diff-lib.con commit git-svn: handle our top-level path being deleted and later re-added (12a6d75)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "commit.h"
   7#include "diff.h"
   8#include "diffcore.h"
   9#include "revision.h"
  10#include "cache-tree.h"
  11#include "path-list.h"
  12
  13/*
  14 * diff-files
  15 */
  16
  17static int read_directory(const char *path, struct path_list *list)
  18{
  19        DIR *dir;
  20        struct dirent *e;
  21
  22        if (!(dir = opendir(path)))
  23                return error("Could not open directory %s", path);
  24
  25        while ((e = readdir(dir)))
  26                if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
  27                        path_list_insert(e->d_name, list);
  28
  29        closedir(dir);
  30        return 0;
  31}
  32
  33static int get_mode(const char *path, int *mode)
  34{
  35        struct stat st;
  36
  37        if (!path || !strcmp(path, "/dev/null"))
  38                *mode = 0;
  39        else if (!strcmp(path, "-"))
  40                *mode = ntohl(create_ce_mode(0666));
  41        else if (stat(path, &st))
  42                return error("Could not access '%s'", path);
  43        else
  44                *mode = st.st_mode;
  45        return 0;
  46}
  47
  48static int queue_diff(struct diff_options *o,
  49                const char *name1, const char *name2)
  50{
  51        int mode1 = 0, mode2 = 0;
  52
  53        if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
  54                return -1;
  55
  56        if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
  57                return error("file/directory conflict: %s, %s", name1, name2);
  58
  59        if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
  60                char buffer1[PATH_MAX], buffer2[PATH_MAX];
  61                struct path_list p1 = {NULL, 0, 0, 1}, p2 = {NULL, 0, 0, 1};
  62                int len1 = 0, len2 = 0, i1, i2, ret = 0;
  63
  64                if (name1 && read_directory(name1, &p1))
  65                        return -1;
  66                if (name2 && read_directory(name2, &p2)) {
  67                        path_list_clear(&p1, 0);
  68                        return -1;
  69                }
  70
  71                if (name1) {
  72                        len1 = strlen(name1);
  73                        if (len1 > 0 && name1[len1 - 1] == '/')
  74                                len1--;
  75                        memcpy(buffer1, name1, len1);
  76                        buffer1[len1++] = '/';
  77                }
  78
  79                if (name2) {
  80                        len2 = strlen(name2);
  81                        if (len2 > 0 && name2[len2 - 1] == '/')
  82                                len2--;
  83                        memcpy(buffer2, name2, len2);
  84                        buffer2[len2++] = '/';
  85                }
  86
  87                for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
  88                        const char *n1, *n2;
  89                        int comp;
  90
  91                        if (i1 == p1.nr)
  92                                comp = 1;
  93                        else if (i2 == p2.nr)
  94                                comp = -1;
  95                        else
  96                                comp = strcmp(p1.items[i1].path,
  97                                        p2.items[i2].path);
  98
  99                        if (comp > 0)
 100                                n1 = NULL;
 101                        else {
 102                                n1 = buffer1;
 103                                strncpy(buffer1 + len1, p1.items[i1++].path,
 104                                                PATH_MAX - len1);
 105                        }
 106
 107                        if (comp < 0)
 108                                n2 = NULL;
 109                        else {
 110                                n2 = buffer2;
 111                                strncpy(buffer2 + len2, p2.items[i2++].path,
 112                                                PATH_MAX - len2);
 113                        }
 114
 115                        ret = queue_diff(o, n1, n2);
 116                }
 117                path_list_clear(&p1, 0);
 118                path_list_clear(&p2, 0);
 119
 120                return ret;
 121        } else {
 122                struct diff_filespec *d1, *d2;
 123
 124                if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
 125                        unsigned tmp;
 126                        const char *tmp_c;
 127                        tmp = mode1; mode1 = mode2; mode2 = tmp;
 128                        tmp_c = name1; name1 = name2; name2 = tmp_c;
 129                }
 130
 131                if (!name1)
 132                        name1 = "/dev/null";
 133                if (!name2)
 134                        name2 = "/dev/null";
 135                d1 = alloc_filespec(name1);
 136                d2 = alloc_filespec(name2);
 137                fill_filespec(d1, null_sha1, mode1);
 138                fill_filespec(d2, null_sha1, mode2);
 139
 140                diff_queue(&diff_queued_diff, d1, d2);
 141                return 0;
 142        }
 143}
 144
 145/*
 146 * Does the path name a blob in the working tree, or a directory
 147 * in the working tree?
 148 */
 149static int is_in_index(const char *path)
 150{
 151        int len, pos;
 152        struct cache_entry *ce;
 153
 154        len = strlen(path);
 155        while (path[len-1] == '/')
 156                len--;
 157        if (!len)
 158                return 1; /* "." */
 159        pos = cache_name_pos(path, len);
 160        if (0 <= pos)
 161                return 1;
 162        pos = -1 - pos;
 163        while (pos < active_nr) {
 164                ce = active_cache[pos++];
 165                if (ce_namelen(ce) <= len ||
 166                    strncmp(ce->name, path, len) ||
 167                    (ce->name[len] > '/'))
 168                        break; /* path cannot be a prefix */
 169                if (ce->name[len] == '/')
 170                        return 1;
 171        }
 172        return 0;
 173}
 174
 175static int handle_diff_files_args(struct rev_info *revs,
 176                                  int argc, const char **argv,
 177                                  unsigned int *options)
 178{
 179        *options = 0;
 180
 181        /* revs->max_count == -2 means --no-index */
 182        while (1 < argc && argv[1][0] == '-') {
 183                if (!strcmp(argv[1], "--base"))
 184                        revs->max_count = 1;
 185                else if (!strcmp(argv[1], "--ours"))
 186                        revs->max_count = 2;
 187                else if (!strcmp(argv[1], "--theirs"))
 188                        revs->max_count = 3;
 189                else if (!strcmp(argv[1], "-n") ||
 190                                !strcmp(argv[1], "--no-index")) {
 191                        revs->max_count = -2;
 192                        DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
 193                        DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
 194                }
 195                else if (!strcmp(argv[1], "-q"))
 196                        *options |= DIFF_SILENT_ON_REMOVED;
 197                else
 198                        return error("invalid option: %s", argv[1]);
 199                argv++; argc--;
 200        }
 201
 202        if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
 203                /*
 204                 * If two files are specified, and at least one is untracked,
 205                 * default to no-index.
 206                 */
 207                read_cache();
 208                if (!is_in_index(revs->diffopt.paths[0]) ||
 209                                        !is_in_index(revs->diffopt.paths[1])) {
 210                        revs->max_count = -2;
 211                        DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
 212                }
 213        }
 214
 215        /*
 216         * Make sure there are NO revision (i.e. pending object) parameter,
 217         * rev.max_count is reasonable (0 <= n <= 3),
 218         * there is no other revision filtering parameters.
 219         */
 220        if (revs->pending.nr || revs->max_count > 3 ||
 221            revs->min_age != -1 || revs->max_age != -1)
 222                return error("no revision allowed with diff-files");
 223
 224        if (revs->max_count == -1 &&
 225            (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 226                revs->combine_merges = revs->dense_combined_merges = 1;
 227
 228        return 0;
 229}
 230
 231static int is_outside_repo(const char *path, int nongit, const char *prefix)
 232{
 233        int i;
 234        if (nongit || !strcmp(path, "-") || is_absolute_path(path))
 235                return 1;
 236        if (prefixcmp(path, "../"))
 237                return 0;
 238        if (!prefix)
 239                return 1;
 240        for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
 241                while (i > 0 && prefix[i - 1] != '/')
 242                        i--;
 243                if (--i < 0)
 244                        return 1;
 245                path += 3;
 246        }
 247        return 0;
 248}
 249
 250int setup_diff_no_index(struct rev_info *revs,
 251                int argc, const char ** argv, int nongit, const char *prefix)
 252{
 253        int i;
 254        for (i = 1; i < argc; i++)
 255                if (argv[i][0] != '-' || argv[i][1] == '\0')
 256                        break;
 257                else if (!strcmp(argv[i], "--")) {
 258                        i++;
 259                        break;
 260                } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
 261                        i = argc - 3;
 262                        DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
 263                        break;
 264                }
 265        if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
 266                                !is_outside_repo(argv[i], nongit, prefix)))
 267                return -1;
 268
 269        diff_setup(&revs->diffopt);
 270        for (i = 1; i < argc - 2; )
 271                if (!strcmp(argv[i], "--no-index"))
 272                        i++;
 273                else {
 274                        int j = diff_opt_parse(&revs->diffopt,
 275                                        argv + i, argc - i);
 276                        if (!j)
 277                                die("invalid diff option/value: %s", argv[i]);
 278                        i += j;
 279                }
 280
 281        if (prefix) {
 282                int len = strlen(prefix);
 283
 284                revs->diffopt.paths = xcalloc(2, sizeof(char*));
 285                for (i = 0; i < 2; i++) {
 286                        const char *p = argv[argc - 2 + i];
 287                        /*
 288                         * stdin should be spelled as '-'; if you have
 289                         * path that is '-', spell it as ./-.
 290                         */
 291                        p = (strcmp(p, "-")
 292                             ? xstrdup(prefix_filename(prefix, len, p))
 293                             : p);
 294                        revs->diffopt.paths[i] = p;
 295                }
 296        }
 297        else
 298                revs->diffopt.paths = argv + argc - 2;
 299        revs->diffopt.nr_paths = 2;
 300        DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
 301        revs->max_count = -2;
 302        if (diff_setup_done(&revs->diffopt) < 0)
 303                die("diff_setup_done failed");
 304        return 0;
 305}
 306
 307int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
 308{
 309        unsigned int options;
 310
 311        if (handle_diff_files_args(revs, argc, argv, &options))
 312                return -1;
 313
 314        if (DIFF_OPT_TST(&revs->diffopt, NO_INDEX)) {
 315                if (revs->diffopt.nr_paths != 2)
 316                        return error("need two files/directories with --no-index");
 317                if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
 318                                revs->diffopt.paths[1]))
 319                        return -1;
 320                diffcore_std(&revs->diffopt);
 321                diff_flush(&revs->diffopt);
 322                /*
 323                 * The return code for --no-index imitates diff(1):
 324                 * 0 = no changes, 1 = changes, else error
 325                 */
 326                return revs->diffopt.found_changes;
 327        }
 328
 329        if (read_cache() < 0) {
 330                perror("read_cache");
 331                return -1;
 332        }
 333        return run_diff_files(revs, options);
 334}
 335
 336int run_diff_files(struct rev_info *revs, unsigned int option)
 337{
 338        int entries, i;
 339        int diff_unmerged_stage = revs->max_count;
 340        int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
 341        unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
 342                              ? CE_MATCH_RACY_IS_DIRTY : 0);
 343
 344        if (diff_unmerged_stage < 0)
 345                diff_unmerged_stage = 2;
 346        entries = active_nr;
 347        for (i = 0; i < entries; i++) {
 348                struct stat st;
 349                unsigned int oldmode, newmode;
 350                struct cache_entry *ce = active_cache[i];
 351                int changed;
 352
 353                if (DIFF_OPT_TST(&revs->diffopt, QUIET) &&
 354                        DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
 355                        break;
 356
 357                if (!ce_path_match(ce, revs->prune_data))
 358                        continue;
 359
 360                if (ce_stage(ce)) {
 361                        struct combine_diff_path *dpath;
 362                        int num_compare_stages = 0;
 363                        size_t path_len;
 364
 365                        path_len = ce_namelen(ce);
 366
 367                        dpath = xmalloc(combine_diff_path_size(5, path_len));
 368                        dpath->path = (char *) &(dpath->parent[5]);
 369
 370                        dpath->next = NULL;
 371                        dpath->len = path_len;
 372                        memcpy(dpath->path, ce->name, path_len);
 373                        dpath->path[path_len] = '\0';
 374                        hashclr(dpath->sha1);
 375                        memset(&(dpath->parent[0]), 0,
 376                               sizeof(struct combine_diff_parent)*5);
 377
 378                        if (lstat(ce->name, &st) < 0) {
 379                                if (errno != ENOENT && errno != ENOTDIR) {
 380                                        perror(ce->name);
 381                                        continue;
 382                                }
 383                                if (silent_on_removed)
 384                                        continue;
 385                        }
 386                        else
 387                                dpath->mode = ntohl(ce_mode_from_stat(ce, st.st_mode));
 388
 389                        while (i < entries) {
 390                                struct cache_entry *nce = active_cache[i];
 391                                int stage;
 392
 393                                if (strcmp(ce->name, nce->name))
 394                                        break;
 395
 396                                /* Stage #2 (ours) is the first parent,
 397                                 * stage #3 (theirs) is the second.
 398                                 */
 399                                stage = ce_stage(nce);
 400                                if (2 <= stage) {
 401                                        int mode = ntohl(nce->ce_mode);
 402                                        num_compare_stages++;
 403                                        hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 404                                        dpath->parent[stage-2].mode = ntohl(ce_mode_from_stat(nce, mode));
 405                                        dpath->parent[stage-2].status =
 406                                                DIFF_STATUS_MODIFIED;
 407                                }
 408
 409                                /* diff against the proper unmerged stage */
 410                                if (stage == diff_unmerged_stage)
 411                                        ce = nce;
 412                                i++;
 413                        }
 414                        /*
 415                         * Compensate for loop update
 416                         */
 417                        i--;
 418
 419                        if (revs->combine_merges && num_compare_stages == 2) {
 420                                show_combined_diff(dpath, 2,
 421                                                   revs->dense_combined_merges,
 422                                                   revs);
 423                                free(dpath);
 424                                continue;
 425                        }
 426                        free(dpath);
 427                        dpath = NULL;
 428
 429                        /*
 430                         * Show the diff for the 'ce' if we found the one
 431                         * from the desired stage.
 432                         */
 433                        diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
 434                        if (ce_stage(ce) != diff_unmerged_stage)
 435                                continue;
 436                }
 437
 438                if (lstat(ce->name, &st) < 0) {
 439                        if (errno != ENOENT && errno != ENOTDIR) {
 440                                perror(ce->name);
 441                                continue;
 442                        }
 443                        if (silent_on_removed)
 444                                continue;
 445                        diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
 446                                       ce->sha1, ce->name, NULL);
 447                        continue;
 448                }
 449                changed = ce_match_stat(ce, &st, ce_option);
 450                if (!changed && !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 451                        continue;
 452                oldmode = ntohl(ce->ce_mode);
 453                newmode = ntohl(ce_mode_from_stat(ce, st.st_mode));
 454                diff_change(&revs->diffopt, oldmode, newmode,
 455                            ce->sha1, (changed ? null_sha1 : ce->sha1),
 456                            ce->name, NULL);
 457
 458        }
 459        diffcore_std(&revs->diffopt);
 460        diff_flush(&revs->diffopt);
 461        return 0;
 462}
 463
 464/*
 465 * diff-index
 466 */
 467
 468/* A file entry went away or appeared */
 469static void diff_index_show_file(struct rev_info *revs,
 470                                 const char *prefix,
 471                                 struct cache_entry *ce,
 472                                 unsigned char *sha1, unsigned int mode)
 473{
 474        diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
 475                       sha1, ce->name, NULL);
 476}
 477
 478static int get_stat_data(struct cache_entry *ce,
 479                         unsigned char **sha1p,
 480                         unsigned int *modep,
 481                         int cached, int match_missing)
 482{
 483        unsigned char *sha1 = ce->sha1;
 484        unsigned int mode = ce->ce_mode;
 485
 486        if (!cached) {
 487                static unsigned char no_sha1[20];
 488                int changed;
 489                struct stat st;
 490                if (lstat(ce->name, &st) < 0) {
 491                        if (errno == ENOENT && match_missing) {
 492                                *sha1p = sha1;
 493                                *modep = mode;
 494                                return 0;
 495                        }
 496                        return -1;
 497                }
 498                changed = ce_match_stat(ce, &st, 0);
 499                if (changed) {
 500                        mode = ce_mode_from_stat(ce, st.st_mode);
 501                        sha1 = no_sha1;
 502                }
 503        }
 504
 505        *sha1p = sha1;
 506        *modep = mode;
 507        return 0;
 508}
 509
 510static void show_new_file(struct rev_info *revs,
 511                          struct cache_entry *new,
 512                          int cached, int match_missing)
 513{
 514        unsigned char *sha1;
 515        unsigned int mode;
 516
 517        /* New file in the index: it might actually be different in
 518         * the working copy.
 519         */
 520        if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
 521                return;
 522
 523        diff_index_show_file(revs, "+", new, sha1, mode);
 524}
 525
 526static int show_modified(struct rev_info *revs,
 527                         struct cache_entry *old,
 528                         struct cache_entry *new,
 529                         int report_missing,
 530                         int cached, int match_missing)
 531{
 532        unsigned int mode, oldmode;
 533        unsigned char *sha1;
 534
 535        if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
 536                if (report_missing)
 537                        diff_index_show_file(revs, "-", old,
 538                                             old->sha1, old->ce_mode);
 539                return -1;
 540        }
 541
 542        if (revs->combine_merges && !cached &&
 543            (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 544                struct combine_diff_path *p;
 545                int pathlen = ce_namelen(new);
 546
 547                p = xmalloc(combine_diff_path_size(2, pathlen));
 548                p->path = (char *) &p->parent[2];
 549                p->next = NULL;
 550                p->len = pathlen;
 551                memcpy(p->path, new->name, pathlen);
 552                p->path[pathlen] = 0;
 553                p->mode = ntohl(mode);
 554                hashclr(p->sha1);
 555                memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 556                p->parent[0].status = DIFF_STATUS_MODIFIED;
 557                p->parent[0].mode = ntohl(new->ce_mode);
 558                hashcpy(p->parent[0].sha1, new->sha1);
 559                p->parent[1].status = DIFF_STATUS_MODIFIED;
 560                p->parent[1].mode = ntohl(old->ce_mode);
 561                hashcpy(p->parent[1].sha1, old->sha1);
 562                show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 563                free(p);
 564                return 0;
 565        }
 566
 567        oldmode = old->ce_mode;
 568        if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 569            !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 570                return 0;
 571
 572        mode = ntohl(mode);
 573        oldmode = ntohl(oldmode);
 574
 575        diff_change(&revs->diffopt, oldmode, mode,
 576                    old->sha1, sha1, old->name, NULL);
 577        return 0;
 578}
 579
 580static int diff_cache(struct rev_info *revs,
 581                      struct cache_entry **ac, int entries,
 582                      const char **pathspec,
 583                      int cached, int match_missing)
 584{
 585        while (entries) {
 586                struct cache_entry *ce = *ac;
 587                int same = (entries > 1) && ce_same_name(ce, ac[1]);
 588
 589                if (DIFF_OPT_TST(&revs->diffopt, QUIET) &&
 590                        DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
 591                        break;
 592
 593                if (!ce_path_match(ce, pathspec))
 594                        goto skip_entry;
 595
 596                switch (ce_stage(ce)) {
 597                case 0:
 598                        /* No stage 1 entry? That means it's a new file */
 599                        if (!same) {
 600                                show_new_file(revs, ce, cached, match_missing);
 601                                break;
 602                        }
 603                        /* Show difference between old and new */
 604                        show_modified(revs, ac[1], ce, 1,
 605                                      cached, match_missing);
 606                        break;
 607                case 1:
 608                        /* No stage 3 (merge) entry?
 609                         * That means it's been deleted.
 610                         */
 611                        if (!same) {
 612                                diff_index_show_file(revs, "-", ce,
 613                                                     ce->sha1, ce->ce_mode);
 614                                break;
 615                        }
 616                        /* We come here with ce pointing at stage 1
 617                         * (original tree) and ac[1] pointing at stage
 618                         * 3 (unmerged).  show-modified with
 619                         * report-missing set to false does not say the
 620                         * file is deleted but reports true if work
 621                         * tree does not have it, in which case we
 622                         * fall through to report the unmerged state.
 623                         * Otherwise, we show the differences between
 624                         * the original tree and the work tree.
 625                         */
 626                        if (!cached &&
 627                            !show_modified(revs, ce, ac[1], 0,
 628                                           cached, match_missing))
 629                                break;
 630                        diff_unmerge(&revs->diffopt, ce->name,
 631                                     ntohl(ce->ce_mode), ce->sha1);
 632                        break;
 633                case 3:
 634                        diff_unmerge(&revs->diffopt, ce->name,
 635                                     0, null_sha1);
 636                        break;
 637
 638                default:
 639                        die("impossible cache entry stage");
 640                }
 641
 642skip_entry:
 643                /*
 644                 * Ignore all the different stages for this file,
 645                 * we've handled the relevant cases now.
 646                 */
 647                do {
 648                        ac++;
 649                        entries--;
 650                } while (entries && ce_same_name(ce, ac[0]));
 651        }
 652        return 0;
 653}
 654
 655/*
 656 * This turns all merge entries into "stage 3". That guarantees that
 657 * when we read in the new tree (into "stage 1"), we won't lose sight
 658 * of the fact that we had unmerged entries.
 659 */
 660static void mark_merge_entries(void)
 661{
 662        int i;
 663        for (i = 0; i < active_nr; i++) {
 664                struct cache_entry *ce = active_cache[i];
 665                if (!ce_stage(ce))
 666                        continue;
 667                ce->ce_flags |= htons(CE_STAGEMASK);
 668        }
 669}
 670
 671int run_diff_index(struct rev_info *revs, int cached)
 672{
 673        int ret;
 674        struct object *ent;
 675        struct tree *tree;
 676        const char *tree_name;
 677        int match_missing = 0;
 678
 679        /*
 680         * Backward compatibility wart - "diff-index -m" does
 681         * not mean "do not ignore merges", but totally different.
 682         */
 683        if (!revs->ignore_merges)
 684                match_missing = 1;
 685
 686        mark_merge_entries();
 687
 688        ent = revs->pending.objects[0].item;
 689        tree_name = revs->pending.objects[0].name;
 690        tree = parse_tree_indirect(ent->sha1);
 691        if (!tree)
 692                return error("bad tree object %s", tree_name);
 693        if (read_tree(tree, 1, revs->prune_data))
 694                return error("unable to read tree object %s", tree_name);
 695        ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
 696                         cached, match_missing);
 697        diffcore_std(&revs->diffopt);
 698        diff_flush(&revs->diffopt);
 699        return ret;
 700}
 701
 702int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 703{
 704        struct tree *tree;
 705        struct rev_info revs;
 706        int i;
 707        struct cache_entry **dst;
 708        struct cache_entry *last = NULL;
 709
 710        /*
 711         * This is used by git-blame to run diff-cache internally;
 712         * it potentially needs to repeatedly run this, so we will
 713         * start by removing the higher order entries the last round
 714         * left behind.
 715         */
 716        dst = active_cache;
 717        for (i = 0; i < active_nr; i++) {
 718                struct cache_entry *ce = active_cache[i];
 719                if (ce_stage(ce)) {
 720                        if (last && !strcmp(ce->name, last->name))
 721                                continue;
 722                        cache_tree_invalidate_path(active_cache_tree,
 723                                                   ce->name);
 724                        last = ce;
 725                        ce->ce_mode = 0;
 726                        ce->ce_flags &= ~htons(CE_STAGEMASK);
 727                }
 728                *dst++ = ce;
 729        }
 730        active_nr = dst - active_cache;
 731
 732        init_revisions(&revs, NULL);
 733        revs.prune_data = opt->paths;
 734        tree = parse_tree_indirect(tree_sha1);
 735        if (!tree)
 736                die("bad tree object %s", sha1_to_hex(tree_sha1));
 737        if (read_tree(tree, 1, opt->paths))
 738                return error("unable to read tree %s", sha1_to_hex(tree_sha1));
 739        return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
 740                          1, 0);
 741}