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