diff-lib.c

   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
  17 static 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(xstrdup(e->d_name), list);
  28
  29         closedir(dir);
  30         return 0;
  31 }
  32
  33 static 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
  48 static 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 (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 static int is_in_index(const char *path)
 146 {
 147         int len = strlen(path);
 148         int pos = cache_name_pos(path, len);
 149         char c;
 150
 151         if (pos < 0)
 152                 return 0;
 153         if (strncmp(active_cache[pos]->name, path, len))
 154                 return 0;
 155         c = active_cache[pos]->name[len];
 156         return c == '\0' || c == '/';
 157 }
 158
 159 static int handle_diff_files_args(struct rev_info *revs,
 160                 int argc, const char **argv, int *silent)
 161 {
 162         *silent = 0;
 163
 164         /* revs->max_count == -2 means --no-index */
 165         while (1 < argc && argv[1][0] == '-') {
 166                 if (!strcmp(argv[1], "--base"))
 167                         revs->max_count = 1;
 168                 else if (!strcmp(argv[1], "--ours"))
 169                         revs->max_count = 2;
 170                 else if (!strcmp(argv[1], "--theirs"))
 171                         revs->max_count = 3;
 172                 else if (!strcmp(argv[1], "-n") ||
 173                                 !strcmp(argv[1], "--no-index")) {
 174                         revs->max_count = -2;
 175                         revs->diffopt.exit_with_status = 1;
 176                 }
 177                 else if (!strcmp(argv[1], "-q"))
 178                         *silent = 1;
 179                 else
 180                         return error("invalid option: %s", argv[1]);
 181                 argv++; argc--;
 182         }
 183
 184         if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
 185                 /*
 186                  * If two files are specified, and at least one is untracked,
 187                  * default to no-index.
 188                  */
 189                 read_cache();
 190                 if (!is_in_index(revs->diffopt.paths[0]) ||
 191                                         !is_in_index(revs->diffopt.paths[1]))
 192                         revs->max_count = -2;
 193         }
 194
 195         /*
 196          * Make sure there are NO revision (i.e. pending object) parameter,
 197          * rev.max_count is reasonable (0 <= n <= 3),
 198          * there is no other revision filtering parameters.
 199          */
 200         if (revs->pending.nr || revs->max_count > 3 ||
 201             revs->min_age != -1 || revs->max_age != -1)
 202                 return error("no revision allowed with diff-files");
 203
 204         if (revs->max_count == -1 &&
 205             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 206                 revs->combine_merges = revs->dense_combined_merges = 1;
 207
 208         return 0;
 209 }
 210
 211 static int is_outside_repo(const char *path, int nongit, const char *prefix)
 212 {
 213         int i;
 214         if (nongit || !strcmp(path, "-") || path[0] == '/')
 215                 return 1;
 216         if (prefixcmp(path, "../"))
 217                 return 0;
 218         if (!prefix)
 219                 return 1;
 220         for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
 221                 while (i > 0 && prefix[i - 1] != '/')
 222                         i--;
 223                 if (--i < 0)
 224                         return 1;
 225                 path += 3;
 226         }
 227         return 0;
 228 }
 229
 230 int setup_diff_no_index(struct rev_info *revs,
 231                 int argc, const char ** argv, int nongit, const char *prefix)
 232 {
 233         int i;
 234         for (i = 1; i < argc; i++)
 235                 if (argv[i][0] != '-' || argv[i][1] == '\0')
 236                         break;
 237                 else if (!strcmp(argv[i], "--")) {
 238                         i++;
 239                         break;
 240                 } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
 241                         i = argc - 3;
 242                         revs->diffopt.exit_with_status = 1;
 243                         break;
 244                 }
 245         if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
 246                                 !is_outside_repo(argv[i], nongit, prefix)))
 247                 return -1;
 248
 249         diff_setup(&revs->diffopt);
 250         for (i = 1; i < argc - 2; )
 251                 if (!strcmp(argv[i], "--no-index"))
 252                         i++;
 253                 else {
 254                         int j = diff_opt_parse(&revs->diffopt,
 255                                         argv + i, argc - i);
 256                         if (!j)
 257                                 die("invalid diff option/value: %s", argv[i]);
 258                         i += j;
 259                 }
 260
 261         if (prefix) {
 262                 int len = strlen(prefix);
 263
 264                 revs->diffopt.paths = xcalloc(2, sizeof(char*));
 265                 for (i = 0; i < 2; i++) {
 266                         const char *p = argv[argc - 2 + i];
 267                         /*
 268                          * stdin should be spelled as '-'; if you have
 269                          * path that is '-', spell it as ./-.
 270                          */
 271                         p = (strcmp(p, "-")
 272                              ? xstrdup(prefix_filename(prefix, len, p))
 273                              : p);
 274                         revs->diffopt.paths[i] = p;
 275                 }
 276         }
 277         else
 278                 revs->diffopt.paths = argv + argc - 2;
 279         revs->diffopt.nr_paths = 2;
 280         revs->max_count = -2;
 281         return 0;
 282 }
 283
 284 int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
 285 {
 286         int silent_on_removed;
 287
 288         if (handle_diff_files_args(revs, argc, argv, &silent_on_removed))
 289                 return -1;
 290
 291         if (revs->max_count == -2) {
 292                 if (revs->diffopt.nr_paths != 2)
 293                         return error("need two files/directories with --no-index");
 294                 if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
 295                                 revs->diffopt.paths[1]))
 296                         return -1;
 297                 diffcore_std(&revs->diffopt);
 298                 diff_flush(&revs->diffopt);
 299                 /*
 300                  * The return code for --no-index imitates diff(1):
 301                  * 0 = no changes, 1 = changes, else error
 302                  */
 303                 return revs->diffopt.found_changes;
 304         }
 305
 306         if (read_cache() < 0) {
 307                 perror("read_cache");
 308                 return -1;
 309         }
 310         return run_diff_files(revs, silent_on_removed);
 311 }
 312
 313 int run_diff_files(struct rev_info *revs, int silent_on_removed)
 314 {
 315         int entries, i;
 316         int diff_unmerged_stage = revs->max_count;
 317
 318         if (diff_unmerged_stage < 0)
 319                 diff_unmerged_stage = 2;
 320         entries = active_nr;
 321         for (i = 0; i < entries; i++) {
 322                 struct stat st;
 323                 unsigned int oldmode, newmode;
 324                 struct cache_entry *ce = active_cache[i];
 325                 int changed;
 326
 327                 if (!ce_path_match(ce, revs->prune_data))
 328                         continue;
 329
 330                 if (ce_stage(ce)) {
 331                         struct combine_diff_path *dpath;
 332                         int num_compare_stages = 0;
 333                         size_t path_len;
 334
 335                         path_len = ce_namelen(ce);
 336
 337                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 338                         dpath->path = (char *) &(dpath->parent[5]);
 339
 340                         dpath->next = NULL;
 341                         dpath->len = path_len;
 342                         memcpy(dpath->path, ce->name, path_len);
 343                         dpath->path[path_len] = '\0';
 344                         hashclr(dpath->sha1);
 345                         memset(&(dpath->parent[0]), 0,
 346                                sizeof(struct combine_diff_parent)*5);
 347
 348                         if (lstat(ce->name, &st) < 0) {
 349                                 if (errno != ENOENT && errno != ENOTDIR) {
 350                                         perror(ce->name);
 351                                         continue;
 352                                 }
 353                                 if (silent_on_removed)
 354                                         continue;
 355                         }
 356                         else
 357                                 dpath->mode = canon_mode(st.st_mode);
 358
 359                         while (i < entries) {
 360                                 struct cache_entry *nce = active_cache[i];
 361                                 int stage;
 362
 363                                 if (strcmp(ce->name, nce->name))
 364                                         break;
 365
 366                                 /* Stage #2 (ours) is the first parent,
 367                                  * stage #3 (theirs) is the second.
 368                                  */
 369                                 stage = ce_stage(nce);
 370                                 if (2 <= stage) {
 371                                         int mode = ntohl(nce->ce_mode);
 372                                         num_compare_stages++;
 373                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 374                                         dpath->parent[stage-2].mode =
 375                                                 canon_mode(mode);
 376                                         dpath->parent[stage-2].status =
 377                                                 DIFF_STATUS_MODIFIED;
 378                                 }
 379
 380                                 /* diff against the proper unmerged stage */
 381                                 if (stage == diff_unmerged_stage)
 382                                         ce = nce;
 383                                 i++;
 384                         }
 385                         /*
 386                          * Compensate for loop update
 387                          */
 388                         i--;
 389
 390                         if (revs->combine_merges && num_compare_stages == 2) {
 391                                 show_combined_diff(dpath, 2,
 392                                                    revs->dense_combined_merges,
 393                                                    revs);
 394                                 free(dpath);
 395                                 continue;
 396                         }
 397                         free(dpath);
 398                         dpath = NULL;
 399
 400                         /*
 401                          * Show the diff for the 'ce' if we found the one
 402                          * from the desired stage.
 403                          */
 404                         diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
 405                         if (ce_stage(ce) != diff_unmerged_stage)
 406                                 continue;
 407                 }
 408
 409                 if (lstat(ce->name, &st) < 0) {
 410                         if (errno != ENOENT && errno != ENOTDIR) {
 411                                 perror(ce->name);
 412                                 continue;
 413                         }
 414                         if (silent_on_removed)
 415                                 continue;
 416                         diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
 417                                        ce->sha1, ce->name, NULL);
 418                         continue;
 419                 }
 420                 changed = ce_match_stat(ce, &st, 0);
 421                 if (!changed && !revs->diffopt.find_copies_harder)
 422                         continue;
 423                 oldmode = ntohl(ce->ce_mode);
 424
 425                 newmode = canon_mode(st.st_mode);
 426                 if (!trust_executable_bit &&
 427                     S_ISREG(newmode) && S_ISREG(oldmode) &&
 428                     ((newmode ^ oldmode) == 0111))
 429                         newmode = oldmode;
 430                 else if (!has_symlinks &&
 431                     S_ISREG(newmode) && S_ISLNK(oldmode))
 432                         newmode = oldmode;
 433                 diff_change(&revs->diffopt, oldmode, newmode,
 434                             ce->sha1, (changed ? null_sha1 : ce->sha1),
 435                             ce->name, NULL);
 436
 437         }
 438         diffcore_std(&revs->diffopt);
 439         diff_flush(&revs->diffopt);
 440         return 0;
 441 }
 442
 443 /*
 444  * diff-index
 445  */
 446
 447 /* A file entry went away or appeared */
 448 static void diff_index_show_file(struct rev_info *revs,
 449                                  const char *prefix,
 450                                  struct cache_entry *ce,
 451                                  unsigned char *sha1, unsigned int mode)
 452 {
 453         diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
 454                        sha1, ce->name, NULL);
 455 }
 456
 457 static int get_stat_data(struct cache_entry *ce,
 458                          unsigned char **sha1p,
 459                          unsigned int *modep,
 460                          int cached, int match_missing)
 461 {
 462         unsigned char *sha1 = ce->sha1;
 463         unsigned int mode = ce->ce_mode;
 464
 465         if (!cached) {
 466                 static unsigned char no_sha1[20];
 467                 int changed;
 468                 struct stat st;
 469                 if (lstat(ce->name, &st) < 0) {
 470                         if (errno == ENOENT && match_missing) {
 471                                 *sha1p = sha1;
 472                                 *modep = mode;
 473                                 return 0;
 474                         }
 475                         return -1;
 476                 }
 477                 changed = ce_match_stat(ce, &st, 0);
 478                 if (changed) {
 479                         mode = ce_mode_from_stat(ce, st.st_mode);
 480                         sha1 = no_sha1;
 481                 }
 482         }
 483
 484         *sha1p = sha1;
 485         *modep = mode;
 486         return 0;
 487 }
 488
 489 static void show_new_file(struct rev_info *revs,
 490                           struct cache_entry *new,
 491                           int cached, int match_missing)
 492 {
 493         unsigned char *sha1;
 494         unsigned int mode;
 495
 496         /* New file in the index: it might actually be different in
 497          * the working copy.
 498          */
 499         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
 500                 return;
 501
 502         diff_index_show_file(revs, "+", new, sha1, mode);
 503 }
 504
 505 static int show_modified(struct rev_info *revs,
 506                          struct cache_entry *old,
 507                          struct cache_entry *new,
 508                          int report_missing,
 509                          int cached, int match_missing)
 510 {
 511         unsigned int mode, oldmode;
 512         unsigned char *sha1;
 513
 514         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
 515                 if (report_missing)
 516                         diff_index_show_file(revs, "-", old,
 517                                              old->sha1, old->ce_mode);
 518                 return -1;
 519         }
 520
 521         if (revs->combine_merges && !cached &&
 522             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 523                 struct combine_diff_path *p;
 524                 int pathlen = ce_namelen(new);
 525
 526                 p = xmalloc(combine_diff_path_size(2, pathlen));
 527                 p->path = (char *) &p->parent[2];
 528                 p->next = NULL;
 529                 p->len = pathlen;
 530                 memcpy(p->path, new->name, pathlen);
 531                 p->path[pathlen] = 0;
 532                 p->mode = ntohl(mode);
 533                 hashclr(p->sha1);
 534                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 535                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 536                 p->parent[0].mode = ntohl(new->ce_mode);
 537                 hashcpy(p->parent[0].sha1, new->sha1);
 538                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 539                 p->parent[1].mode = ntohl(old->ce_mode);
 540                 hashcpy(p->parent[1].sha1, old->sha1);
 541                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 542                 free(p);
 543                 return 0;
 544         }
 545
 546         oldmode = old->ce_mode;
 547         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 548             !revs->diffopt.find_copies_harder)
 549                 return 0;
 550
 551         mode = ntohl(mode);
 552         oldmode = ntohl(oldmode);
 553
 554         diff_change(&revs->diffopt, oldmode, mode,
 555                     old->sha1, sha1, old->name, NULL);
 556         return 0;
 557 }
 558
 559 static int diff_cache(struct rev_info *revs,
 560                       struct cache_entry **ac, int entries,
 561                       const char **pathspec,
 562                       int cached, int match_missing)
 563 {
 564         while (entries) {
 565                 struct cache_entry *ce = *ac;
 566                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
 567
 568                 if (!ce_path_match(ce, pathspec))
 569                         goto skip_entry;
 570
 571                 switch (ce_stage(ce)) {
 572                 case 0:
 573                         /* No stage 1 entry? That means it's a new file */
 574                         if (!same) {
 575                                 show_new_file(revs, ce, cached, match_missing);
 576                                 break;
 577                         }
 578                         /* Show difference between old and new */
 579                         show_modified(revs, ac[1], ce, 1,
 580                                       cached, match_missing);
 581                         break;
 582                 case 1:
 583                         /* No stage 3 (merge) entry?
 584                          * That means it's been deleted.
 585                          */
 586                         if (!same) {
 587                                 diff_index_show_file(revs, "-", ce,
 588                                                      ce->sha1, ce->ce_mode);
 589                                 break;
 590                         }
 591                         /* We come here with ce pointing at stage 1
 592                          * (original tree) and ac[1] pointing at stage
 593                          * 3 (unmerged).  show-modified with
 594                          * report-missing set to false does not say the
 595                          * file is deleted but reports true if work
 596                          * tree does not have it, in which case we
 597                          * fall through to report the unmerged state.
 598                          * Otherwise, we show the differences between
 599                          * the original tree and the work tree.
 600                          */
 601                         if (!cached &&
 602                             !show_modified(revs, ce, ac[1], 0,
 603                                            cached, match_missing))
 604                                 break;
 605                         diff_unmerge(&revs->diffopt, ce->name,
 606                                      ntohl(ce->ce_mode), ce->sha1);
 607                         break;
 608                 case 3:
 609                         diff_unmerge(&revs->diffopt, ce->name,
 610                                      0, null_sha1);
 611                         break;
 612
 613                 default:
 614                         die("impossible cache entry stage");
 615                 }
 616
 617 skip_entry:
 618                 /*
 619                  * Ignore all the different stages for this file,
 620                  * we've handled the relevant cases now.
 621                  */
 622                 do {
 623                         ac++;
 624                         entries--;
 625                 } while (entries && ce_same_name(ce, ac[0]));
 626         }
 627         return 0;
 628 }
 629
 630 /*
 631  * This turns all merge entries into "stage 3". That guarantees that
 632  * when we read in the new tree (into "stage 1"), we won't lose sight
 633  * of the fact that we had unmerged entries.
 634  */
 635 static void mark_merge_entries(void)
 636 {
 637         int i;
 638         for (i = 0; i < active_nr; i++) {
 639                 struct cache_entry *ce = active_cache[i];
 640                 if (!ce_stage(ce))
 641                         continue;
 642                 ce->ce_flags |= htons(CE_STAGEMASK);
 643         }
 644 }
 645
 646 int run_diff_index(struct rev_info *revs, int cached)
 647 {
 648         int ret;
 649         struct object *ent;
 650         struct tree *tree;
 651         const char *tree_name;
 652         int match_missing = 0;
 653
 654         /*
 655          * Backward compatibility wart - "diff-index -m" does
 656          * not mean "do not ignore merges", but totally different.
 657          */
 658         if (!revs->ignore_merges)
 659                 match_missing = 1;
 660
 661         mark_merge_entries();
 662
 663         ent = revs->pending.objects[0].item;
 664         tree_name = revs->pending.objects[0].name;
 665         tree = parse_tree_indirect(ent->sha1);
 666         if (!tree)
 667                 return error("bad tree object %s", tree_name);
 668         if (read_tree(tree, 1, revs->prune_data))
 669                 return error("unable to read tree object %s", tree_name);
 670         ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
 671                          cached, match_missing);
 672         diffcore_std(&revs->diffopt);
 673         diff_flush(&revs->diffopt);
 674         return ret;
 675 }
 676
 677 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 678 {
 679         struct tree *tree;
 680         struct rev_info revs;
 681         int i;
 682         struct cache_entry **dst;
 683         struct cache_entry *last = NULL;
 684
 685         /*
 686          * This is used by git-blame to run diff-cache internally;
 687          * it potentially needs to repeatedly run this, so we will
 688          * start by removing the higher order entries the last round
 689          * left behind.
 690          */
 691         dst = active_cache;
 692         for (i = 0; i < active_nr; i++) {
 693                 struct cache_entry *ce = active_cache[i];
 694                 if (ce_stage(ce)) {
 695                         if (last && !strcmp(ce->name, last->name))
 696                                 continue;
 697                         cache_tree_invalidate_path(active_cache_tree,
 698                                                    ce->name);
 699                         last = ce;
 700                         ce->ce_mode = 0;
 701                         ce->ce_flags &= ~htons(CE_STAGEMASK);
 702                 }
 703                 *dst++ = ce;
 704         }
 705         active_nr = dst - active_cache;
 706
 707         init_revisions(&revs, NULL);
 708         revs.prune_data = opt->paths;
 709         tree = parse_tree_indirect(tree_sha1);
 710         if (!tree)
 711                 die("bad tree object %s", sha1_to_hex(tree_sha1));
 712         if (read_tree(tree, 1, opt->paths))
 713                 return error("unable to read tree %s", sha1_to_hex(tree_sha1));
 714         return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
 715                           1, 0);
 716 }