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