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 "gettext.h"
  10 #include "hex.h"
  11 #include "revision.h"
  12 #include "cache-tree.h"
  13 #include "unpack-trees.h"
  14 #include "refs.h"
  15 #include "submodule.h"
  16 #include "dir.h"
  17 #include "fsmonitor.h"
  18 #include "commit-reach.h"
  19
  20 /*
  21  * diff-files
  22  */
  23
  24 /*
  25  * Has the work tree entity been removed?
  26  *
  27  * Return 1 if it was removed from the work tree, 0 if an entity to be
  28  * compared with the cache entry ce still exists (the latter includes
  29  * the case where a directory that is not a submodule repository
  30  * exists for ce that is a submodule -- it is a submodule that is not
  31  * checked out).  Return negative for an error.
  32  */
  33 static int check_removed(const struct index_state *istate, const struct cache_entry *ce, struct stat *st)
  34 {
  35         assert(is_fsmonitor_refreshed(istate));
  36         if (!(ce->ce_flags & CE_FSMONITOR_VALID) && lstat(ce->name, st) < 0) {
  37                 if (!is_missing_file_error(errno))
  38                         return -1;
  39                 return 1;
  40         }
  41         if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  42                 return 1;
  43         if (S_ISDIR(st->st_mode)) {
  44                 struct object_id sub;
  45
  46                 /*
  47                  * If ce is already a gitlink, we can have a plain
  48                  * directory (i.e. the submodule is not checked out),
  49                  * or a checked out submodule.  Either case this is not
  50                  * a case where something was removed from the work tree,
  51                  * so we will return 0.
  52                  *
  53                  * Otherwise, if the directory is not a submodule
  54                  * repository, that means ce which was a blob turned into
  55                  * a directory --- the blob was removed!
  56                  */
  57                 if (!S_ISGITLINK(ce->ce_mode) &&
  58                     resolve_gitlink_ref(ce->name, "HEAD", &sub))
  59                         return 1;
  60         }
  61         return 0;
  62 }
  63
  64 /*
  65  * Has a file changed or has a submodule new commits or a dirty work tree?
  66  *
  67  * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  68  * option is set, the caller does not only want to know if a submodule is
  69  * modified at all but wants to know all the conditions that are met (new
  70  * commits, untracked content and/or modified content).
  71  */
  72 static int match_stat_with_submodule(struct diff_options *diffopt,
  73                                      const struct cache_entry *ce,
  74                                      struct stat *st, unsigned ce_option,
  75                                      unsigned *dirty_submodule)
  76 {
  77         int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
  78         if (S_ISGITLINK(ce->ce_mode)) {
  79                 struct diff_flags orig_flags = diffopt->flags;
  80                 if (!diffopt->flags.override_submodule_config)
  81                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  82                 if (diffopt->flags.ignore_submodules)
  83                         changed = 0;
  84                 else if (!diffopt->flags.ignore_dirty_submodules &&
  85                          (!changed || diffopt->flags.dirty_submodules))
  86                         *dirty_submodule = is_submodule_modified(ce->name,
  87                                                                  diffopt->flags.ignore_untracked_in_submodules);
  88                 diffopt->flags = orig_flags;
  89         }
  90         return changed;
  91 }
  92
  93 int run_diff_files(struct rev_info *revs, unsigned int option)
  94 {
  95         int entries, i;
  96         int diff_unmerged_stage = revs->max_count;
  97         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
  98                               ? CE_MATCH_RACY_IS_DIRTY : 0);
  99         uint64_t start = getnanotime();
 100         struct index_state *istate = revs->diffopt.repo->index;
 101
 102         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
 103
 104         refresh_fsmonitor(istate);
 105
 106         if (diff_unmerged_stage < 0)
 107                 diff_unmerged_stage = 2;
 108         entries = istate->cache_nr;
 109         for (i = 0; i < entries; i++) {
 110                 unsigned int oldmode, newmode;
 111                 struct cache_entry *ce = istate->cache[i];
 112                 int changed;
 113                 unsigned dirty_submodule = 0;
 114                 const struct object_id *old_oid, *new_oid;
 115
 116                 if (diff_can_quit_early(&revs->diffopt))
 117                         break;
 118
 119                 if (!ce_path_match(istate, ce, &revs->prune_data, NULL))
 120                         continue;
 121
 122                 if (revs->diffopt.prefix &&
 123                     strncmp(ce->name, revs->diffopt.prefix, revs->diffopt.prefix_length))
 124                         continue;
 125
 126                 if (ce_stage(ce)) {
 127                         struct combine_diff_path *dpath;
 128                         struct diff_filepair *pair;
 129                         unsigned int wt_mode = 0;
 130                         int num_compare_stages = 0;
 131                         size_t path_len;
 132                         struct stat st;
 133
 134                         path_len = ce_namelen(ce);
 135
 136                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 137                         dpath->path = (char *) &(dpath->parent[5]);
 138
 139                         dpath->next = NULL;
 140                         memcpy(dpath->path, ce->name, path_len);
 141                         dpath->path[path_len] = '\0';
 142                         oidclr(&dpath->oid);
 143                         memset(&(dpath->parent[0]), 0,
 144                                sizeof(struct combine_diff_parent)*5);
 145
 146                         changed = check_removed(istate, ce, &st);
 147                         if (!changed)
 148                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
 149                         else {
 150                                 if (changed < 0) {
 151                                         perror(ce->name);
 152                                         continue;
 153                                 }
 154                                 wt_mode = 0;
 155                         }
 156                         dpath->mode = wt_mode;
 157
 158                         while (i < entries) {
 159                                 struct cache_entry *nce = istate->cache[i];
 160                                 int stage;
 161
 162                                 if (strcmp(ce->name, nce->name))
 163                                         break;
 164
 165                                 /* Stage #2 (ours) is the first parent,
 166                                  * stage #3 (theirs) is the second.
 167                                  */
 168                                 stage = ce_stage(nce);
 169                                 if (2 <= stage) {
 170                                         int mode = nce->ce_mode;
 171                                         num_compare_stages++;
 172                                         oidcpy(&dpath->parent[stage - 2].oid,
 173                                                &nce->oid);
 174                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 175                                         dpath->parent[stage-2].status =
 176                                                 DIFF_STATUS_MODIFIED;
 177                                 }
 178
 179                                 /* diff against the proper unmerged stage */
 180                                 if (stage == diff_unmerged_stage)
 181                                         ce = nce;
 182                                 i++;
 183                         }
 184                         /*
 185                          * Compensate for loop update
 186                          */
 187                         i--;
 188
 189                         if (revs->combine_merges && num_compare_stages == 2) {
 190                                 show_combined_diff(dpath, 2, revs);
 191                                 free(dpath);
 192                                 continue;
 193                         }
 194                         FREE_AND_NULL(dpath);
 195
 196                         /*
 197                          * Show the diff for the 'ce' if we found the one
 198                          * from the desired stage.
 199                          */
 200                         pair = diff_unmerge(&revs->diffopt, ce->name);
 201                         if (wt_mode)
 202                                 pair->two->mode = wt_mode;
 203                         if (ce_stage(ce) != diff_unmerged_stage)
 204                                 continue;
 205                 }
 206
 207                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 208                         continue;
 209
 210                 /*
 211                  * When CE_VALID is set (via "update-index --assume-unchanged"
 212                  * or via adding paths while core.ignorestat is set to true),
 213                  * the user has promised that the working tree file for that
 214                  * path will not be modified.  When CE_FSMONITOR_VALID is true,
 215                  * the fsmonitor knows that the path hasn't been modified since
 216                  * we refreshed the cached stat information.  In either case,
 217                  * we do not have to stat to see if the path has been removed
 218                  * or modified.
 219                  */
 220                 if (ce->ce_flags & (CE_VALID | CE_FSMONITOR_VALID)) {
 221                         changed = 0;
 222                         newmode = ce->ce_mode;
 223                 } else {
 224                         struct stat st;
 225
 226                         changed = check_removed(istate, ce, &st);
 227                         if (changed) {
 228                                 if (changed < 0) {
 229                                         perror(ce->name);
 230                                         continue;
 231                                 }
 232                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 233                                                &ce->oid,
 234                                                !is_null_oid(&ce->oid),
 235                                                ce->name, 0);
 236                                 continue;
 237                         } else if (revs->diffopt.ita_invisible_in_index &&
 238                                    ce_intent_to_add(ce)) {
 239                                 newmode = ce_mode_from_stat(ce, st.st_mode);
 240                                 diff_addremove(&revs->diffopt, '+', newmode,
 241                                                null_oid(), 0, ce->name, 0);
 242                                 continue;
 243                         }
 244
 245                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 246                                                             ce_option, &dirty_submodule);
 247                         newmode = ce_mode_from_stat(ce, st.st_mode);
 248                 }
 249
 250                 if (!changed && !dirty_submodule) {
 251                         ce_mark_uptodate(ce);
 252                         mark_fsmonitor_valid(istate, ce);
 253                         if (!revs->diffopt.flags.find_copies_harder)
 254                                 continue;
 255                 }
 256                 oldmode = ce->ce_mode;
 257                 old_oid = &ce->oid;
 258                 new_oid = changed ? null_oid() : &ce->oid;
 259                 diff_change(&revs->diffopt, oldmode, newmode,
 260                             old_oid, new_oid,
 261                             !is_null_oid(old_oid),
 262                             !is_null_oid(new_oid),
 263                             ce->name, 0, dirty_submodule);
 264
 265         }
 266         diffcore_std(&revs->diffopt);
 267         diff_flush(&revs->diffopt);
 268         trace_performance_since(start, "diff-files");
 269         return 0;
 270 }
 271
 272 /*
 273  * diff-index
 274  */
 275
 276 /* A file entry went away or appeared */
 277 static void diff_index_show_file(struct rev_info *revs,
 278                                  const char *prefix,
 279                                  const struct cache_entry *ce,
 280                                  const struct object_id *oid, int oid_valid,
 281                                  unsigned int mode,
 282                                  unsigned dirty_submodule)
 283 {
 284         diff_addremove(&revs->diffopt, prefix[0], mode,
 285                        oid, oid_valid, ce->name, dirty_submodule);
 286 }
 287
 288 static int get_stat_data(const struct index_state *istate,
 289                          const struct cache_entry *ce,
 290                          const struct object_id **oidp,
 291                          unsigned int *modep,
 292                          int cached, int match_missing,
 293                          unsigned *dirty_submodule, struct diff_options *diffopt)
 294 {
 295         const struct object_id *oid = &ce->oid;
 296         unsigned int mode = ce->ce_mode;
 297
 298         if (!cached && !ce_uptodate(ce)) {
 299                 int changed;
 300                 struct stat st;
 301                 changed = check_removed(istate, ce, &st);
 302                 if (changed < 0)
 303                         return -1;
 304                 else if (changed) {
 305                         if (match_missing) {
 306                                 *oidp = oid;
 307                                 *modep = mode;
 308                                 return 0;
 309                         }
 310                         return -1;
 311                 }
 312                 changed = match_stat_with_submodule(diffopt, ce, &st,
 313                                                     0, dirty_submodule);
 314                 if (changed) {
 315                         mode = ce_mode_from_stat(ce, st.st_mode);
 316                         oid = null_oid();
 317                 }
 318         }
 319
 320         *oidp = oid;
 321         *modep = mode;
 322         return 0;
 323 }
 324
 325 static void show_new_file(struct rev_info *revs,
 326                           const struct cache_entry *new_file,
 327                           int cached, int match_missing)
 328 {
 329         const struct object_id *oid;
 330         unsigned int mode;
 331         unsigned dirty_submodule = 0;
 332         struct index_state *istate = revs->diffopt.repo->index;
 333
 334         if (new_file && S_ISSPARSEDIR(new_file->ce_mode)) {
 335                 diff_tree_oid(NULL, &new_file->oid, new_file->name, &revs->diffopt);
 336                 return;
 337         }
 338
 339         /*
 340          * New file in the index: it might actually be different in
 341          * the working tree.
 342          */
 343         if (get_stat_data(istate, new_file, &oid, &mode, cached, match_missing,
 344             &dirty_submodule, &revs->diffopt) < 0)
 345                 return;
 346
 347         diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
 348 }
 349
 350 static int show_modified(struct rev_info *revs,
 351                          const struct cache_entry *old_entry,
 352                          const struct cache_entry *new_entry,
 353                          int report_missing,
 354                          int cached, int match_missing)
 355 {
 356         unsigned int mode, oldmode;
 357         const struct object_id *oid;
 358         unsigned dirty_submodule = 0;
 359         struct index_state *istate = revs->diffopt.repo->index;
 360
 361         assert(S_ISSPARSEDIR(old_entry->ce_mode) ==
 362                S_ISSPARSEDIR(new_entry->ce_mode));
 363
 364         /*
 365          * If both are sparse directory entries, then expand the
 366          * modifications to the file level. If only one was a sparse
 367          * directory, then they appear as an add and delete instead of
 368          * a modification.
 369          */
 370         if (S_ISSPARSEDIR(new_entry->ce_mode)) {
 371                 diff_tree_oid(&old_entry->oid, &new_entry->oid, new_entry->name, &revs->diffopt);
 372                 return 0;
 373         }
 374
 375         if (get_stat_data(istate, new_entry, &oid, &mode, cached, match_missing,
 376                           &dirty_submodule, &revs->diffopt) < 0) {
 377                 if (report_missing)
 378                         diff_index_show_file(revs, "-", old_entry,
 379                                              &old_entry->oid, 1, old_entry->ce_mode,
 380                                              0);
 381                 return -1;
 382         }
 383
 384         if (revs->combine_merges && !cached &&
 385             (!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
 386                 struct combine_diff_path *p;
 387                 int pathlen = ce_namelen(new_entry);
 388
 389                 p = xmalloc(combine_diff_path_size(2, pathlen));
 390                 p->path = (char *) &p->parent[2];
 391                 p->next = NULL;
 392                 memcpy(p->path, new_entry->name, pathlen);
 393                 p->path[pathlen] = 0;
 394                 p->mode = mode;
 395                 oidclr(&p->oid);
 396                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 397                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 398                 p->parent[0].mode = new_entry->ce_mode;
 399                 oidcpy(&p->parent[0].oid, &new_entry->oid);
 400                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 401                 p->parent[1].mode = old_entry->ce_mode;
 402                 oidcpy(&p->parent[1].oid, &old_entry->oid);
 403                 show_combined_diff(p, 2, revs);
 404                 free(p);
 405                 return 0;
 406         }
 407
 408         oldmode = old_entry->ce_mode;
 409         if (mode == oldmode && oideq(oid, &old_entry->oid) && !dirty_submodule &&
 410             !revs->diffopt.flags.find_copies_harder)
 411                 return 0;
 412
 413         diff_change(&revs->diffopt, oldmode, mode,
 414                     &old_entry->oid, oid, 1, !is_null_oid(oid),
 415                     old_entry->name, 0, dirty_submodule);
 416         return 0;
 417 }
 418
 419 /*
 420  * This gets a mix of an existing index and a tree, one pathname entry
 421  * at a time. The index entry may be a single stage-0 one, but it could
 422  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 423  * give you the position and number of entries in the index).
 424  */
 425 static void do_oneway_diff(struct unpack_trees_options *o,
 426                            const struct cache_entry *idx,
 427                            const struct cache_entry *tree)
 428 {
 429         struct rev_info *revs = o->unpack_data;
 430         int match_missing, cached;
 431
 432         /*
 433          * i-t-a entries do not actually exist in the index (if we're
 434          * looking at its content)
 435          */
 436         if (o->index_only &&
 437             revs->diffopt.ita_invisible_in_index &&
 438             idx && ce_intent_to_add(idx)) {
 439                 idx = NULL;
 440                 if (!tree)
 441                         return; /* nothing to diff.. */
 442         }
 443
 444         /* if the entry is not checked out, don't examine work tree */
 445         cached = o->index_only ||
 446                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 447
 448         match_missing = revs->match_missing;
 449
 450         if (cached && idx && ce_stage(idx)) {
 451                 struct diff_filepair *pair;
 452                 pair = diff_unmerge(&revs->diffopt, idx->name);
 453                 if (tree)
 454                         fill_filespec(pair->one, &tree->oid, 1,
 455                                       tree->ce_mode);
 456                 return;
 457         }
 458
 459         /*
 460          * Something added to the tree?
 461          */
 462         if (!tree) {
 463                 show_new_file(revs, idx, cached, match_missing);
 464                 return;
 465         }
 466
 467         /*
 468          * Something removed from the tree?
 469          */
 470         if (!idx) {
 471                 if (S_ISSPARSEDIR(tree->ce_mode)) {
 472                         diff_tree_oid(&tree->oid, NULL, tree->name, &revs->diffopt);
 473                         return;
 474                 }
 475
 476                 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
 477                                      tree->ce_mode, 0);
 478                 return;
 479         }
 480
 481         /* Show difference between old and new */
 482         show_modified(revs, tree, idx, 1, cached, match_missing);
 483 }
 484
 485 /*
 486  * The unpack_trees() interface is designed for merging, so
 487  * the different source entries are designed primarily for
 488  * the source trees, with the old index being really mainly
 489  * used for being replaced by the result.
 490  *
 491  * For diffing, the index is more important, and we only have a
 492  * single tree.
 493  *
 494  * We're supposed to advance o->pos to skip what we have already processed.
 495  *
 496  * This wrapper makes it all more readable, and takes care of all
 497  * the fairly complex unpack_trees() semantic requirements, including
 498  * the skipping, the path matching, the type conflict cases etc.
 499  */
 500 static int oneway_diff(const struct cache_entry * const *src,
 501                        struct unpack_trees_options *o)
 502 {
 503         const struct cache_entry *idx = src[0];
 504         const struct cache_entry *tree = src[1];
 505         struct rev_info *revs = o->unpack_data;
 506
 507         /*
 508          * Unpack-trees generates a DF/conflict entry if
 509          * there was a directory in the index and a tree
 510          * in the tree. From a diff standpoint, that's a
 511          * delete of the tree and a create of the file.
 512          */
 513         if (tree == o->df_conflict_entry)
 514                 tree = NULL;
 515
 516         if (ce_path_match(revs->diffopt.repo->index,
 517                           idx ? idx : tree,
 518                           &revs->prune_data, NULL)) {
 519                 do_oneway_diff(o, idx, tree);
 520                 if (diff_can_quit_early(&revs->diffopt)) {
 521                         o->exiting_early = 1;
 522                         return -1;
 523                 }
 524         }
 525
 526         return 0;
 527 }
 528
 529 static int diff_cache(struct rev_info *revs,
 530                       const struct object_id *tree_oid,
 531                       const char *tree_name,
 532                       int cached)
 533 {
 534         struct tree *tree;
 535         struct tree_desc t;
 536         struct unpack_trees_options opts;
 537
 538         tree = parse_tree_indirect(tree_oid);
 539         if (!tree)
 540                 return error("bad tree object %s",
 541                              tree_name ? tree_name : oid_to_hex(tree_oid));
 542         memset(&opts, 0, sizeof(opts));
 543         opts.head_idx = 1;
 544         opts.index_only = cached;
 545         opts.diff_index_cached = (cached &&
 546                                   !revs->diffopt.flags.find_copies_harder);
 547         opts.merge = 1;
 548         opts.fn = oneway_diff;
 549         opts.unpack_data = revs;
 550         opts.src_index = revs->diffopt.repo->index;
 551         opts.dst_index = NULL;
 552         opts.pathspec = &revs->diffopt.pathspec;
 553         opts.pathspec->recursive = 1;
 554
 555         init_tree_desc(&t, tree->buffer, tree->size);
 556         return unpack_trees(1, &t, &opts);
 557 }
 558
 559 void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb)
 560 {
 561         int i;
 562         struct commit *mb_child[2] = {0};
 563         struct commit_list *merge_bases;
 564
 565         for (i = 0; i < revs->pending.nr; i++) {
 566                 struct object *obj = revs->pending.objects[i].item;
 567                 if (obj->flags)
 568                         die(_("--merge-base does not work with ranges"));
 569                 if (obj->type != OBJ_COMMIT)
 570                         die(_("--merge-base only works with commits"));
 571         }
 572
 573         /*
 574          * This check must go after the for loop above because A...B
 575          * ranges produce three pending commits, resulting in a
 576          * misleading error message.
 577          */
 578         if (revs->pending.nr < 1 || revs->pending.nr > 2)
 579                 BUG("unexpected revs->pending.nr: %d", revs->pending.nr);
 580
 581         for (i = 0; i < revs->pending.nr; i++)
 582                 mb_child[i] = lookup_commit_reference(the_repository, &revs->pending.objects[i].item->oid);
 583         if (revs->pending.nr == 1) {
 584                 struct object_id oid;
 585
 586                 if (repo_get_oid(the_repository, "HEAD", &oid))
 587                         die(_("unable to get HEAD"));
 588
 589                 mb_child[1] = lookup_commit_reference(the_repository, &oid);
 590         }
 591
 592         merge_bases = repo_get_merge_bases(the_repository, mb_child[0], mb_child[1]);
 593         if (!merge_bases)
 594                 die(_("no merge base found"));
 595         if (merge_bases->next)
 596                 die(_("multiple merge bases found"));
 597
 598         oidcpy(mb, &merge_bases->item->object.oid);
 599
 600         free_commit_list(merge_bases);
 601 }
 602
 603 int run_diff_index(struct rev_info *revs, unsigned int option)
 604 {
 605         struct object_array_entry *ent;
 606         int cached = !!(option & DIFF_INDEX_CACHED);
 607         int merge_base = !!(option & DIFF_INDEX_MERGE_BASE);
 608         struct object_id oid;
 609         const char *name;
 610         char merge_base_hex[GIT_MAX_HEXSZ + 1];
 611         struct index_state *istate = revs->diffopt.repo->index;
 612
 613         if (revs->pending.nr != 1)
 614                 BUG("run_diff_index must be passed exactly one tree");
 615
 616         trace_performance_enter();
 617         ent = revs->pending.objects;
 618
 619         refresh_fsmonitor(istate);
 620
 621         if (merge_base) {
 622                 diff_get_merge_base(revs, &oid);
 623                 name = oid_to_hex_r(merge_base_hex, &oid);
 624         } else {
 625                 oidcpy(&oid, &ent->item->oid);
 626                 name = ent->name;
 627         }
 628
 629         if (diff_cache(revs, &oid, name, cached))
 630                 exit(128);
 631
 632         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 633         diffcore_fix_diff_index();
 634         diffcore_std(&revs->diffopt);
 635         diff_flush(&revs->diffopt);
 636         trace_performance_leave("diff-index");
 637         return 0;
 638 }
 639
 640 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 641 {
 642         struct rev_info revs;
 643
 644         repo_init_revisions(opt->repo, &revs, NULL);
 645         copy_pathspec(&revs.prune_data, &opt->pathspec);
 646         diff_setup_done(&revs.diffopt);
 647         revs.diffopt = *opt;
 648
 649         if (diff_cache(&revs, tree_oid, NULL, 1))
 650                 exit(128);
 651         release_revisions(&revs);
 652         return 0;
 653 }
 654
 655 int index_differs_from(struct repository *r,
 656                        const char *def, const struct diff_flags *flags,
 657                        int ita_invisible_in_index)
 658 {
 659         struct rev_info rev;
 660         struct setup_revision_opt opt;
 661         unsigned has_changes;
 662
 663         repo_init_revisions(r, &rev, NULL);
 664         memset(&opt, 0, sizeof(opt));
 665         opt.def = def;
 666         setup_revisions(0, NULL, &rev, &opt);
 667         rev.diffopt.flags.quick = 1;
 668         rev.diffopt.flags.exit_with_status = 1;
 669         if (flags)
 670                 diff_flags_or(&rev.diffopt.flags, flags);
 671         rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 672         run_diff_index(&rev, 1);
 673         has_changes = rev.diffopt.flags.has_changes;
 674         release_revisions(&rev);
 675         return (has_changes != 0);
 676 }
 677
 678 static struct strbuf *idiff_prefix_cb(struct diff_options *opt UNUSED, void *data)
 679 {
 680         return data;
 681 }
 682
 683 void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
 684                     int indent, struct diff_options *diffopt)
 685 {
 686         struct diff_options opts;
 687         struct strbuf prefix = STRBUF_INIT;
 688
 689         memcpy(&opts, diffopt, sizeof(opts));
 690         opts.output_format = DIFF_FORMAT_PATCH;
 691         opts.output_prefix = idiff_prefix_cb;
 692         strbuf_addchars(&prefix, ' ', indent);
 693         opts.output_prefix_data = &prefix;
 694         diff_setup_done(&opts);
 695
 696         diff_tree_oid(oid1, oid2, "", &opts);
 697         diffcore_std(&opts);
 698         diff_flush(&opts);
 699
 700         strbuf_release(&prefix);
 701 }