090        }
3091}
3092
3093static void run_diff_cmd(const char *pgm,
3094                         const char *name,
3095                         const char *other,
3096                         const char *attr_path,
3097                         struct diff_filespec *one,
3098                         struct diff_filespec *two,
3099                         struct strbuf *msg,
3100                         struct diff_options *o,
3101                         struct diff_filepair *p)
3102{
3103        const char *xfrm_msg = NULL;
3104        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3105        int must_show_header = 0;
3106
3107
3108        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3109                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3110                if (drv && drv->external)
3111                        pgm = drv->external;
3112        }
3113
3114        if (msg) {
3115                /*
3116                 * don't use colors when the header is intended for an
3117                 * external diff driver
3118                 */
3119                fill_metainfo(msg, name, other, one, two, o, p,
3120                              &must_show_header,
3121                              want_color(o->use_color) && !pgm);
3122                xfrm_msg = msg->len ? msg->buf : NULL;
3123        }
3124
3125        if (pgm) {
3126                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3127                                  complete_rewrite, o);
3128                return;
3129        }
3130        if (one && two)
3131                builtin_diff(name, other ? other : name,
3132                             one, two, xfrm_msg, must_show_header,
3133                             o, complete_rewrite);
3134        else
3135                fprintf(o->file, "* Unmerged path %s\n", name);
3136}
3137
3138static void diff_fill_sha1_info(struct diff_filespec *one)
3139{
3140        if (DIFF_FILE_VALID(one)) {
3141                if (!one->sha1_valid) {
3142                        struct stat st;
3143                        if (one->is_stdin) {
3144                                hashcpy(one->sha1, null_sha1);
3145                                return;
3146                        }
3147                        if (lstat(one->path, &st) < 0)
3148                                die_errno("stat '%s'", one->path);
3149                        if (index_path(one->sha1, one->path, &st, 0))
3150                                die("cannot hash %s", one->path);
3151                }
3152        }
3153        else
3154                hashclr(one->sha1);
3155}
3156
3157static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3158{
3159        /* Strip the prefix but do not molest /dev/null and absolute paths */
3160        if (*namep && **namep != '/') {
3161                *namep += prefix_length;
3162                if (**namep == '/')
3163                        ++*namep;
3164        }
3165        if (*otherp && **otherp != '/') {
3166                *otherp += prefix_length;
3167                if (**otherp == '/')
3168                        ++*otherp;
3169        }
3170}
3171
3172static void run_diff(struct diff_filepair *p, struct diff_options *o)
3173{
3174        const char *pgm = external_diff();
3175        struct strbuf msg;
3176        struct diff_filespec *one = p->one;
3177        struct diff_filespec *two = p->two;
3178        const char *name;
3179        const char *other;
3180        const char *attr_path;
3181
3182        name  = p->one->path;
3183        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3184        attr_path = name;
3185        if (o->prefix_length)
3186                strip_prefix(o->prefix_length, &name, &other);
3187
3188        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3189                pgm = NULL;
3190
3191        if (DIFF_PAIR_UNMERGED(p)) {
3192                run_diff_cmd(pgm, name, NULL, attr_path,
3193                             NULL, NULL, NULL, o, p);
3194                return;
3195        }
3196
3197        diff_fill_sha1_info(one);
3198        diff_fill_sha1_info(two);
3199
3200        if (!pgm &&
3201            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3202            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3203                /*
3204                 * a filepair that changes between file and symlink
3205                 * needs to be split into deletion and creation.
3206                 */
3207                struct diff_filespec *null = alloc_filespec(two->path);
3208                run_diff_cmd(NULL, name, other, attr_path,
3209                             one, null, &msg, o, p);
3210                free(null);
3211                strbuf_release(&msg);
3212
3213                null = alloc_filespec(one->path);
3214                run_diff_cmd(NULL, name, other, attr_path,
3215                             null, two, &msg, o, p);
3216                free(null);
3217        }
3218        else
3219                run_diff_cmd(pgm, name, other, attr_path,
3220                             one, two, &msg, o, p);
3221
3222        strbuf_release(&msg);
3223}
3224
3225static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3226                         struct diffstat_t *diffstat)
3227{
3228        const char *name;
3229        const char *other;
3230
3231        if (DIFF_PAIR_UNMERGED(p)) {
3232                /* unmerged */
3233                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3234                return;
3235        }
3236
3237        name = p->one->path;
3238        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3239
3240        if (o->prefix_length)
3241                strip_prefix(o->prefix_length, &name, &other);
3242
3243        diff_fill_sha1_info(p->one);
3244        diff_fill_sha1_info(p->two);
3245
3246        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3247}
3248
3249static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3250{
3251        const char *name;
3252        const char *other;
3253        const char *attr_path;
3254
3255        if (DIFF_PAIR_UNMERGED(p)) {
3256                /* unmerged */
3257                return;
3258        }
3259
3260        name = p->one->path;
3261        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3262        attr_path = other ? other : name;
3263
3264        if (o->prefix_length)
3265                strip_prefix(o->prefix_length, &name, &other);
3266
3267        diff_fill_sha1_info(p->one);
3268        diff_fill_sha1_info(p->two);
3269
3270        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3271}
3272
3273void diff_setup(struct diff_options *options)
3274{
3275        memcpy(options, &default_diff_options, sizeof(*options));
3276
3277        options->file = stdout;
3278
3279        options->line_termination = '\n';
3280        options->break_opt = -1;
3281        options->rename_limit = -1;
3282        options->dirstat_permille = diff_dirstat_permille_default;
3283        options->context = diff_context_default;
3284        options->ws_error_highlight = WSEH_NEW;
3285        DIFF_OPT_SET(options, RENAME_EMPTY);
3286
3287        /* pathchange left =NULL by default */
3288        options->change = diff_change;
3289        options->add_remove = diff_addremove;
3290        options->use_color = diff_use_color_default;
3291        options->detect_rename = diff_detect_rename_default;
3292        options->xdl_opts |= diff_algorithm;
3293        if (diff_compaction_heuristic)
3294                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3295
3296        options->orderfile = diff_order_file_cfg;
3297
3298        if (diff_no_prefix) {
3299                options->a_prefix = options->b_prefix = "";
3300        } else if (!diff_mnemonic_prefix) {
3301                options->a_prefix = "a/";
3302                options->b_prefix = "b/";
3303        }
3304}
3305
3306void diff_setup_done(struct diff_options *options)
3307{
3308        int count = 0;
3309
3310        if (options->set_default)
3311                options->set_default(options);
3312
3313        if (options->output_format & DIFF_FORMAT_NAME)
3314                count++;
3315        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3316                count++;
3317        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3318                count++;
3319        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3320                count++;
3321        if (count > 1)
3322                die("--name-only, --name-status, --check and -s are mutually exclusive");
3323
3324        /*
3325         * Most of the time we can say "there are changes"
3326         * only by checking if there are changed paths, but
3327         * --ignore-whitespace* options force us to look
3328         * inside contents.
3329         */
3330
3331        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3332            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3333            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3334                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3335        else
3336                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3337
3338        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3339                options->detect_rename = DIFF_DETECT_COPY;
3340
3341        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3342                options->prefix = NULL;
3343        if (options->prefix)
3344                options->prefix_length = strlen(options->prefix);
3345        else
3346                options->prefix_length = 0;
3347
3348        if (options->output_format & (DIFF_FORMAT_NAME |
3349                                      DIFF_FORMAT_NAME_STATUS |
3350                                      DIFF_FORMAT_CHECKDIFF |
3351                                      DIFF_FORMAT_NO_OUTPUT))
3352                options->output_format &= ~(DIFF_FORMAT_RAW |
3353                                            DIFF_FORMAT_NUMSTAT |
3354                                            DIFF_FORMAT_DIFFSTAT |
3355                                            DIFF_FORMAT_SHORTSTAT |
3356                                            DIFF_FORMAT_DIRSTAT |
3357                                            DIFF_FORMAT_SUMMARY |
3358                                            DIFF_FORMAT_PATCH);
3359
3360        /*
3361         * These cases always need recursive; we do not drop caller-supplied
3362         * recursive bits for other formats here.
3363         */
3364        if (options->output_format & (DIFF_FORMAT_PATCH |
3365                                      DIFF_FORMAT_NUMSTAT |
3366                                      DIFF_FORMAT_DIFFSTAT |
3367                                      DIFF_FORMAT_SHORTSTAT |
3368                                      DIFF_FORMAT_DIRSTAT |
3369                                      DIFF_FORMAT_SUMMARY |
3370                                      DIFF_FORMAT_CHECKDIFF))
3371                DIFF_OPT_SET(options, RECURSIVE);
3372        /*
3373         * Also pickaxe would not work very well if you do not say recursive
3374         */
3375        if (options->pickaxe)
3376                DIFF_OPT_SET(options, RECURSIVE);
3377        /*
3378         * When patches are generated, submodules diffed against the work tree
3379         * must be checked for dirtiness too so it can be shown in the output
3380         */
3381        if (options->output_format & DIFF_FORMAT_PATCH)
3382                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3383
3384        if (options->detect_rename && options->rename_limit < 0)
3385                options->rename_limit = diff_rename_limit_default;
3386        if (options->setup & DIFF_SETUP_USE_CACHE) {
3387                if (!active_cache)
3388                        /* read-cache does not die even when it fails
3389                         * so it is safe for us to do this here.  Also
3390                         * it does not smudge active_cache or active_nr
3391                         * when it fails, so we do not have to worry about
3392                         * cleaning it up ourselves either.
3393                         */
3394                        read_cache();
3395        }
3396        if (options->abbrev <= 0 || 40 < options->abbrev)
3397                options->abbrev = 40; /* full */
3398
3399        /*
3400         * It does not make sense to show the first hit we happened
3401         * to have found.  It does not make sense not to return with
3402         * exit code in such a case either.
3403         */
3404        if (DIFF_OPT_TST(options, QUICK)) {
3405                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3406                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3407        }
3408
3409        options->diff_path_counter = 0;
3410
3411        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3412                die(_("--follow requires exactly one pathspec"));
3413}
3414
3415static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3416{
3417        char c, *eq;
3418        int len;
3419
3420        if (*arg != '-')
3421                return 0;
3422        c = *++arg;
3423        if (!c)
3424                return 0;
3425        if (c == arg_short) {
3426                c = *++arg;
3427                if (!c)
3428                        return 1;
3429                if (val && isdigit(c)) {
3430                        char *end;
3431                        int n = strtoul(arg, &end, 10);
3432                        if (*end)
3433                                return 0;
3434                        *val = n;
3435                        return 1;
3436                }
3437                return 0;
3438        }
3439        if (c != '-')
3440                return 0;
3441        arg++;
3442        eq = strchrnul(arg, '=');
3443        len = eq - arg;
3444        if (!len || strncmp(arg, arg_long, len))
3445                return 0;
3446        if (*eq) {
3447                int n;
3448                char *end;
3449                if (!isdigit(*++eq))
3450                        return 0;
3451                n = strtoul(eq, &end, 10);
3452                if (*end)
3453                        return 0;
3454                *val = n;
3455        }
3456        return 1;
3457}
3458
3459static int diff_scoreopt_parse(const char *opt);
3460
3461static inline int short_opt(char opt, const char **argv,
3462                            const char **optarg)
3463{
3464        const char *arg = argv[0];
3465        if (arg[0] != '-' || arg[1] != opt)
3466                return 0;
3467        if (arg[2] != '\0') {
3468                *optarg = arg + 2;
3469                return 1;
3470        }
3471        if (!argv[1])
3472                die("Option '%c' requires a value", opt);
3473        *optarg = argv[1];
3474        return 2;
3475}
3476
3477int parse_long_opt(const char *opt, const char **argv,
3478                   const char **optarg)
3479{
3480        const char *arg = argv[0];
3481        if (!skip_prefix(arg, "--", &arg))
3482                return 0;
3483        if (!skip_prefix(arg, opt, &arg))
3484                return 0;
3485        if (*arg == '=') { /* stuck form: --option=value */
3486                *optarg = arg + 1;
3487                return 1;
3488        }
3489        if (*arg != '\0')
3490                return 0;
3491        /* separate form: --option value */
3492        if (!argv[1])
3493                die("Option '--%s' requires a value", opt);
3494        *optarg = argv[1];
3495        return 2;
3496}
3497
3498static int stat_opt(struct diff_options *options, const char **av)
3499{
3500        const char *arg = av[0];
3501        char *end;
3502        int width = options->stat_width;
3503        int name_width = options->stat_name_width;
3504        int graph_width = options->stat_graph_width;
3505        int count = options->stat_count;
3506        int argcount = 1;
3507
3508        if (!skip_prefix(arg, "--stat", &arg))
3509                die("BUG: stat option does not begin with --stat: %s", arg);
3510        end = (char *)arg;
3511
3512        switch (*arg) {
3513        case '-':
3514                if (skip_prefix(arg, "-width", &arg)) {
3515                        if (*arg == '=')
3516                                width = strtoul(arg + 1, &end, 10);
3517                        else if (!*arg && !av[1])
3518                                die("Option '--stat-width' requires a value");
3519                        else if (!*arg) {
3520                                width = strtoul(av[1], &end, 10);
3521                                argcount = 2;
3522                        }
3523                } else if (skip_prefix(arg, "-name-width", &arg)) {
3524                        if (*arg == '=')
3525                                name_width = strtoul(arg + 1, &end, 10);
3526                        else if (!*arg && !av[1])
3527                                die("Option '--stat-name-width' requires a value");
3528                        else if (!*arg) {
3529                                name_width = strtoul(av[1], &end, 10);
3530                                argcount = 2;
3531                        }
3532                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3533                        if (*arg == '=')
3534                                graph_width = strtoul(arg + 1, &end, 10);
3535                        else if (!*arg && !av[1])
3536                                die("Option '--stat-graph-width' requires a value");
3537                        else if (!*arg) {
3538                                graph_width = strtoul(av[1], &end, 10);
3539                                argcount = 2;
3540                        }
3541                } else if (skip_prefix(arg, "-count", &arg)) {
3542                        if (*arg == '=')
3543                                count = strtoul(arg + 1, &end, 10);
3544                        else if (!*arg && !av[1])
3545                                die("Option '--stat-count' requires a value");
3546                        else if (!*arg) {
3547                                count = strtoul(av[1], &end, 10);
3548                                argcount = 2;
3549                        }
3550                }
3551                break;
3552        case '=':
3553                width = strtoul(arg+1, &end, 10);
3554                if (*end == ',')
3555                        name_width = strtoul(end+1, &end, 10);
3556                if (*end == ',')
3557                        count = strtoul(end+1, &end, 10);
3558        }
3559
3560        /* Important! This checks all the error cases! */
3561        if (*end)
3562                return 0;
3563        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3564        options->stat_name_width = name_width;
3565        options->stat_graph_width = graph_width;
3566        options->stat_width = width;
3567        options->stat_count = count;
3568        return argcount;
3569}
3570
3571static int parse_dirstat_opt(struct diff_options *options, const char *params)
3572{
3573        struct strbuf errmsg = STRBUF_INIT;
3574        if (parse_dirstat_params(options, params, &errmsg))
3575                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3576                    errmsg.buf);
3577        strbuf_release(&errmsg);
3578        /*
3579         * The caller knows a dirstat-related option is given from the command
3580         * line; allow it to say "return this_function();"
3581         */
3582        options->output_format |= DIFF_FORMAT_DIRSTAT;
3583        return 1;
3584}
3585
3586static int parse_submodule_opt(struct diff_options *options, const char *value)
3587{
3588        if (parse_submodule_params(options, value))
3589                die(_("Failed to parse --submodule option parameter: '%s'"),
3590                        value);
3591        return 1;
3592}
3593
3594static const char diff_status_letters[] = {
3595        DIFF_STATUS_ADDED,
3596        DIFF_STATUS_COPIED,
3597        DIFF_STATUS_DELETED,
3598        DIFF_STATUS_MODIFIED,
3599        DIFF_STATUS_RENAMED,
3600        DIFF_STATUS_TYPE_CHANGED,
3601        DIFF_STATUS_UNKNOWN,
3602        DIFF_STATUS_UNMERGED,
3603        DIFF_STATUS_FILTER_AON,
3604        DIFF_STATUS_FILTER_BROKEN,
3605        '\0',
3606};
3607
3608static unsigned int filter_bit['Z' + 1];
3609
3610static void prepare_filter_bits(void)
3611{
3612        int i;
3613
3614        if (!filter_bit[DIFF_STATUS_ADDED]) {
3615                for (i = 0; diff_status_letters[i]; i++)
3616                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3617        }
3618}
3619
3620static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3621{
3622        return opt->filter & filter_bit[(int) status];
3623}
3624
3625static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3626{
3627        int i, optch;
3628
3629        prepare_filter_bits();
3630
3631        /*
3632         * If there is a negation e.g. 'd' in the input, and we haven't
3633         * initialized the filter field with another --diff-filter, start
3634         * from full set of bits, except for AON.
3635         */
3636        if (!opt->filter) {
3637                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3638                        if (optch < 'a' || 'z' < optch)
3639                                continue;
3640                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3641                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3642                        break;
3643                }
3644        }
3645
3646        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3647                unsigned int bit;
3648                int negate;
3649
3650                if ('a' <= optch && optch <= 'z') {
3651                        negate = 1;
3652                        optch = toupper(optch);
3653                } else {
3654                        negate = 0;
3655                }
3656
3657                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3658                if (!bit)
3659                        return optarg[i];
3660                if (negate)
3661                        opt->filter &= ~bit;
3662                else
3663                        opt->filter |= bit;
3664        }
3665        return 0;
3666}
3667
3668static void enable_patch_output(int *fmt) {
3669        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3670        *fmt |= DIFF_FORMAT_PATCH;
3671}
3672
3673static int parse_one_token(const char **arg, const char *token)
3674{
3675        const char *rest;
3676        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
3677                *arg = rest;
3678                return 1;
3679        }
3680        return 0;
3681}
3682
3683static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
3684{
3685        const char *orig_arg = arg;
3686        unsigned val = 0;
3687        while (*arg) {
3688                if (parse_one_token(&arg, "none"))
3689                        val = 0;
3690                else if (parse_one_token(&arg, "default"))
3691                        val = WSEH_NEW;
3692                else if (parse_one_token(&arg, "all"))
3693                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
3694                else if (parse_one_token(&arg, "new"))
3695                        val |= WSEH_NEW;
3696                else if (parse_one_token(&arg, "old"))
3697                        val |= WSEH_OLD;
3698                else if (parse_one_token(&arg, "context"))
3699                        val |= WSEH_CONTEXT;
3700                else {
3701                        error("unknown value after ws-error-highlight=%.*s",
3702                              (int)(arg - orig_arg), orig_arg);
3703                        return 0;
3704                }
3705                if (*arg)
3706                        arg++;
3707        }
3708        opt->ws_error_highlight = val;
3709        return 1;
3710}
3711
3712int diff_opt_parse(struct diff_options *options,
3713                   const char **av, int ac, const char *prefix)
3714{
3715        const char *arg = av[0];
3716        const char *optarg;
3717        int argcount;
3718
3719        if (!prefix)
3720                prefix = "";
3721
3722        /* Output format options */
3723        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3724            || opt_arg(arg, 'U', "unified", &options->context))
3725                enable_patch_output(&options->output_format);
3726        else if (!strcmp(arg, "--raw"))
3727                options->output_format |= DIFF_FORMAT_RAW;
3728        else if (!strcmp(arg, "--patch-with-raw")) {
3729                enable_patch_output(&options->output_format);
3730                options->output_format |= DIFF_FORMAT_RAW;
3731        } else if (!strcmp(arg, "--numstat"))
3732                options->output_format |= DIFF_FORMAT_NUMSTAT;
3733        else if (!strcmp(arg, "--shortstat"))
3734                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3735        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3736                return parse_dirstat_opt(options, "");
3737        else if (skip_prefix(arg, "-X", &arg))
3738                return parse_dirstat_opt(options, arg);
3739        else if (skip_prefix(arg, "--dirstat=", &arg))
3740                return parse_dirstat_opt(options, arg);
3741        else if (!strcmp(arg, "--cumulative"))
3742                return parse_dirstat_opt(options, "cumulative");
3743        else if (!strcmp(arg, "--dirstat-by-file"))
3744                return parse_dirstat_opt(options, "files");
3745        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3746                parse_dirstat_opt(options, "files");
3747                return parse_dirstat_opt(options, arg);
3748        }
3749        else if (!strcmp(arg, "--check"))
3750                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3751        else if (!strcmp(arg, "--summary"))
3752                options->output_format |= DIFF_FORMAT_SUMMARY;
3753        else if (!strcmp(arg, "--patch-with-stat")) {
3754                enable_patch_output(&options->output_format);
3755                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3756        } else if (!strcmp(arg, "--name-only"))
3757                options->output_format |= DIFF_FORMAT_NAME;
3758        else if (!strcmp(arg, "--name-status"))
3759                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3760        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3761                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3762        else if (starts_with(arg, "--stat"))
3763                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3764                return stat_opt(options, av);
3765
3766        /* renames options */
3767        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3768                 !strcmp(arg, "--break-rewrites")) {
3769                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3770                        return error("invalid argument to -B: %s", arg+2);
3771        }
3772        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3773                 !strcmp(arg, "--find-renames")) {
3774                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3775                        return error("invalid argument to -M: %s", arg+2);
3776                options->detect_rename = DIFF_DETECT_RENAME;
3777        }
3778        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3779                options->irreversible_delete = 1;
3780        }
3781        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3782                 !strcmp(arg, "--find-copies")) {
3783                if (options->detect_rename == DIFF_DETECT_COPY)
3784                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3785                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3786                        return error("invalid argument to -C: %s", arg+2);
3787                options->detect_rename = DIFF_DETECT_COPY;
3788        }
3789        else if (!strcmp(arg, "--no-renames"))
3790                options->detect_rename = 0;
3791        else if (!strcmp(arg, "--rename-empty"))
3792                DIFF_OPT_SET(options, RENAME_EMPTY);
3793        else if (!strcmp(arg, "--no-rename-empty"))
3794                DIFF_OPT_CLR(options, RENAME_EMPTY);
3795        else if (!strcmp(arg, "--relative"))
3796                DIFF_OPT_SET(options, RELATIVE_NAME);
3797        else if (skip_prefix(arg, "--relative=", &arg)) {
3798                DIFF_OPT_SET(options, RELATIVE_NAME);
3799                options->prefix = arg;
3800        }
3801
3802        /* xdiff options */
3803        else if (!strcmp(arg, "--minimal"))
3804                DIFF_XDL_SET(options, NEED_MINIMAL);
3805        else if (!strcmp(arg, "--no-minimal"))
3806                DIFF_XDL_CLR(options, NEED_MINIMAL);
3807        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3808                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3809        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3810                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3811        else if (!strcmp(arg, "--ignore-space-at-eol"))
3812                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3813        else if (!strcmp(arg, "--ignore-blank-lines"))
3814                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3815        else if (!strcmp(arg, "--compaction-heuristic"))
3816                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3817        else if (!strcmp(arg, "--no-compaction-heuristic"))
3818                DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
3819        else if (!strcmp(arg, "--patience"))
3820                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3821        else if (!strcmp(arg, "--histogram"))
3822                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3823        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3824                long value = parse_algorithm_value(optarg);
3825                if (value < 0)
3826                        return error("option diff-algorithm accepts \"myers\", "
3827                                     "\"minimal\", \"patience\" and \"histogram\"");
3828                /* clear out previous settings */
3829                DIFF_XDL_CLR(options, NEED_MINIMAL);
3830                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3831                options->xdl_opts |= value;
3832                return argcount;
3833        }
3834
3835        /* flags options */
3836        else if (!strcmp(arg, "--binary")) {
3837                enable_patch_output(&options->output_format);
3838                DIFF_OPT_SET(options, BINARY);
3839        }
3840        else if (!strcmp(arg, "--full-index"))
3841                DIFF_OPT_SET(options, FULL_INDEX);
3842        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3843                DIFF_OPT_SET(options, TEXT);
3844        else if (!strcmp(arg, "-R"))
3845                DIFF_OPT_SET(options, REVERSE_DIFF);
3846        else if (!strcmp(arg, "--find-copies-harder"))
3847                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3848        else if (!strcmp(arg, "--follow"))
3849                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3850        else if (!strcmp(arg, "--no-follow")) {
3851                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3852                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
3853        } else if (!strcmp(arg, "--color"))
3854                options->use_color = 1;
3855        else if (skip_prefix(arg, "--color=", &arg)) {
3856                int value = git_config_colorbool(NULL, arg);
3857                if (value < 0)
3858                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3859                options->use_color = value;
3860        }
3861        else if (!strcmp(arg, "--no-color"))
3862                options->use_color = 0;
3863        else if (!strcmp(arg, "--color-words")) {
3864                options->use_color = 1;
3865                options->word_diff = DIFF_WORDS_COLOR;
3866        }
3867        else if (skip_prefix(arg, "--color-words=", &arg)) {
3868                options->use_color = 1;
3869                options->word_diff = DIFF_WORDS_COLOR;
3870                options->word_regex = arg;
3871        }
3872        else if (!strcmp(arg, "--word-diff")) {
3873                if (options->word_diff == DIFF_WORDS_NONE)
3874                        options->word_diff = DIFF_WORDS_PLAIN;
3875        }
3876        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3877                if (!strcmp(arg, "plain"))
3878                        options->word_diff = DIFF_WORDS_PLAIN;
3879                else if (!strcmp(arg, "color")) {
3880                        options->use_color = 1;
3881                        options->word_diff = DIFF_WORDS_COLOR;
3882                }
3883                else if (!strcmp(arg, "porcelain"))
3884                        options->word_diff = DIFF_WORDS_PORCELAIN;
3885                else if (!strcmp(arg, "none"))
3886                        options->word_diff = DIFF_WORDS_NONE;
3887                else
3888                        die("bad --word-diff argument: %s", arg);
3889        }
3890        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3891                if (options->word_diff == DIFF_WORDS_NONE)
3892                        options->word_diff = DIFF_WORDS_PLAIN;
3893                options->word_regex = optarg;
3894                return argcount;
3895        }
3896        else if (!strcmp(arg, "--exit-code"))
3897                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3898        else if (!strcmp(arg, "--quiet"))
3899                DIFF_OPT_SET(options, QUICK);
3900        else if (!strcmp(arg, "--ext-diff"))
3901                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3902        else if (!strcmp(arg, "--no-ext-diff"))
3903                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3904        else if (!strcmp(arg, "--textconv"))
3905                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3906        else if (!strcmp(arg, "--no-textconv"))
3907                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3908        else if (!strcmp(arg, "--ignore-submodules")) {
3909                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3910                handle_ignore_submodules_arg(options, "all");
3911        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3912                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3913                handle_ignore_submodules_arg(options, arg);
3914        } else if (!strcmp(arg, "--submodule"))
3915                DIFF_OPT_SET(options, SUBMODULE_LOG);
3916        else if (skip_prefix(arg, "--submodule=", &arg))
3917                return parse_submodule_opt(options, arg);
3918        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
3919                return parse_ws_error_highlight(options, arg);
3920
3921        /* misc options */
3922        else if (!strcmp(arg, "-z"))
3923                options->line_termination = 0;
3924        else if ((argcount = short_opt('l', av, &optarg))) {
3925                options->rename_limit = strtoul(optarg, NULL, 10);
3926                return argcount;
3927        }
3928        else if ((argcount = short_opt('S', av, &optarg))) {
3929                options->pickaxe = optarg;
3930                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3931                return argcount;
3932        } else if ((argcount = short_opt('G', av, &optarg))) {
3933                options->pickaxe = optarg;
3934                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3935                return argcount;
3936        }
3937        else if (!strcmp(arg, "--pickaxe-all"))
3938                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3939        else if (!strcmp(arg, "--pickaxe-regex"))
3940                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3941        else if ((argcount = short_opt('O', av, &optarg))) {
3942                const char *path = prefix_filename(prefix, strlen(prefix), optarg);
3943                options->orderfile = xstrdup(path);
3944                return argcount;
3945        }
3946        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3947                int offending = parse_diff_filter_opt(optarg, options);
3948                if (offending)
3949                        die("unknown change class '%c' in --diff-filter=%s",
3950                            offending, optarg);
3951                return argcount;
3952        }
3953        else if (!strcmp(arg, "--abbrev"))
3954                options->abbrev = DEFAULT_ABBREV;
3955        else if (skip_prefix(arg, "--abbrev=", &arg)) {
3956                options->abbrev = strtoul(arg, NULL, 10);
3957                if (options->abbrev < MINIMUM_ABBREV)
3958                        options->abbrev = MINIMUM_ABBREV;
3959                else if (40 < options->abbrev)
3960                        options->abbrev = 40;
3961        }
3962        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3963                options->a_prefix = optarg;
3964                return argcount;
3965        }
3966        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3967                options->b_prefix = optarg;
3968                return argcount;
3969        }
3970        else if (!strcmp(arg, "--no-prefix"))
3971                options->a_prefix = options->b_prefix = "";
3972        else if (opt_arg(arg, '\0', "inter-hunk-context",
3973                         &options->interhunkcontext))
3974                ;
3975        else if (!strcmp(arg, "-W"))
3976                DIFF_OPT_SET(options, FUNCCONTEXT);
3977        else if (!strcmp(arg, "--function-context"))
3978                DIFF_OPT_SET(options, FUNCCONTEXT);
3979        else if (!strcmp(arg, "--no-function-context"))
3980                DIFF_OPT_CLR(options, FUNCCONTEXT);
3981        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3982                const char *path = prefix_filename(prefix, strlen(prefix), optarg);
3983                options->file = fopen(path, "w");
3984                if (!options->file)
3985                        die_errno("Could not open '%s'", path);
3986                options->close_file = 1;
3987                return argcount;
3988        } else
3989                return 0;
3990        return 1;
3991}
3992
3993int parse_rename_score(const char **cp_p)
3994{
3995        unsigned long num, scale;
3996        int ch, dot;
3997        const char *cp = *cp_p;
3998
3999        num = 0;
4000        scale = 1;
4001        dot = 0;
4002        for (;;) {
4003                ch = *cp;
4004                if ( !dot && ch == '.' ) {
4005                        scale = 1;
4006                        dot = 1;
4007                } else if ( ch == '%' ) {
4008                        scale = dot ? scale*100 : 100;
4009                        cp++;   /* % is always at the end */
4010                        break;
4011                } else if ( ch >= '0' && ch <= '9' ) {
4012                        if ( scale < 100000 ) {
4013                                scale *= 10;
4014                                num = (num*10) + (ch-'0');
4015                        }
4016                } else {
4017                        break;
4018                }
4019                cp++;
4020        }
4021        *cp_p = cp;
4022
4023        /* user says num divided by scale and we say internally that
4024         * is MAX_SCORE * num / scale.
4025         */
4026        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4027}
4028
4029static int diff_scoreopt_parse(const char *opt)
4030{
4031        int opt1, opt2, cmd;
4032
4033        if (*opt++ != '-')
4034                return -1;
4035        cmd = *opt++;
4036        if (cmd == '-') {
4037                /* convert the long-form arguments into short-form versions */
4038                if (skip_prefix(opt, "break-rewrites", &opt)) {
4039                        if (*opt == 0 || *opt++ == '=')
4040                                cmd = 'B';
4041                } else if (skip_prefix(opt, "find-copies", &opt)) {
4042                        if (*opt == 0 || *opt++ == '=')
4043                                cmd = 'C';
4044                } else if (skip_prefix(opt, "find-renames", &opt)) {
4045                        if (*opt == 0 || *opt++ == '=')
4046                                cmd = 'M';
4047                }
4048        }
4049        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4050                return -1; /* that is not a -M, -C, or -B option */
4051
4052        opt1 = parse_rename_score(&opt);
4053        if (cmd != 'B')
4054                opt2 = 0;
4055        else {
4056                if (*opt == 0)
4057                        opt2 = 0;
4058                else if (*opt != '/')
4059                        return -1; /* we expect -B80/99 or -B80 */
4060                else {
4061                        opt++;
4062                        opt2 = parse_rename_score(&opt);
4063                }
4064        }
4065        if (*opt != 0)
4066                return -1;
4067        return opt1 | (opt2 << 16);
4068}
4069
4070struct diff_queue_struct diff_queued_diff;
4071
4072void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4073{
4074        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4075        queue->queue[queue->nr++] = dp;
4076}
4077
4078struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4079                                 struct diff_filespec *one,
4080                                 struct diff_filespec *two)
4081{
4082        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4083        dp->one = one;
4084        dp->two = two;
4085        if (queue)
4086                diff_q(queue, dp);
4087        return dp;
4088}
4089
4090void diff_free_filepair(struct diff_filepair *p)
4091{
4092        free_filespec(p->one);
4093        free_filespec(p->two);
4094        free(p);
4095}
4096
4097/* This is different from find_unique_abbrev() in that
4098 * it stuffs the result with dots for alignment.
4099 */
4100const char *diff_unique_abbrev(const unsigned char *sha1, int len)
4101{
4102        int abblen;
4103        const char *abbrev;
4104        if (len == 40)
4105                return sha1_to_hex(sha1);
4106
4107        abbrev = find_unique_abbrev(sha1, len);
4108        abblen = strlen(abbrev);
4109        if (abblen < 37) {
4110                static char hex[41];
4111                if (len < abblen && abblen <= len + 2)
4112                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4113                else
4114                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4115                return hex;
4116        }
4117        return sha1_to_hex(sha1);
4118}
4119
4120static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4121{
4122        int line_termination = opt->line_termination;
4123        int inter_name_termination = line_termination ? '\t' : '\0';
4124
4125        fprintf(opt->file, "%s", diff_line_prefix(opt));
4126        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4127                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4128                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
4129                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
4130        }
4131        if (p->score) {
4132                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4133                        inter_name_termination);
4134        } else {
4135                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4136        }
4137
4138        if (p->status == DIFF_STATUS_COPIED ||
4139            p->status == DIFF_STATUS_RENAMED) {
4140                const char *name_a, *name_b;
4141                name_a = p->one->path;
4142                name_b = p->two->path;
4143                strip_prefix(opt->prefix_length, &name_a, &name_b);
4144                write_name_quoted(name_a, opt->file, inter_name_termination);
4145                write_name_quoted(name_b, opt->file, line_termination);
4146        } else {
4147                const char *name_a, *name_b;
4148                name_a = p->one->mode ? p->one->path : p->two->path;
4149                name_b = NULL;
4150                strip_prefix(opt->prefix_length, &name_a, &name_b);
4151                write_name_quoted(name_a, opt->file, line_termination);
4152        }
4153}
4154
4155int diff_unmodified_pair(struct diff_filepair *p)
4156{
4157        /* This function is written stricter than necessary to support
4158         * the currently implemented transformers, but the idea is to
4159         * let transformers to produce diff_filepairs any way they want,
4160         * and filter and clean them up here before producing the output.
4161         */
4162        struct diff_filespec *one = p->one, *two = p->two;
4163
4164        if (DIFF_PAIR_UNMERGED(p))
4165                return 0; /* unmerged is interesting */
4166
4167        /* deletion, addition, mode or type change
4168         * and rename are all interesting.
4169         */
4170        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4171            DIFF_PAIR_MODE_CHANGED(p) ||
4172            strcmp(one->path, two->path))
4173                return 0;
4174
4175        /* both are valid and point at the same path.  that is, we are
4176         * dealing with a change.
4177         */
4178        if (one->sha1_valid && two->sha1_valid &&
4179            !hashcmp(one->sha1, two->sha1) &&
4180            !one->dirty_submodule && !two->dirty_submodule)
4181                return 1; /* no change */
4182        if (!one->sha1_valid && !two->sha1_valid)
4183                return 1; /* both look at the same file on the filesystem. */
4184        return 0;
4185}
4186
4187static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4188{
4189        if (diff_unmodified_pair(p))
4190                return;
4191
4192        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4193            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4194                return; /* no tree diffs in patch format */
4195
4196        run_diff(p, o);
4197}
4198
4199static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4200                            struct diffstat_t *diffstat)
4201{
4202        if (diff_unmodified_pair(p))
4203                return;
4204
4205        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4206            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4207                return; /* no useful stat for tree diffs */
4208
4209        run_diffstat(p, o, diffstat);
4210}
4211
4212static void diff_flush_checkdiff(struct diff_filepair *p,
4213                struct diff_options *o)
4214{
4215        if (diff_unmodified_pair(p))
4216                return;
4217
4218        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4219            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4220                return; /* nothing to check in tree diffs */
4221
4222        run_checkdiff(p, o);
4223}
4224
4225int diff_queue_is_empty(void)
4226{
4227        struct diff_queue_struct *q = &diff_queued_diff;
4228        int i;
4229        for (i = 0; i < q->nr; i++)
4230                if (!diff_unmodified_pair(q->queue[i]))
4231                        return 0;
4232        return 1;
4233}
4234
4235#if DIFF_DEBUG
4236void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4237{
4238        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4239                x, one ? one : "",
4240                s->path,
4241                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4242                s->mode,
4243                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4244        fprintf(stderr, "queue[%d] %s size %lu\n",
4245                x, one ? one : "",
4246                s->size);
4247}
4248
4249void diff_debug_filepair(const struct diff_filepair *p, int i)
4250{
4251        diff_debug_filespec(p->one, i, "one");
4252        diff_debug_filespec(p->two, i, "two");
4253        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4254                p->score, p->status ? p->status : '?',
4255                p->one->rename_used, p->broken_pair);
4256}
4257
4258void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4259{
4260        int i;
4261        if (msg)
4262                fprintf(stderr, "%s\n", msg);
4263        fprintf(stderr, "q->nr = %d\n", q->nr);
4264        for (i = 0; i < q->nr; i++) {
4265                struct diff_filepair *p = q->queue[i];
4266                diff_debug_filepair(p, i);
4267        }
4268}
4269#endif
4270
4271static void diff_resolve_rename_copy(void)
4272{
4273        int i;
4274        struct diff_filepair *p;
4275        struct diff_queue_struct *q = &diff_queued_diff;
4276
4277        diff_debug_queue("resolve-rename-copy", q);
4278
4279        for (i = 0; i < q->nr; i++) {
4280                p = q->queue[i];
4281                p->status = 0; /* undecided */
4282                if (DIFF_PAIR_UNMERGED(p))
4283                        p->status = DIFF_STATUS_UNMERGED;
4284                else if (!DIFF_FILE_VALID(p->one))
4285                        p->status = DIFF_STATUS_ADDED;
4286                else if (!DIFF_FILE_VALID(p->two))
4287                        p->status = DIFF_STATUS_DELETED;
4288                else if (DIFF_PAIR_TYPE_CHANGED(p))
4289                        p->status = DIFF_STATUS_TYPE_CHANGED;
4290
4291                /* from this point on, we are dealing with a pair
4292                 * whose both sides are valid and of the same type, i.e.
4293                 * either in-place edit or rename/copy edit.
4294                 */
4295                else if (DIFF_PAIR_RENAME(p)) {
4296                        /*
4297                         * A rename might have re-connected a broken
4298                         * pair up, causing the pathnames to be the
4299                         * same again. If so, that's not a rename at
4300                         * all, just a modification..
4301                         *
4302                         * Otherwise, see if this source was used for
4303                         * multiple renames, in which case we decrement
4304                         * the count, and call it a copy.
4305                         */
4306                        if (!strcmp(p->one->path, p->two->path))
4307                                p->status = DIFF_STATUS_MODIFIED;
4308                        else if (--p->one->rename_used > 0)
4309                                p->status = DIFF_STATUS_COPIED;
4310                        else
4311                                p->status = DIFF_STATUS_RENAMED;
4312                }
4313                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4314                         p->one->mode != p->two->mode ||
4315                         p->one->dirty_submodule ||
4316                         p->two->dirty_submodule ||
4317                         is_null_sha1(p->one->sha1))
4318                        p->status = DIFF_STATUS_MODIFIED;
4319                else {
4320                        /* This is a "no-change" entry and should not
4321                         * happen anymore, but prepare for broken callers.
4322                         */
4323                        error("feeding unmodified %s to diffcore",
4324                              p->one->path);
4325                        p->status = DIFF_STATUS_UNKNOWN;
4326                }
4327        }
4328        diff_debug_queue("resolve-rename-copy done", q);
4329}
4330
4331static int check_pair_status(struct diff_filepair *p)
4332{
4333        switch (p->status) {
4334        case DIFF_STATUS_UNKNOWN:
4335                return 0;
4336        case 0:
4337                die("internal error in diff-resolve-rename-copy");
4338        default:
4339                return 1;
4340        }
4341}
4342
4343static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4344{
4345        int fmt = opt->output_format;
4346
4347        if (fmt & DIFF_FORMAT_CHECKDIFF)
4348                diff_flush_checkdiff(p, opt);
4349        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4350                diff_flush_raw(p, opt);
4351        else if (fmt & DIFF_FORMAT_NAME) {
4352                const char *name_a, *name_b;
4353                name_a = p->two->path;
4354                name_b = NULL;
4355                strip_prefix(opt->prefix_length, &name_a, &name_b);
4356                write_name_quoted(name_a, opt->file, opt->line_termination);
4357        }
4358}
4359
4360static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4361{
4362        if (fs->mode)
4363                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4364        else
4365                fprintf(file, " %s ", newdelete);
4366        write_name_quoted(fs->path, file, '\n');
4367}
4368
4369
4370static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4371                const char *line_prefix)
4372{
4373        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4374                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4375                        p->two->mode, show_name ? ' ' : '\n');
4376                if (show_name) {
4377                        write_name_quoted(p->two->path, file, '\n');
4378                }
4379        }
4380}
4381
4382static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4383                        const char *line_prefix)
4384{
4385        char *names = pprint_rename(p->one->path, p->two->path);
4386
4387        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4388        free(names);
4389        show_mode_change(file, p, 0, line_prefix);
4390}
4391
4392static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4393{
4394        FILE *file = opt->file;
4395        const char *line_prefix = diff_line_prefix(opt);
4396
4397        switch(p->status) {
4398        case DIFF_STATUS_DELETED:
4399                fputs(line_prefix, file);
4400                show_file_mode_name(file, "delete", p->one);
4401                break;
4402        case DIFF_STATUS_ADDED:
4403                fputs(line_prefix, file);
4404                show_file_mode_name(file, "create", p->two);
4405                break;
4406        case DIFF_STATUS_COPIED:
4407                fputs(line_prefix, file);
4408                show_rename_copy(file, "copy", p, line_prefix);
4409                break;
4410        case DIFF_STATUS_RENAMED:
4411                fputs(line_prefix, file);
4412                show_rename_copy(file, "rename", p, line_prefix);
4413                break;
4414        default:
4415                if (p->score) {
4416                        fprintf(file, "%s rewrite ", line_prefix);
4417                        write_name_quoted(p->two->path, file, ' ');
4418                        fprintf(file, "(%d%%)\n", similarity_index(p));
4419                }
4420                show_mode_change(file, p, !p->score, line_prefix);
4421                break;
4422        }
4423}
4424
4425struct patch_id_t {
4426        git_SHA_CTX *ctx;
4427        int patchlen;
4428};
4429
4430static int remove_space(char *line, int len)
4431{
4432        int i;
4433        char *dst = line;
4434        unsigned char c;
4435
4436        for (i = 0; i < len; i++)
4437                if (!isspace((c = line[i])))
4438                        *dst++ = c;
4439
4440        return dst - line;
4441}
4442
4443static void patch_id_consume(void *priv, char *line, unsigned long len)
4444{
4445        struct patch_id_t *data = priv;
4446        int new_len;
4447
4448        /* Ignore line numbers when computing the SHA1 of the patch */
4449        if (starts_with(line, "@@ -"))
4450                return;
4451
4452        new_len = remove_space(line, len);
4453
4454        git_SHA1_Update(data->ctx, line, new_len);
4455        data->patchlen += new_len;
4456}
4457
4458/* returns 0 upon success, and writes result into sha1 */
4459static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4460{
4461        struct diff_queue_struct *q = &diff_queued_diff;
4462        int i;
4463        git_SHA_CTX ctx;
4464        struct patch_id_t data;
4465        char buffer[PATH_MAX * 4 + 20];
4466
4467        git_SHA1_Init(&ctx);
4468        memset(&data, 0, sizeof(struct patch_id_t));
4469        data.ctx = &ctx;
4470
4471        for (i = 0; i < q->nr; i++) {
4472                xpparam_t xpp;
4473                xdemitconf_t xecfg;
4474                mmfile_t mf1, mf2;
4475                struct diff_filepair *p = q->queue[i];
4476                int len1, len2;
4477
4478                memset(&xpp, 0, sizeof(xpp));
4479                memset(&xecfg, 0, sizeof(xecfg));
4480                if (p->status == 0)
4481                        return error("internal diff status error");
4482                if (p->status == DIFF_STATUS_UNKNOWN)
4483                        continue;
4484                if (diff_unmodified_pair(p))
4485                        continue;
4486                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4487                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4488                        continue;
4489                if (DIFF_PAIR_UNMERGED(p))
4490                        continue;
4491
4492                diff_fill_sha1_info(p->one);
4493                diff_fill_sha1_info(p->two);
4494                if (fill_mmfile(&mf1, p->one) < 0 ||
4495                                fill_mmfile(&mf2, p->two) < 0)
4496                        return error("unable to read files to diff");
4497
4498                len1 = remove_space(p->one->path, strlen(p->one->path));
4499                len2 = remove_space(p->two->path, strlen(p->two->path));
4500                if (p->one->mode == 0)
4501                        len1 = snprintf(buffer, sizeof(buffer),
4502                                        "diff--gita/%.*sb/%.*s"
4503                                        "newfilemode%06o"
4504                                        "---/dev/null"
4505                                        "+++b/%.*s",
4506                                        len1, p->one->path,
4507                                        len2, p->two->path,
4508                                        p->two->mode,
4509                                        len2, p->two->path);
4510                else if (p->two->mode == 0)
4511                        len1 = snprintf(buffer, sizeof(buffer),
4512                                        "diff--gita/%.*sb/%.*s"
4513                                        "deletedfilemode%06o"
4514                                        "---a/%.*s"
4515                                        "+++/dev/null",
4516                                        len1, p->one->path,
4517                                        len2, p->two->path,
4518                                        p->one->mode,
4519                                        len1, p->one->path);
4520                else
4521                        len1 = snprintf(buffer, sizeof(buffer),
4522                                        "diff--gita/%.*sb/%.*s"
4523                                        "---a/%.*s"
4524                                        "+++b/%.*s",
4525                                        len1, p->one->path,
4526                                        len2, p->two->path,
4527                                        len1, p->one->path,
4528                                        len2, p->two->path);
4529                git_SHA1_Update(&ctx, buffer, len1);
4530
4531                if (diff_filespec_is_binary(p->one) ||
4532                    diff_filespec_is_binary(p->two)) {
4533                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4534                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4535                        continue;
4536                }
4537
4538                xpp.flags = 0;
4539                xecfg.ctxlen = 3;
4540                xecfg.flags = 0;
4541                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4542                                  &xpp, &xecfg))
4543                        return error("unable to generate patch-id diff for %s",
4544                                     p->one->path);
4545        }
4546
4547        git_SHA1_Final(sha1, &ctx);
4548        return 0;
4549}
4550
4551int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4552{
4553        struct diff_queue_struct *q = &diff_queued_diff;
4554        int i;
4555        int result = diff_get_patch_id(options, sha1);
4556
4557        for (i = 0; i < q->nr; i++)
4558                diff_free_filepair(q->queue[i]);
4559
4560        free(q->queue);
4561        DIFF_QUEUE_CLEAR(q);
4562
4563        return result;
4564}
4565
4566static int is_summary_empty(const struct diff_queue_struct *q)
4567{
4568        int i;
4569
4570        for (i = 0; i < q->nr; i++) {
4571                const struct diff_filepair *p = q->queue[i];
4572
4573                switch (p->status) {
4574                case DIFF_STATUS_DELETED:
4575                case DIFF_STATUS_ADDED:
4576                case DIFF_STATUS_COPIED:
4577                case DIFF_STATUS_RENAMED:
4578                        return 0;
4579                default:
4580                        if (p->score)
4581                                return 0;
4582                        if (p->one->mode && p->two->mode &&
4583                            p->one->mode != p->two->mode)
4584                                return 0;
4585                        break;
4586                }
4587        }
4588        return 1;
4589}
4590
4591static const char rename_limit_warning[] =
4592"inexact rename detection was skipped due to too many files.";
4593
4594static const char degrade_cc_to_c_warning[] =
4595"only found copies from modified paths due to too many files.";
4596
4597static const char rename_limit_advice[] =
4598"you may want to set your %s variable to at least "
4599"%d and retry the command.";
4600
4601void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4602{
4603        if (degraded_cc)
4604                warning(degrade_cc_to_c_warning);
4605        else if (needed)
4606                warning(rename_limit_warning);
4607        else
4608                return;
4609        if (0 < needed && needed < 32767)
4610                warning(rename_limit_advice, varname, needed);
4611}
4612
4613void diff_flush(struct diff_options *options)
4614{
4615        struct diff_queue_struct *q = &diff_queued_diff;
4616        int i, output_format = options->output_format;
4617        int separator = 0;
4618        int dirstat_by_line = 0;
4619
4620        /*
4621         * Order: raw, stat, summary, patch
4622         * or:    name/name-status/checkdiff (other bits clear)
4623         */
4624        if (!q->nr)
4625                goto free_queue;
4626
4627        if (output_format & (DIFF_FORMAT_RAW |
4628                             DIFF_FORMAT_NAME |
4629                             DIFF_FORMAT_NAME_STATUS |
4630                             DIFF_FORMAT_CHECKDIFF)) {
4631                for (i = 0; i < q->nr; i++) {
4632                        struct diff_filepair *p = q->queue[i];
4633                        if (check_pair_status(p))
4634                                flush_one_pair(p, options);
4635                }
4636                separator++;
4637        }
4638
4639        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4640                dirstat_by_line = 1;
4641
4642        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4643            dirstat_by_line) {
4644                struct diffstat_t diffstat;
4645
4646                memset(&diffstat, 0, sizeof(struct diffstat_t));
4647                for (i = 0; i < q->nr; i++) {
4648                        struct diff_filepair *p = q->queue[i];
4649                        if (check_pair_status(p))
4650                                diff_flush_stat(p, options, &diffstat);
4651                }
4652                if (output_format & DIFF_FORMAT_NUMSTAT)
4653                        show_numstat(&diffstat, options);
4654                if (output_format & DIFF_FORMAT_DIFFSTAT)
4655                        show_stats(&diffstat, options);
4656                if (output_format & DIFF_FORMAT_SHORTSTAT)
4657                        show_shortstats(&diffstat, options);
4658                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4659                        show_dirstat_by_line(&diffstat, options);
4660                free_diffstat_info(&diffstat);
4661                separator++;
4662        }
4663        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4664                show_dirstat(options);
4665
4666        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4667                for (i = 0; i < q->nr; i++) {
4668                        diff_summary(options, q->queue[i]);
4669                }
4670                separator++;
4671        }
4672
4673        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4674            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4675            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4676                /*
4677                 * run diff_flush_patch for the exit status. setting
4678                 * options->file to /dev/null should be safe, because we
4679                 * aren't supposed to produce any output anyway.
4680                 */
4681                if (options->close_file)
4682                        fclose(options->file);
4683                options->file = fopen("/dev/null", "w");
4684                if (!options->file)
4685                        die_errno("Could not open /dev/null");
4686                options->close_file = 1;
4687                for (i = 0; i < q->nr; i++) {
4688                        struct diff_filepair *p = q->queue[i];
4689                        if (check_pair_status(p))
4690                                diff_flush_patch(p, options);
4691                        if (options->found_changes)
4692                                break;
4693                }
4694        }
4695
4696        if (output_format & DIFF_FORMAT_PATCH) {
4697                if (separator) {
4698                        fprintf(options->file, "%s%c",
4699                                diff_line_prefix(options),
4700                                options->line_termination);
4701                        if (options->stat_sep) {
4702                                /* attach patch instead of inline */
4703                                fputs(options->stat_sep, options->file);
4704                        }
4705                }
4706
4707                for (i = 0; i < q->nr; i++) {
4708                        struct diff_filepair *p = q->queue[i];
4709                        if (check_pair_status(p))
4710                                diff_flush_patch(p, options);
4711                }
4712        }
4713
4714        if (output_format & DIFF_FORMAT_CALLBACK)
4715                options->format_callback(q, options, options->format_callback_data);
4716
4717        for (i = 0; i < q->nr; i++)
4718                diff_free_filepair(q->queue[i]);
4719free_queue:
4720        free(q->queue);
4721        DIFF_QUEUE_CLEAR(q);
4722        if (options->close_file)
4723                fclose(options->file);
4724
4725        /*
4726         * Report the content-level differences with HAS_CHANGES;
4727         * diff_addremove/diff_change does not set the bit when
4728         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4729         */
4730        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4731                if (options->found_changes)
4732                        DIFF_OPT_SET(options, HAS_CHANGES);
4733                else
4734                        DIFF_OPT_CLR(options, HAS_CHANGES);
4735        }
4736}
4737
4738static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4739{
4740        return (((p->status == DIFF_STATUS_MODIFIED) &&
4741                 ((p->score &&
4742                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4743                  (!p->score &&
4744                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4745                ((p->status != DIFF_STATUS_MODIFIED) &&
4746                 filter_bit_tst(p->status, options)));
4747}
4748
4749static void diffcore_apply_filter(struct diff_options *options)
4750{
4751        int i;
4752        struct diff_queue_struct *q = &diff_queued_diff;
4753        struct diff_queue_struct outq;
4754
4755        DIFF_QUEUE_CLEAR(&outq);
4756
4757        if (!options->filter)
4758                return;
4759
4760        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4761                int found;
4762                for (i = found = 0; !found && i < q->nr; i++) {
4763                        if (match_filter(options, q->queue[i]))
4764                                found++;
4765                }
4766                if (found)
4767                        return;
4768
4769                /* otherwise we will clear the whole queue
4770                 * by copying the empty outq at the end of this
4771                 * function, but first clear the current entries
4772                 * in the queue.
4773                 */
4774                for (i = 0; i < q->nr; i++)
4775                        diff_free_filepair(q->queue[i]);
4776        }
4777        else {
4778                /* Only the matching ones */
4779                for (i = 0; i < q->nr; i++) {
4780                        struct diff_filepair *p = q->queue[i];
4781                        if (match_filter(options, p))
4782                                diff_q(&outq, p);
4783                        else
4784                                diff_free_filepair(p);
4785                }
4786        }
4787        free(q->queue);
4788        *q = outq;
4789}
4790
4791/* Check whether two filespecs with the same mode and size are identical */
4792static int diff_filespec_is_identical(struct diff_filespec *one,
4793                                      struct diff_filespec *two)
4794{
4795        if (S_ISGITLINK(one->mode))
4796                return 0;
4797        if (diff_populate_filespec(one, 0))
4798                return 0;
4799        if (diff_populate_filespec(two, 0))
4800                return 0;
4801        return !memcmp(one->data, two->data, one->size);
4802}
4803
4804static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4805{
4806        if (p->done_skip_stat_unmatch)
4807                return p->skip_stat_unmatch_result;
4808
4809        p->done_skip_stat_unmatch = 1;
4810        p->skip_stat_unmatch_result = 0;
4811        /*
4812         * 1. Entries that come from stat info dirtiness
4813         *    always have both sides (iow, not create/delete),
4814         *    one side of the object name is unknown, with
4815         *    the same mode and size.  Keep the ones that
4816         *    do not match these criteria.  They have real
4817         *    differences.
4818         *
4819         * 2. At this point, the file is known to be modified,
4820         *    with the same mode and size, and the object
4821         *    name of one side is unknown.  Need to inspect
4822         *    the identical contents.
4823         */
4824        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4825            !DIFF_FILE_VALID(p->two) ||
4826            (p->one->sha1_valid && p->two->sha1_valid) ||
4827            (p->one->mode != p->two->mode) ||
4828            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4829            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4830            (p->one->size != p->two->size) ||
4831            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4832                p->skip_stat_unmatch_result = 1;
4833        return p->skip_stat_unmatch_result;
4834}
4835
4836static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4837{
4838        int i;
4839        struct diff_queue_struct *q = &diff_queued_diff;
4840        struct diff_queue_struct outq;
4841        DIFF_QUEUE_CLEAR(&outq);
4842
4843        for (i = 0; i < q->nr; i++) {
4844                struct diff_filepair *p = q->queue[i];
4845
4846                if (diff_filespec_check_stat_unmatch(p))
4847                        diff_q(&outq, p);
4848                else {
4849                        /*
4850                         * The caller can subtract 1 from skip_stat_unmatch
4851                         * to determine how many paths were dirty only
4852                         * due to stat info mismatch.
4853                         */
4854                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4855                                diffopt->skip_stat_unmatch++;
4856                        diff_free_filepair(p);
4857                }
4858        }
4859        free(q->queue);
4860        *q = outq;
4861}
4862
4863static int diffnamecmp(const void *a_, const void *b_)
4864{
4865        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4866        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4867        const char *name_a, *name_b;
4868
4869        name_a = a->one ? a->one->path : a->two->path;
4870        name_b = b->one ? b->one->path : b->two->path;
4871        return strcmp(name_a, name_b);
4872}
4873
4874void diffcore_fix_diff_index(struct diff_options *options)
4875{
4876        struct diff_queue_struct *q = &diff_queued_diff;
4877        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4878}
4879
4880void diffcore_std(struct diff_options *options)
4881{
4882        /* NOTE please keep the following in sync with diff_tree_combined() */
4883        if (options->skip_stat_unmatch)
4884                diffcore_skip_stat_unmatch(options);
4885        if (!options->found_follow) {
4886                /* See try_to_follow_renames() in tree-diff.c */
4887                if (options->break_opt != -1)
4888                        diffcore_break(options->break_opt);
4889                if (options->detect_rename)
4890                        diffcore_rename(options);
4891                if (options->break_opt != -1)
4892                        diffcore_merge_broken();
4893        }
4894        if (options->pickaxe)
4895                diffcore_pickaxe(options);
4896        if (options->orderfile)
4897                diffcore_order(options->orderfile);
4898        if (!options->found_follow)
4899                /* See try_to_follow_renames() in tree-diff.c */
4900                diff_resolve_rename_copy();
4901        diffcore_apply_filter(options);
4902
4903        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4904                DIFF_OPT_SET(options, HAS_CHANGES);
4905        else
4906                DIFF_OPT_CLR(options, HAS_CHANGES);
4907
4908        options->found_follow = 0;
4909}
4910
4911int diff_result_code(struct diff_options *opt, int status)
4912{
4913        int result = 0;
4914
4915        diff_warn_rename_limit("diff.renameLimit",
4916                               opt->needed_rename_limit,
4917                               opt->degraded_cc_to_c);
4918        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4919            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4920                return status;
4921        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4922            DIFF_OPT_TST(opt, HAS_CHANGES))
4923                result |= 01;
4924        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4925            DIFF_OPT_TST(opt, CHECK_FAILED))
4926                result |= 02;
4927        return result;
4928}
4929
4930int diff_can_quit_early(struct diff_options *opt)
4931{
4932        return (DIFF_OPT_TST(opt, QUICK) &&
4933                !opt->filter &&
4934                DIFF_OPT_TST(opt, HAS_CHANGES));
4935}
4936
4937/*
4938 * Shall changes to this submodule be ignored?
4939 *
4940 * Submodule changes can be configured to be ignored separately for each path,
4941 * but that configuration can be overridden from the command line.
4942 */
4943static int is_submodule_ignored(const char *path, struct diff_options *options)
4944{
4945        int ignored = 0;
4946        unsigned orig_flags = options->flags;
4947        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4948                set_diffopt_flags_from_submodule_config(options, path);
4949        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4950                ignored = 1;
4951        options->flags = orig_flags;
4952        return ignored;
4953}
4954
4955void diff_addremove(struct diff_options *options,
4956                    int addremove, unsigned mode,
4957                    const unsigned char *sha1,
4958                    int sha1_valid,
4959                    const char *concatpath, unsigned dirty_submodule)
4960{
4961        struct diff_filespec *one, *two;
4962
4963        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4964                return;
4965
4966        /* This may look odd, but it is a preparation for
4967         * feeding "there are unchanged files which should
4968         * not produce diffs, but when you are doing copy
4969         * detection you would need them, so here they are"
4970         * entries to the diff-core.  They will be prefixed
4971         * with something like '=' or '*' (I haven't decided
4972         * which but should not make any difference).
4973         * Feeding the same new and old to diff_change()
4974         * also has the same effect.
4975         * Before the final output happens, they are pruned after
4976         * merged into rename/copy pairs as appropriate.
4977         */
4978        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4979                addremove = (addremove == '+' ? '-' :
4980                             addremove == '-' ? '+' : addremove);
4981
4982        if (options->prefix &&
4983            strncmp(concatpath, options->prefix, options->prefix_length))
4984                return;
4985
4986        one = alloc_filespec(concatpath);
4987        two = alloc_filespec(concatpath);
4988
4989        if (addremove != '+')
4990                fill_filespec(one, sha1, sha1_valid, mode);
4991        if (addremove != '-') {
4992                fill_filespec(two, sha1, sha1_valid, mode);
4993                two->dirty_submodule = dirty_submodule;
4994        }
4995
4996        diff_queue(&diff_queued_diff, one, two);
4997        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4998                DIFF_OPT_SET(options, HAS_CHANGES);
4999}
5000
5001void diff_change(struct diff_options *options,
5002                 unsigned old_mode, unsigned new_mode,
5003                 const unsigned char *old_sha1,
5004                 const unsigned char *new_sha1,
5005                 int old_sha1_valid, int new_sha1_valid,
5006                 const char *concatpath,
5007                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5008{
5009        struct diff_filespec *one, *two;
5010        struct diff_filepair *p;
5011
5012        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5013            is_submodule_ignored(concatpath, options))
5014                return;
5015
5016        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5017                unsigned tmp;
5018                const unsigned char *tmp_c;
5019                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
5020                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
5021                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
5022                        new_sha1_valid = tmp;
5023                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
5024                        new_dirty_submodule = tmp;
5025        }
5026
5027        if (options->prefix &&
5028            strncmp(concatpath, options->prefix, options->prefix_length))
5029                return;
5030
5031        one = alloc_filespec(concatpath);
5032        two = alloc_filespec(concatpath);
5033        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
5034        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
5035        one->dirty_submodule = old_dirty_submodule;
5036        two->dirty_submodule = new_dirty_submodule;
5037        p = diff_queue(&diff_queued_diff, one, two);
5038
5039        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5040                return;
5041
5042        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5043            !diff_filespec_check_stat_unmatch(p))
5044                return;
5045
5046        DIFF_OPT_SET(options, HAS_CHANGES);
5047}
5048
5049struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5050{
5051        struct diff_filepair *pair;
5052        struct diff_filespec *one, *two;
5053
5054        if (options->prefix &&
5055            strncmp(path, options->prefix, options->prefix_length))
5056                return NULL;
5057
5058        one = alloc_filespec(path);
5059        two = alloc_filespec(path);
5060        pair = diff_queue(&diff_queued_diff, one, two);
5061        pair->is_unmerged = 1;
5062        return pair;
5063}
5064
5065static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5066                size_t *outsize)
5067{
5068        struct diff_tempfile *temp;
5069        const char *argv[3];
5070        const char **arg = argv;
5071        struct child_process child = CHILD_PROCESS_INIT;
5072        struct strbuf buf = STRBUF_INIT;
5073        int err = 0;
5074
5075        temp = prepare_temp_file(spec->path, spec);
5076        *arg++ = pgm;
5077        *arg++ = temp->name;
5078        *arg = NULL;
5079
5080        child.use_shell = 1;
5081        child.argv = argv;
5082        child.out = -1;
5083        if (start_command(&child)) {
5084                remove_tempfile();
5085                return NULL;
5086        }
5087
5088        if (strbuf_read(&buf, child.out, 0) < 0)
5089                err = error("error reading from textconv command '%s'", pgm);
5090        close(child.out);
5091
5092        if (finish_command(&child) || err) {
5093                strbuf_release(&buf);
5094                remove_tempfile();
5095                return NULL;
5096        }
5097        remove_tempfile();
5098
5099        return strbuf_detach(&buf, outsize);
5100}
5101
5102size_t fill_textconv(struct userdiff_driver *driver,
5103                     struct diff_filespec *df,
5104                     char **outbuf)
5105{
5106        size_t size;
5107
5108        if (!driver) {
5109                if (!DIFF_FILE_VALID(df)) {
5110                        *outbuf = "";
5111                        return 0;
5112                }
5113                if (diff_populate_filespec(df, 0))
5114                        die("unable to read files to diff");
5115                *outbuf = df->data;
5116                return df->size;
5117        }
5118
5119        if (!driver->textconv)
5120                die("BUG: fill_textconv called with non-textconv driver");
5121
5122        if (driver->textconv_cache && df->sha1_valid) {
5123                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
5124                                          &size);
5125                if (*outbuf)
5126                        return size;
5127        }
5128
5129        *outbuf = run_textconv(driver->textconv, df, &size);
5130        if (!*outbuf)
5131                die("unable to read files to diff");
5132
5133        if (driver->textconv_cache && df->sha1_valid) {
5134                /* ignore errors, as we might be in a readonly repository */
5135                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
5136                                size);
5137                /*
5138                 * we could save up changes and flush them all at the end,
5139                 * but we would need an extra call after all diffing is done.
5140                 * Since generating a cache entry is the slow path anyway,
5141                 * this extra overhead probably isn't a big deal.
5142                 */
5143                notes_cache_write(driver->textconv_cache);
5144        }
5145
5146        return size;
5147}
5148
5149void setup_diff_pager(struct diff_options *opt)
5150{
5151        /*
5152         * If the user asked for our exit code, then either they want --quiet
5153         * or --exit-code. We should definitely not bother with a pager in the
5154         * former case, as we will generate no output. Since we still properly
5155         * report our exit code even when a pager is run, we _could_ run a
5156         * pager with --exit-code. But since we have not done so historically,
5157         * and because it is easy to find people oneline advising "git diff
5158         * --exit-code" in hooks and other scripts, we do not do so.
5159         */
5160        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5161            check_pager_config("diff") != 0)
5162                setup_pager();
5163}