diff.con commit diff --stat: do not count "unmerged" entries (82dfc2c)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28static int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static int diff_stat_graph_width;
  35static int diff_dirstat_permille_default = 30;
  36static struct diff_options default_diff_options;
  37
  38static char diff_colors[][COLOR_MAXLEN] = {
  39        GIT_COLOR_RESET,
  40        GIT_COLOR_NORMAL,       /* PLAIN */
  41        GIT_COLOR_BOLD,         /* METAINFO */
  42        GIT_COLOR_CYAN,         /* FRAGINFO */
  43        GIT_COLOR_RED,          /* OLD */
  44        GIT_COLOR_GREEN,        /* NEW */
  45        GIT_COLOR_YELLOW,       /* COMMIT */
  46        GIT_COLOR_BG_RED,       /* WHITESPACE */
  47        GIT_COLOR_NORMAL,       /* FUNCINFO */
  48};
  49
  50static int parse_diff_color_slot(const char *var, int ofs)
  51{
  52        if (!strcasecmp(var+ofs, "plain"))
  53                return DIFF_PLAIN;
  54        if (!strcasecmp(var+ofs, "meta"))
  55                return DIFF_METAINFO;
  56        if (!strcasecmp(var+ofs, "frag"))
  57                return DIFF_FRAGINFO;
  58        if (!strcasecmp(var+ofs, "old"))
  59                return DIFF_FILE_OLD;
  60        if (!strcasecmp(var+ofs, "new"))
  61                return DIFF_FILE_NEW;
  62        if (!strcasecmp(var+ofs, "commit"))
  63                return DIFF_COMMIT;
  64        if (!strcasecmp(var+ofs, "whitespace"))
  65                return DIFF_WHITESPACE;
  66        if (!strcasecmp(var+ofs, "func"))
  67                return DIFF_FUNCINFO;
  68        return -1;
  69}
  70
  71static int parse_dirstat_params(struct diff_options *options, const char *params,
  72                                struct strbuf *errmsg)
  73{
  74        const char *p = params;
  75        int p_len, ret = 0;
  76
  77        while (*p) {
  78                p_len = strchrnul(p, ',') - p;
  79                if (!memcmp(p, "changes", p_len)) {
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  81                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  82                } else if (!memcmp(p, "lines", p_len)) {
  83                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  84                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  85                } else if (!memcmp(p, "files", p_len)) {
  86                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  87                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  88                } else if (!memcmp(p, "noncumulative", p_len)) {
  89                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  90                } else if (!memcmp(p, "cumulative", p_len)) {
  91                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  92                } else if (isdigit(*p)) {
  93                        char *end;
  94                        int permille = strtoul(p, &end, 10) * 10;
  95                        if (*end == '.' && isdigit(*++end)) {
  96                                /* only use first digit */
  97                                permille += *end - '0';
  98                                /* .. and ignore any further digits */
  99                                while (isdigit(*++end))
 100                                        ; /* nothing */
 101                        }
 102                        if (end - p == p_len)
 103                                options->dirstat_permille = permille;
 104                        else {
 105                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 106                                            p_len, p);
 107                                ret++;
 108                        }
 109                } else {
 110                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 111                                    p_len, p);
 112                        ret++;
 113                }
 114
 115                p += p_len;
 116
 117                if (*p)
 118                        p++; /* more parameters, swallow separator */
 119        }
 120        return ret;
 121}
 122
 123static int git_config_rename(const char *var, const char *value)
 124{
 125        if (!value)
 126                return DIFF_DETECT_RENAME;
 127        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 128                return  DIFF_DETECT_COPY;
 129        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 130}
 131
 132/*
 133 * These are to give UI layer defaults.
 134 * The core-level commands such as git-diff-files should
 135 * never be affected by the setting of diff.renames
 136 * the user happens to have in the configuration file.
 137 */
 138int git_diff_ui_config(const char *var, const char *value, void *cb)
 139{
 140        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 141                diff_use_color_default = git_config_colorbool(var, value);
 142                return 0;
 143        }
 144        if (!strcmp(var, "diff.renames")) {
 145                diff_detect_rename_default = git_config_rename(var, value);
 146                return 0;
 147        }
 148        if (!strcmp(var, "diff.autorefreshindex")) {
 149                diff_auto_refresh_index = git_config_bool(var, value);
 150                return 0;
 151        }
 152        if (!strcmp(var, "diff.mnemonicprefix")) {
 153                diff_mnemonic_prefix = git_config_bool(var, value);
 154                return 0;
 155        }
 156        if (!strcmp(var, "diff.noprefix")) {
 157                diff_no_prefix = git_config_bool(var, value);
 158                return 0;
 159        }
 160        if (!strcmp(var, "diff.statgraphwidth")) {
 161                diff_stat_graph_width = git_config_int(var, value);
 162                return 0;
 163        }
 164        if (!strcmp(var, "diff.external"))
 165                return git_config_string(&external_diff_cmd_cfg, var, value);
 166        if (!strcmp(var, "diff.wordregex"))
 167                return git_config_string(&diff_word_regex_cfg, var, value);
 168
 169        if (!strcmp(var, "diff.ignoresubmodules"))
 170                handle_ignore_submodules_arg(&default_diff_options, value);
 171
 172        if (git_color_config(var, value, cb) < 0)
 173                return -1;
 174
 175        return git_diff_basic_config(var, value, cb);
 176}
 177
 178int git_diff_basic_config(const char *var, const char *value, void *cb)
 179{
 180        if (!strcmp(var, "diff.renamelimit")) {
 181                diff_rename_limit_default = git_config_int(var, value);
 182                return 0;
 183        }
 184
 185        if (userdiff_config(var, value) < 0)
 186                return -1;
 187
 188        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 189                int slot = parse_diff_color_slot(var, 11);
 190                if (slot < 0)
 191                        return 0;
 192                if (!value)
 193                        return config_error_nonbool(var);
 194                color_parse(value, var, diff_colors[slot]);
 195                return 0;
 196        }
 197
 198        /* like GNU diff's --suppress-blank-empty option  */
 199        if (!strcmp(var, "diff.suppressblankempty") ||
 200                        /* for backwards compatibility */
 201                        !strcmp(var, "diff.suppress-blank-empty")) {
 202                diff_suppress_blank_empty = git_config_bool(var, value);
 203                return 0;
 204        }
 205
 206        if (!strcmp(var, "diff.dirstat")) {
 207                struct strbuf errmsg = STRBUF_INIT;
 208                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 209                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 210                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 211                                errmsg.buf);
 212                strbuf_release(&errmsg);
 213                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 214                return 0;
 215        }
 216
 217        if (!prefixcmp(var, "submodule."))
 218                return parse_submodule_config_option(var, value);
 219
 220        return git_default_config(var, value, cb);
 221}
 222
 223static char *quote_two(const char *one, const char *two)
 224{
 225        int need_one = quote_c_style(one, NULL, NULL, 1);
 226        int need_two = quote_c_style(two, NULL, NULL, 1);
 227        struct strbuf res = STRBUF_INIT;
 228
 229        if (need_one + need_two) {
 230                strbuf_addch(&res, '"');
 231                quote_c_style(one, &res, NULL, 1);
 232                quote_c_style(two, &res, NULL, 1);
 233                strbuf_addch(&res, '"');
 234        } else {
 235                strbuf_addstr(&res, one);
 236                strbuf_addstr(&res, two);
 237        }
 238        return strbuf_detach(&res, NULL);
 239}
 240
 241static const char *external_diff(void)
 242{
 243        static const char *external_diff_cmd = NULL;
 244        static int done_preparing = 0;
 245
 246        if (done_preparing)
 247                return external_diff_cmd;
 248        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 249        if (!external_diff_cmd)
 250                external_diff_cmd = external_diff_cmd_cfg;
 251        done_preparing = 1;
 252        return external_diff_cmd;
 253}
 254
 255static struct diff_tempfile {
 256        const char *name; /* filename external diff should read from */
 257        char hex[41];
 258        char mode[10];
 259        char tmp_path[PATH_MAX];
 260} diff_temp[2];
 261
 262typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 263
 264struct emit_callback {
 265        int color_diff;
 266        unsigned ws_rule;
 267        int blank_at_eof_in_preimage;
 268        int blank_at_eof_in_postimage;
 269        int lno_in_preimage;
 270        int lno_in_postimage;
 271        sane_truncate_fn truncate;
 272        const char **label_path;
 273        struct diff_words_data *diff_words;
 274        struct diff_options *opt;
 275        int *found_changesp;
 276        struct strbuf *header;
 277};
 278
 279static int count_lines(const char *data, int size)
 280{
 281        int count, ch, completely_empty = 1, nl_just_seen = 0;
 282        count = 0;
 283        while (0 < size--) {
 284                ch = *data++;
 285                if (ch == '\n') {
 286                        count++;
 287                        nl_just_seen = 1;
 288                        completely_empty = 0;
 289                }
 290                else {
 291                        nl_just_seen = 0;
 292                        completely_empty = 0;
 293                }
 294        }
 295        if (completely_empty)
 296                return 0;
 297        if (!nl_just_seen)
 298                count++; /* no trailing newline */
 299        return count;
 300}
 301
 302static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 303{
 304        if (!DIFF_FILE_VALID(one)) {
 305                mf->ptr = (char *)""; /* does not matter */
 306                mf->size = 0;
 307                return 0;
 308        }
 309        else if (diff_populate_filespec(one, 0))
 310                return -1;
 311
 312        mf->ptr = one->data;
 313        mf->size = one->size;
 314        return 0;
 315}
 316
 317/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 318static unsigned long diff_filespec_size(struct diff_filespec *one)
 319{
 320        if (!DIFF_FILE_VALID(one))
 321                return 0;
 322        diff_populate_filespec(one, 1);
 323        return one->size;
 324}
 325
 326static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 327{
 328        char *ptr = mf->ptr;
 329        long size = mf->size;
 330        int cnt = 0;
 331
 332        if (!size)
 333                return cnt;
 334        ptr += size - 1; /* pointing at the very end */
 335        if (*ptr != '\n')
 336                ; /* incomplete line */
 337        else
 338                ptr--; /* skip the last LF */
 339        while (mf->ptr < ptr) {
 340                char *prev_eol;
 341                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 342                        if (*prev_eol == '\n')
 343                                break;
 344                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 345                        break;
 346                cnt++;
 347                ptr = prev_eol - 1;
 348        }
 349        return cnt;
 350}
 351
 352static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 353                               struct emit_callback *ecbdata)
 354{
 355        int l1, l2, at;
 356        unsigned ws_rule = ecbdata->ws_rule;
 357        l1 = count_trailing_blank(mf1, ws_rule);
 358        l2 = count_trailing_blank(mf2, ws_rule);
 359        if (l2 <= l1) {
 360                ecbdata->blank_at_eof_in_preimage = 0;
 361                ecbdata->blank_at_eof_in_postimage = 0;
 362                return;
 363        }
 364        at = count_lines(mf1->ptr, mf1->size);
 365        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 366
 367        at = count_lines(mf2->ptr, mf2->size);
 368        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 369}
 370
 371static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 372                        int first, const char *line, int len)
 373{
 374        int has_trailing_newline, has_trailing_carriage_return;
 375        int nofirst;
 376        FILE *file = o->file;
 377
 378        if (o->output_prefix) {
 379                struct strbuf *msg = NULL;
 380                msg = o->output_prefix(o, o->output_prefix_data);
 381                assert(msg);
 382                fwrite(msg->buf, msg->len, 1, file);
 383        }
 384
 385        if (len == 0) {
 386                has_trailing_newline = (first == '\n');
 387                has_trailing_carriage_return = (!has_trailing_newline &&
 388                                                (first == '\r'));
 389                nofirst = has_trailing_newline || has_trailing_carriage_return;
 390        } else {
 391                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 392                if (has_trailing_newline)
 393                        len--;
 394                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 395                if (has_trailing_carriage_return)
 396                        len--;
 397                nofirst = 0;
 398        }
 399
 400        if (len || !nofirst) {
 401                fputs(set, file);
 402                if (!nofirst)
 403                        fputc(first, file);
 404                fwrite(line, len, 1, file);
 405                fputs(reset, file);
 406        }
 407        if (has_trailing_carriage_return)
 408                fputc('\r', file);
 409        if (has_trailing_newline)
 410                fputc('\n', file);
 411}
 412
 413static void emit_line(struct diff_options *o, const char *set, const char *reset,
 414                      const char *line, int len)
 415{
 416        emit_line_0(o, set, reset, line[0], line+1, len-1);
 417}
 418
 419static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 420{
 421        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 422              ecbdata->blank_at_eof_in_preimage &&
 423              ecbdata->blank_at_eof_in_postimage &&
 424              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 425              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 426                return 0;
 427        return ws_blank_line(line, len, ecbdata->ws_rule);
 428}
 429
 430static void emit_add_line(const char *reset,
 431                          struct emit_callback *ecbdata,
 432                          const char *line, int len)
 433{
 434        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 435        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 436
 437        if (!*ws)
 438                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 439        else if (new_blank_line_at_eof(ecbdata, line, len))
 440                /* Blank line at EOF - paint '+' as well */
 441                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 442        else {
 443                /* Emit just the prefix, then the rest. */
 444                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 445                ws_check_emit(line, len, ecbdata->ws_rule,
 446                              ecbdata->opt->file, set, reset, ws);
 447        }
 448}
 449
 450static void emit_hunk_header(struct emit_callback *ecbdata,
 451                             const char *line, int len)
 452{
 453        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 454        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 455        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 456        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 457        static const char atat[2] = { '@', '@' };
 458        const char *cp, *ep;
 459        struct strbuf msgbuf = STRBUF_INIT;
 460        int org_len = len;
 461        int i = 1;
 462
 463        /*
 464         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 465         * it always is at least 10 bytes long.
 466         */
 467        if (len < 10 ||
 468            memcmp(line, atat, 2) ||
 469            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 470                emit_line(ecbdata->opt, plain, reset, line, len);
 471                return;
 472        }
 473        ep += 2; /* skip over @@ */
 474
 475        /* The hunk header in fraginfo color */
 476        strbuf_add(&msgbuf, frag, strlen(frag));
 477        strbuf_add(&msgbuf, line, ep - line);
 478        strbuf_add(&msgbuf, reset, strlen(reset));
 479
 480        /*
 481         * trailing "\r\n"
 482         */
 483        for ( ; i < 3; i++)
 484                if (line[len - i] == '\r' || line[len - i] == '\n')
 485                        len--;
 486
 487        /* blank before the func header */
 488        for (cp = ep; ep - line < len; ep++)
 489                if (*ep != ' ' && *ep != '\t')
 490                        break;
 491        if (ep != cp) {
 492                strbuf_add(&msgbuf, plain, strlen(plain));
 493                strbuf_add(&msgbuf, cp, ep - cp);
 494                strbuf_add(&msgbuf, reset, strlen(reset));
 495        }
 496
 497        if (ep < line + len) {
 498                strbuf_add(&msgbuf, func, strlen(func));
 499                strbuf_add(&msgbuf, ep, line + len - ep);
 500                strbuf_add(&msgbuf, reset, strlen(reset));
 501        }
 502
 503        strbuf_add(&msgbuf, line + len, org_len - len);
 504        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 505        strbuf_release(&msgbuf);
 506}
 507
 508static struct diff_tempfile *claim_diff_tempfile(void) {
 509        int i;
 510        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 511                if (!diff_temp[i].name)
 512                        return diff_temp + i;
 513        die("BUG: diff is failing to clean up its tempfiles");
 514}
 515
 516static int remove_tempfile_installed;
 517
 518static void remove_tempfile(void)
 519{
 520        int i;
 521        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 522                if (diff_temp[i].name == diff_temp[i].tmp_path)
 523                        unlink_or_warn(diff_temp[i].name);
 524                diff_temp[i].name = NULL;
 525        }
 526}
 527
 528static void remove_tempfile_on_signal(int signo)
 529{
 530        remove_tempfile();
 531        sigchain_pop(signo);
 532        raise(signo);
 533}
 534
 535static void print_line_count(FILE *file, int count)
 536{
 537        switch (count) {
 538        case 0:
 539                fprintf(file, "0,0");
 540                break;
 541        case 1:
 542                fprintf(file, "1");
 543                break;
 544        default:
 545                fprintf(file, "1,%d", count);
 546                break;
 547        }
 548}
 549
 550static void emit_rewrite_lines(struct emit_callback *ecb,
 551                               int prefix, const char *data, int size)
 552{
 553        const char *endp = NULL;
 554        static const char *nneof = " No newline at end of file\n";
 555        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 556        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 557
 558        while (0 < size) {
 559                int len;
 560
 561                endp = memchr(data, '\n', size);
 562                len = endp ? (endp - data + 1) : size;
 563                if (prefix != '+') {
 564                        ecb->lno_in_preimage++;
 565                        emit_line_0(ecb->opt, old, reset, '-',
 566                                    data, len);
 567                } else {
 568                        ecb->lno_in_postimage++;
 569                        emit_add_line(reset, ecb, data, len);
 570                }
 571                size -= len;
 572                data += len;
 573        }
 574        if (!endp) {
 575                const char *plain = diff_get_color(ecb->color_diff,
 576                                                   DIFF_PLAIN);
 577                putc('\n', ecb->opt->file);
 578                emit_line_0(ecb->opt, plain, reset, '\\',
 579                            nneof, strlen(nneof));
 580        }
 581}
 582
 583static void emit_rewrite_diff(const char *name_a,
 584                              const char *name_b,
 585                              struct diff_filespec *one,
 586                              struct diff_filespec *two,
 587                              struct userdiff_driver *textconv_one,
 588                              struct userdiff_driver *textconv_two,
 589                              struct diff_options *o)
 590{
 591        int lc_a, lc_b;
 592        const char *name_a_tab, *name_b_tab;
 593        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 594        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 595        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 596        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 597        const char *a_prefix, *b_prefix;
 598        char *data_one, *data_two;
 599        size_t size_one, size_two;
 600        struct emit_callback ecbdata;
 601        char *line_prefix = "";
 602        struct strbuf *msgbuf;
 603
 604        if (o && o->output_prefix) {
 605                msgbuf = o->output_prefix(o, o->output_prefix_data);
 606                line_prefix = msgbuf->buf;
 607        }
 608
 609        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 610                a_prefix = o->b_prefix;
 611                b_prefix = o->a_prefix;
 612        } else {
 613                a_prefix = o->a_prefix;
 614                b_prefix = o->b_prefix;
 615        }
 616
 617        name_a += (*name_a == '/');
 618        name_b += (*name_b == '/');
 619        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 620        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 621
 622        strbuf_reset(&a_name);
 623        strbuf_reset(&b_name);
 624        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 625        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 626
 627        size_one = fill_textconv(textconv_one, one, &data_one);
 628        size_two = fill_textconv(textconv_two, two, &data_two);
 629
 630        memset(&ecbdata, 0, sizeof(ecbdata));
 631        ecbdata.color_diff = want_color(o->use_color);
 632        ecbdata.found_changesp = &o->found_changes;
 633        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 634        ecbdata.opt = o;
 635        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 636                mmfile_t mf1, mf2;
 637                mf1.ptr = (char *)data_one;
 638                mf2.ptr = (char *)data_two;
 639                mf1.size = size_one;
 640                mf2.size = size_two;
 641                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 642        }
 643        ecbdata.lno_in_preimage = 1;
 644        ecbdata.lno_in_postimage = 1;
 645
 646        lc_a = count_lines(data_one, size_one);
 647        lc_b = count_lines(data_two, size_two);
 648        fprintf(o->file,
 649                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 650                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 651                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 652                line_prefix, fraginfo);
 653        if (!o->irreversible_delete)
 654                print_line_count(o->file, lc_a);
 655        else
 656                fprintf(o->file, "?,?");
 657        fprintf(o->file, " +");
 658        print_line_count(o->file, lc_b);
 659        fprintf(o->file, " @@%s\n", reset);
 660        if (lc_a && !o->irreversible_delete)
 661                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 662        if (lc_b)
 663                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 664        if (textconv_one)
 665                free((char *)data_one);
 666        if (textconv_two)
 667                free((char *)data_two);
 668}
 669
 670struct diff_words_buffer {
 671        mmfile_t text;
 672        long alloc;
 673        struct diff_words_orig {
 674                const char *begin, *end;
 675        } *orig;
 676        int orig_nr, orig_alloc;
 677};
 678
 679static void diff_words_append(char *line, unsigned long len,
 680                struct diff_words_buffer *buffer)
 681{
 682        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 683        line++;
 684        len--;
 685        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 686        buffer->text.size += len;
 687        buffer->text.ptr[buffer->text.size] = '\0';
 688}
 689
 690struct diff_words_style_elem {
 691        const char *prefix;
 692        const char *suffix;
 693        const char *color; /* NULL; filled in by the setup code if
 694                            * color is enabled */
 695};
 696
 697struct diff_words_style {
 698        enum diff_words_type type;
 699        struct diff_words_style_elem new, old, ctx;
 700        const char *newline;
 701};
 702
 703static struct diff_words_style diff_words_styles[] = {
 704        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 705        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 706        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 707};
 708
 709struct diff_words_data {
 710        struct diff_words_buffer minus, plus;
 711        const char *current_plus;
 712        int last_minus;
 713        struct diff_options *opt;
 714        regex_t *word_regex;
 715        enum diff_words_type type;
 716        struct diff_words_style *style;
 717};
 718
 719static int fn_out_diff_words_write_helper(FILE *fp,
 720                                          struct diff_words_style_elem *st_el,
 721                                          const char *newline,
 722                                          size_t count, const char *buf,
 723                                          const char *line_prefix)
 724{
 725        int print = 0;
 726
 727        while (count) {
 728                char *p = memchr(buf, '\n', count);
 729                if (print)
 730                        fputs(line_prefix, fp);
 731                if (p != buf) {
 732                        if (st_el->color && fputs(st_el->color, fp) < 0)
 733                                return -1;
 734                        if (fputs(st_el->prefix, fp) < 0 ||
 735                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 736                            fputs(st_el->suffix, fp) < 0)
 737                                return -1;
 738                        if (st_el->color && *st_el->color
 739                            && fputs(GIT_COLOR_RESET, fp) < 0)
 740                                return -1;
 741                }
 742                if (!p)
 743                        return 0;
 744                if (fputs(newline, fp) < 0)
 745                        return -1;
 746                count -= p + 1 - buf;
 747                buf = p + 1;
 748                print = 1;
 749        }
 750        return 0;
 751}
 752
 753/*
 754 * '--color-words' algorithm can be described as:
 755 *
 756 *   1. collect a the minus/plus lines of a diff hunk, divided into
 757 *      minus-lines and plus-lines;
 758 *
 759 *   2. break both minus-lines and plus-lines into words and
 760 *      place them into two mmfile_t with one word for each line;
 761 *
 762 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 763 *
 764 * And for the common parts of the both file, we output the plus side text.
 765 * diff_words->current_plus is used to trace the current position of the plus file
 766 * which printed. diff_words->last_minus is used to trace the last minus word
 767 * printed.
 768 *
 769 * For '--graph' to work with '--color-words', we need to output the graph prefix
 770 * on each line of color words output. Generally, there are two conditions on
 771 * which we should output the prefix.
 772 *
 773 *   1. diff_words->last_minus == 0 &&
 774 *      diff_words->current_plus == diff_words->plus.text.ptr
 775 *
 776 *      that is: the plus text must start as a new line, and if there is no minus
 777 *      word printed, a graph prefix must be printed.
 778 *
 779 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 780 *      *(diff_words->current_plus - 1) == '\n'
 781 *
 782 *      that is: a graph prefix must be printed following a '\n'
 783 */
 784static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 785{
 786        if ((diff_words->last_minus == 0 &&
 787                diff_words->current_plus == diff_words->plus.text.ptr) ||
 788                (diff_words->current_plus > diff_words->plus.text.ptr &&
 789                *(diff_words->current_plus - 1) == '\n')) {
 790                return 1;
 791        } else {
 792                return 0;
 793        }
 794}
 795
 796static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 797{
 798        struct diff_words_data *diff_words = priv;
 799        struct diff_words_style *style = diff_words->style;
 800        int minus_first, minus_len, plus_first, plus_len;
 801        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 802        struct diff_options *opt = diff_words->opt;
 803        struct strbuf *msgbuf;
 804        char *line_prefix = "";
 805
 806        if (line[0] != '@' || parse_hunk_header(line, len,
 807                        &minus_first, &minus_len, &plus_first, &plus_len))
 808                return;
 809
 810        assert(opt);
 811        if (opt->output_prefix) {
 812                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 813                line_prefix = msgbuf->buf;
 814        }
 815
 816        /* POSIX requires that first be decremented by one if len == 0... */
 817        if (minus_len) {
 818                minus_begin = diff_words->minus.orig[minus_first].begin;
 819                minus_end =
 820                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 821        } else
 822                minus_begin = minus_end =
 823                        diff_words->minus.orig[minus_first].end;
 824
 825        if (plus_len) {
 826                plus_begin = diff_words->plus.orig[plus_first].begin;
 827                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 828        } else
 829                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 830
 831        if (color_words_output_graph_prefix(diff_words)) {
 832                fputs(line_prefix, diff_words->opt->file);
 833        }
 834        if (diff_words->current_plus != plus_begin) {
 835                fn_out_diff_words_write_helper(diff_words->opt->file,
 836                                &style->ctx, style->newline,
 837                                plus_begin - diff_words->current_plus,
 838                                diff_words->current_plus, line_prefix);
 839                if (*(plus_begin - 1) == '\n')
 840                        fputs(line_prefix, diff_words->opt->file);
 841        }
 842        if (minus_begin != minus_end) {
 843                fn_out_diff_words_write_helper(diff_words->opt->file,
 844                                &style->old, style->newline,
 845                                minus_end - minus_begin, minus_begin,
 846                                line_prefix);
 847        }
 848        if (plus_begin != plus_end) {
 849                fn_out_diff_words_write_helper(diff_words->opt->file,
 850                                &style->new, style->newline,
 851                                plus_end - plus_begin, plus_begin,
 852                                line_prefix);
 853        }
 854
 855        diff_words->current_plus = plus_end;
 856        diff_words->last_minus = minus_first;
 857}
 858
 859/* This function starts looking at *begin, and returns 0 iff a word was found. */
 860static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 861                int *begin, int *end)
 862{
 863        if (word_regex && *begin < buffer->size) {
 864                regmatch_t match[1];
 865                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 866                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 867                                        '\n', match[0].rm_eo - match[0].rm_so);
 868                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 869                        *begin += match[0].rm_so;
 870                        return *begin >= *end;
 871                }
 872                return -1;
 873        }
 874
 875        /* find the next word */
 876        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 877                (*begin)++;
 878        if (*begin >= buffer->size)
 879                return -1;
 880
 881        /* find the end of the word */
 882        *end = *begin + 1;
 883        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 884                (*end)++;
 885
 886        return 0;
 887}
 888
 889/*
 890 * This function splits the words in buffer->text, stores the list with
 891 * newline separator into out, and saves the offsets of the original words
 892 * in buffer->orig.
 893 */
 894static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 895                regex_t *word_regex)
 896{
 897        int i, j;
 898        long alloc = 0;
 899
 900        out->size = 0;
 901        out->ptr = NULL;
 902
 903        /* fake an empty "0th" word */
 904        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 905        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 906        buffer->orig_nr = 1;
 907
 908        for (i = 0; i < buffer->text.size; i++) {
 909                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 910                        return;
 911
 912                /* store original boundaries */
 913                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 914                                buffer->orig_alloc);
 915                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 916                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 917                buffer->orig_nr++;
 918
 919                /* store one word */
 920                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 921                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 922                out->ptr[out->size + j - i] = '\n';
 923                out->size += j - i + 1;
 924
 925                i = j - 1;
 926        }
 927}
 928
 929/* this executes the word diff on the accumulated buffers */
 930static void diff_words_show(struct diff_words_data *diff_words)
 931{
 932        xpparam_t xpp;
 933        xdemitconf_t xecfg;
 934        mmfile_t minus, plus;
 935        struct diff_words_style *style = diff_words->style;
 936
 937        struct diff_options *opt = diff_words->opt;
 938        struct strbuf *msgbuf;
 939        char *line_prefix = "";
 940
 941        assert(opt);
 942        if (opt->output_prefix) {
 943                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 944                line_prefix = msgbuf->buf;
 945        }
 946
 947        /* special case: only removal */
 948        if (!diff_words->plus.text.size) {
 949                fputs(line_prefix, diff_words->opt->file);
 950                fn_out_diff_words_write_helper(diff_words->opt->file,
 951                        &style->old, style->newline,
 952                        diff_words->minus.text.size,
 953                        diff_words->minus.text.ptr, line_prefix);
 954                diff_words->minus.text.size = 0;
 955                return;
 956        }
 957
 958        diff_words->current_plus = diff_words->plus.text.ptr;
 959        diff_words->last_minus = 0;
 960
 961        memset(&xpp, 0, sizeof(xpp));
 962        memset(&xecfg, 0, sizeof(xecfg));
 963        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 964        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 965        xpp.flags = 0;
 966        /* as only the hunk header will be parsed, we need a 0-context */
 967        xecfg.ctxlen = 0;
 968        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 969                      &xpp, &xecfg);
 970        free(minus.ptr);
 971        free(plus.ptr);
 972        if (diff_words->current_plus != diff_words->plus.text.ptr +
 973                        diff_words->plus.text.size) {
 974                if (color_words_output_graph_prefix(diff_words))
 975                        fputs(line_prefix, diff_words->opt->file);
 976                fn_out_diff_words_write_helper(diff_words->opt->file,
 977                        &style->ctx, style->newline,
 978                        diff_words->plus.text.ptr + diff_words->plus.text.size
 979                        - diff_words->current_plus, diff_words->current_plus,
 980                        line_prefix);
 981        }
 982        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 983}
 984
 985/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 986static void diff_words_flush(struct emit_callback *ecbdata)
 987{
 988        if (ecbdata->diff_words->minus.text.size ||
 989            ecbdata->diff_words->plus.text.size)
 990                diff_words_show(ecbdata->diff_words);
 991}
 992
 993static void diff_filespec_load_driver(struct diff_filespec *one)
 994{
 995        /* Use already-loaded driver */
 996        if (one->driver)
 997                return;
 998
 999        if (S_ISREG(one->mode))
1000                one->driver = userdiff_find_by_path(one->path);
1001
1002        /* Fallback to default settings */
1003        if (!one->driver)
1004                one->driver = userdiff_find_by_name("default");
1005}
1006
1007static const char *userdiff_word_regex(struct diff_filespec *one)
1008{
1009        diff_filespec_load_driver(one);
1010        return one->driver->word_regex;
1011}
1012
1013static void init_diff_words_data(struct emit_callback *ecbdata,
1014                                 struct diff_options *orig_opts,
1015                                 struct diff_filespec *one,
1016                                 struct diff_filespec *two)
1017{
1018        int i;
1019        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1020        memcpy(o, orig_opts, sizeof(struct diff_options));
1021
1022        ecbdata->diff_words =
1023                xcalloc(1, sizeof(struct diff_words_data));
1024        ecbdata->diff_words->type = o->word_diff;
1025        ecbdata->diff_words->opt = o;
1026        if (!o->word_regex)
1027                o->word_regex = userdiff_word_regex(one);
1028        if (!o->word_regex)
1029                o->word_regex = userdiff_word_regex(two);
1030        if (!o->word_regex)
1031                o->word_regex = diff_word_regex_cfg;
1032        if (o->word_regex) {
1033                ecbdata->diff_words->word_regex = (regex_t *)
1034                        xmalloc(sizeof(regex_t));
1035                if (regcomp(ecbdata->diff_words->word_regex,
1036                            o->word_regex,
1037                            REG_EXTENDED | REG_NEWLINE))
1038                        die ("Invalid regular expression: %s",
1039                             o->word_regex);
1040        }
1041        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1042                if (o->word_diff == diff_words_styles[i].type) {
1043                        ecbdata->diff_words->style =
1044                                &diff_words_styles[i];
1045                        break;
1046                }
1047        }
1048        if (want_color(o->use_color)) {
1049                struct diff_words_style *st = ecbdata->diff_words->style;
1050                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1051                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1052                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1053        }
1054}
1055
1056static void free_diff_words_data(struct emit_callback *ecbdata)
1057{
1058        if (ecbdata->diff_words) {
1059                diff_words_flush(ecbdata);
1060                free (ecbdata->diff_words->opt);
1061                free (ecbdata->diff_words->minus.text.ptr);
1062                free (ecbdata->diff_words->minus.orig);
1063                free (ecbdata->diff_words->plus.text.ptr);
1064                free (ecbdata->diff_words->plus.orig);
1065                if (ecbdata->diff_words->word_regex) {
1066                        regfree(ecbdata->diff_words->word_regex);
1067                        free(ecbdata->diff_words->word_regex);
1068                }
1069                free(ecbdata->diff_words);
1070                ecbdata->diff_words = NULL;
1071        }
1072}
1073
1074const char *diff_get_color(int diff_use_color, enum color_diff ix)
1075{
1076        if (want_color(diff_use_color))
1077                return diff_colors[ix];
1078        return "";
1079}
1080
1081static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1082{
1083        const char *cp;
1084        unsigned long allot;
1085        size_t l = len;
1086
1087        if (ecb->truncate)
1088                return ecb->truncate(line, len);
1089        cp = line;
1090        allot = l;
1091        while (0 < l) {
1092                (void) utf8_width(&cp, &l);
1093                if (!cp)
1094                        break; /* truncated in the middle? */
1095        }
1096        return allot - l;
1097}
1098
1099static void find_lno(const char *line, struct emit_callback *ecbdata)
1100{
1101        const char *p;
1102        ecbdata->lno_in_preimage = 0;
1103        ecbdata->lno_in_postimage = 0;
1104        p = strchr(line, '-');
1105        if (!p)
1106                return; /* cannot happen */
1107        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1108        p = strchr(p, '+');
1109        if (!p)
1110                return; /* cannot happen */
1111        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1112}
1113
1114static void fn_out_consume(void *priv, char *line, unsigned long len)
1115{
1116        struct emit_callback *ecbdata = priv;
1117        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1118        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1119        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1120        struct diff_options *o = ecbdata->opt;
1121        char *line_prefix = "";
1122        struct strbuf *msgbuf;
1123
1124        if (o && o->output_prefix) {
1125                msgbuf = o->output_prefix(o, o->output_prefix_data);
1126                line_prefix = msgbuf->buf;
1127        }
1128
1129        if (ecbdata->header) {
1130                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1131                strbuf_reset(ecbdata->header);
1132                ecbdata->header = NULL;
1133        }
1134        *(ecbdata->found_changesp) = 1;
1135
1136        if (ecbdata->label_path[0]) {
1137                const char *name_a_tab, *name_b_tab;
1138
1139                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1140                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1141
1142                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1143                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1144                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1145                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1146                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1147        }
1148
1149        if (diff_suppress_blank_empty
1150            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1151                line[0] = '\n';
1152                len = 1;
1153        }
1154
1155        if (line[0] == '@') {
1156                if (ecbdata->diff_words)
1157                        diff_words_flush(ecbdata);
1158                len = sane_truncate_line(ecbdata, line, len);
1159                find_lno(line, ecbdata);
1160                emit_hunk_header(ecbdata, line, len);
1161                if (line[len-1] != '\n')
1162                        putc('\n', ecbdata->opt->file);
1163                return;
1164        }
1165
1166        if (len < 1) {
1167                emit_line(ecbdata->opt, reset, reset, line, len);
1168                if (ecbdata->diff_words
1169                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1170                        fputs("~\n", ecbdata->opt->file);
1171                return;
1172        }
1173
1174        if (ecbdata->diff_words) {
1175                if (line[0] == '-') {
1176                        diff_words_append(line, len,
1177                                          &ecbdata->diff_words->minus);
1178                        return;
1179                } else if (line[0] == '+') {
1180                        diff_words_append(line, len,
1181                                          &ecbdata->diff_words->plus);
1182                        return;
1183                } else if (!prefixcmp(line, "\\ ")) {
1184                        /*
1185                         * Eat the "no newline at eof" marker as if we
1186                         * saw a "+" or "-" line with nothing on it,
1187                         * and return without diff_words_flush() to
1188                         * defer processing. If this is the end of
1189                         * preimage, more "+" lines may come after it.
1190                         */
1191                        return;
1192                }
1193                diff_words_flush(ecbdata);
1194                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1195                        emit_line(ecbdata->opt, plain, reset, line, len);
1196                        fputs("~\n", ecbdata->opt->file);
1197                } else {
1198                        /*
1199                         * Skip the prefix character, if any.  With
1200                         * diff_suppress_blank_empty, there may be
1201                         * none.
1202                         */
1203                        if (line[0] != '\n') {
1204                              line++;
1205                              len--;
1206                        }
1207                        emit_line(ecbdata->opt, plain, reset, line, len);
1208                }
1209                return;
1210        }
1211
1212        if (line[0] != '+') {
1213                const char *color =
1214                        diff_get_color(ecbdata->color_diff,
1215                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1216                ecbdata->lno_in_preimage++;
1217                if (line[0] == ' ')
1218                        ecbdata->lno_in_postimage++;
1219                emit_line(ecbdata->opt, color, reset, line, len);
1220        } else {
1221                ecbdata->lno_in_postimage++;
1222                emit_add_line(reset, ecbdata, line + 1, len - 1);
1223        }
1224}
1225
1226static char *pprint_rename(const char *a, const char *b)
1227{
1228        const char *old = a;
1229        const char *new = b;
1230        struct strbuf name = STRBUF_INIT;
1231        int pfx_length, sfx_length;
1232        int len_a = strlen(a);
1233        int len_b = strlen(b);
1234        int a_midlen, b_midlen;
1235        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1236        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1237
1238        if (qlen_a || qlen_b) {
1239                quote_c_style(a, &name, NULL, 0);
1240                strbuf_addstr(&name, " => ");
1241                quote_c_style(b, &name, NULL, 0);
1242                return strbuf_detach(&name, NULL);
1243        }
1244
1245        /* Find common prefix */
1246        pfx_length = 0;
1247        while (*old && *new && *old == *new) {
1248                if (*old == '/')
1249                        pfx_length = old - a + 1;
1250                old++;
1251                new++;
1252        }
1253
1254        /* Find common suffix */
1255        old = a + len_a;
1256        new = b + len_b;
1257        sfx_length = 0;
1258        while (a <= old && b <= new && *old == *new) {
1259                if (*old == '/')
1260                        sfx_length = len_a - (old - a);
1261                old--;
1262                new--;
1263        }
1264
1265        /*
1266         * pfx{mid-a => mid-b}sfx
1267         * {pfx-a => pfx-b}sfx
1268         * pfx{sfx-a => sfx-b}
1269         * name-a => name-b
1270         */
1271        a_midlen = len_a - pfx_length - sfx_length;
1272        b_midlen = len_b - pfx_length - sfx_length;
1273        if (a_midlen < 0)
1274                a_midlen = 0;
1275        if (b_midlen < 0)
1276                b_midlen = 0;
1277
1278        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1279        if (pfx_length + sfx_length) {
1280                strbuf_add(&name, a, pfx_length);
1281                strbuf_addch(&name, '{');
1282        }
1283        strbuf_add(&name, a + pfx_length, a_midlen);
1284        strbuf_addstr(&name, " => ");
1285        strbuf_add(&name, b + pfx_length, b_midlen);
1286        if (pfx_length + sfx_length) {
1287                strbuf_addch(&name, '}');
1288                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1289        }
1290        return strbuf_detach(&name, NULL);
1291}
1292
1293struct diffstat_t {
1294        int nr;
1295        int alloc;
1296        struct diffstat_file {
1297                char *from_name;
1298                char *name;
1299                char *print_name;
1300                unsigned is_unmerged:1;
1301                unsigned is_binary:1;
1302                unsigned is_renamed:1;
1303                unsigned is_interesting:1;
1304                uintmax_t added, deleted;
1305        } **files;
1306};
1307
1308static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1309                                          const char *name_a,
1310                                          const char *name_b)
1311{
1312        struct diffstat_file *x;
1313        x = xcalloc(sizeof (*x), 1);
1314        if (diffstat->nr == diffstat->alloc) {
1315                diffstat->alloc = alloc_nr(diffstat->alloc);
1316                diffstat->files = xrealloc(diffstat->files,
1317                                diffstat->alloc * sizeof(x));
1318        }
1319        diffstat->files[diffstat->nr++] = x;
1320        if (name_b) {
1321                x->from_name = xstrdup(name_a);
1322                x->name = xstrdup(name_b);
1323                x->is_renamed = 1;
1324        }
1325        else {
1326                x->from_name = NULL;
1327                x->name = xstrdup(name_a);
1328        }
1329        return x;
1330}
1331
1332static void diffstat_consume(void *priv, char *line, unsigned long len)
1333{
1334        struct diffstat_t *diffstat = priv;
1335        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1336
1337        if (line[0] == '+')
1338                x->added++;
1339        else if (line[0] == '-')
1340                x->deleted++;
1341}
1342
1343const char mime_boundary_leader[] = "------------";
1344
1345static int scale_linear(int it, int width, int max_change)
1346{
1347        if (!it)
1348                return 0;
1349        /*
1350         * make sure that at least one '-' or '+' is printed if
1351         * there is any change to this path. The easiest way is to
1352         * scale linearly as if the alloted width is one column shorter
1353         * than it is, and then add 1 to the result.
1354         */
1355        return 1 + (it * (width - 1) / max_change);
1356}
1357
1358static void show_name(FILE *file,
1359                      const char *prefix, const char *name, int len)
1360{
1361        fprintf(file, " %s%-*s |", prefix, len, name);
1362}
1363
1364static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1365{
1366        if (cnt <= 0)
1367                return;
1368        fprintf(file, "%s", set);
1369        while (cnt--)
1370                putc(ch, file);
1371        fprintf(file, "%s", reset);
1372}
1373
1374static void fill_print_name(struct diffstat_file *file)
1375{
1376        char *pname;
1377
1378        if (file->print_name)
1379                return;
1380
1381        if (!file->is_renamed) {
1382                struct strbuf buf = STRBUF_INIT;
1383                if (quote_c_style(file->name, &buf, NULL, 0)) {
1384                        pname = strbuf_detach(&buf, NULL);
1385                } else {
1386                        pname = file->name;
1387                        strbuf_release(&buf);
1388                }
1389        } else {
1390                pname = pprint_rename(file->from_name, file->name);
1391        }
1392        file->print_name = pname;
1393}
1394
1395int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1396{
1397        struct strbuf sb = STRBUF_INIT;
1398        int ret;
1399
1400        if (!files) {
1401                assert(insertions == 0 && deletions == 0);
1402                return fprintf(fp, "%s\n", " 0 files changed");
1403        }
1404
1405        strbuf_addf(&sb,
1406                    (files == 1) ? " %d file changed" : " %d files changed",
1407                    files);
1408
1409        /*
1410         * For binary diff, the caller may want to print "x files
1411         * changed" with insertions == 0 && deletions == 0.
1412         *
1413         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1414         * is probably less confusing (i.e skip over "2 files changed
1415         * but nothing about added/removed lines? Is this a bug in Git?").
1416         */
1417        if (insertions || deletions == 0) {
1418                /*
1419                 * TRANSLATORS: "+" in (+) is a line addition marker;
1420                 * do not translate it.
1421                 */
1422                strbuf_addf(&sb,
1423                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1424                            insertions);
1425        }
1426
1427        if (deletions || insertions == 0) {
1428                /*
1429                 * TRANSLATORS: "-" in (-) is a line removal marker;
1430                 * do not translate it.
1431                 */
1432                strbuf_addf(&sb,
1433                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1434                            deletions);
1435        }
1436        strbuf_addch(&sb, '\n');
1437        ret = fputs(sb.buf, fp);
1438        strbuf_release(&sb);
1439        return ret;
1440}
1441
1442static void show_stats(struct diffstat_t *data, struct diff_options *options)
1443{
1444        int i, len, add, del, adds = 0, dels = 0;
1445        uintmax_t max_change = 0, max_len = 0;
1446        int total_files = data->nr, count;
1447        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1448        const char *reset, *add_c, *del_c;
1449        const char *line_prefix = "";
1450        int extra_shown = 0;
1451        struct strbuf *msg = NULL;
1452
1453        if (data->nr == 0)
1454                return;
1455
1456        if (options->output_prefix) {
1457                msg = options->output_prefix(options, options->output_prefix_data);
1458                line_prefix = msg->buf;
1459        }
1460
1461        count = options->stat_count ? options->stat_count : data->nr;
1462
1463        reset = diff_get_color_opt(options, DIFF_RESET);
1464        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1465        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1466
1467        /*
1468         * Find the longest filename and max number of changes
1469         */
1470        for (i = 0; (i < count) && (i < data->nr); i++) {
1471                struct diffstat_file *file = data->files[i];
1472                uintmax_t change = file->added + file->deleted;
1473
1474                if (!file->is_interesting && (change == 0)) {
1475                        count++; /* not shown == room for one more */
1476                        continue;
1477                }
1478                fill_print_name(file);
1479                len = strlen(file->print_name);
1480                if (max_len < len)
1481                        max_len = len;
1482
1483                if (file->is_unmerged) {
1484                        /* "Unmerged" is 8 characters */
1485                        bin_width = bin_width < 8 ? 8 : bin_width;
1486                        continue;
1487                }
1488                if (file->is_binary) {
1489                        /* "Bin XXX -> YYY bytes" */
1490                        int w = 14 + decimal_width(file->added)
1491                                + decimal_width(file->deleted);
1492                        bin_width = bin_width < w ? w : bin_width;
1493                        /* Display change counts aligned with "Bin" */
1494                        number_width = 3;
1495                        continue;
1496                }
1497
1498                if (max_change < change)
1499                        max_change = change;
1500        }
1501        count = i; /* where we can stop scanning in data->files[] */
1502
1503        /*
1504         * We have width = stat_width or term_columns() columns total.
1505         * We want a maximum of min(max_len, stat_name_width) for the name part.
1506         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1507         * We also need 1 for " " and 4 + decimal_width(max_change)
1508         * for " | NNNN " and one the empty column at the end, altogether
1509         * 6 + decimal_width(max_change).
1510         *
1511         * If there's not enough space, we will use the smaller of
1512         * stat_name_width (if set) and 5/8*width for the filename,
1513         * and the rest for constant elements + graph part, but no more
1514         * than stat_graph_width for the graph part.
1515         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1516         * for the standard terminal size).
1517         *
1518         * In other words: stat_width limits the maximum width, and
1519         * stat_name_width fixes the maximum width of the filename,
1520         * and is also used to divide available columns if there
1521         * aren't enough.
1522         *
1523         * Binary files are displayed with "Bin XXX -> YYY bytes"
1524         * instead of the change count and graph. This part is treated
1525         * similarly to the graph part, except that it is not
1526         * "scaled". If total width is too small to accomodate the
1527         * guaranteed minimum width of the filename part and the
1528         * separators and this message, this message will "overflow"
1529         * making the line longer than the maximum width.
1530         */
1531
1532        if (options->stat_width == -1)
1533                width = term_columns() - options->output_prefix_length;
1534        else
1535                width = options->stat_width ? options->stat_width : 80;
1536        number_width = decimal_width(max_change) > number_width ?
1537                decimal_width(max_change) : number_width;
1538
1539        if (options->stat_graph_width == -1)
1540                options->stat_graph_width = diff_stat_graph_width;
1541
1542        /*
1543         * Guarantee 3/8*16==6 for the graph part
1544         * and 5/8*16==10 for the filename part
1545         */
1546        if (width < 16 + 6 + number_width)
1547                width = 16 + 6 + number_width;
1548
1549        /*
1550         * First assign sizes that are wanted, ignoring available width.
1551         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1552         * starting from "XXX" should fit in graph_width.
1553         */
1554        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1555        if (options->stat_graph_width &&
1556            options->stat_graph_width < graph_width)
1557                graph_width = options->stat_graph_width;
1558
1559        name_width = (options->stat_name_width > 0 &&
1560                      options->stat_name_width < max_len) ?
1561                options->stat_name_width : max_len;
1562
1563        /*
1564         * Adjust adjustable widths not to exceed maximum width
1565         */
1566        if (name_width + number_width + 6 + graph_width > width) {
1567                if (graph_width > width * 3/8 - number_width - 6) {
1568                        graph_width = width * 3/8 - number_width - 6;
1569                        if (graph_width < 6)
1570                                graph_width = 6;
1571                }
1572
1573                if (options->stat_graph_width &&
1574                    graph_width > options->stat_graph_width)
1575                        graph_width = options->stat_graph_width;
1576                if (name_width > width - number_width - 6 - graph_width)
1577                        name_width = width - number_width - 6 - graph_width;
1578                else
1579                        graph_width = width - number_width - 6 - name_width;
1580        }
1581
1582        /*
1583         * From here name_width is the width of the name area,
1584         * and graph_width is the width of the graph area.
1585         * max_change is used to scale graph properly.
1586         */
1587        for (i = 0; i < count; i++) {
1588                const char *prefix = "";
1589                struct diffstat_file *file = data->files[i];
1590                char *name = file->print_name;
1591                uintmax_t added = file->added;
1592                uintmax_t deleted = file->deleted;
1593                int name_len;
1594
1595                if (!file->is_interesting && (added + deleted == 0))
1596                        continue;
1597
1598                /*
1599                 * "scale" the filename
1600                 */
1601                len = name_width;
1602                name_len = strlen(name);
1603                if (name_width < name_len) {
1604                        char *slash;
1605                        prefix = "...";
1606                        len -= 3;
1607                        name += name_len - len;
1608                        slash = strchr(name, '/');
1609                        if (slash)
1610                                name = slash;
1611                }
1612
1613                if (file->is_binary) {
1614                        fprintf(options->file, "%s", line_prefix);
1615                        show_name(options->file, prefix, name, len);
1616                        fprintf(options->file, " %*s", number_width, "Bin");
1617                        if (!added && !deleted) {
1618                                putc('\n', options->file);
1619                                continue;
1620                        }
1621                        fprintf(options->file, " %s%"PRIuMAX"%s",
1622                                del_c, deleted, reset);
1623                        fprintf(options->file, " -> ");
1624                        fprintf(options->file, "%s%"PRIuMAX"%s",
1625                                add_c, added, reset);
1626                        fprintf(options->file, " bytes");
1627                        fprintf(options->file, "\n");
1628                        continue;
1629                }
1630                else if (file->is_unmerged) {
1631                        fprintf(options->file, "%s", line_prefix);
1632                        show_name(options->file, prefix, name, len);
1633                        fprintf(options->file, " Unmerged\n");
1634                        continue;
1635                }
1636
1637                /*
1638                 * scale the add/delete
1639                 */
1640                add = added;
1641                del = deleted;
1642
1643                if (graph_width <= max_change) {
1644                        int total = add + del;
1645
1646                        total = scale_linear(add + del, graph_width, max_change);
1647                        if (total < 2 && add && del)
1648                                /* width >= 2 due to the sanity check */
1649                                total = 2;
1650                        if (add < del) {
1651                                add = scale_linear(add, graph_width, max_change);
1652                                del = total - add;
1653                        } else {
1654                                del = scale_linear(del, graph_width, max_change);
1655                                add = total - del;
1656                        }
1657                }
1658                fprintf(options->file, "%s", line_prefix);
1659                show_name(options->file, prefix, name, len);
1660                fprintf(options->file, " %*"PRIuMAX"%s",
1661                        number_width, added + deleted,
1662                        added + deleted ? " " : "");
1663                show_graph(options->file, '+', add, add_c, reset);
1664                show_graph(options->file, '-', del, del_c, reset);
1665                fprintf(options->file, "\n");
1666        }
1667
1668        for (i = 0; i < data->nr; i++) {
1669                struct diffstat_file *file = data->files[i];
1670                uintmax_t added = file->added;
1671                uintmax_t deleted = file->deleted;
1672
1673                if (file->is_unmerged ||
1674                    (!file->is_interesting && (added + deleted == 0))) {
1675                        total_files--;
1676                        continue;
1677                }
1678
1679                if (!file->is_binary) {
1680                        adds += added;
1681                        dels += deleted;
1682                }
1683                if (i < count)
1684                        continue;
1685                if (!extra_shown)
1686                        fprintf(options->file, "%s ...\n", line_prefix);
1687                extra_shown = 1;
1688        }
1689        fprintf(options->file, "%s", line_prefix);
1690        print_stat_summary(options->file, total_files, adds, dels);
1691}
1692
1693static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1694{
1695        int i, adds = 0, dels = 0, total_files = data->nr;
1696
1697        if (data->nr == 0)
1698                return;
1699
1700        for (i = 0; i < data->nr; i++) {
1701                int added = data->files[i]->added;
1702                int deleted= data->files[i]->deleted;
1703
1704                if (data->files[i]->is_unmerged)
1705                        continue;
1706                if (!data->files[i]->is_interesting && (added + deleted == 0)) {
1707                        total_files--;
1708                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1709                        adds += added;
1710                        dels += deleted;
1711                }
1712        }
1713        if (options->output_prefix) {
1714                struct strbuf *msg = NULL;
1715                msg = options->output_prefix(options,
1716                                options->output_prefix_data);
1717                fprintf(options->file, "%s", msg->buf);
1718        }
1719        print_stat_summary(options->file, total_files, adds, dels);
1720}
1721
1722static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1723{
1724        int i;
1725
1726        if (data->nr == 0)
1727                return;
1728
1729        for (i = 0; i < data->nr; i++) {
1730                struct diffstat_file *file = data->files[i];
1731
1732                if (options->output_prefix) {
1733                        struct strbuf *msg = NULL;
1734                        msg = options->output_prefix(options,
1735                                        options->output_prefix_data);
1736                        fprintf(options->file, "%s", msg->buf);
1737                }
1738
1739                if (file->is_binary)
1740                        fprintf(options->file, "-\t-\t");
1741                else
1742                        fprintf(options->file,
1743                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1744                                file->added, file->deleted);
1745                if (options->line_termination) {
1746                        fill_print_name(file);
1747                        if (!file->is_renamed)
1748                                write_name_quoted(file->name, options->file,
1749                                                  options->line_termination);
1750                        else {
1751                                fputs(file->print_name, options->file);
1752                                putc(options->line_termination, options->file);
1753                        }
1754                } else {
1755                        if (file->is_renamed) {
1756                                putc('\0', options->file);
1757                                write_name_quoted(file->from_name, options->file, '\0');
1758                        }
1759                        write_name_quoted(file->name, options->file, '\0');
1760                }
1761        }
1762}
1763
1764struct dirstat_file {
1765        const char *name;
1766        unsigned long changed;
1767};
1768
1769struct dirstat_dir {
1770        struct dirstat_file *files;
1771        int alloc, nr, permille, cumulative;
1772};
1773
1774static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1775                unsigned long changed, const char *base, int baselen)
1776{
1777        unsigned long this_dir = 0;
1778        unsigned int sources = 0;
1779        const char *line_prefix = "";
1780        struct strbuf *msg = NULL;
1781
1782        if (opt->output_prefix) {
1783                msg = opt->output_prefix(opt, opt->output_prefix_data);
1784                line_prefix = msg->buf;
1785        }
1786
1787        while (dir->nr) {
1788                struct dirstat_file *f = dir->files;
1789                int namelen = strlen(f->name);
1790                unsigned long this;
1791                char *slash;
1792
1793                if (namelen < baselen)
1794                        break;
1795                if (memcmp(f->name, base, baselen))
1796                        break;
1797                slash = strchr(f->name + baselen, '/');
1798                if (slash) {
1799                        int newbaselen = slash + 1 - f->name;
1800                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1801                        sources++;
1802                } else {
1803                        this = f->changed;
1804                        dir->files++;
1805                        dir->nr--;
1806                        sources += 2;
1807                }
1808                this_dir += this;
1809        }
1810
1811        /*
1812         * We don't report dirstat's for
1813         *  - the top level
1814         *  - or cases where everything came from a single directory
1815         *    under this directory (sources == 1).
1816         */
1817        if (baselen && sources != 1) {
1818                if (this_dir) {
1819                        int permille = this_dir * 1000 / changed;
1820                        if (permille >= dir->permille) {
1821                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1822                                        permille / 10, permille % 10, baselen, base);
1823                                if (!dir->cumulative)
1824                                        return 0;
1825                        }
1826                }
1827        }
1828        return this_dir;
1829}
1830
1831static int dirstat_compare(const void *_a, const void *_b)
1832{
1833        const struct dirstat_file *a = _a;
1834        const struct dirstat_file *b = _b;
1835        return strcmp(a->name, b->name);
1836}
1837
1838static void show_dirstat(struct diff_options *options)
1839{
1840        int i;
1841        unsigned long changed;
1842        struct dirstat_dir dir;
1843        struct diff_queue_struct *q = &diff_queued_diff;
1844
1845        dir.files = NULL;
1846        dir.alloc = 0;
1847        dir.nr = 0;
1848        dir.permille = options->dirstat_permille;
1849        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1850
1851        changed = 0;
1852        for (i = 0; i < q->nr; i++) {
1853                struct diff_filepair *p = q->queue[i];
1854                const char *name;
1855                unsigned long copied, added, damage;
1856                int content_changed;
1857
1858                name = p->two->path ? p->two->path : p->one->path;
1859
1860                if (p->one->sha1_valid && p->two->sha1_valid)
1861                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1862                else
1863                        content_changed = 1;
1864
1865                if (!content_changed) {
1866                        /*
1867                         * The SHA1 has not changed, so pre-/post-content is
1868                         * identical. We can therefore skip looking at the
1869                         * file contents altogether.
1870                         */
1871                        damage = 0;
1872                        goto found_damage;
1873                }
1874
1875                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1876                        /*
1877                         * In --dirstat-by-file mode, we don't really need to
1878                         * look at the actual file contents at all.
1879                         * The fact that the SHA1 changed is enough for us to
1880                         * add this file to the list of results
1881                         * (with each file contributing equal damage).
1882                         */
1883                        damage = 1;
1884                        goto found_damage;
1885                }
1886
1887                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1888                        diff_populate_filespec(p->one, 0);
1889                        diff_populate_filespec(p->two, 0);
1890                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1891                                               &copied, &added);
1892                        diff_free_filespec_data(p->one);
1893                        diff_free_filespec_data(p->two);
1894                } else if (DIFF_FILE_VALID(p->one)) {
1895                        diff_populate_filespec(p->one, 1);
1896                        copied = added = 0;
1897                        diff_free_filespec_data(p->one);
1898                } else if (DIFF_FILE_VALID(p->two)) {
1899                        diff_populate_filespec(p->two, 1);
1900                        copied = 0;
1901                        added = p->two->size;
1902                        diff_free_filespec_data(p->two);
1903                } else
1904                        continue;
1905
1906                /*
1907                 * Original minus copied is the removed material,
1908                 * added is the new material.  They are both damages
1909                 * made to the preimage.
1910                 * If the resulting damage is zero, we know that
1911                 * diffcore_count_changes() considers the two entries to
1912                 * be identical, but since content_changed is true, we
1913                 * know that there must have been _some_ kind of change,
1914                 * so we force all entries to have damage > 0.
1915                 */
1916                damage = (p->one->size - copied) + added;
1917                if (!damage)
1918                        damage = 1;
1919
1920found_damage:
1921                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1922                dir.files[dir.nr].name = name;
1923                dir.files[dir.nr].changed = damage;
1924                changed += damage;
1925                dir.nr++;
1926        }
1927
1928        /* This can happen even with many files, if everything was renames */
1929        if (!changed)
1930                return;
1931
1932        /* Show all directories with more than x% of the changes */
1933        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1934        gather_dirstat(options, &dir, changed, "", 0);
1935}
1936
1937static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1938{
1939        int i;
1940        unsigned long changed;
1941        struct dirstat_dir dir;
1942
1943        if (data->nr == 0)
1944                return;
1945
1946        dir.files = NULL;
1947        dir.alloc = 0;
1948        dir.nr = 0;
1949        dir.permille = options->dirstat_permille;
1950        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1951
1952        changed = 0;
1953        for (i = 0; i < data->nr; i++) {
1954                struct diffstat_file *file = data->files[i];
1955                unsigned long damage = file->added + file->deleted;
1956                if (file->is_binary)
1957                        /*
1958                         * binary files counts bytes, not lines. Must find some
1959                         * way to normalize binary bytes vs. textual lines.
1960                         * The following heuristic assumes that there are 64
1961                         * bytes per "line".
1962                         * This is stupid and ugly, but very cheap...
1963                         */
1964                        damage = (damage + 63) / 64;
1965                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1966                dir.files[dir.nr].name = file->name;
1967                dir.files[dir.nr].changed = damage;
1968                changed += damage;
1969                dir.nr++;
1970        }
1971
1972        /* This can happen even with many files, if everything was renames */
1973        if (!changed)
1974                return;
1975
1976        /* Show all directories with more than x% of the changes */
1977        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1978        gather_dirstat(options, &dir, changed, "", 0);
1979}
1980
1981static void free_diffstat_info(struct diffstat_t *diffstat)
1982{
1983        int i;
1984        for (i = 0; i < diffstat->nr; i++) {
1985                struct diffstat_file *f = diffstat->files[i];
1986                if (f->name != f->print_name)
1987                        free(f->print_name);
1988                free(f->name);
1989                free(f->from_name);
1990                free(f);
1991        }
1992        free(diffstat->files);
1993}
1994
1995struct checkdiff_t {
1996        const char *filename;
1997        int lineno;
1998        int conflict_marker_size;
1999        struct diff_options *o;
2000        unsigned ws_rule;
2001        unsigned status;
2002};
2003
2004static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2005{
2006        char firstchar;
2007        int cnt;
2008
2009        if (len < marker_size + 1)
2010                return 0;
2011        firstchar = line[0];
2012        switch (firstchar) {
2013        case '=': case '>': case '<': case '|':
2014                break;
2015        default:
2016                return 0;
2017        }
2018        for (cnt = 1; cnt < marker_size; cnt++)
2019                if (line[cnt] != firstchar)
2020                        return 0;
2021        /* line[1] thru line[marker_size-1] are same as firstchar */
2022        if (len < marker_size + 1 || !isspace(line[marker_size]))
2023                return 0;
2024        return 1;
2025}
2026
2027static void checkdiff_consume(void *priv, char *line, unsigned long len)
2028{
2029        struct checkdiff_t *data = priv;
2030        int marker_size = data->conflict_marker_size;
2031        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2032        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2033        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2034        char *err;
2035        char *line_prefix = "";
2036        struct strbuf *msgbuf;
2037
2038        assert(data->o);
2039        if (data->o->output_prefix) {
2040                msgbuf = data->o->output_prefix(data->o,
2041                        data->o->output_prefix_data);
2042                line_prefix = msgbuf->buf;
2043        }
2044
2045        if (line[0] == '+') {
2046                unsigned bad;
2047                data->lineno++;
2048                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2049                        data->status |= 1;
2050                        fprintf(data->o->file,
2051                                "%s%s:%d: leftover conflict marker\n",
2052                                line_prefix, data->filename, data->lineno);
2053                }
2054                bad = ws_check(line + 1, len - 1, data->ws_rule);
2055                if (!bad)
2056                        return;
2057                data->status |= bad;
2058                err = whitespace_error_string(bad);
2059                fprintf(data->o->file, "%s%s:%d: %s.\n",
2060                        line_prefix, data->filename, data->lineno, err);
2061                free(err);
2062                emit_line(data->o, set, reset, line, 1);
2063                ws_check_emit(line + 1, len - 1, data->ws_rule,
2064                              data->o->file, set, reset, ws);
2065        } else if (line[0] == ' ') {
2066                data->lineno++;
2067        } else if (line[0] == '@') {
2068                char *plus = strchr(line, '+');
2069                if (plus)
2070                        data->lineno = strtol(plus, NULL, 10) - 1;
2071                else
2072                        die("invalid diff");
2073        }
2074}
2075
2076static unsigned char *deflate_it(char *data,
2077                                 unsigned long size,
2078                                 unsigned long *result_size)
2079{
2080        int bound;
2081        unsigned char *deflated;
2082        git_zstream stream;
2083
2084        memset(&stream, 0, sizeof(stream));
2085        git_deflate_init(&stream, zlib_compression_level);
2086        bound = git_deflate_bound(&stream, size);
2087        deflated = xmalloc(bound);
2088        stream.next_out = deflated;
2089        stream.avail_out = bound;
2090
2091        stream.next_in = (unsigned char *)data;
2092        stream.avail_in = size;
2093        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2094                ; /* nothing */
2095        git_deflate_end(&stream);
2096        *result_size = stream.total_out;
2097        return deflated;
2098}
2099
2100static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2101{
2102        void *cp;
2103        void *delta;
2104        void *deflated;
2105        void *data;
2106        unsigned long orig_size;
2107        unsigned long delta_size;
2108        unsigned long deflate_size;
2109        unsigned long data_size;
2110
2111        /* We could do deflated delta, or we could do just deflated two,
2112         * whichever is smaller.
2113         */
2114        delta = NULL;
2115        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2116        if (one->size && two->size) {
2117                delta = diff_delta(one->ptr, one->size,
2118                                   two->ptr, two->size,
2119                                   &delta_size, deflate_size);
2120                if (delta) {
2121                        void *to_free = delta;
2122                        orig_size = delta_size;
2123                        delta = deflate_it(delta, delta_size, &delta_size);
2124                        free(to_free);
2125                }
2126        }
2127
2128        if (delta && delta_size < deflate_size) {
2129                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2130                free(deflated);
2131                data = delta;
2132                data_size = delta_size;
2133        }
2134        else {
2135                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2136                free(delta);
2137                data = deflated;
2138                data_size = deflate_size;
2139        }
2140
2141        /* emit data encoded in base85 */
2142        cp = data;
2143        while (data_size) {
2144                int bytes = (52 < data_size) ? 52 : data_size;
2145                char line[70];
2146                data_size -= bytes;
2147                if (bytes <= 26)
2148                        line[0] = bytes + 'A' - 1;
2149                else
2150                        line[0] = bytes - 26 + 'a' - 1;
2151                encode_85(line + 1, cp, bytes);
2152                cp = (char *) cp + bytes;
2153                fprintf(file, "%s", prefix);
2154                fputs(line, file);
2155                fputc('\n', file);
2156        }
2157        fprintf(file, "%s\n", prefix);
2158        free(data);
2159}
2160
2161static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2162{
2163        fprintf(file, "%sGIT binary patch\n", prefix);
2164        emit_binary_diff_body(file, one, two, prefix);
2165        emit_binary_diff_body(file, two, one, prefix);
2166}
2167
2168int diff_filespec_is_binary(struct diff_filespec *one)
2169{
2170        if (one->is_binary == -1) {
2171                diff_filespec_load_driver(one);
2172                if (one->driver->binary != -1)
2173                        one->is_binary = one->driver->binary;
2174                else {
2175                        if (!one->data && DIFF_FILE_VALID(one))
2176                                diff_populate_filespec(one, 0);
2177                        if (one->data)
2178                                one->is_binary = buffer_is_binary(one->data,
2179                                                one->size);
2180                        if (one->is_binary == -1)
2181                                one->is_binary = 0;
2182                }
2183        }
2184        return one->is_binary;
2185}
2186
2187static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2188{
2189        diff_filespec_load_driver(one);
2190        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2191}
2192
2193void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2194{
2195        if (!options->a_prefix)
2196                options->a_prefix = a;
2197        if (!options->b_prefix)
2198                options->b_prefix = b;
2199}
2200
2201struct userdiff_driver *get_textconv(struct diff_filespec *one)
2202{
2203        if (!DIFF_FILE_VALID(one))
2204                return NULL;
2205
2206        diff_filespec_load_driver(one);
2207        return userdiff_get_textconv(one->driver);
2208}
2209
2210static void builtin_diff(const char *name_a,
2211                         const char *name_b,
2212                         struct diff_filespec *one,
2213                         struct diff_filespec *two,
2214                         const char *xfrm_msg,
2215                         int must_show_header,
2216                         struct diff_options *o,
2217                         int complete_rewrite)
2218{
2219        mmfile_t mf1, mf2;
2220        const char *lbl[2];
2221        char *a_one, *b_two;
2222        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2223        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2224        const char *a_prefix, *b_prefix;
2225        struct userdiff_driver *textconv_one = NULL;
2226        struct userdiff_driver *textconv_two = NULL;
2227        struct strbuf header = STRBUF_INIT;
2228        struct strbuf *msgbuf;
2229        char *line_prefix = "";
2230
2231        if (o->output_prefix) {
2232                msgbuf = o->output_prefix(o, o->output_prefix_data);
2233                line_prefix = msgbuf->buf;
2234        }
2235
2236        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2237                        (!one->mode || S_ISGITLINK(one->mode)) &&
2238                        (!two->mode || S_ISGITLINK(two->mode))) {
2239                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2240                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2241                show_submodule_summary(o->file, one ? one->path : two->path,
2242                                one->sha1, two->sha1, two->dirty_submodule,
2243                                del, add, reset);
2244                return;
2245        }
2246
2247        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2248                textconv_one = get_textconv(one);
2249                textconv_two = get_textconv(two);
2250        }
2251
2252        diff_set_mnemonic_prefix(o, "a/", "b/");
2253        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2254                a_prefix = o->b_prefix;
2255                b_prefix = o->a_prefix;
2256        } else {
2257                a_prefix = o->a_prefix;
2258                b_prefix = o->b_prefix;
2259        }
2260
2261        /* Never use a non-valid filename anywhere if at all possible */
2262        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2263        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2264
2265        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2266        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2267        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2268        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2269        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2270        if (lbl[0][0] == '/') {
2271                /* /dev/null */
2272                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2273                if (xfrm_msg)
2274                        strbuf_addstr(&header, xfrm_msg);
2275                must_show_header = 1;
2276        }
2277        else if (lbl[1][0] == '/') {
2278                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2279                if (xfrm_msg)
2280                        strbuf_addstr(&header, xfrm_msg);
2281                must_show_header = 1;
2282        }
2283        else {
2284                if (one->mode != two->mode) {
2285                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2286                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2287                        must_show_header = 1;
2288                }
2289                if (xfrm_msg)
2290                        strbuf_addstr(&header, xfrm_msg);
2291
2292                /*
2293                 * we do not run diff between different kind
2294                 * of objects.
2295                 */
2296                if ((one->mode ^ two->mode) & S_IFMT)
2297                        goto free_ab_and_return;
2298                if (complete_rewrite &&
2299                    (textconv_one || !diff_filespec_is_binary(one)) &&
2300                    (textconv_two || !diff_filespec_is_binary(two))) {
2301                        fprintf(o->file, "%s", header.buf);
2302                        strbuf_reset(&header);
2303                        emit_rewrite_diff(name_a, name_b, one, two,
2304                                                textconv_one, textconv_two, o);
2305                        o->found_changes = 1;
2306                        goto free_ab_and_return;
2307                }
2308        }
2309
2310        if (o->irreversible_delete && lbl[1][0] == '/') {
2311                fprintf(o->file, "%s", header.buf);
2312                strbuf_reset(&header);
2313                goto free_ab_and_return;
2314        } else if (!DIFF_OPT_TST(o, TEXT) &&
2315            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2316              (!textconv_two && diff_filespec_is_binary(two)) )) {
2317                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2318                        die("unable to read files to diff");
2319                /* Quite common confusing case */
2320                if (mf1.size == mf2.size &&
2321                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2322                        if (must_show_header)
2323                                fprintf(o->file, "%s", header.buf);
2324                        goto free_ab_and_return;
2325                }
2326                fprintf(o->file, "%s", header.buf);
2327                strbuf_reset(&header);
2328                if (DIFF_OPT_TST(o, BINARY))
2329                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2330                else
2331                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2332                                line_prefix, lbl[0], lbl[1]);
2333                o->found_changes = 1;
2334        } else {
2335                /* Crazy xdl interfaces.. */
2336                const char *diffopts = getenv("GIT_DIFF_OPTS");
2337                xpparam_t xpp;
2338                xdemitconf_t xecfg;
2339                struct emit_callback ecbdata;
2340                const struct userdiff_funcname *pe;
2341
2342                if (must_show_header) {
2343                        fprintf(o->file, "%s", header.buf);
2344                        strbuf_reset(&header);
2345                }
2346
2347                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2348                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2349
2350                pe = diff_funcname_pattern(one);
2351                if (!pe)
2352                        pe = diff_funcname_pattern(two);
2353
2354                memset(&xpp, 0, sizeof(xpp));
2355                memset(&xecfg, 0, sizeof(xecfg));
2356                memset(&ecbdata, 0, sizeof(ecbdata));
2357                ecbdata.label_path = lbl;
2358                ecbdata.color_diff = want_color(o->use_color);
2359                ecbdata.found_changesp = &o->found_changes;
2360                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2361                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2362                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2363                ecbdata.opt = o;
2364                ecbdata.header = header.len ? &header : NULL;
2365                xpp.flags = o->xdl_opts;
2366                xecfg.ctxlen = o->context;
2367                xecfg.interhunkctxlen = o->interhunkcontext;
2368                xecfg.flags = XDL_EMIT_FUNCNAMES;
2369                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2370                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2371                if (pe)
2372                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2373                if (!diffopts)
2374                        ;
2375                else if (!prefixcmp(diffopts, "--unified="))
2376                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2377                else if (!prefixcmp(diffopts, "-u"))
2378                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2379                if (o->word_diff)
2380                        init_diff_words_data(&ecbdata, o, one, two);
2381                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2382                              &xpp, &xecfg);
2383                if (o->word_diff)
2384                        free_diff_words_data(&ecbdata);
2385                if (textconv_one)
2386                        free(mf1.ptr);
2387                if (textconv_two)
2388                        free(mf2.ptr);
2389                xdiff_clear_find_func(&xecfg);
2390        }
2391
2392 free_ab_and_return:
2393        strbuf_release(&header);
2394        diff_free_filespec_data(one);
2395        diff_free_filespec_data(two);
2396        free(a_one);
2397        free(b_two);
2398        return;
2399}
2400
2401static void builtin_diffstat(const char *name_a, const char *name_b,
2402                             struct diff_filespec *one,
2403                             struct diff_filespec *two,
2404                             struct diffstat_t *diffstat,
2405                             struct diff_options *o,
2406                             struct diff_filepair *p)
2407{
2408        mmfile_t mf1, mf2;
2409        struct diffstat_file *data;
2410        int same_contents;
2411        int complete_rewrite = 0;
2412
2413        if (!DIFF_PAIR_UNMERGED(p)) {
2414                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2415                        complete_rewrite = 1;
2416        }
2417
2418        data = diffstat_add(diffstat, name_a, name_b);
2419        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2420
2421        if (!one || !two) {
2422                data->is_unmerged = 1;
2423                return;
2424        }
2425
2426        same_contents = !hashcmp(one->sha1, two->sha1);
2427
2428        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2429                data->is_binary = 1;
2430                if (same_contents) {
2431                        data->added = 0;
2432                        data->deleted = 0;
2433                } else {
2434                        data->added = diff_filespec_size(two);
2435                        data->deleted = diff_filespec_size(one);
2436                }
2437        }
2438
2439        else if (complete_rewrite) {
2440                diff_populate_filespec(one, 0);
2441                diff_populate_filespec(two, 0);
2442                data->deleted = count_lines(one->data, one->size);
2443                data->added = count_lines(two->data, two->size);
2444        }
2445
2446        else if (!same_contents) {
2447                /* Crazy xdl interfaces.. */
2448                xpparam_t xpp;
2449                xdemitconf_t xecfg;
2450
2451                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2452                        die("unable to read files to diff");
2453
2454                memset(&xpp, 0, sizeof(xpp));
2455                memset(&xecfg, 0, sizeof(xecfg));
2456                xpp.flags = o->xdl_opts;
2457                xecfg.ctxlen = o->context;
2458                xecfg.interhunkctxlen = o->interhunkcontext;
2459                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2460                              &xpp, &xecfg);
2461        }
2462
2463        diff_free_filespec_data(one);
2464        diff_free_filespec_data(two);
2465}
2466
2467static void builtin_checkdiff(const char *name_a, const char *name_b,
2468                              const char *attr_path,
2469                              struct diff_filespec *one,
2470                              struct diff_filespec *two,
2471                              struct diff_options *o)
2472{
2473        mmfile_t mf1, mf2;
2474        struct checkdiff_t data;
2475
2476        if (!two)
2477                return;
2478
2479        memset(&data, 0, sizeof(data));
2480        data.filename = name_b ? name_b : name_a;
2481        data.lineno = 0;
2482        data.o = o;
2483        data.ws_rule = whitespace_rule(attr_path);
2484        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2485
2486        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2487                die("unable to read files to diff");
2488
2489        /*
2490         * All the other codepaths check both sides, but not checking
2491         * the "old" side here is deliberate.  We are checking the newly
2492         * introduced changes, and as long as the "new" side is text, we
2493         * can and should check what it introduces.
2494         */
2495        if (diff_filespec_is_binary(two))
2496                goto free_and_return;
2497        else {
2498                /* Crazy xdl interfaces.. */
2499                xpparam_t xpp;
2500                xdemitconf_t xecfg;
2501
2502                memset(&xpp, 0, sizeof(xpp));
2503                memset(&xecfg, 0, sizeof(xecfg));
2504                xecfg.ctxlen = 1; /* at least one context line */
2505                xpp.flags = 0;
2506                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2507                              &xpp, &xecfg);
2508
2509                if (data.ws_rule & WS_BLANK_AT_EOF) {
2510                        struct emit_callback ecbdata;
2511                        int blank_at_eof;
2512
2513                        ecbdata.ws_rule = data.ws_rule;
2514                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2515                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2516
2517                        if (blank_at_eof) {
2518                                static char *err;
2519                                if (!err)
2520                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2521                                fprintf(o->file, "%s:%d: %s.\n",
2522                                        data.filename, blank_at_eof, err);
2523                                data.status = 1; /* report errors */
2524                        }
2525                }
2526        }
2527 free_and_return:
2528        diff_free_filespec_data(one);
2529        diff_free_filespec_data(two);
2530        if (data.status)
2531                DIFF_OPT_SET(o, CHECK_FAILED);
2532}
2533
2534struct diff_filespec *alloc_filespec(const char *path)
2535{
2536        int namelen = strlen(path);
2537        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2538
2539        memset(spec, 0, sizeof(*spec));
2540        spec->path = (char *)(spec + 1);
2541        memcpy(spec->path, path, namelen+1);
2542        spec->count = 1;
2543        spec->is_binary = -1;
2544        return spec;
2545}
2546
2547void free_filespec(struct diff_filespec *spec)
2548{
2549        if (!--spec->count) {
2550                diff_free_filespec_data(spec);
2551                free(spec);
2552        }
2553}
2554
2555void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2556                   int sha1_valid, unsigned short mode)
2557{
2558        if (mode) {
2559                spec->mode = canon_mode(mode);
2560                hashcpy(spec->sha1, sha1);
2561                spec->sha1_valid = sha1_valid;
2562        }
2563}
2564
2565/*
2566 * Given a name and sha1 pair, if the index tells us the file in
2567 * the work tree has that object contents, return true, so that
2568 * prepare_temp_file() does not have to inflate and extract.
2569 */
2570static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2571{
2572        struct cache_entry *ce;
2573        struct stat st;
2574        int pos, len;
2575
2576        /*
2577         * We do not read the cache ourselves here, because the
2578         * benchmark with my previous version that always reads cache
2579         * shows that it makes things worse for diff-tree comparing
2580         * two linux-2.6 kernel trees in an already checked out work
2581         * tree.  This is because most diff-tree comparisons deal with
2582         * only a small number of files, while reading the cache is
2583         * expensive for a large project, and its cost outweighs the
2584         * savings we get by not inflating the object to a temporary
2585         * file.  Practically, this code only helps when we are used
2586         * by diff-cache --cached, which does read the cache before
2587         * calling us.
2588         */
2589        if (!active_cache)
2590                return 0;
2591
2592        /* We want to avoid the working directory if our caller
2593         * doesn't need the data in a normal file, this system
2594         * is rather slow with its stat/open/mmap/close syscalls,
2595         * and the object is contained in a pack file.  The pack
2596         * is probably already open and will be faster to obtain
2597         * the data through than the working directory.  Loose
2598         * objects however would tend to be slower as they need
2599         * to be individually opened and inflated.
2600         */
2601        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2602                return 0;
2603
2604        len = strlen(name);
2605        pos = cache_name_pos(name, len);
2606        if (pos < 0)
2607                return 0;
2608        ce = active_cache[pos];
2609
2610        /*
2611         * This is not the sha1 we are looking for, or
2612         * unreusable because it is not a regular file.
2613         */
2614        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2615                return 0;
2616
2617        /*
2618         * If ce is marked as "assume unchanged", there is no
2619         * guarantee that work tree matches what we are looking for.
2620         */
2621        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2622                return 0;
2623
2624        /*
2625         * If ce matches the file in the work tree, we can reuse it.
2626         */
2627        if (ce_uptodate(ce) ||
2628            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2629                return 1;
2630
2631        return 0;
2632}
2633
2634static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2635{
2636        int len;
2637        char *data = xmalloc(100), *dirty = "";
2638
2639        /* Are we looking at the work tree? */
2640        if (s->dirty_submodule)
2641                dirty = "-dirty";
2642
2643        len = snprintf(data, 100,
2644                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2645        s->data = data;
2646        s->size = len;
2647        s->should_free = 1;
2648        if (size_only) {
2649                s->data = NULL;
2650                free(data);
2651        }
2652        return 0;
2653}
2654
2655/*
2656 * While doing rename detection and pickaxe operation, we may need to
2657 * grab the data for the blob (or file) for our own in-core comparison.
2658 * diff_filespec has data and size fields for this purpose.
2659 */
2660int diff_populate_filespec(struct diff_filespec *s, int size_only)
2661{
2662        int err = 0;
2663        if (!DIFF_FILE_VALID(s))
2664                die("internal error: asking to populate invalid file.");
2665        if (S_ISDIR(s->mode))
2666                return -1;
2667
2668        if (s->data)
2669                return 0;
2670
2671        if (size_only && 0 < s->size)
2672                return 0;
2673
2674        if (S_ISGITLINK(s->mode))
2675                return diff_populate_gitlink(s, size_only);
2676
2677        if (!s->sha1_valid ||
2678            reuse_worktree_file(s->path, s->sha1, 0)) {
2679                struct strbuf buf = STRBUF_INIT;
2680                struct stat st;
2681                int fd;
2682
2683                if (lstat(s->path, &st) < 0) {
2684                        if (errno == ENOENT) {
2685                        err_empty:
2686                                err = -1;
2687                        empty:
2688                                s->data = (char *)"";
2689                                s->size = 0;
2690                                return err;
2691                        }
2692                }
2693                s->size = xsize_t(st.st_size);
2694                if (!s->size)
2695                        goto empty;
2696                if (S_ISLNK(st.st_mode)) {
2697                        struct strbuf sb = STRBUF_INIT;
2698
2699                        if (strbuf_readlink(&sb, s->path, s->size))
2700                                goto err_empty;
2701                        s->size = sb.len;
2702                        s->data = strbuf_detach(&sb, NULL);
2703                        s->should_free = 1;
2704                        return 0;
2705                }
2706                if (size_only)
2707                        return 0;
2708                fd = open(s->path, O_RDONLY);
2709                if (fd < 0)
2710                        goto err_empty;
2711                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2712                close(fd);
2713                s->should_munmap = 1;
2714
2715                /*
2716                 * Convert from working tree format to canonical git format
2717                 */
2718                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2719                        size_t size = 0;
2720                        munmap(s->data, s->size);
2721                        s->should_munmap = 0;
2722                        s->data = strbuf_detach(&buf, &size);
2723                        s->size = size;
2724                        s->should_free = 1;
2725                }
2726        }
2727        else {
2728                enum object_type type;
2729                if (size_only) {
2730                        type = sha1_object_info(s->sha1, &s->size);
2731                        if (type < 0)
2732                                die("unable to read %s", sha1_to_hex(s->sha1));
2733                } else {
2734                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2735                        if (!s->data)
2736                                die("unable to read %s", sha1_to_hex(s->sha1));
2737                        s->should_free = 1;
2738                }
2739        }
2740        return 0;
2741}
2742
2743void diff_free_filespec_blob(struct diff_filespec *s)
2744{
2745        if (s->should_free)
2746                free(s->data);
2747        else if (s->should_munmap)
2748                munmap(s->data, s->size);
2749
2750        if (s->should_free || s->should_munmap) {
2751                s->should_free = s->should_munmap = 0;
2752                s->data = NULL;
2753        }
2754}
2755
2756void diff_free_filespec_data(struct diff_filespec *s)
2757{
2758        diff_free_filespec_blob(s);
2759        free(s->cnt_data);
2760        s->cnt_data = NULL;
2761}
2762
2763static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2764                           void *blob,
2765                           unsigned long size,
2766                           const unsigned char *sha1,
2767                           int mode)
2768{
2769        int fd;
2770        struct strbuf buf = STRBUF_INIT;
2771        struct strbuf template = STRBUF_INIT;
2772        char *path_dup = xstrdup(path);
2773        const char *base = basename(path_dup);
2774
2775        /* Generate "XXXXXX_basename.ext" */
2776        strbuf_addstr(&template, "XXXXXX_");
2777        strbuf_addstr(&template, base);
2778
2779        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2780                        strlen(base) + 1);
2781        if (fd < 0)
2782                die_errno("unable to create temp-file");
2783        if (convert_to_working_tree(path,
2784                        (const char *)blob, (size_t)size, &buf)) {
2785                blob = buf.buf;
2786                size = buf.len;
2787        }
2788        if (write_in_full(fd, blob, size) != size)
2789                die_errno("unable to write temp-file");
2790        close(fd);
2791        temp->name = temp->tmp_path;
2792        strcpy(temp->hex, sha1_to_hex(sha1));
2793        temp->hex[40] = 0;
2794        sprintf(temp->mode, "%06o", mode);
2795        strbuf_release(&buf);
2796        strbuf_release(&template);
2797        free(path_dup);
2798}
2799
2800static struct diff_tempfile *prepare_temp_file(const char *name,
2801                struct diff_filespec *one)
2802{
2803        struct diff_tempfile *temp = claim_diff_tempfile();
2804
2805        if (!DIFF_FILE_VALID(one)) {
2806        not_a_valid_file:
2807                /* A '-' entry produces this for file-2, and
2808                 * a '+' entry produces this for file-1.
2809                 */
2810                temp->name = "/dev/null";
2811                strcpy(temp->hex, ".");
2812                strcpy(temp->mode, ".");
2813                return temp;
2814        }
2815
2816        if (!remove_tempfile_installed) {
2817                atexit(remove_tempfile);
2818                sigchain_push_common(remove_tempfile_on_signal);
2819                remove_tempfile_installed = 1;
2820        }
2821
2822        if (!one->sha1_valid ||
2823            reuse_worktree_file(name, one->sha1, 1)) {
2824                struct stat st;
2825                if (lstat(name, &st) < 0) {
2826                        if (errno == ENOENT)
2827                                goto not_a_valid_file;
2828                        die_errno("stat(%s)", name);
2829                }
2830                if (S_ISLNK(st.st_mode)) {
2831                        struct strbuf sb = STRBUF_INIT;
2832                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2833                                die_errno("readlink(%s)", name);
2834                        prep_temp_blob(name, temp, sb.buf, sb.len,
2835                                       (one->sha1_valid ?
2836                                        one->sha1 : null_sha1),
2837                                       (one->sha1_valid ?
2838                                        one->mode : S_IFLNK));
2839                        strbuf_release(&sb);
2840                }
2841                else {
2842                        /* we can borrow from the file in the work tree */
2843                        temp->name = name;
2844                        if (!one->sha1_valid)
2845                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2846                        else
2847                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2848                        /* Even though we may sometimes borrow the
2849                         * contents from the work tree, we always want
2850                         * one->mode.  mode is trustworthy even when
2851                         * !(one->sha1_valid), as long as
2852                         * DIFF_FILE_VALID(one).
2853                         */
2854                        sprintf(temp->mode, "%06o", one->mode);
2855                }
2856                return temp;
2857        }
2858        else {
2859                if (diff_populate_filespec(one, 0))
2860                        die("cannot read data blob for %s", one->path);
2861                prep_temp_blob(name, temp, one->data, one->size,
2862                               one->sha1, one->mode);
2863        }
2864        return temp;
2865}
2866
2867/* An external diff command takes:
2868 *
2869 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2870 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2871 *
2872 */
2873static void run_external_diff(const char *pgm,
2874                              const char *name,
2875                              const char *other,
2876                              struct diff_filespec *one,
2877                              struct diff_filespec *two,
2878                              const char *xfrm_msg,
2879                              int complete_rewrite)
2880{
2881        const char *spawn_arg[10];
2882        int retval;
2883        const char **arg = &spawn_arg[0];
2884
2885        if (one && two) {
2886                struct diff_tempfile *temp_one, *temp_two;
2887                const char *othername = (other ? other : name);
2888                temp_one = prepare_temp_file(name, one);
2889                temp_two = prepare_temp_file(othername, two);
2890                *arg++ = pgm;
2891                *arg++ = name;
2892                *arg++ = temp_one->name;
2893                *arg++ = temp_one->hex;
2894                *arg++ = temp_one->mode;
2895                *arg++ = temp_two->name;
2896                *arg++ = temp_two->hex;
2897                *arg++ = temp_two->mode;
2898                if (other) {
2899                        *arg++ = other;
2900                        *arg++ = xfrm_msg;
2901                }
2902        } else {
2903                *arg++ = pgm;
2904                *arg++ = name;
2905        }
2906        *arg = NULL;
2907        fflush(NULL);
2908        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2909        remove_tempfile();
2910        if (retval) {
2911                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2912                exit(1);
2913        }
2914}
2915
2916static int similarity_index(struct diff_filepair *p)
2917{
2918        return p->score * 100 / MAX_SCORE;
2919}
2920
2921static void fill_metainfo(struct strbuf *msg,
2922                          const char *name,
2923                          const char *other,
2924                          struct diff_filespec *one,
2925                          struct diff_filespec *two,
2926                          struct diff_options *o,
2927                          struct diff_filepair *p,
2928                          int *must_show_header,
2929                          int use_color)
2930{
2931        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2932        const char *reset = diff_get_color(use_color, DIFF_RESET);
2933        struct strbuf *msgbuf;
2934        char *line_prefix = "";
2935
2936        *must_show_header = 1;
2937        if (o->output_prefix) {
2938                msgbuf = o->output_prefix(o, o->output_prefix_data);
2939                line_prefix = msgbuf->buf;
2940        }
2941        strbuf_init(msg, PATH_MAX * 2 + 300);
2942        switch (p->status) {
2943        case DIFF_STATUS_COPIED:
2944                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2945                            line_prefix, set, similarity_index(p));
2946                strbuf_addf(msg, "%s\n%s%scopy from ",
2947                            reset,  line_prefix, set);
2948                quote_c_style(name, msg, NULL, 0);
2949                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2950                quote_c_style(other, msg, NULL, 0);
2951                strbuf_addf(msg, "%s\n", reset);
2952                break;
2953        case DIFF_STATUS_RENAMED:
2954                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2955                            line_prefix, set, similarity_index(p));
2956                strbuf_addf(msg, "%s\n%s%srename from ",
2957                            reset, line_prefix, set);
2958                quote_c_style(name, msg, NULL, 0);
2959                strbuf_addf(msg, "%s\n%s%srename to ",
2960                            reset, line_prefix, set);
2961                quote_c_style(other, msg, NULL, 0);
2962                strbuf_addf(msg, "%s\n", reset);
2963                break;
2964        case DIFF_STATUS_MODIFIED:
2965                if (p->score) {
2966                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2967                                    line_prefix,
2968                                    set, similarity_index(p), reset);
2969                        break;
2970                }
2971                /* fallthru */
2972        default:
2973                *must_show_header = 0;
2974        }
2975        if (one && two && hashcmp(one->sha1, two->sha1)) {
2976                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2977
2978                if (DIFF_OPT_TST(o, BINARY)) {
2979                        mmfile_t mf;
2980                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2981                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2982                                abbrev = 40;
2983                }
2984                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2985                            find_unique_abbrev(one->sha1, abbrev));
2986                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2987                if (one->mode == two->mode)
2988                        strbuf_addf(msg, " %06o", one->mode);
2989                strbuf_addf(msg, "%s\n", reset);
2990        }
2991}
2992
2993static void run_diff_cmd(const char *pgm,
2994                         const char *name,
2995                         const char *other,
2996                         const char *attr_path,
2997                         struct diff_filespec *one,
2998                         struct diff_filespec *two,
2999                         struct strbuf *msg,
3000                         struct diff_options *o,
3001                         struct diff_filepair *p)
3002{
3003        const char *xfrm_msg = NULL;
3004        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3005        int must_show_header = 0;
3006
3007
3008        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3009                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3010                if (drv && drv->external)
3011                        pgm = drv->external;
3012        }
3013
3014        if (msg) {
3015                /*
3016                 * don't use colors when the header is intended for an
3017                 * external diff driver
3018                 */
3019                fill_metainfo(msg, name, other, one, two, o, p,
3020                              &must_show_header,
3021                              want_color(o->use_color) && !pgm);
3022                xfrm_msg = msg->len ? msg->buf : NULL;
3023        }
3024
3025        if (pgm) {
3026                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3027                                  complete_rewrite);
3028                return;
3029        }
3030        if (one && two)
3031                builtin_diff(name, other ? other : name,
3032                             one, two, xfrm_msg, must_show_header,
3033                             o, complete_rewrite);
3034        else
3035                fprintf(o->file, "* Unmerged path %s\n", name);
3036}
3037
3038static void diff_fill_sha1_info(struct diff_filespec *one)
3039{
3040        if (DIFF_FILE_VALID(one)) {
3041                if (!one->sha1_valid) {
3042                        struct stat st;
3043                        if (one->is_stdin) {
3044                                hashcpy(one->sha1, null_sha1);
3045                                return;
3046                        }
3047                        if (lstat(one->path, &st) < 0)
3048                                die_errno("stat '%s'", one->path);
3049                        if (index_path(one->sha1, one->path, &st, 0))
3050                                die("cannot hash %s", one->path);
3051                }
3052        }
3053        else
3054                hashclr(one->sha1);
3055}
3056
3057static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3058{
3059        /* Strip the prefix but do not molest /dev/null and absolute paths */
3060        if (*namep && **namep != '/') {
3061                *namep += prefix_length;
3062                if (**namep == '/')
3063                        ++*namep;
3064        }
3065        if (*otherp && **otherp != '/') {
3066                *otherp += prefix_length;
3067                if (**otherp == '/')
3068                        ++*otherp;
3069        }
3070}
3071
3072static void run_diff(struct diff_filepair *p, struct diff_options *o)
3073{
3074        const char *pgm = external_diff();
3075        struct strbuf msg;
3076        struct diff_filespec *one = p->one;
3077        struct diff_filespec *two = p->two;
3078        const char *name;
3079        const char *other;
3080        const char *attr_path;
3081
3082        name  = p->one->path;
3083        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3084        attr_path = name;
3085        if (o->prefix_length)
3086                strip_prefix(o->prefix_length, &name, &other);
3087
3088        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3089                pgm = NULL;
3090
3091        if (DIFF_PAIR_UNMERGED(p)) {
3092                run_diff_cmd(pgm, name, NULL, attr_path,
3093                             NULL, NULL, NULL, o, p);
3094                return;
3095        }
3096
3097        diff_fill_sha1_info(one);
3098        diff_fill_sha1_info(two);
3099
3100        if (!pgm &&
3101            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3102            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3103                /*
3104                 * a filepair that changes between file and symlink
3105                 * needs to be split into deletion and creation.
3106                 */
3107                struct diff_filespec *null = alloc_filespec(two->path);
3108                run_diff_cmd(NULL, name, other, attr_path,
3109                             one, null, &msg, o, p);
3110                free(null);
3111                strbuf_release(&msg);
3112
3113                null = alloc_filespec(one->path);
3114                run_diff_cmd(NULL, name, other, attr_path,
3115                             null, two, &msg, o, p);
3116                free(null);
3117        }
3118        else
3119                run_diff_cmd(pgm, name, other, attr_path,
3120                             one, two, &msg, o, p);
3121
3122        strbuf_release(&msg);
3123}
3124
3125static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3126                         struct diffstat_t *diffstat)
3127{
3128        const char *name;
3129        const char *other;
3130
3131        if (DIFF_PAIR_UNMERGED(p)) {
3132                /* unmerged */
3133                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3134                return;
3135        }
3136
3137        name = p->one->path;
3138        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3139
3140        if (o->prefix_length)
3141                strip_prefix(o->prefix_length, &name, &other);
3142
3143        diff_fill_sha1_info(p->one);
3144        diff_fill_sha1_info(p->two);
3145
3146        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3147}
3148
3149static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3150{
3151        const char *name;
3152        const char *other;
3153        const char *attr_path;
3154
3155        if (DIFF_PAIR_UNMERGED(p)) {
3156                /* unmerged */
3157                return;
3158        }
3159
3160        name = p->one->path;
3161        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3162        attr_path = other ? other : name;
3163
3164        if (o->prefix_length)
3165                strip_prefix(o->prefix_length, &name, &other);
3166
3167        diff_fill_sha1_info(p->one);
3168        diff_fill_sha1_info(p->two);
3169
3170        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3171}
3172
3173void diff_setup(struct diff_options *options)
3174{
3175        memcpy(options, &default_diff_options, sizeof(*options));
3176
3177        options->file = stdout;
3178
3179        options->line_termination = '\n';
3180        options->break_opt = -1;
3181        options->rename_limit = -1;
3182        options->dirstat_permille = diff_dirstat_permille_default;
3183        options->context = 3;
3184        DIFF_OPT_SET(options, RENAME_EMPTY);
3185
3186        options->change = diff_change;
3187        options->add_remove = diff_addremove;
3188        options->use_color = diff_use_color_default;
3189        options->detect_rename = diff_detect_rename_default;
3190
3191        if (diff_no_prefix) {
3192                options->a_prefix = options->b_prefix = "";
3193        } else if (!diff_mnemonic_prefix) {
3194                options->a_prefix = "a/";
3195                options->b_prefix = "b/";
3196        }
3197}
3198
3199void diff_setup_done(struct diff_options *options)
3200{
3201        int count = 0;
3202
3203        if (options->output_format & DIFF_FORMAT_NAME)
3204                count++;
3205        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3206                count++;
3207        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3208                count++;
3209        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3210                count++;
3211        if (count > 1)
3212                die("--name-only, --name-status, --check and -s are mutually exclusive");
3213
3214        /*
3215         * Most of the time we can say "there are changes"
3216         * only by checking if there are changed paths, but
3217         * --ignore-whitespace* options force us to look
3218         * inside contents.
3219         */
3220
3221        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3222            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3223            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3224                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3225        else
3226                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3227
3228        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3229                options->detect_rename = DIFF_DETECT_COPY;
3230
3231        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3232                options->prefix = NULL;
3233        if (options->prefix)
3234                options->prefix_length = strlen(options->prefix);
3235        else
3236                options->prefix_length = 0;
3237
3238        if (options->output_format & (DIFF_FORMAT_NAME |
3239                                      DIFF_FORMAT_NAME_STATUS |
3240                                      DIFF_FORMAT_CHECKDIFF |
3241                                      DIFF_FORMAT_NO_OUTPUT))
3242                options->output_format &= ~(DIFF_FORMAT_RAW |
3243                                            DIFF_FORMAT_NUMSTAT |
3244                                            DIFF_FORMAT_DIFFSTAT |
3245                                            DIFF_FORMAT_SHORTSTAT |
3246                                            DIFF_FORMAT_DIRSTAT |
3247                                            DIFF_FORMAT_SUMMARY |
3248                                            DIFF_FORMAT_PATCH);
3249
3250        /*
3251         * These cases always need recursive; we do not drop caller-supplied
3252         * recursive bits for other formats here.
3253         */
3254        if (options->output_format & (DIFF_FORMAT_PATCH |
3255                                      DIFF_FORMAT_NUMSTAT |
3256                                      DIFF_FORMAT_DIFFSTAT |
3257                                      DIFF_FORMAT_SHORTSTAT |
3258                                      DIFF_FORMAT_DIRSTAT |
3259                                      DIFF_FORMAT_SUMMARY |
3260                                      DIFF_FORMAT_CHECKDIFF))
3261                DIFF_OPT_SET(options, RECURSIVE);
3262        /*
3263         * Also pickaxe would not work very well if you do not say recursive
3264         */
3265        if (options->pickaxe)
3266                DIFF_OPT_SET(options, RECURSIVE);
3267        /*
3268         * When patches are generated, submodules diffed against the work tree
3269         * must be checked for dirtiness too so it can be shown in the output
3270         */
3271        if (options->output_format & DIFF_FORMAT_PATCH)
3272                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3273
3274        if (options->detect_rename && options->rename_limit < 0)
3275                options->rename_limit = diff_rename_limit_default;
3276        if (options->setup & DIFF_SETUP_USE_CACHE) {
3277                if (!active_cache)
3278                        /* read-cache does not die even when it fails
3279                         * so it is safe for us to do this here.  Also
3280                         * it does not smudge active_cache or active_nr
3281                         * when it fails, so we do not have to worry about
3282                         * cleaning it up ourselves either.
3283                         */
3284                        read_cache();
3285        }
3286        if (options->abbrev <= 0 || 40 < options->abbrev)
3287                options->abbrev = 40; /* full */
3288
3289        /*
3290         * It does not make sense to show the first hit we happened
3291         * to have found.  It does not make sense not to return with
3292         * exit code in such a case either.
3293         */
3294        if (DIFF_OPT_TST(options, QUICK)) {
3295                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3296                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3297        }
3298}
3299
3300static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3301{
3302        char c, *eq;
3303        int len;
3304
3305        if (*arg != '-')
3306                return 0;
3307        c = *++arg;
3308        if (!c)
3309                return 0;
3310        if (c == arg_short) {
3311                c = *++arg;
3312                if (!c)
3313                        return 1;
3314                if (val && isdigit(c)) {
3315                        char *end;
3316                        int n = strtoul(arg, &end, 10);
3317                        if (*end)
3318                                return 0;
3319                        *val = n;
3320                        return 1;
3321                }
3322                return 0;
3323        }
3324        if (c != '-')
3325                return 0;
3326        arg++;
3327        eq = strchr(arg, '=');
3328        if (eq)
3329                len = eq - arg;
3330        else
3331                len = strlen(arg);
3332        if (!len || strncmp(arg, arg_long, len))
3333                return 0;
3334        if (eq) {
3335                int n;
3336                char *end;
3337                if (!isdigit(*++eq))
3338                        return 0;
3339                n = strtoul(eq, &end, 10);
3340                if (*end)
3341                        return 0;
3342                *val = n;
3343        }
3344        return 1;
3345}
3346
3347static int diff_scoreopt_parse(const char *opt);
3348
3349static inline int short_opt(char opt, const char **argv,
3350                            const char **optarg)
3351{
3352        const char *arg = argv[0];
3353        if (arg[0] != '-' || arg[1] != opt)
3354                return 0;
3355        if (arg[2] != '\0') {
3356                *optarg = arg + 2;
3357                return 1;
3358        }
3359        if (!argv[1])
3360                die("Option '%c' requires a value", opt);
3361        *optarg = argv[1];
3362        return 2;
3363}
3364
3365int parse_long_opt(const char *opt, const char **argv,
3366                   const char **optarg)
3367{
3368        const char *arg = argv[0];
3369        if (arg[0] != '-' || arg[1] != '-')
3370                return 0;
3371        arg += strlen("--");
3372        if (prefixcmp(arg, opt))
3373                return 0;
3374        arg += strlen(opt);
3375        if (*arg == '=') { /* sticked form: --option=value */
3376                *optarg = arg + 1;
3377                return 1;
3378        }
3379        if (*arg != '\0')
3380                return 0;
3381        /* separate form: --option value */
3382        if (!argv[1])
3383                die("Option '--%s' requires a value", opt);
3384        *optarg = argv[1];
3385        return 2;
3386}
3387
3388static int stat_opt(struct diff_options *options, const char **av)
3389{
3390        const char *arg = av[0];
3391        char *end;
3392        int width = options->stat_width;
3393        int name_width = options->stat_name_width;
3394        int graph_width = options->stat_graph_width;
3395        int count = options->stat_count;
3396        int argcount = 1;
3397
3398        arg += strlen("--stat");
3399        end = (char *)arg;
3400
3401        switch (*arg) {
3402        case '-':
3403                if (!prefixcmp(arg, "-width")) {
3404                        arg += strlen("-width");
3405                        if (*arg == '=')
3406                                width = strtoul(arg + 1, &end, 10);
3407                        else if (!*arg && !av[1])
3408                                die("Option '--stat-width' requires a value");
3409                        else if (!*arg) {
3410                                width = strtoul(av[1], &end, 10);
3411                                argcount = 2;
3412                        }
3413                } else if (!prefixcmp(arg, "-name-width")) {
3414                        arg += strlen("-name-width");
3415                        if (*arg == '=')
3416                                name_width = strtoul(arg + 1, &end, 10);
3417                        else if (!*arg && !av[1])
3418                                die("Option '--stat-name-width' requires a value");
3419                        else if (!*arg) {
3420                                name_width = strtoul(av[1], &end, 10);
3421                                argcount = 2;
3422                        }
3423                } else if (!prefixcmp(arg, "-graph-width")) {
3424                        arg += strlen("-graph-width");
3425                        if (*arg == '=')
3426                                graph_width = strtoul(arg + 1, &end, 10);
3427                        else if (!*arg && !av[1])
3428                                die("Option '--stat-graph-width' requires a value");
3429                        else if (!*arg) {
3430                                graph_width = strtoul(av[1], &end, 10);
3431                                argcount = 2;
3432                        }
3433                } else if (!prefixcmp(arg, "-count")) {
3434                        arg += strlen("-count");
3435                        if (*arg == '=')
3436                                count = strtoul(arg + 1, &end, 10);
3437                        else if (!*arg && !av[1])
3438                                die("Option '--stat-count' requires a value");
3439                        else if (!*arg) {
3440                                count = strtoul(av[1], &end, 10);
3441                                argcount = 2;
3442                        }
3443                }
3444                break;
3445        case '=':
3446                width = strtoul(arg+1, &end, 10);
3447                if (*end == ',')
3448                        name_width = strtoul(end+1, &end, 10);
3449                if (*end == ',')
3450                        count = strtoul(end+1, &end, 10);
3451        }
3452
3453        /* Important! This checks all the error cases! */
3454        if (*end)
3455                return 0;
3456        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3457        options->stat_name_width = name_width;
3458        options->stat_graph_width = graph_width;
3459        options->stat_width = width;
3460        options->stat_count = count;
3461        return argcount;
3462}
3463
3464static int parse_dirstat_opt(struct diff_options *options, const char *params)
3465{
3466        struct strbuf errmsg = STRBUF_INIT;
3467        if (parse_dirstat_params(options, params, &errmsg))
3468                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3469                    errmsg.buf);
3470        strbuf_release(&errmsg);
3471        /*
3472         * The caller knows a dirstat-related option is given from the command
3473         * line; allow it to say "return this_function();"
3474         */
3475        options->output_format |= DIFF_FORMAT_DIRSTAT;
3476        return 1;
3477}
3478
3479int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3480{
3481        const char *arg = av[0];
3482        const char *optarg;
3483        int argcount;
3484
3485        /* Output format options */
3486        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3487                options->output_format |= DIFF_FORMAT_PATCH;
3488        else if (opt_arg(arg, 'U', "unified", &options->context))
3489                options->output_format |= DIFF_FORMAT_PATCH;
3490        else if (!strcmp(arg, "--raw"))
3491                options->output_format |= DIFF_FORMAT_RAW;
3492        else if (!strcmp(arg, "--patch-with-raw"))
3493                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3494        else if (!strcmp(arg, "--numstat"))
3495                options->output_format |= DIFF_FORMAT_NUMSTAT;
3496        else if (!strcmp(arg, "--shortstat"))
3497                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3498        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3499                return parse_dirstat_opt(options, "");
3500        else if (!prefixcmp(arg, "-X"))
3501                return parse_dirstat_opt(options, arg + 2);
3502        else if (!prefixcmp(arg, "--dirstat="))
3503                return parse_dirstat_opt(options, arg + 10);
3504        else if (!strcmp(arg, "--cumulative"))
3505                return parse_dirstat_opt(options, "cumulative");
3506        else if (!strcmp(arg, "--dirstat-by-file"))
3507                return parse_dirstat_opt(options, "files");
3508        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3509                parse_dirstat_opt(options, "files");
3510                return parse_dirstat_opt(options, arg + 18);
3511        }
3512        else if (!strcmp(arg, "--check"))
3513                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3514        else if (!strcmp(arg, "--summary"))
3515                options->output_format |= DIFF_FORMAT_SUMMARY;
3516        else if (!strcmp(arg, "--patch-with-stat"))
3517                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3518        else if (!strcmp(arg, "--name-only"))
3519                options->output_format |= DIFF_FORMAT_NAME;
3520        else if (!strcmp(arg, "--name-status"))
3521                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3522        else if (!strcmp(arg, "-s"))
3523                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3524        else if (!prefixcmp(arg, "--stat"))
3525                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3526                return stat_opt(options, av);
3527
3528        /* renames options */
3529        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3530                 !strcmp(arg, "--break-rewrites")) {
3531                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3532                        return error("invalid argument to -B: %s", arg+2);
3533        }
3534        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3535                 !strcmp(arg, "--find-renames")) {
3536                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3537                        return error("invalid argument to -M: %s", arg+2);
3538                options->detect_rename = DIFF_DETECT_RENAME;
3539        }
3540        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3541                options->irreversible_delete = 1;
3542        }
3543        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3544                 !strcmp(arg, "--find-copies")) {
3545                if (options->detect_rename == DIFF_DETECT_COPY)
3546                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3547                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3548                        return error("invalid argument to -C: %s", arg+2);
3549                options->detect_rename = DIFF_DETECT_COPY;
3550        }
3551        else if (!strcmp(arg, "--no-renames"))
3552                options->detect_rename = 0;
3553        else if (!strcmp(arg, "--rename-empty"))
3554                DIFF_OPT_SET(options, RENAME_EMPTY);
3555        else if (!strcmp(arg, "--no-rename-empty"))
3556                DIFF_OPT_CLR(options, RENAME_EMPTY);
3557        else if (!strcmp(arg, "--relative"))
3558                DIFF_OPT_SET(options, RELATIVE_NAME);
3559        else if (!prefixcmp(arg, "--relative=")) {
3560                DIFF_OPT_SET(options, RELATIVE_NAME);
3561                options->prefix = arg + 11;
3562        }
3563
3564        /* xdiff options */
3565        else if (!strcmp(arg, "--minimal"))
3566                DIFF_XDL_SET(options, NEED_MINIMAL);
3567        else if (!strcmp(arg, "--no-minimal"))
3568                DIFF_XDL_CLR(options, NEED_MINIMAL);
3569        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3570                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3571        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3572                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3573        else if (!strcmp(arg, "--ignore-space-at-eol"))
3574                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3575        else if (!strcmp(arg, "--patience"))
3576                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3577        else if (!strcmp(arg, "--histogram"))
3578                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3579
3580        /* flags options */
3581        else if (!strcmp(arg, "--binary")) {
3582                options->output_format |= DIFF_FORMAT_PATCH;
3583                DIFF_OPT_SET(options, BINARY);
3584        }
3585        else if (!strcmp(arg, "--full-index"))
3586                DIFF_OPT_SET(options, FULL_INDEX);
3587        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3588                DIFF_OPT_SET(options, TEXT);
3589        else if (!strcmp(arg, "-R"))
3590                DIFF_OPT_SET(options, REVERSE_DIFF);
3591        else if (!strcmp(arg, "--find-copies-harder"))
3592                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3593        else if (!strcmp(arg, "--follow"))
3594                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3595        else if (!strcmp(arg, "--color"))
3596                options->use_color = 1;
3597        else if (!prefixcmp(arg, "--color=")) {
3598                int value = git_config_colorbool(NULL, arg+8);
3599                if (value < 0)
3600                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3601                options->use_color = value;
3602        }
3603        else if (!strcmp(arg, "--no-color"))
3604                options->use_color = 0;
3605        else if (!strcmp(arg, "--color-words")) {
3606                options->use_color = 1;
3607                options->word_diff = DIFF_WORDS_COLOR;
3608        }
3609        else if (!prefixcmp(arg, "--color-words=")) {
3610                options->use_color = 1;
3611                options->word_diff = DIFF_WORDS_COLOR;
3612                options->word_regex = arg + 14;
3613        }
3614        else if (!strcmp(arg, "--word-diff")) {
3615                if (options->word_diff == DIFF_WORDS_NONE)
3616                        options->word_diff = DIFF_WORDS_PLAIN;
3617        }
3618        else if (!prefixcmp(arg, "--word-diff=")) {
3619                const char *type = arg + 12;
3620                if (!strcmp(type, "plain"))
3621                        options->word_diff = DIFF_WORDS_PLAIN;
3622                else if (!strcmp(type, "color")) {
3623                        options->use_color = 1;
3624                        options->word_diff = DIFF_WORDS_COLOR;
3625                }
3626                else if (!strcmp(type, "porcelain"))
3627                        options->word_diff = DIFF_WORDS_PORCELAIN;
3628                else if (!strcmp(type, "none"))
3629                        options->word_diff = DIFF_WORDS_NONE;
3630                else
3631                        die("bad --word-diff argument: %s", type);
3632        }
3633        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3634                if (options->word_diff == DIFF_WORDS_NONE)
3635                        options->word_diff = DIFF_WORDS_PLAIN;
3636                options->word_regex = optarg;
3637                return argcount;
3638        }
3639        else if (!strcmp(arg, "--exit-code"))
3640                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3641        else if (!strcmp(arg, "--quiet"))
3642                DIFF_OPT_SET(options, QUICK);
3643        else if (!strcmp(arg, "--ext-diff"))
3644                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3645        else if (!strcmp(arg, "--no-ext-diff"))
3646                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3647        else if (!strcmp(arg, "--textconv"))
3648                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3649        else if (!strcmp(arg, "--no-textconv"))
3650                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3651        else if (!strcmp(arg, "--ignore-submodules")) {
3652                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3653                handle_ignore_submodules_arg(options, "all");
3654        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3655                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3656                handle_ignore_submodules_arg(options, arg + 20);
3657        } else if (!strcmp(arg, "--submodule"))
3658                DIFF_OPT_SET(options, SUBMODULE_LOG);
3659        else if (!prefixcmp(arg, "--submodule=")) {
3660                if (!strcmp(arg + 12, "log"))
3661                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3662        }
3663
3664        /* misc options */
3665        else if (!strcmp(arg, "-z"))
3666                options->line_termination = 0;
3667        else if ((argcount = short_opt('l', av, &optarg))) {
3668                options->rename_limit = strtoul(optarg, NULL, 10);
3669                return argcount;
3670        }
3671        else if ((argcount = short_opt('S', av, &optarg))) {
3672                options->pickaxe = optarg;
3673                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3674                return argcount;
3675        } else if ((argcount = short_opt('G', av, &optarg))) {
3676                options->pickaxe = optarg;
3677                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3678                return argcount;
3679        }
3680        else if (!strcmp(arg, "--pickaxe-all"))
3681                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3682        else if (!strcmp(arg, "--pickaxe-regex"))
3683                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3684        else if ((argcount = short_opt('O', av, &optarg))) {
3685                options->orderfile = optarg;
3686                return argcount;
3687        }
3688        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3689                options->filter = optarg;
3690                return argcount;
3691        }
3692        else if (!strcmp(arg, "--abbrev"))
3693                options->abbrev = DEFAULT_ABBREV;
3694        else if (!prefixcmp(arg, "--abbrev=")) {
3695                options->abbrev = strtoul(arg + 9, NULL, 10);
3696                if (options->abbrev < MINIMUM_ABBREV)
3697                        options->abbrev = MINIMUM_ABBREV;
3698                else if (40 < options->abbrev)
3699                        options->abbrev = 40;
3700        }
3701        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3702                options->a_prefix = optarg;
3703                return argcount;
3704        }
3705        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3706                options->b_prefix = optarg;
3707                return argcount;
3708        }
3709        else if (!strcmp(arg, "--no-prefix"))
3710                options->a_prefix = options->b_prefix = "";
3711        else if (opt_arg(arg, '\0', "inter-hunk-context",
3712                         &options->interhunkcontext))
3713                ;
3714        else if (!strcmp(arg, "-W"))
3715                DIFF_OPT_SET(options, FUNCCONTEXT);
3716        else if (!strcmp(arg, "--function-context"))
3717                DIFF_OPT_SET(options, FUNCCONTEXT);
3718        else if (!strcmp(arg, "--no-function-context"))
3719                DIFF_OPT_CLR(options, FUNCCONTEXT);
3720        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3721                options->file = fopen(optarg, "w");
3722                if (!options->file)
3723                        die_errno("Could not open '%s'", optarg);
3724                options->close_file = 1;
3725                return argcount;
3726        } else
3727                return 0;
3728        return 1;
3729}
3730
3731int parse_rename_score(const char **cp_p)
3732{
3733        unsigned long num, scale;
3734        int ch, dot;
3735        const char *cp = *cp_p;
3736
3737        num = 0;
3738        scale = 1;
3739        dot = 0;
3740        for (;;) {
3741                ch = *cp;
3742                if ( !dot && ch == '.' ) {
3743                        scale = 1;
3744                        dot = 1;
3745                } else if ( ch == '%' ) {
3746                        scale = dot ? scale*100 : 100;
3747                        cp++;   /* % is always at the end */
3748                        break;
3749                } else if ( ch >= '0' && ch <= '9' ) {
3750                        if ( scale < 100000 ) {
3751                                scale *= 10;
3752                                num = (num*10) + (ch-'0');
3753                        }
3754                } else {
3755                        break;
3756                }
3757                cp++;
3758        }
3759        *cp_p = cp;
3760
3761        /* user says num divided by scale and we say internally that
3762         * is MAX_SCORE * num / scale.
3763         */
3764        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3765}
3766
3767static int diff_scoreopt_parse(const char *opt)
3768{
3769        int opt1, opt2, cmd;
3770
3771        if (*opt++ != '-')
3772                return -1;
3773        cmd = *opt++;
3774        if (cmd == '-') {
3775                /* convert the long-form arguments into short-form versions */
3776                if (!prefixcmp(opt, "break-rewrites")) {
3777                        opt += strlen("break-rewrites");
3778                        if (*opt == 0 || *opt++ == '=')
3779                                cmd = 'B';
3780                } else if (!prefixcmp(opt, "find-copies")) {
3781                        opt += strlen("find-copies");
3782                        if (*opt == 0 || *opt++ == '=')
3783                                cmd = 'C';
3784                } else if (!prefixcmp(opt, "find-renames")) {
3785                        opt += strlen("find-renames");
3786                        if (*opt == 0 || *opt++ == '=')
3787                                cmd = 'M';
3788                }
3789        }
3790        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3791                return -1; /* that is not a -M, -C nor -B option */
3792
3793        opt1 = parse_rename_score(&opt);
3794        if (cmd != 'B')
3795                opt2 = 0;
3796        else {
3797                if (*opt == 0)
3798                        opt2 = 0;
3799                else if (*opt != '/')
3800                        return -1; /* we expect -B80/99 or -B80 */
3801                else {
3802                        opt++;
3803                        opt2 = parse_rename_score(&opt);
3804                }
3805        }
3806        if (*opt != 0)
3807                return -1;
3808        return opt1 | (opt2 << 16);
3809}
3810
3811struct diff_queue_struct diff_queued_diff;
3812
3813void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3814{
3815        if (queue->alloc <= queue->nr) {
3816                queue->alloc = alloc_nr(queue->alloc);
3817                queue->queue = xrealloc(queue->queue,
3818                                        sizeof(dp) * queue->alloc);
3819        }
3820        queue->queue[queue->nr++] = dp;
3821}
3822
3823struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3824                                 struct diff_filespec *one,
3825                                 struct diff_filespec *two)
3826{
3827        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3828        dp->one = one;
3829        dp->two = two;
3830        if (queue)
3831                diff_q(queue, dp);
3832        return dp;
3833}
3834
3835void diff_free_filepair(struct diff_filepair *p)
3836{
3837        free_filespec(p->one);
3838        free_filespec(p->two);
3839        free(p);
3840}
3841
3842/* This is different from find_unique_abbrev() in that
3843 * it stuffs the result with dots for alignment.
3844 */
3845const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3846{
3847        int abblen;
3848        const char *abbrev;
3849        if (len == 40)
3850                return sha1_to_hex(sha1);
3851
3852        abbrev = find_unique_abbrev(sha1, len);
3853        abblen = strlen(abbrev);
3854        if (abblen < 37) {
3855                static char hex[41];
3856                if (len < abblen && abblen <= len + 2)
3857                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3858                else
3859                        sprintf(hex, "%s...", abbrev);
3860                return hex;
3861        }
3862        return sha1_to_hex(sha1);
3863}
3864
3865static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3866{
3867        int line_termination = opt->line_termination;
3868        int inter_name_termination = line_termination ? '\t' : '\0';
3869        if (opt->output_prefix) {
3870                struct strbuf *msg = NULL;
3871                msg = opt->output_prefix(opt, opt->output_prefix_data);
3872                fprintf(opt->file, "%s", msg->buf);
3873        }
3874
3875        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3876                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3877                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3878                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3879        }
3880        if (p->score) {
3881                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3882                        inter_name_termination);
3883        } else {
3884                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3885        }
3886
3887        if (p->status == DIFF_STATUS_COPIED ||
3888            p->status == DIFF_STATUS_RENAMED) {
3889                const char *name_a, *name_b;
3890                name_a = p->one->path;
3891                name_b = p->two->path;
3892                strip_prefix(opt->prefix_length, &name_a, &name_b);
3893                write_name_quoted(name_a, opt->file, inter_name_termination);
3894                write_name_quoted(name_b, opt->file, line_termination);
3895        } else {
3896                const char *name_a, *name_b;
3897                name_a = p->one->mode ? p->one->path : p->two->path;
3898                name_b = NULL;
3899                strip_prefix(opt->prefix_length, &name_a, &name_b);
3900                write_name_quoted(name_a, opt->file, line_termination);
3901        }
3902}
3903
3904int diff_unmodified_pair(struct diff_filepair *p)
3905{
3906        /* This function is written stricter than necessary to support
3907         * the currently implemented transformers, but the idea is to
3908         * let transformers to produce diff_filepairs any way they want,
3909         * and filter and clean them up here before producing the output.
3910         */
3911        struct diff_filespec *one = p->one, *two = p->two;
3912
3913        if (DIFF_PAIR_UNMERGED(p))
3914                return 0; /* unmerged is interesting */
3915
3916        /* deletion, addition, mode or type change
3917         * and rename are all interesting.
3918         */
3919        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3920            DIFF_PAIR_MODE_CHANGED(p) ||
3921            strcmp(one->path, two->path))
3922                return 0;
3923
3924        /* both are valid and point at the same path.  that is, we are
3925         * dealing with a change.
3926         */
3927        if (one->sha1_valid && two->sha1_valid &&
3928            !hashcmp(one->sha1, two->sha1) &&
3929            !one->dirty_submodule && !two->dirty_submodule)
3930                return 1; /* no change */
3931        if (!one->sha1_valid && !two->sha1_valid)
3932                return 1; /* both look at the same file on the filesystem. */
3933        return 0;
3934}
3935
3936static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3937{
3938        if (diff_unmodified_pair(p))
3939                return;
3940
3941        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3942            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3943                return; /* no tree diffs in patch format */
3944
3945        run_diff(p, o);
3946}
3947
3948static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3949                            struct diffstat_t *diffstat)
3950{
3951        if (diff_unmodified_pair(p))
3952                return;
3953
3954        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3955            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3956                return; /* no useful stat for tree diffs */
3957
3958        run_diffstat(p, o, diffstat);
3959}
3960
3961static void diff_flush_checkdiff(struct diff_filepair *p,
3962                struct diff_options *o)
3963{
3964        if (diff_unmodified_pair(p))
3965                return;
3966
3967        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3968            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3969                return; /* nothing to check in tree diffs */
3970
3971        run_checkdiff(p, o);
3972}
3973
3974int diff_queue_is_empty(void)
3975{
3976        struct diff_queue_struct *q = &diff_queued_diff;
3977        int i;
3978        for (i = 0; i < q->nr; i++)
3979                if (!diff_unmodified_pair(q->queue[i]))
3980                        return 0;
3981        return 1;
3982}
3983
3984#if DIFF_DEBUG
3985void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3986{
3987        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3988                x, one ? one : "",
3989                s->path,
3990                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3991                s->mode,
3992                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3993        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3994                x, one ? one : "",
3995                s->size, s->xfrm_flags);
3996}
3997
3998void diff_debug_filepair(const struct diff_filepair *p, int i)
3999{
4000        diff_debug_filespec(p->one, i, "one");
4001        diff_debug_filespec(p->two, i, "two");
4002        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4003                p->score, p->status ? p->status : '?',
4004                p->one->rename_used, p->broken_pair);
4005}
4006
4007void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4008{
4009        int i;
4010        if (msg)
4011                fprintf(stderr, "%s\n", msg);
4012        fprintf(stderr, "q->nr = %d\n", q->nr);
4013        for (i = 0; i < q->nr; i++) {
4014                struct diff_filepair *p = q->queue[i];
4015                diff_debug_filepair(p, i);
4016        }
4017}
4018#endif
4019
4020static void diff_resolve_rename_copy(void)
4021{
4022        int i;
4023        struct diff_filepair *p;
4024        struct diff_queue_struct *q = &diff_queued_diff;
4025
4026        diff_debug_queue("resolve-rename-copy", q);
4027
4028        for (i = 0; i < q->nr; i++) {
4029                p = q->queue[i];
4030                p->status = 0; /* undecided */
4031                if (DIFF_PAIR_UNMERGED(p))
4032                        p->status = DIFF_STATUS_UNMERGED;
4033                else if (!DIFF_FILE_VALID(p->one))
4034                        p->status = DIFF_STATUS_ADDED;
4035                else if (!DIFF_FILE_VALID(p->two))
4036                        p->status = DIFF_STATUS_DELETED;
4037                else if (DIFF_PAIR_TYPE_CHANGED(p))
4038                        p->status = DIFF_STATUS_TYPE_CHANGED;
4039
4040                /* from this point on, we are dealing with a pair
4041                 * whose both sides are valid and of the same type, i.e.
4042                 * either in-place edit or rename/copy edit.
4043                 */
4044                else if (DIFF_PAIR_RENAME(p)) {
4045                        /*
4046                         * A rename might have re-connected a broken
4047                         * pair up, causing the pathnames to be the
4048                         * same again. If so, that's not a rename at
4049                         * all, just a modification..
4050                         *
4051                         * Otherwise, see if this source was used for
4052                         * multiple renames, in which case we decrement
4053                         * the count, and call it a copy.
4054                         */
4055                        if (!strcmp(p->one->path, p->two->path))
4056                                p->status = DIFF_STATUS_MODIFIED;
4057                        else if (--p->one->rename_used > 0)
4058                                p->status = DIFF_STATUS_COPIED;
4059                        else
4060                                p->status = DIFF_STATUS_RENAMED;
4061                }
4062                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4063                         p->one->mode != p->two->mode ||
4064                         p->one->dirty_submodule ||
4065                         p->two->dirty_submodule ||
4066                         is_null_sha1(p->one->sha1))
4067                        p->status = DIFF_STATUS_MODIFIED;
4068                else {
4069                        /* This is a "no-change" entry and should not
4070                         * happen anymore, but prepare for broken callers.
4071                         */
4072                        error("feeding unmodified %s to diffcore",
4073                              p->one->path);
4074                        p->status = DIFF_STATUS_UNKNOWN;
4075                }
4076        }
4077        diff_debug_queue("resolve-rename-copy done", q);
4078}
4079
4080static int check_pair_status(struct diff_filepair *p)
4081{
4082        switch (p->status) {
4083        case DIFF_STATUS_UNKNOWN:
4084                return 0;
4085        case 0:
4086                die("internal error in diff-resolve-rename-copy");
4087        default:
4088                return 1;
4089        }
4090}
4091
4092static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4093{
4094        int fmt = opt->output_format;
4095
4096        if (fmt & DIFF_FORMAT_CHECKDIFF)
4097                diff_flush_checkdiff(p, opt);
4098        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4099                diff_flush_raw(p, opt);
4100        else if (fmt & DIFF_FORMAT_NAME) {
4101                const char *name_a, *name_b;
4102                name_a = p->two->path;
4103                name_b = NULL;
4104                strip_prefix(opt->prefix_length, &name_a, &name_b);
4105                write_name_quoted(name_a, opt->file, opt->line_termination);
4106        }
4107}
4108
4109static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4110{
4111        if (fs->mode)
4112                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4113        else
4114                fprintf(file, " %s ", newdelete);
4115        write_name_quoted(fs->path, file, '\n');
4116}
4117
4118
4119static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4120                const char *line_prefix)
4121{
4122        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4123                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4124                        p->two->mode, show_name ? ' ' : '\n');
4125                if (show_name) {
4126                        write_name_quoted(p->two->path, file, '\n');
4127                }
4128        }
4129}
4130
4131static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4132                        const char *line_prefix)
4133{
4134        char *names = pprint_rename(p->one->path, p->two->path);
4135
4136        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4137        free(names);
4138        show_mode_change(file, p, 0, line_prefix);
4139}
4140
4141static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4142{
4143        FILE *file = opt->file;
4144        char *line_prefix = "";
4145
4146        if (opt->output_prefix) {
4147                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4148                line_prefix = buf->buf;
4149        }
4150
4151        switch(p->status) {
4152        case DIFF_STATUS_DELETED:
4153                fputs(line_prefix, file);
4154                show_file_mode_name(file, "delete", p->one);
4155                break;
4156        case DIFF_STATUS_ADDED:
4157                fputs(line_prefix, file);
4158                show_file_mode_name(file, "create", p->two);
4159                break;
4160        case DIFF_STATUS_COPIED:
4161                fputs(line_prefix, file);
4162                show_rename_copy(file, "copy", p, line_prefix);
4163                break;
4164        case DIFF_STATUS_RENAMED:
4165                fputs(line_prefix, file);
4166                show_rename_copy(file, "rename", p, line_prefix);
4167                break;
4168        default:
4169                if (p->score) {
4170                        fprintf(file, "%s rewrite ", line_prefix);
4171                        write_name_quoted(p->two->path, file, ' ');
4172                        fprintf(file, "(%d%%)\n", similarity_index(p));
4173                }
4174                show_mode_change(file, p, !p->score, line_prefix);
4175                break;
4176        }
4177}
4178
4179struct patch_id_t {
4180        git_SHA_CTX *ctx;
4181        int patchlen;
4182};
4183
4184static int remove_space(char *line, int len)
4185{
4186        int i;
4187        char *dst = line;
4188        unsigned char c;
4189
4190        for (i = 0; i < len; i++)
4191                if (!isspace((c = line[i])))
4192                        *dst++ = c;
4193
4194        return dst - line;
4195}
4196
4197static void patch_id_consume(void *priv, char *line, unsigned long len)
4198{
4199        struct patch_id_t *data = priv;
4200        int new_len;
4201
4202        /* Ignore line numbers when computing the SHA1 of the patch */
4203        if (!prefixcmp(line, "@@ -"))
4204                return;
4205
4206        new_len = remove_space(line, len);
4207
4208        git_SHA1_Update(data->ctx, line, new_len);
4209        data->patchlen += new_len;
4210}
4211
4212/* returns 0 upon success, and writes result into sha1 */
4213static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4214{
4215        struct diff_queue_struct *q = &diff_queued_diff;
4216        int i;
4217        git_SHA_CTX ctx;
4218        struct patch_id_t data;
4219        char buffer[PATH_MAX * 4 + 20];
4220
4221        git_SHA1_Init(&ctx);
4222        memset(&data, 0, sizeof(struct patch_id_t));
4223        data.ctx = &ctx;
4224
4225        for (i = 0; i < q->nr; i++) {
4226                xpparam_t xpp;
4227                xdemitconf_t xecfg;
4228                mmfile_t mf1, mf2;
4229                struct diff_filepair *p = q->queue[i];
4230                int len1, len2;
4231
4232                memset(&xpp, 0, sizeof(xpp));
4233                memset(&xecfg, 0, sizeof(xecfg));
4234                if (p->status == 0)
4235                        return error("internal diff status error");
4236                if (p->status == DIFF_STATUS_UNKNOWN)
4237                        continue;
4238                if (diff_unmodified_pair(p))
4239                        continue;
4240                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4241                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4242                        continue;
4243                if (DIFF_PAIR_UNMERGED(p))
4244                        continue;
4245
4246                diff_fill_sha1_info(p->one);
4247                diff_fill_sha1_info(p->two);
4248                if (fill_mmfile(&mf1, p->one) < 0 ||
4249                                fill_mmfile(&mf2, p->two) < 0)
4250                        return error("unable to read files to diff");
4251
4252                len1 = remove_space(p->one->path, strlen(p->one->path));
4253                len2 = remove_space(p->two->path, strlen(p->two->path));
4254                if (p->one->mode == 0)
4255                        len1 = snprintf(buffer, sizeof(buffer),
4256                                        "diff--gita/%.*sb/%.*s"
4257                                        "newfilemode%06o"
4258                                        "---/dev/null"
4259                                        "+++b/%.*s",
4260                                        len1, p->one->path,
4261                                        len2, p->two->path,
4262                                        p->two->mode,
4263                                        len2, p->two->path);
4264                else if (p->two->mode == 0)
4265                        len1 = snprintf(buffer, sizeof(buffer),
4266                                        "diff--gita/%.*sb/%.*s"
4267                                        "deletedfilemode%06o"
4268                                        "---a/%.*s"
4269                                        "+++/dev/null",
4270                                        len1, p->one->path,
4271                                        len2, p->two->path,
4272                                        p->one->mode,
4273                                        len1, p->one->path);
4274                else
4275                        len1 = snprintf(buffer, sizeof(buffer),
4276                                        "diff--gita/%.*sb/%.*s"
4277                                        "---a/%.*s"
4278                                        "+++b/%.*s",
4279                                        len1, p->one->path,
4280                                        len2, p->two->path,
4281                                        len1, p->one->path,
4282                                        len2, p->two->path);
4283                git_SHA1_Update(&ctx, buffer, len1);
4284
4285                if (diff_filespec_is_binary(p->one) ||
4286                    diff_filespec_is_binary(p->two)) {
4287                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4288                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4289                        continue;
4290                }
4291
4292                xpp.flags = 0;
4293                xecfg.ctxlen = 3;
4294                xecfg.flags = 0;
4295                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4296                              &xpp, &xecfg);
4297        }
4298
4299        git_SHA1_Final(sha1, &ctx);
4300        return 0;
4301}
4302
4303int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4304{
4305        struct diff_queue_struct *q = &diff_queued_diff;
4306        int i;
4307        int result = diff_get_patch_id(options, sha1);
4308
4309        for (i = 0; i < q->nr; i++)
4310                diff_free_filepair(q->queue[i]);
4311
4312        free(q->queue);
4313        DIFF_QUEUE_CLEAR(q);
4314
4315        return result;
4316}
4317
4318static int is_summary_empty(const struct diff_queue_struct *q)
4319{
4320        int i;
4321
4322        for (i = 0; i < q->nr; i++) {
4323                const struct diff_filepair *p = q->queue[i];
4324
4325                switch (p->status) {
4326                case DIFF_STATUS_DELETED:
4327                case DIFF_STATUS_ADDED:
4328                case DIFF_STATUS_COPIED:
4329                case DIFF_STATUS_RENAMED:
4330                        return 0;
4331                default:
4332                        if (p->score)
4333                                return 0;
4334                        if (p->one->mode && p->two->mode &&
4335                            p->one->mode != p->two->mode)
4336                                return 0;
4337                        break;
4338                }
4339        }
4340        return 1;
4341}
4342
4343static const char rename_limit_warning[] =
4344"inexact rename detection was skipped due to too many files.";
4345
4346static const char degrade_cc_to_c_warning[] =
4347"only found copies from modified paths due to too many files.";
4348
4349static const char rename_limit_advice[] =
4350"you may want to set your %s variable to at least "
4351"%d and retry the command.";
4352
4353void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4354{
4355        if (degraded_cc)
4356                warning(degrade_cc_to_c_warning);
4357        else if (needed)
4358                warning(rename_limit_warning);
4359        else
4360                return;
4361        if (0 < needed && needed < 32767)
4362                warning(rename_limit_advice, varname, needed);
4363}
4364
4365void diff_flush(struct diff_options *options)
4366{
4367        struct diff_queue_struct *q = &diff_queued_diff;
4368        int i, output_format = options->output_format;
4369        int separator = 0;
4370        int dirstat_by_line = 0;
4371
4372        /*
4373         * Order: raw, stat, summary, patch
4374         * or:    name/name-status/checkdiff (other bits clear)
4375         */
4376        if (!q->nr)
4377                goto free_queue;
4378
4379        if (output_format & (DIFF_FORMAT_RAW |
4380                             DIFF_FORMAT_NAME |
4381                             DIFF_FORMAT_NAME_STATUS |
4382                             DIFF_FORMAT_CHECKDIFF)) {
4383                for (i = 0; i < q->nr; i++) {
4384                        struct diff_filepair *p = q->queue[i];
4385                        if (check_pair_status(p))
4386                                flush_one_pair(p, options);
4387                }
4388                separator++;
4389        }
4390
4391        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4392                dirstat_by_line = 1;
4393
4394        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4395            dirstat_by_line) {
4396                struct diffstat_t diffstat;
4397
4398                memset(&diffstat, 0, sizeof(struct diffstat_t));
4399                for (i = 0; i < q->nr; i++) {
4400                        struct diff_filepair *p = q->queue[i];
4401                        if (check_pair_status(p))
4402                                diff_flush_stat(p, options, &diffstat);
4403                }
4404                if (output_format & DIFF_FORMAT_NUMSTAT)
4405                        show_numstat(&diffstat, options);
4406                if (output_format & DIFF_FORMAT_DIFFSTAT)
4407                        show_stats(&diffstat, options);
4408                if (output_format & DIFF_FORMAT_SHORTSTAT)
4409                        show_shortstats(&diffstat, options);
4410                if (output_format & DIFF_FORMAT_DIRSTAT)
4411                        show_dirstat_by_line(&diffstat, options);
4412                free_diffstat_info(&diffstat);
4413                separator++;
4414        }
4415        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4416                show_dirstat(options);
4417
4418        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4419                for (i = 0; i < q->nr; i++) {
4420                        diff_summary(options, q->queue[i]);
4421                }
4422                separator++;
4423        }
4424
4425        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4426            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4427            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4428                /*
4429                 * run diff_flush_patch for the exit status. setting
4430                 * options->file to /dev/null should be safe, becaue we
4431                 * aren't supposed to produce any output anyway.
4432                 */
4433                if (options->close_file)
4434                        fclose(options->file);
4435                options->file = fopen("/dev/null", "w");
4436                if (!options->file)
4437                        die_errno("Could not open /dev/null");
4438                options->close_file = 1;
4439                for (i = 0; i < q->nr; i++) {
4440                        struct diff_filepair *p = q->queue[i];
4441                        if (check_pair_status(p))
4442                                diff_flush_patch(p, options);
4443                        if (options->found_changes)
4444                                break;
4445                }
4446        }
4447
4448        if (output_format & DIFF_FORMAT_PATCH) {
4449                if (separator) {
4450                        if (options->output_prefix) {
4451                                struct strbuf *msg = NULL;
4452                                msg = options->output_prefix(options,
4453                                        options->output_prefix_data);
4454                                fwrite(msg->buf, msg->len, 1, stdout);
4455                        }
4456                        putc(options->line_termination, options->file);
4457                        if (options->stat_sep) {
4458                                /* attach patch instead of inline */
4459                                fputs(options->stat_sep, options->file);
4460                        }
4461                }
4462
4463                for (i = 0; i < q->nr; i++) {
4464                        struct diff_filepair *p = q->queue[i];
4465                        if (check_pair_status(p))
4466                                diff_flush_patch(p, options);
4467                }
4468        }
4469
4470        if (output_format & DIFF_FORMAT_CALLBACK)
4471                options->format_callback(q, options, options->format_callback_data);
4472
4473        for (i = 0; i < q->nr; i++)
4474                diff_free_filepair(q->queue[i]);
4475free_queue:
4476        free(q->queue);
4477        DIFF_QUEUE_CLEAR(q);
4478        if (options->close_file)
4479                fclose(options->file);
4480
4481        /*
4482         * Report the content-level differences with HAS_CHANGES;
4483         * diff_addremove/diff_change does not set the bit when
4484         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4485         */
4486        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4487                if (options->found_changes)
4488                        DIFF_OPT_SET(options, HAS_CHANGES);
4489                else
4490                        DIFF_OPT_CLR(options, HAS_CHANGES);
4491        }
4492}
4493
4494static void diffcore_apply_filter(const char *filter)
4495{
4496        int i;
4497        struct diff_queue_struct *q = &diff_queued_diff;
4498        struct diff_queue_struct outq;
4499        DIFF_QUEUE_CLEAR(&outq);
4500
4501        if (!filter)
4502                return;
4503
4504        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4505                int found;
4506                for (i = found = 0; !found && i < q->nr; i++) {
4507                        struct diff_filepair *p = q->queue[i];
4508                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4509                             ((p->score &&
4510                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4511                              (!p->score &&
4512                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4513                            ((p->status != DIFF_STATUS_MODIFIED) &&
4514                             strchr(filter, p->status)))
4515                                found++;
4516                }
4517                if (found)
4518                        return;
4519
4520                /* otherwise we will clear the whole queue
4521                 * by copying the empty outq at the end of this
4522                 * function, but first clear the current entries
4523                 * in the queue.
4524                 */
4525                for (i = 0; i < q->nr; i++)
4526                        diff_free_filepair(q->queue[i]);
4527        }
4528        else {
4529                /* Only the matching ones */
4530                for (i = 0; i < q->nr; i++) {
4531                        struct diff_filepair *p = q->queue[i];
4532
4533                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4534                             ((p->score &&
4535                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4536                              (!p->score &&
4537                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4538                            ((p->status != DIFF_STATUS_MODIFIED) &&
4539                             strchr(filter, p->status)))
4540                                diff_q(&outq, p);
4541                        else
4542                                diff_free_filepair(p);
4543                }
4544        }
4545        free(q->queue);
4546        *q = outq;
4547}
4548
4549/* Check whether two filespecs with the same mode and size are identical */
4550static int diff_filespec_is_identical(struct diff_filespec *one,
4551                                      struct diff_filespec *two)
4552{
4553        if (S_ISGITLINK(one->mode))
4554                return 0;
4555        if (diff_populate_filespec(one, 0))
4556                return 0;
4557        if (diff_populate_filespec(two, 0))
4558                return 0;
4559        return !memcmp(one->data, two->data, one->size);
4560}
4561
4562static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4563{
4564        int i;
4565        struct diff_queue_struct *q = &diff_queued_diff;
4566        struct diff_queue_struct outq;
4567        DIFF_QUEUE_CLEAR(&outq);
4568
4569        for (i = 0; i < q->nr; i++) {
4570                struct diff_filepair *p = q->queue[i];
4571
4572                /*
4573                 * 1. Entries that come from stat info dirtiness
4574                 *    always have both sides (iow, not create/delete),
4575                 *    one side of the object name is unknown, with
4576                 *    the same mode and size.  Keep the ones that
4577                 *    do not match these criteria.  They have real
4578                 *    differences.
4579                 *
4580                 * 2. At this point, the file is known to be modified,
4581                 *    with the same mode and size, and the object
4582                 *    name of one side is unknown.  Need to inspect
4583                 *    the identical contents.
4584                 */
4585                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4586                    !DIFF_FILE_VALID(p->two) ||
4587                    (p->one->sha1_valid && p->two->sha1_valid) ||
4588                    (p->one->mode != p->two->mode) ||
4589                    diff_populate_filespec(p->one, 1) ||
4590                    diff_populate_filespec(p->two, 1) ||
4591                    (p->one->size != p->two->size) ||
4592                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4593                        diff_q(&outq, p);
4594                else {
4595                        /*
4596                         * The caller can subtract 1 from skip_stat_unmatch
4597                         * to determine how many paths were dirty only
4598                         * due to stat info mismatch.
4599                         */
4600                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4601                                diffopt->skip_stat_unmatch++;
4602                        diff_free_filepair(p);
4603                }
4604        }
4605        free(q->queue);
4606        *q = outq;
4607}
4608
4609static int diffnamecmp(const void *a_, const void *b_)
4610{
4611        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4612        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4613        const char *name_a, *name_b;
4614
4615        name_a = a->one ? a->one->path : a->two->path;
4616        name_b = b->one ? b->one->path : b->two->path;
4617        return strcmp(name_a, name_b);
4618}
4619
4620void diffcore_fix_diff_index(struct diff_options *options)
4621{
4622        struct diff_queue_struct *q = &diff_queued_diff;
4623        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4624}
4625
4626void diffcore_std(struct diff_options *options)
4627{
4628        if (options->skip_stat_unmatch)
4629                diffcore_skip_stat_unmatch(options);
4630        if (!options->found_follow) {
4631                /* See try_to_follow_renames() in tree-diff.c */
4632                if (options->break_opt != -1)
4633                        diffcore_break(options->break_opt);
4634                if (options->detect_rename)
4635                        diffcore_rename(options);
4636                if (options->break_opt != -1)
4637                        diffcore_merge_broken();
4638        }
4639        if (options->pickaxe)
4640                diffcore_pickaxe(options);
4641        if (options->orderfile)
4642                diffcore_order(options->orderfile);
4643        if (!options->found_follow)
4644                /* See try_to_follow_renames() in tree-diff.c */
4645                diff_resolve_rename_copy();
4646        diffcore_apply_filter(options->filter);
4647
4648        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4649                DIFF_OPT_SET(options, HAS_CHANGES);
4650        else
4651                DIFF_OPT_CLR(options, HAS_CHANGES);
4652
4653        options->found_follow = 0;
4654}
4655
4656int diff_result_code(struct diff_options *opt, int status)
4657{
4658        int result = 0;
4659
4660        diff_warn_rename_limit("diff.renamelimit",
4661                               opt->needed_rename_limit,
4662                               opt->degraded_cc_to_c);
4663        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4664            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4665                return status;
4666        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4667            DIFF_OPT_TST(opt, HAS_CHANGES))
4668                result |= 01;
4669        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4670            DIFF_OPT_TST(opt, CHECK_FAILED))
4671                result |= 02;
4672        return result;
4673}
4674
4675int diff_can_quit_early(struct diff_options *opt)
4676{
4677        return (DIFF_OPT_TST(opt, QUICK) &&
4678                !opt->filter &&
4679                DIFF_OPT_TST(opt, HAS_CHANGES));
4680}
4681
4682/*
4683 * Shall changes to this submodule be ignored?
4684 *
4685 * Submodule changes can be configured to be ignored separately for each path,
4686 * but that configuration can be overridden from the command line.
4687 */
4688static int is_submodule_ignored(const char *path, struct diff_options *options)
4689{
4690        int ignored = 0;
4691        unsigned orig_flags = options->flags;
4692        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4693                set_diffopt_flags_from_submodule_config(options, path);
4694        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4695                ignored = 1;
4696        options->flags = orig_flags;
4697        return ignored;
4698}
4699
4700void diff_addremove(struct diff_options *options,
4701                    int addremove, unsigned mode,
4702                    const unsigned char *sha1,
4703                    int sha1_valid,
4704                    const char *concatpath, unsigned dirty_submodule)
4705{
4706        struct diff_filespec *one, *two;
4707
4708        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4709                return;
4710
4711        /* This may look odd, but it is a preparation for
4712         * feeding "there are unchanged files which should
4713         * not produce diffs, but when you are doing copy
4714         * detection you would need them, so here they are"
4715         * entries to the diff-core.  They will be prefixed
4716         * with something like '=' or '*' (I haven't decided
4717         * which but should not make any difference).
4718         * Feeding the same new and old to diff_change()
4719         * also has the same effect.
4720         * Before the final output happens, they are pruned after
4721         * merged into rename/copy pairs as appropriate.
4722         */
4723        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4724                addremove = (addremove == '+' ? '-' :
4725                             addremove == '-' ? '+' : addremove);
4726
4727        if (options->prefix &&
4728            strncmp(concatpath, options->prefix, options->prefix_length))
4729                return;
4730
4731        one = alloc_filespec(concatpath);
4732        two = alloc_filespec(concatpath);
4733
4734        if (addremove != '+')
4735                fill_filespec(one, sha1, sha1_valid, mode);
4736        if (addremove != '-') {
4737                fill_filespec(two, sha1, sha1_valid, mode);
4738                two->dirty_submodule = dirty_submodule;
4739        }
4740
4741        diff_queue(&diff_queued_diff, one, two);
4742        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4743                DIFF_OPT_SET(options, HAS_CHANGES);
4744}
4745
4746void diff_change(struct diff_options *options,
4747                 unsigned old_mode, unsigned new_mode,
4748                 const unsigned char *old_sha1,
4749                 const unsigned char *new_sha1,
4750                 int old_sha1_valid, int new_sha1_valid,
4751                 const char *concatpath,
4752                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4753{
4754        struct diff_filespec *one, *two;
4755
4756        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4757            is_submodule_ignored(concatpath, options))
4758                return;
4759
4760        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4761                unsigned tmp;
4762                const unsigned char *tmp_c;
4763                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4764                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4765                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4766                        new_sha1_valid = tmp;
4767                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4768                        new_dirty_submodule = tmp;
4769        }
4770
4771        if (options->prefix &&
4772            strncmp(concatpath, options->prefix, options->prefix_length))
4773                return;
4774
4775        one = alloc_filespec(concatpath);
4776        two = alloc_filespec(concatpath);
4777        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4778        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4779        one->dirty_submodule = old_dirty_submodule;
4780        two->dirty_submodule = new_dirty_submodule;
4781
4782        diff_queue(&diff_queued_diff, one, two);
4783        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4784                DIFF_OPT_SET(options, HAS_CHANGES);
4785}
4786
4787struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4788{
4789        struct diff_filepair *pair;
4790        struct diff_filespec *one, *two;
4791
4792        if (options->prefix &&
4793            strncmp(path, options->prefix, options->prefix_length))
4794                return NULL;
4795
4796        one = alloc_filespec(path);
4797        two = alloc_filespec(path);
4798        pair = diff_queue(&diff_queued_diff, one, two);
4799        pair->is_unmerged = 1;
4800        return pair;
4801}
4802
4803static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4804                size_t *outsize)
4805{
4806        struct diff_tempfile *temp;
4807        const char *argv[3];
4808        const char **arg = argv;
4809        struct child_process child;
4810        struct strbuf buf = STRBUF_INIT;
4811        int err = 0;
4812
4813        temp = prepare_temp_file(spec->path, spec);
4814        *arg++ = pgm;
4815        *arg++ = temp->name;
4816        *arg = NULL;
4817
4818        memset(&child, 0, sizeof(child));
4819        child.use_shell = 1;
4820        child.argv = argv;
4821        child.out = -1;
4822        if (start_command(&child)) {
4823                remove_tempfile();
4824                return NULL;
4825        }
4826
4827        if (strbuf_read(&buf, child.out, 0) < 0)
4828                err = error("error reading from textconv command '%s'", pgm);
4829        close(child.out);
4830
4831        if (finish_command(&child) || err) {
4832                strbuf_release(&buf);
4833                remove_tempfile();
4834                return NULL;
4835        }
4836        remove_tempfile();
4837
4838        return strbuf_detach(&buf, outsize);
4839}
4840
4841size_t fill_textconv(struct userdiff_driver *driver,
4842                     struct diff_filespec *df,
4843                     char **outbuf)
4844{
4845        size_t size;
4846
4847        if (!driver || !driver->textconv) {
4848                if (!DIFF_FILE_VALID(df)) {
4849                        *outbuf = "";
4850                        return 0;
4851                }
4852                if (diff_populate_filespec(df, 0))
4853                        die("unable to read files to diff");
4854                *outbuf = df->data;
4855                return df->size;
4856        }
4857
4858        if (driver->textconv_cache && df->sha1_valid) {
4859                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4860                                          &size);
4861                if (*outbuf)
4862                        return size;
4863        }
4864
4865        *outbuf = run_textconv(driver->textconv, df, &size);
4866        if (!*outbuf)
4867                die("unable to read files to diff");
4868
4869        if (driver->textconv_cache && df->sha1_valid) {
4870                /* ignore errors, as we might be in a readonly repository */
4871                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4872                                size);
4873                /*
4874                 * we could save up changes and flush them all at the end,
4875                 * but we would need an extra call after all diffing is done.
4876                 * Since generating a cache entry is the slow path anyway,
4877                 * this extra overhead probably isn't a big deal.
4878                 */
4879                notes_cache_write(driver->textconv_cache);
4880        }
4881
4882        return size;
4883}