revision.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "blob.h"
   4 #include "tree.h"
   5 #include "commit.h"
   6 #include "diff.h"
   7 #include "refs.h"
   8 #include "revision.h"
   9 #include "graph.h"
  10 #include "grep.h"
  11 #include "reflog-walk.h"
  12 #include "patch-ids.h"
  13 #include "decorate.h"
  14 #include "log-tree.h"
  15
  16 volatile show_early_output_fn_t show_early_output;
  17
  18 char *path_name(const struct name_path *path, const char *name)
  19 {
  20         const struct name_path *p;
  21         char *n, *m;
  22         int nlen = strlen(name);
  23         int len = nlen + 1;
  24
  25         for (p = path; p; p = p->up) {
  26                 if (p->elem_len)
  27                         len += p->elem_len + 1;
  28         }
  29         n = xmalloc(len);
  30         m = n + len - (nlen + 1);
  31         strcpy(m, name);
  32         for (p = path; p; p = p->up) {
  33                 if (p->elem_len) {
  34                         m -= p->elem_len + 1;
  35                         memcpy(m, p->elem, p->elem_len);
  36                         m[p->elem_len] = '/';
  37                 }
  38         }
  39         return n;
  40 }
  41
  42 void add_object(struct object *obj,
  43                 struct object_array *p,
  44                 struct name_path *path,
  45                 const char *name)
  46 {
  47         add_object_array(obj, path_name(path, name), p);
  48 }
  49
  50 static void mark_blob_uninteresting(struct blob *blob)
  51 {
  52         if (!blob)
  53                 return;
  54         if (blob->object.flags & UNINTERESTING)
  55                 return;
  56         blob->object.flags |= UNINTERESTING;
  57 }
  58
  59 void mark_tree_uninteresting(struct tree *tree)
  60 {
  61         struct tree_desc desc;
  62         struct name_entry entry;
  63         struct object *obj = &tree->object;
  64
  65         if (!tree)
  66                 return;
  67         if (obj->flags & UNINTERESTING)
  68                 return;
  69         obj->flags |= UNINTERESTING;
  70         if (!has_sha1_file(obj->sha1))
  71                 return;
  72         if (parse_tree(tree) < 0)
  73                 die("bad tree %s", sha1_to_hex(obj->sha1));
  74
  75         init_tree_desc(&desc, tree->buffer, tree->size);
  76         while (tree_entry(&desc, &entry)) {
  77                 switch (object_type(entry.mode)) {
  78                 case OBJ_TREE:
  79                         mark_tree_uninteresting(lookup_tree(entry.sha1));
  80                         break;
  81                 case OBJ_BLOB:
  82                         mark_blob_uninteresting(lookup_blob(entry.sha1));
  83                         break;
  84                 default:
  85                         /* Subproject commit - not in this repository */
  86                         break;
  87                 }
  88         }
  89
  90         /*
  91          * We don't care about the tree any more
  92          * after it has been marked uninteresting.
  93          */
  94         free(tree->buffer);
  95         tree->buffer = NULL;
  96 }
  97
  98 void mark_parents_uninteresting(struct commit *commit)
  99 {
 100         struct commit_list *parents = commit->parents;
 101
 102         while (parents) {
 103                 struct commit *commit = parents->item;
 104                 if (!(commit->object.flags & UNINTERESTING)) {
 105                         commit->object.flags |= UNINTERESTING;
 106
 107                         /*
 108                          * Normally we haven't parsed the parent
 109                          * yet, so we won't have a parent of a parent
 110                          * here. However, it may turn out that we've
 111                          * reached this commit some other way (where it
 112                          * wasn't uninteresting), in which case we need
 113                          * to mark its parents recursively too..
 114                          */
 115                         if (commit->parents)
 116                                 mark_parents_uninteresting(commit);
 117                 }
 118
 119                 /*
 120                  * A missing commit is ok iff its parent is marked
 121                  * uninteresting.
 122                  *
 123                  * We just mark such a thing parsed, so that when
 124                  * it is popped next time around, we won't be trying
 125                  * to parse it and get an error.
 126                  */
 127                 if (!has_sha1_file(commit->object.sha1))
 128                         commit->object.parsed = 1;
 129                 parents = parents->next;
 130         }
 131 }
 132
 133 static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 134 {
 135         if (revs->no_walk && (obj->flags & UNINTERESTING))
 136                 revs->no_walk = 0;
 137         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 138                 struct strbuf buf = STRBUF_INIT;
 139                 int len = interpret_branch_name(name, &buf);
 140                 int st;
 141
 142                 if (0 < len && name[len] && buf.len)
 143                         strbuf_addstr(&buf, name + len);
 144                 st = add_reflog_for_walk(revs->reflog_info,
 145                                          (struct commit *)obj,
 146                                          buf.buf[0] ? buf.buf: name);
 147                 strbuf_release(&buf);
 148                 if (st)
 149                         return;
 150         }
 151         add_object_array_with_mode(obj, name, &revs->pending, mode);
 152 }
 153
 154 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 155 {
 156         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 157 }
 158
 159 void add_head_to_pending(struct rev_info *revs)
 160 {
 161         unsigned char sha1[20];
 162         struct object *obj;
 163         if (get_sha1("HEAD", sha1))
 164                 return;
 165         obj = parse_object(sha1);
 166         if (!obj)
 167                 return;
 168         add_pending_object(revs, obj, "HEAD");
 169 }
 170
 171 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 172 {
 173         struct object *object;
 174
 175         object = parse_object(sha1);
 176         if (!object)
 177                 die("bad object %s", name);
 178         object->flags |= flags;
 179         return object;
 180 }
 181
 182 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 183 {
 184         unsigned long flags = object->flags;
 185
 186         /*
 187          * Tag object? Look what it points to..
 188          */
 189         while (object->type == OBJ_TAG) {
 190                 struct tag *tag = (struct tag *) object;
 191                 if (revs->tag_objects && !(flags & UNINTERESTING))
 192                         add_pending_object(revs, object, tag->tag);
 193                 if (!tag->tagged)
 194                         die("bad tag");
 195                 object = parse_object(tag->tagged->sha1);
 196                 if (!object) {
 197                         if (flags & UNINTERESTING)
 198                                 return NULL;
 199                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 200                 }
 201         }
 202
 203         /*
 204          * Commit object? Just return it, we'll do all the complex
 205          * reachability crud.
 206          */
 207         if (object->type == OBJ_COMMIT) {
 208                 struct commit *commit = (struct commit *)object;
 209                 if (parse_commit(commit) < 0)
 210                         die("unable to parse commit %s", name);
 211                 if (flags & UNINTERESTING) {
 212                         commit->object.flags |= UNINTERESTING;
 213                         mark_parents_uninteresting(commit);
 214                         revs->limited = 1;
 215                 }
 216                 if (revs->show_source && !commit->util)
 217                         commit->util = (void *) name;
 218                 return commit;
 219         }
 220
 221         /*
 222          * Tree object? Either mark it uninteresting, or add it
 223          * to the list of objects to look at later..
 224          */
 225         if (object->type == OBJ_TREE) {
 226                 struct tree *tree = (struct tree *)object;
 227                 if (!revs->tree_objects)
 228                         return NULL;
 229                 if (flags & UNINTERESTING) {
 230                         mark_tree_uninteresting(tree);
 231                         return NULL;
 232                 }
 233                 add_pending_object(revs, object, "");
 234                 return NULL;
 235         }
 236
 237         /*
 238          * Blob object? You know the drill by now..
 239          */
 240         if (object->type == OBJ_BLOB) {
 241                 struct blob *blob = (struct blob *)object;
 242                 if (!revs->blob_objects)
 243                         return NULL;
 244                 if (flags & UNINTERESTING) {
 245                         mark_blob_uninteresting(blob);
 246                         return NULL;
 247                 }
 248                 add_pending_object(revs, object, "");
 249                 return NULL;
 250         }
 251         die("%s is unknown object", name);
 252 }
 253
 254 static int everybody_uninteresting(struct commit_list *orig)
 255 {
 256         struct commit_list *list = orig;
 257         while (list) {
 258                 struct commit *commit = list->item;
 259                 list = list->next;
 260                 if (commit->object.flags & UNINTERESTING)
 261                         continue;
 262                 return 0;
 263         }
 264         return 1;
 265 }
 266
 267 /*
 268  * The goal is to get REV_TREE_NEW as the result only if the
 269  * diff consists of all '+' (and no other changes), REV_TREE_OLD
 270  * if the whole diff is removal of old data, and otherwise
 271  * REV_TREE_DIFFERENT (of course if the trees are the same we
 272  * want REV_TREE_SAME).
 273  * That means that once we get to REV_TREE_DIFFERENT, we do not
 274  * have to look any further.
 275  */
 276 static int tree_difference = REV_TREE_SAME;
 277
 278 static void file_add_remove(struct diff_options *options,
 279                     int addremove, unsigned mode,
 280                     const unsigned char *sha1,
 281                     const char *fullpath, unsigned dirty_submodule)
 282 {
 283         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 284
 285         tree_difference |= diff;
 286         if (tree_difference == REV_TREE_DIFFERENT)
 287                 DIFF_OPT_SET(options, HAS_CHANGES);
 288 }
 289
 290 static void file_change(struct diff_options *options,
 291                  unsigned old_mode, unsigned new_mode,
 292                  const unsigned char *old_sha1,
 293                  const unsigned char *new_sha1,
 294                  const char *fullpath,
 295                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 296 {
 297         tree_difference = REV_TREE_DIFFERENT;
 298         DIFF_OPT_SET(options, HAS_CHANGES);
 299 }
 300
 301 static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
 302 {
 303         struct tree *t1 = parent->tree;
 304         struct tree *t2 = commit->tree;
 305
 306         if (!t1)
 307                 return REV_TREE_NEW;
 308         if (!t2)
 309                 return REV_TREE_OLD;
 310
 311         if (revs->simplify_by_decoration) {
 312                 /*
 313                  * If we are simplifying by decoration, then the commit
 314                  * is worth showing if it has a tag pointing at it.
 315                  */
 316                 if (lookup_decoration(&name_decoration, &commit->object))
 317                         return REV_TREE_DIFFERENT;
 318                 /*
 319                  * A commit that is not pointed by a tag is uninteresting
 320                  * if we are not limited by path.  This means that you will
 321                  * see the usual "commits that touch the paths" plus any
 322                  * tagged commit by specifying both --simplify-by-decoration
 323                  * and pathspec.
 324                  */
 325                 if (!revs->prune_data)
 326                         return REV_TREE_SAME;
 327         }
 328
 329         tree_difference = REV_TREE_SAME;
 330         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 331         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 332                            &revs->pruning) < 0)
 333                 return REV_TREE_DIFFERENT;
 334         return tree_difference;
 335 }
 336
 337 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 338 {
 339         int retval;
 340         void *tree;
 341         unsigned long size;
 342         struct tree_desc empty, real;
 343         struct tree *t1 = commit->tree;
 344
 345         if (!t1)
 346                 return 0;
 347
 348         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 349         if (!tree)
 350                 return 0;
 351         init_tree_desc(&real, tree, size);
 352         init_tree_desc(&empty, "", 0);
 353
 354         tree_difference = REV_TREE_SAME;
 355         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 356         retval = diff_tree(&empty, &real, "", &revs->pruning);
 357         free(tree);
 358
 359         return retval >= 0 && (tree_difference == REV_TREE_SAME);
 360 }
 361
 362 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 363 {
 364         struct commit_list **pp, *parent;
 365         int tree_changed = 0, tree_same = 0;
 366
 367         /*
 368          * If we don't do pruning, everything is interesting
 369          */
 370         if (!revs->prune)
 371                 return;
 372
 373         if (!commit->tree)
 374                 return;
 375
 376         if (!commit->parents) {
 377                 if (rev_same_tree_as_empty(revs, commit))
 378                         commit->object.flags |= TREESAME;
 379                 return;
 380         }
 381
 382         /*
 383          * Normal non-merge commit? If we don't want to make the
 384          * history dense, we consider it always to be a change..
 385          */
 386         if (!revs->dense && !commit->parents->next)
 387                 return;
 388
 389         pp = &commit->parents;
 390         while ((parent = *pp) != NULL) {
 391                 struct commit *p = parent->item;
 392
 393                 if (parse_commit(p) < 0)
 394                         die("cannot simplify commit %s (because of %s)",
 395                             sha1_to_hex(commit->object.sha1),
 396                             sha1_to_hex(p->object.sha1));
 397                 switch (rev_compare_tree(revs, p, commit)) {
 398                 case REV_TREE_SAME:
 399                         tree_same = 1;
 400                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 401                                 /* Even if a merge with an uninteresting
 402                                  * side branch brought the entire change
 403                                  * we are interested in, we do not want
 404                                  * to lose the other branches of this
 405                                  * merge, so we just keep going.
 406                                  */
 407                                 pp = &parent->next;
 408                                 continue;
 409                         }
 410                         parent->next = NULL;
 411                         commit->parents = parent;
 412                         commit->object.flags |= TREESAME;
 413                         return;
 414
 415                 case REV_TREE_NEW:
 416                         if (revs->remove_empty_trees &&
 417                             rev_same_tree_as_empty(revs, p)) {
 418                                 /* We are adding all the specified
 419                                  * paths from this parent, so the
 420                                  * history beyond this parent is not
 421                                  * interesting.  Remove its parents
 422                                  * (they are grandparents for us).
 423                                  * IOW, we pretend this parent is a
 424                                  * "root" commit.
 425                                  */
 426                                 if (parse_commit(p) < 0)
 427                                         die("cannot simplify commit %s (invalid %s)",
 428                                             sha1_to_hex(commit->object.sha1),
 429                                             sha1_to_hex(p->object.sha1));
 430                                 p->parents = NULL;
 431                         }
 432                 /* fallthrough */
 433                 case REV_TREE_OLD:
 434                 case REV_TREE_DIFFERENT:
 435                         tree_changed = 1;
 436                         pp = &parent->next;
 437                         continue;
 438                 }
 439                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 440         }
 441         if (tree_changed && !tree_same)
 442                 return;
 443         commit->object.flags |= TREESAME;
 444 }
 445
 446 static void insert_by_date_cached(struct commit *p, struct commit_list **head,
 447                     struct commit_list *cached_base, struct commit_list **cache)
 448 {
 449         struct commit_list *new_entry;
 450
 451         if (cached_base && p->date < cached_base->item->date)
 452                 new_entry = insert_by_date(p, &cached_base->next);
 453         else
 454                 new_entry = insert_by_date(p, head);
 455
 456         if (cache && (!*cache || p->date < (*cache)->item->date))
 457                 *cache = new_entry;
 458 }
 459
 460 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 461                     struct commit_list **list, struct commit_list **cache_ptr)
 462 {
 463         struct commit_list *parent = commit->parents;
 464         unsigned left_flag;
 465         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 466
 467         if (commit->object.flags & ADDED)
 468                 return 0;
 469         commit->object.flags |= ADDED;
 470
 471         /*
 472          * If the commit is uninteresting, don't try to
 473          * prune parents - we want the maximal uninteresting
 474          * set.
 475          *
 476          * Normally we haven't parsed the parent
 477          * yet, so we won't have a parent of a parent
 478          * here. However, it may turn out that we've
 479          * reached this commit some other way (where it
 480          * wasn't uninteresting), in which case we need
 481          * to mark its parents recursively too..
 482          */
 483         if (commit->object.flags & UNINTERESTING) {
 484                 while (parent) {
 485                         struct commit *p = parent->item;
 486                         parent = parent->next;
 487                         if (p)
 488                                 p->object.flags |= UNINTERESTING;
 489                         if (parse_commit(p) < 0)
 490                                 continue;
 491                         if (p->parents)
 492                                 mark_parents_uninteresting(p);
 493                         if (p->object.flags & SEEN)
 494                                 continue;
 495                         p->object.flags |= SEEN;
 496                         insert_by_date_cached(p, list, cached_base, cache_ptr);
 497                 }
 498                 return 0;
 499         }
 500
 501         /*
 502          * Ok, the commit wasn't uninteresting. Try to
 503          * simplify the commit history and find the parent
 504          * that has no differences in the path set if one exists.
 505          */
 506         try_to_simplify_commit(revs, commit);
 507
 508         if (revs->no_walk)
 509                 return 0;
 510
 511         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 512
 513         for (parent = commit->parents; parent; parent = parent->next) {
 514                 struct commit *p = parent->item;
 515
 516                 if (parse_commit(p) < 0)
 517                         return -1;
 518                 if (revs->show_source && !p->util)
 519                         p->util = commit->util;
 520                 p->object.flags |= left_flag;
 521                 if (!(p->object.flags & SEEN)) {
 522                         p->object.flags |= SEEN;
 523                         insert_by_date_cached(p, list, cached_base, cache_ptr);
 524                 }
 525                 if (revs->first_parent_only)
 526                         break;
 527         }
 528         return 0;
 529 }
 530
 531 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 532 {
 533         struct commit_list *p;
 534         int left_count = 0, right_count = 0;
 535         int left_first;
 536         struct patch_ids ids;
 537
 538         /* First count the commits on the left and on the right */
 539         for (p = list; p; p = p->next) {
 540                 struct commit *commit = p->item;
 541                 unsigned flags = commit->object.flags;
 542                 if (flags & BOUNDARY)
 543                         ;
 544                 else if (flags & SYMMETRIC_LEFT)
 545                         left_count++;
 546                 else
 547                         right_count++;
 548         }
 549
 550         if (!left_count || !right_count)
 551                 return;
 552
 553         left_first = left_count < right_count;
 554         init_patch_ids(&ids);
 555         if (revs->diffopt.nr_paths) {
 556                 ids.diffopts.nr_paths = revs->diffopt.nr_paths;
 557                 ids.diffopts.paths = revs->diffopt.paths;
 558                 ids.diffopts.pathlens = revs->diffopt.pathlens;
 559         }
 560
 561         /* Compute patch-ids for one side */
 562         for (p = list; p; p = p->next) {
 563                 struct commit *commit = p->item;
 564                 unsigned flags = commit->object.flags;
 565
 566                 if (flags & BOUNDARY)
 567                         continue;
 568                 /*
 569                  * If we have fewer left, left_first is set and we omit
 570                  * commits on the right branch in this loop.  If we have
 571                  * fewer right, we skip the left ones.
 572                  */
 573                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 574                         continue;
 575                 commit->util = add_commit_patch_id(commit, &ids);
 576         }
 577
 578         /* Check the other side */
 579         for (p = list; p; p = p->next) {
 580                 struct commit *commit = p->item;
 581                 struct patch_id *id;
 582                 unsigned flags = commit->object.flags;
 583
 584                 if (flags & BOUNDARY)
 585                         continue;
 586                 /*
 587                  * If we have fewer left, left_first is set and we omit
 588                  * commits on the left branch in this loop.
 589                  */
 590                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 591                         continue;
 592
 593                 /*
 594                  * Have we seen the same patch id?
 595                  */
 596                 id = has_commit_patch_id(commit, &ids);
 597                 if (!id)
 598                         continue;
 599                 id->seen = 1;
 600                 commit->object.flags |= SHOWN;
 601         }
 602
 603         /* Now check the original side for seen ones */
 604         for (p = list; p; p = p->next) {
 605                 struct commit *commit = p->item;
 606                 struct patch_id *ent;
 607
 608                 ent = commit->util;
 609                 if (!ent)
 610                         continue;
 611                 if (ent->seen)
 612                         commit->object.flags |= SHOWN;
 613                 commit->util = NULL;
 614         }
 615
 616         free_patch_ids(&ids);
 617 }
 618
 619 /* How many extra uninteresting commits we want to see.. */
 620 #define SLOP 5
 621
 622 static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 623 {
 624         /*
 625          * No source list at all? We're definitely done..
 626          */
 627         if (!src)
 628                 return 0;
 629
 630         /*
 631          * Does the destination list contain entries with a date
 632          * before the source list? Definitely _not_ done.
 633          */
 634         if (date < src->item->date)
 635                 return SLOP;
 636
 637         /*
 638          * Does the source list still have interesting commits in
 639          * it? Definitely not done..
 640          */
 641         if (!everybody_uninteresting(src))
 642                 return SLOP;
 643
 644         /* Ok, we're closing in.. */
 645         return slop-1;
 646 }
 647
 648 static int limit_list(struct rev_info *revs)
 649 {
 650         int slop = SLOP;
 651         unsigned long date = ~0ul;
 652         struct commit_list *list = revs->commits;
 653         struct commit_list *newlist = NULL;
 654         struct commit_list **p = &newlist;
 655
 656         while (list) {
 657                 struct commit_list *entry = list;
 658                 struct commit *commit = list->item;
 659                 struct object *obj = &commit->object;
 660                 show_early_output_fn_t show;
 661
 662                 list = list->next;
 663                 free(entry);
 664
 665                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 666                         obj->flags |= UNINTERESTING;
 667                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 668                         return -1;
 669                 if (obj->flags & UNINTERESTING) {
 670                         mark_parents_uninteresting(commit);
 671                         if (revs->show_all)
 672                                 p = &commit_list_insert(commit, p)->next;
 673                         slop = still_interesting(list, date, slop);
 674                         if (slop)
 675                                 continue;
 676                         /* If showing all, add the whole pending list to the end */
 677                         if (revs->show_all)
 678                                 *p = list;
 679                         break;
 680                 }
 681                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 682                         continue;
 683                 date = commit->date;
 684                 p = &commit_list_insert(commit, p)->next;
 685
 686                 show = show_early_output;
 687                 if (!show)
 688                         continue;
 689
 690                 show(revs, newlist);
 691                 show_early_output = NULL;
 692         }
 693         if (revs->cherry_pick)
 694                 cherry_pick_list(newlist, revs);
 695
 696         revs->commits = newlist;
 697         return 0;
 698 }
 699
 700 struct all_refs_cb {
 701         int all_flags;
 702         int warned_bad_reflog;
 703         struct rev_info *all_revs;
 704         const char *name_for_errormsg;
 705 };
 706
 707 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 708 {
 709         struct all_refs_cb *cb = cb_data;
 710         struct object *object = get_reference(cb->all_revs, path, sha1,
 711                                               cb->all_flags);
 712         add_pending_object(cb->all_revs, object, path);
 713         return 0;
 714 }
 715
 716 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
 717         unsigned flags)
 718 {
 719         cb->all_revs = revs;
 720         cb->all_flags = flags;
 721 }
 722
 723 static void handle_refs(struct rev_info *revs, unsigned flags,
 724                 int (*for_each)(each_ref_fn, void *))
 725 {
 726         struct all_refs_cb cb;
 727         init_all_refs_cb(&cb, revs, flags);
 728         for_each(handle_one_ref, &cb);
 729 }
 730
 731 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 732 {
 733         struct all_refs_cb *cb = cb_data;
 734         if (!is_null_sha1(sha1)) {
 735                 struct object *o = parse_object(sha1);
 736                 if (o) {
 737                         o->flags |= cb->all_flags;
 738                         add_pending_object(cb->all_revs, o, "");
 739                 }
 740                 else if (!cb->warned_bad_reflog) {
 741                         warning("reflog of '%s' references pruned commits",
 742                                 cb->name_for_errormsg);
 743                         cb->warned_bad_reflog = 1;
 744                 }
 745         }
 746 }
 747
 748 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 749                 const char *email, unsigned long timestamp, int tz,
 750                 const char *message, void *cb_data)
 751 {
 752         handle_one_reflog_commit(osha1, cb_data);
 753         handle_one_reflog_commit(nsha1, cb_data);
 754         return 0;
 755 }
 756
 757 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 758 {
 759         struct all_refs_cb *cb = cb_data;
 760         cb->warned_bad_reflog = 0;
 761         cb->name_for_errormsg = path;
 762         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 763         return 0;
 764 }
 765
 766 static void handle_reflog(struct rev_info *revs, unsigned flags)
 767 {
 768         struct all_refs_cb cb;
 769         cb.all_revs = revs;
 770         cb.all_flags = flags;
 771         for_each_reflog(handle_one_reflog, &cb);
 772 }
 773
 774 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 775 {
 776         unsigned char sha1[20];
 777         struct object *it;
 778         struct commit *commit;
 779         struct commit_list *parents;
 780
 781         if (*arg == '^') {
 782                 flags ^= UNINTERESTING;
 783                 arg++;
 784         }
 785         if (get_sha1(arg, sha1))
 786                 return 0;
 787         while (1) {
 788                 it = get_reference(revs, arg, sha1, 0);
 789                 if (it->type != OBJ_TAG)
 790                         break;
 791                 if (!((struct tag*)it)->tagged)
 792                         return 0;
 793                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 794         }
 795         if (it->type != OBJ_COMMIT)
 796                 return 0;
 797         commit = (struct commit *)it;
 798         for (parents = commit->parents; parents; parents = parents->next) {
 799                 it = &parents->item->object;
 800                 it->flags |= flags;
 801                 add_pending_object(revs, it, arg);
 802         }
 803         return 1;
 804 }
 805
 806 void init_revisions(struct rev_info *revs, const char *prefix)
 807 {
 808         memset(revs, 0, sizeof(*revs));
 809
 810         revs->abbrev = DEFAULT_ABBREV;
 811         revs->ignore_merges = 1;
 812         revs->simplify_history = 1;
 813         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 814         DIFF_OPT_SET(&revs->pruning, QUICK);
 815         revs->pruning.add_remove = file_add_remove;
 816         revs->pruning.change = file_change;
 817         revs->lifo = 1;
 818         revs->dense = 1;
 819         revs->prefix = prefix;
 820         revs->max_age = -1;
 821         revs->min_age = -1;
 822         revs->skip_count = -1;
 823         revs->max_count = -1;
 824
 825         revs->commit_format = CMIT_FMT_DEFAULT;
 826
 827         revs->grep_filter.status_only = 1;
 828         revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
 829         revs->grep_filter.regflags = REG_NEWLINE;
 830
 831         diff_setup(&revs->diffopt);
 832         if (prefix && !revs->diffopt.prefix) {
 833                 revs->diffopt.prefix = prefix;
 834                 revs->diffopt.prefix_length = strlen(prefix);
 835         }
 836 }
 837
 838 static void add_pending_commit_list(struct rev_info *revs,
 839                                     struct commit_list *commit_list,
 840                                     unsigned int flags)
 841 {
 842         while (commit_list) {
 843                 struct object *object = &commit_list->item->object;
 844                 object->flags |= flags;
 845                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
 846                 commit_list = commit_list->next;
 847         }
 848 }
 849
 850 static void prepare_show_merge(struct rev_info *revs)
 851 {
 852         struct commit_list *bases;
 853         struct commit *head, *other;
 854         unsigned char sha1[20];
 855         const char **prune = NULL;
 856         int i, prune_num = 1; /* counting terminating NULL */
 857
 858         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 859                 die("--merge without HEAD?");
 860         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 861                 die("--merge without MERGE_HEAD?");
 862         add_pending_object(revs, &head->object, "HEAD");
 863         add_pending_object(revs, &other->object, "MERGE_HEAD");
 864         bases = get_merge_bases(head, other, 1);
 865         add_pending_commit_list(revs, bases, UNINTERESTING);
 866         free_commit_list(bases);
 867         head->object.flags |= SYMMETRIC_LEFT;
 868
 869         if (!active_nr)
 870                 read_cache();
 871         for (i = 0; i < active_nr; i++) {
 872                 struct cache_entry *ce = active_cache[i];
 873                 if (!ce_stage(ce))
 874                         continue;
 875                 if (ce_path_match(ce, revs->prune_data)) {
 876                         prune_num++;
 877                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
 878                         prune[prune_num-2] = ce->name;
 879                         prune[prune_num-1] = NULL;
 880                 }
 881                 while ((i+1 < active_nr) &&
 882                        ce_same_name(ce, active_cache[i+1]))
 883                         i++;
 884         }
 885         revs->prune_data = prune;
 886         revs->limited = 1;
 887 }
 888
 889 int handle_revision_arg(const char *arg, struct rev_info *revs,
 890                         int flags,
 891                         int cant_be_filename)
 892 {
 893         unsigned mode;
 894         char *dotdot;
 895         struct object *object;
 896         unsigned char sha1[20];
 897         int local_flags;
 898
 899         dotdot = strstr(arg, "..");
 900         if (dotdot) {
 901                 unsigned char from_sha1[20];
 902                 const char *next = dotdot + 2;
 903                 const char *this = arg;
 904                 int symmetric = *next == '.';
 905                 unsigned int flags_exclude = flags ^ UNINTERESTING;
 906
 907                 *dotdot = 0;
 908                 next += symmetric;
 909
 910                 if (!*next)
 911                         next = "HEAD";
 912                 if (dotdot == arg)
 913                         this = "HEAD";
 914                 if (!get_sha1(this, from_sha1) &&
 915                     !get_sha1(next, sha1)) {
 916                         struct commit *a, *b;
 917                         struct commit_list *exclude;
 918
 919                         a = lookup_commit_reference(from_sha1);
 920                         b = lookup_commit_reference(sha1);
 921                         if (!a || !b) {
 922                                 die(symmetric ?
 923                                     "Invalid symmetric difference expression %s...%s" :
 924                                     "Invalid revision range %s..%s",
 925                                     arg, next);
 926                         }
 927
 928                         if (!cant_be_filename) {
 929                                 *dotdot = '.';
 930                                 verify_non_filename(revs->prefix, arg);
 931                         }
 932
 933                         if (symmetric) {
 934                                 exclude = get_merge_bases(a, b, 1);
 935                                 add_pending_commit_list(revs, exclude,
 936                                                         flags_exclude);
 937                                 free_commit_list(exclude);
 938                                 a->object.flags |= flags | SYMMETRIC_LEFT;
 939                         } else
 940                                 a->object.flags |= flags_exclude;
 941                         b->object.flags |= flags;
 942                         add_pending_object(revs, &a->object, this);
 943                         add_pending_object(revs, &b->object, next);
 944                         return 0;
 945                 }
 946                 *dotdot = '.';
 947         }
 948         dotdot = strstr(arg, "^@");
 949         if (dotdot && !dotdot[2]) {
 950                 *dotdot = 0;
 951                 if (add_parents_only(revs, arg, flags))
 952                         return 0;
 953                 *dotdot = '^';
 954         }
 955         dotdot = strstr(arg, "^!");
 956         if (dotdot && !dotdot[2]) {
 957                 *dotdot = 0;
 958                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 959                         *dotdot = '^';
 960         }
 961
 962         local_flags = 0;
 963         if (*arg == '^') {
 964                 local_flags = UNINTERESTING;
 965                 arg++;
 966         }
 967         if (get_sha1_with_mode(arg, sha1, &mode))
 968                 return -1;
 969         if (!cant_be_filename)
 970                 verify_non_filename(revs->prefix, arg);
 971         object = get_reference(revs, arg, sha1, flags ^ local_flags);
 972         add_pending_object_with_mode(revs, object, arg, mode);
 973         return 0;
 974 }
 975
 976 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb, const char ***prune_data)
 977 {
 978         const char **prune = *prune_data;
 979         int prune_nr;
 980         int prune_alloc;
 981
 982         /* count existing ones */
 983         if (!prune)
 984                 prune_nr = 0;
 985         else
 986                 for (prune_nr = 0; prune[prune_nr]; prune_nr++)
 987                         ;
 988         prune_alloc = prune_nr; /* not really, but we do not know */
 989
 990         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
 991                 int len = sb->len;
 992                 if (len && sb->buf[len - 1] == '\n')
 993                         sb->buf[--len] = '\0';
 994                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
 995                 prune[prune_nr++] = xstrdup(sb->buf);
 996         }
 997         if (prune) {
 998                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
 999                 prune[prune_nr] = NULL;
1000         }
1001         *prune_data = prune;
1002 }
1003
1004 static void read_revisions_from_stdin(struct rev_info *revs, const char ***prune)
1005 {
1006         struct strbuf sb;
1007         int seen_dashdash = 0;
1008
1009         strbuf_init(&sb, 1000);
1010         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1011                 int len = sb.len;
1012                 if (len && sb.buf[len - 1] == '\n')
1013                         sb.buf[--len] = '\0';
1014                 if (!len)
1015                         break;
1016                 if (sb.buf[0] == '-') {
1017                         if (len == 2 && sb.buf[1] == '-') {
1018                                 seen_dashdash = 1;
1019                                 break;
1020                         }
1021                         die("options not supported in --stdin mode");
1022                 }
1023                 if (handle_revision_arg(sb.buf, revs, 0, 1))
1024                         die("bad revision '%s'", sb.buf);
1025         }
1026         if (seen_dashdash)
1027                 read_pathspec_from_stdin(revs, &sb, prune);
1028         strbuf_release(&sb);
1029 }
1030
1031 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1032 {
1033         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1034 }
1035
1036 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1037 {
1038         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1039 }
1040
1041 static void add_message_grep(struct rev_info *revs, const char *pattern)
1042 {
1043         add_grep(revs, pattern, GREP_PATTERN_BODY);
1044 }
1045
1046 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1047                                int *unkc, const char **unkv)
1048 {
1049         const char *arg = argv[0];
1050
1051         /* pseudo revision arguments */
1052         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1053             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1054             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1055             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1056             !strcmp(arg, "--bisect"))
1057         {
1058                 unkv[(*unkc)++] = arg;
1059                 return 1;
1060         }
1061
1062         if (!prefixcmp(arg, "--max-count=")) {
1063                 revs->max_count = atoi(arg + 12);
1064         } else if (!prefixcmp(arg, "--skip=")) {
1065                 revs->skip_count = atoi(arg + 7);
1066         } else if ((*arg == '-') && isdigit(arg[1])) {
1067         /* accept -<digit>, like traditional "head" */
1068                 revs->max_count = atoi(arg + 1);
1069         } else if (!strcmp(arg, "-n")) {
1070                 if (argc <= 1)
1071                         return error("-n requires an argument");
1072                 revs->max_count = atoi(argv[1]);
1073                 return 2;
1074         } else if (!prefixcmp(arg, "-n")) {
1075                 revs->max_count = atoi(arg + 2);
1076         } else if (!prefixcmp(arg, "--max-age=")) {
1077                 revs->max_age = atoi(arg + 10);
1078         } else if (!prefixcmp(arg, "--since=")) {
1079                 revs->max_age = approxidate(arg + 8);
1080         } else if (!prefixcmp(arg, "--after=")) {
1081                 revs->max_age = approxidate(arg + 8);
1082         } else if (!prefixcmp(arg, "--min-age=")) {
1083                 revs->min_age = atoi(arg + 10);
1084         } else if (!prefixcmp(arg, "--before=")) {
1085                 revs->min_age = approxidate(arg + 9);
1086         } else if (!prefixcmp(arg, "--until=")) {
1087                 revs->min_age = approxidate(arg + 8);
1088         } else if (!strcmp(arg, "--first-parent")) {
1089                 revs->first_parent_only = 1;
1090         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1091                 init_reflog_walk(&revs->reflog_info);
1092         } else if (!strcmp(arg, "--default")) {
1093                 if (argc <= 1)
1094                         return error("bad --default argument");
1095                 revs->def = argv[1];
1096                 return 2;
1097         } else if (!strcmp(arg, "--merge")) {
1098                 revs->show_merge = 1;
1099         } else if (!strcmp(arg, "--topo-order")) {
1100                 revs->lifo = 1;
1101                 revs->topo_order = 1;
1102         } else if (!strcmp(arg, "--simplify-merges")) {
1103                 revs->simplify_merges = 1;
1104                 revs->rewrite_parents = 1;
1105                 revs->simplify_history = 0;
1106                 revs->limited = 1;
1107         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1108                 revs->simplify_merges = 1;
1109                 revs->rewrite_parents = 1;
1110                 revs->simplify_history = 0;
1111                 revs->simplify_by_decoration = 1;
1112                 revs->limited = 1;
1113                 revs->prune = 1;
1114                 load_ref_decorations(DECORATE_SHORT_REFS);
1115         } else if (!strcmp(arg, "--date-order")) {
1116                 revs->lifo = 0;
1117                 revs->topo_order = 1;
1118         } else if (!prefixcmp(arg, "--early-output")) {
1119                 int count = 100;
1120                 switch (arg[14]) {
1121                 case '=':
1122                         count = atoi(arg+15);
1123                         /* Fallthrough */
1124                 case 0:
1125                         revs->topo_order = 1;
1126                        revs->early_output = count;
1127                 }
1128         } else if (!strcmp(arg, "--parents")) {
1129                 revs->rewrite_parents = 1;
1130                 revs->print_parents = 1;
1131         } else if (!strcmp(arg, "--dense")) {
1132                 revs->dense = 1;
1133         } else if (!strcmp(arg, "--sparse")) {
1134                 revs->dense = 0;
1135         } else if (!strcmp(arg, "--show-all")) {
1136                 revs->show_all = 1;
1137         } else if (!strcmp(arg, "--remove-empty")) {
1138                 revs->remove_empty_trees = 1;
1139         } else if (!strcmp(arg, "--merges")) {
1140                 revs->merges_only = 1;
1141         } else if (!strcmp(arg, "--no-merges")) {
1142                 revs->no_merges = 1;
1143         } else if (!strcmp(arg, "--boundary")) {
1144                 revs->boundary = 1;
1145         } else if (!strcmp(arg, "--left-right")) {
1146                 revs->left_right = 1;
1147         } else if (!strcmp(arg, "--cherry-pick")) {
1148                 revs->cherry_pick = 1;
1149                 revs->limited = 1;
1150         } else if (!strcmp(arg, "--objects")) {
1151                 revs->tag_objects = 1;
1152                 revs->tree_objects = 1;
1153                 revs->blob_objects = 1;
1154         } else if (!strcmp(arg, "--objects-edge")) {
1155                 revs->tag_objects = 1;
1156                 revs->tree_objects = 1;
1157                 revs->blob_objects = 1;
1158                 revs->edge_hint = 1;
1159         } else if (!strcmp(arg, "--unpacked")) {
1160                 revs->unpacked = 1;
1161         } else if (!prefixcmp(arg, "--unpacked=")) {
1162                 die("--unpacked=<packfile> no longer supported.");
1163         } else if (!strcmp(arg, "-r")) {
1164                 revs->diff = 1;
1165                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1166         } else if (!strcmp(arg, "-t")) {
1167                 revs->diff = 1;
1168                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1169                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1170         } else if (!strcmp(arg, "-m")) {
1171                 revs->ignore_merges = 0;
1172         } else if (!strcmp(arg, "-c")) {
1173                 revs->diff = 1;
1174                 revs->dense_combined_merges = 0;
1175                 revs->combine_merges = 1;
1176         } else if (!strcmp(arg, "--cc")) {
1177                 revs->diff = 1;
1178                 revs->dense_combined_merges = 1;
1179                 revs->combine_merges = 1;
1180         } else if (!strcmp(arg, "-v")) {
1181                 revs->verbose_header = 1;
1182         } else if (!strcmp(arg, "--pretty")) {
1183                 revs->verbose_header = 1;
1184                 revs->pretty_given = 1;
1185                 get_commit_format(arg+8, revs);
1186         } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1187                 revs->verbose_header = 1;
1188                 revs->pretty_given = 1;
1189                 get_commit_format(arg+9, revs);
1190         } else if (!strcmp(arg, "--show-notes")) {
1191                 revs->show_notes = 1;
1192                 revs->show_notes_given = 1;
1193         } else if (!strcmp(arg, "--no-notes")) {
1194                 revs->show_notes = 0;
1195                 revs->show_notes_given = 1;
1196         } else if (!strcmp(arg, "--oneline")) {
1197                 revs->verbose_header = 1;
1198                 get_commit_format("oneline", revs);
1199                 revs->pretty_given = 1;
1200                 revs->abbrev_commit = 1;
1201         } else if (!strcmp(arg, "--graph")) {
1202                 revs->topo_order = 1;
1203                 revs->rewrite_parents = 1;
1204                 revs->graph = graph_init(revs);
1205         } else if (!strcmp(arg, "--root")) {
1206                 revs->show_root_diff = 1;
1207         } else if (!strcmp(arg, "--no-commit-id")) {
1208                 revs->no_commit_id = 1;
1209         } else if (!strcmp(arg, "--always")) {
1210                 revs->always_show_header = 1;
1211         } else if (!strcmp(arg, "--no-abbrev")) {
1212                 revs->abbrev = 0;
1213         } else if (!strcmp(arg, "--abbrev")) {
1214                 revs->abbrev = DEFAULT_ABBREV;
1215         } else if (!prefixcmp(arg, "--abbrev=")) {
1216                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1217                 if (revs->abbrev < MINIMUM_ABBREV)
1218                         revs->abbrev = MINIMUM_ABBREV;
1219                 else if (revs->abbrev > 40)
1220                         revs->abbrev = 40;
1221         } else if (!strcmp(arg, "--abbrev-commit")) {
1222                 revs->abbrev_commit = 1;
1223         } else if (!strcmp(arg, "--full-diff")) {
1224                 revs->diff = 1;
1225                 revs->full_diff = 1;
1226         } else if (!strcmp(arg, "--full-history")) {
1227                 revs->simplify_history = 0;
1228         } else if (!strcmp(arg, "--relative-date")) {
1229                 revs->date_mode = DATE_RELATIVE;
1230                 revs->date_mode_explicit = 1;
1231         } else if (!strncmp(arg, "--date=", 7)) {
1232                 revs->date_mode = parse_date_format(arg + 7);
1233                 revs->date_mode_explicit = 1;
1234         } else if (!strcmp(arg, "--log-size")) {
1235                 revs->show_log_size = 1;
1236         }
1237         /*
1238          * Grepping the commit log
1239          */
1240         else if (!prefixcmp(arg, "--author=")) {
1241                 add_header_grep(revs, GREP_HEADER_AUTHOR, arg+9);
1242         } else if (!prefixcmp(arg, "--committer=")) {
1243                 add_header_grep(revs, GREP_HEADER_COMMITTER, arg+12);
1244         } else if (!prefixcmp(arg, "--grep=")) {
1245                 add_message_grep(revs, arg+7);
1246         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1247                 revs->grep_filter.regflags |= REG_EXTENDED;
1248         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1249                 revs->grep_filter.regflags |= REG_ICASE;
1250         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1251                 revs->grep_filter.fixed = 1;
1252         } else if (!strcmp(arg, "--all-match")) {
1253                 revs->grep_filter.all_match = 1;
1254         } else if (!prefixcmp(arg, "--encoding=")) {
1255                 arg += 11;
1256                 if (strcmp(arg, "none"))
1257                         git_log_output_encoding = xstrdup(arg);
1258                 else
1259                         git_log_output_encoding = "";
1260         } else if (!strcmp(arg, "--reverse")) {
1261                 revs->reverse ^= 1;
1262         } else if (!strcmp(arg, "--children")) {
1263                 revs->children.name = "children";
1264                 revs->limited = 1;
1265         } else {
1266                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1267                 if (!opts)
1268                         unkv[(*unkc)++] = arg;
1269                 return opts;
1270         }
1271
1272         return 1;
1273 }
1274
1275 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1276                         const struct option *options,
1277                         const char * const usagestr[])
1278 {
1279         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1280                                     &ctx->cpidx, ctx->out);
1281         if (n <= 0) {
1282                 error("unknown option `%s'", ctx->argv[0]);
1283                 usage_with_options(usagestr, options);
1284         }
1285         ctx->argv += n;
1286         ctx->argc -= n;
1287 }
1288
1289 static int for_each_bad_bisect_ref(each_ref_fn fn, void *cb_data)
1290 {
1291         return for_each_ref_in("refs/bisect/bad", fn, cb_data);
1292 }
1293
1294 static int for_each_good_bisect_ref(each_ref_fn fn, void *cb_data)
1295 {
1296         return for_each_ref_in("refs/bisect/good", fn, cb_data);
1297 }
1298
1299 static void append_prune_data(const char ***prune_data, const char **av)
1300 {
1301         const char **prune = *prune_data;
1302         int prune_nr;
1303         int prune_alloc;
1304
1305         if (!prune) {
1306                 *prune_data = av;
1307                 return;
1308         }
1309
1310         /* count existing ones */
1311         for (prune_nr = 0; prune[prune_nr]; prune_nr++)
1312                 ;
1313         prune_alloc = prune_nr; /* not really, but we do not know */
1314
1315         while (*av) {
1316                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1317                 prune[prune_nr++] = *av;
1318                 av++;
1319         }
1320         if (prune) {
1321                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1322                 prune[prune_nr] = NULL;
1323         }
1324         *prune_data = prune;
1325 }
1326
1327 /*
1328  * Parse revision information, filling in the "rev_info" structure,
1329  * and removing the used arguments from the argument list.
1330  *
1331  * Returns the number of arguments left that weren't recognized
1332  * (which are also moved to the head of the argument list)
1333  */
1334 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
1335 {
1336         int i, flags, left, seen_dashdash, read_from_stdin;
1337         const char **prune_data = NULL;
1338
1339         /* First, search for "--" */
1340         seen_dashdash = 0;
1341         for (i = 1; i < argc; i++) {
1342                 const char *arg = argv[i];
1343                 if (strcmp(arg, "--"))
1344                         continue;
1345                 argv[i] = NULL;
1346                 argc = i;
1347                 if (argv[i + 1])
1348                         prune_data = argv + i + 1;
1349                 seen_dashdash = 1;
1350                 break;
1351         }
1352
1353         /* Second, deal with arguments and options */
1354         flags = 0;
1355         read_from_stdin = 0;
1356         for (left = i = 1; i < argc; i++) {
1357                 const char *arg = argv[i];
1358                 if (*arg == '-') {
1359                         int opts;
1360
1361                         if (!strcmp(arg, "--all")) {
1362                                 handle_refs(revs, flags, for_each_ref);
1363                                 handle_refs(revs, flags, head_ref);
1364                                 continue;
1365                         }
1366                         if (!strcmp(arg, "--branches")) {
1367                                 handle_refs(revs, flags, for_each_branch_ref);
1368                                 continue;
1369                         }
1370                         if (!strcmp(arg, "--bisect")) {
1371                                 handle_refs(revs, flags, for_each_bad_bisect_ref);
1372                                 handle_refs(revs, flags ^ UNINTERESTING, for_each_good_bisect_ref);
1373                                 revs->bisect = 1;
1374                                 continue;
1375                         }
1376                         if (!strcmp(arg, "--tags")) {
1377                                 handle_refs(revs, flags, for_each_tag_ref);
1378                                 continue;
1379                         }
1380                         if (!strcmp(arg, "--remotes")) {
1381                                 handle_refs(revs, flags, for_each_remote_ref);
1382                                 continue;
1383                         }
1384                         if (!prefixcmp(arg, "--glob=")) {
1385                                 struct all_refs_cb cb;
1386                                 init_all_refs_cb(&cb, revs, flags);
1387                                 for_each_glob_ref(handle_one_ref, arg + 7, &cb);
1388                                 continue;
1389                         }
1390                         if (!prefixcmp(arg, "--branches=")) {
1391                                 struct all_refs_cb cb;
1392                                 init_all_refs_cb(&cb, revs, flags);
1393                                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1394                                 continue;
1395                         }
1396                         if (!prefixcmp(arg, "--tags=")) {
1397                                 struct all_refs_cb cb;
1398                                 init_all_refs_cb(&cb, revs, flags);
1399                                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1400                                 continue;
1401                         }
1402                         if (!prefixcmp(arg, "--remotes=")) {
1403                                 struct all_refs_cb cb;
1404                                 init_all_refs_cb(&cb, revs, flags);
1405                                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1406                                 continue;
1407                         }
1408                         if (!strcmp(arg, "--reflog")) {
1409                                 handle_reflog(revs, flags);
1410                                 continue;
1411                         }
1412                         if (!strcmp(arg, "--not")) {
1413                                 flags ^= UNINTERESTING;
1414                                 continue;
1415                         }
1416                         if (!strcmp(arg, "--no-walk")) {
1417                                 revs->no_walk = 1;
1418                                 continue;
1419                         }
1420                         if (!strcmp(arg, "--do-walk")) {
1421                                 revs->no_walk = 0;
1422                                 continue;
1423                         }
1424                         if (!strcmp(arg, "--stdin")) {
1425                                 if (revs->disable_stdin) {
1426                                         argv[left++] = arg;
1427                                         continue;
1428                                 }
1429                                 if (read_from_stdin++)
1430                                         die("--stdin given twice?");
1431                                 read_revisions_from_stdin(revs, &prune_data);
1432                                 continue;
1433                         }
1434
1435                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1436                         if (opts > 0) {
1437                                 i += opts - 1;
1438                                 continue;
1439                         }
1440                         if (opts < 0)
1441                                 exit(128);
1442                         continue;
1443                 }
1444
1445                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1446                         int j;
1447                         if (seen_dashdash || *arg == '^')
1448                                 die("bad revision '%s'", arg);
1449
1450                         /* If we didn't have a "--":
1451                          * (1) all filenames must exist;
1452                          * (2) all rev-args must not be interpretable
1453                          *     as a valid filename.
1454                          * but the latter we have checked in the main loop.
1455                          */
1456                         for (j = i; j < argc; j++)
1457                                 verify_filename(revs->prefix, argv[j]);
1458
1459                         append_prune_data(&prune_data, argv + i);
1460                         break;
1461                 }
1462         }
1463
1464         if (prune_data)
1465                 revs->prune_data = get_pathspec(revs->prefix, prune_data);
1466
1467         if (revs->def == NULL)
1468                 revs->def = def;
1469         if (revs->show_merge)
1470                 prepare_show_merge(revs);
1471         if (revs->def && !revs->pending.nr) {
1472                 unsigned char sha1[20];
1473                 struct object *object;
1474                 unsigned mode;
1475                 if (get_sha1_with_mode(revs->def, sha1, &mode))
1476                         die("bad default revision '%s'", revs->def);
1477                 object = get_reference(revs, revs->def, sha1, 0);
1478                 add_pending_object_with_mode(revs, object, revs->def, mode);
1479         }
1480
1481         /* Did the user ask for any diff output? Run the diff! */
1482         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1483                 revs->diff = 1;
1484
1485         /* Pickaxe, diff-filter and rename following need diffs */
1486         if (revs->diffopt.pickaxe ||
1487             revs->diffopt.filter ||
1488             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1489                 revs->diff = 1;
1490
1491         if (revs->topo_order)
1492                 revs->limited = 1;
1493
1494         if (revs->prune_data) {
1495                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1496                 /* Can't prune commits with rename following: the paths change.. */
1497                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1498                         revs->prune = 1;
1499                 if (!revs->full_diff)
1500                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1501         }
1502         if (revs->combine_merges) {
1503                 revs->ignore_merges = 0;
1504                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1505                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1506         }
1507         revs->diffopt.abbrev = revs->abbrev;
1508         if (diff_setup_done(&revs->diffopt) < 0)
1509                 die("diff_setup_done failed");
1510
1511         compile_grep_patterns(&revs->grep_filter);
1512
1513         if (revs->reverse && revs->reflog_info)
1514                 die("cannot combine --reverse with --walk-reflogs");
1515         if (revs->rewrite_parents && revs->children.name)
1516                 die("cannot combine --parents and --children");
1517
1518         /*
1519          * Limitations on the graph functionality
1520          */
1521         if (revs->reverse && revs->graph)
1522                 die("cannot combine --reverse with --graph");
1523
1524         if (revs->reflog_info && revs->graph)
1525                 die("cannot combine --walk-reflogs with --graph");
1526
1527         return left;
1528 }
1529
1530 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1531 {
1532         struct commit_list *l = xcalloc(1, sizeof(*l));
1533
1534         l->item = child;
1535         l->next = add_decoration(&revs->children, &parent->object, l);
1536 }
1537
1538 static int remove_duplicate_parents(struct commit *commit)
1539 {
1540         struct commit_list **pp, *p;
1541         int surviving_parents;
1542
1543         /* Examine existing parents while marking ones we have seen... */
1544         pp = &commit->parents;
1545         while ((p = *pp) != NULL) {
1546                 struct commit *parent = p->item;
1547                 if (parent->object.flags & TMP_MARK) {
1548                         *pp = p->next;
1549                         continue;
1550                 }
1551                 parent->object.flags |= TMP_MARK;
1552                 pp = &p->next;
1553         }
1554         /* count them while clearing the temporary mark */
1555         surviving_parents = 0;
1556         for (p = commit->parents; p; p = p->next) {
1557                 p->item->object.flags &= ~TMP_MARK;
1558                 surviving_parents++;
1559         }
1560         return surviving_parents;
1561 }
1562
1563 struct merge_simplify_state {
1564         struct commit *simplified;
1565 };
1566
1567 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1568 {
1569         struct merge_simplify_state *st;
1570
1571         st = lookup_decoration(&revs->merge_simplification, &commit->object);
1572         if (!st) {
1573                 st = xcalloc(1, sizeof(*st));
1574                 add_decoration(&revs->merge_simplification, &commit->object, st);
1575         }
1576         return st;
1577 }
1578
1579 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1580 {
1581         struct commit_list *p;
1582         struct merge_simplify_state *st, *pst;
1583         int cnt;
1584
1585         st = locate_simplify_state(revs, commit);
1586
1587         /*
1588          * Have we handled this one?
1589          */
1590         if (st->simplified)
1591                 return tail;
1592
1593         /*
1594          * An UNINTERESTING commit simplifies to itself, so does a
1595          * root commit.  We do not rewrite parents of such commit
1596          * anyway.
1597          */
1598         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1599                 st->simplified = commit;
1600                 return tail;
1601         }
1602
1603         /*
1604          * Do we know what commit all of our parents should be rewritten to?
1605          * Otherwise we are not ready to rewrite this one yet.
1606          */
1607         for (cnt = 0, p = commit->parents; p; p = p->next) {
1608                 pst = locate_simplify_state(revs, p->item);
1609                 if (!pst->simplified) {
1610                         tail = &commit_list_insert(p->item, tail)->next;
1611                         cnt++;
1612                 }
1613         }
1614         if (cnt) {
1615                 tail = &commit_list_insert(commit, tail)->next;
1616                 return tail;
1617         }
1618
1619         /*
1620          * Rewrite our list of parents.
1621          */
1622         for (p = commit->parents; p; p = p->next) {
1623                 pst = locate_simplify_state(revs, p->item);
1624                 p->item = pst->simplified;
1625         }
1626         cnt = remove_duplicate_parents(commit);
1627
1628         /*
1629          * It is possible that we are a merge and one side branch
1630          * does not have any commit that touches the given paths;
1631          * in such a case, the immediate parents will be rewritten
1632          * to different commits.
1633          *
1634          *      o----X          X: the commit we are looking at;
1635          *     /    /           o: a commit that touches the paths;
1636          * ---o----'
1637          *
1638          * Further reduce the parents by removing redundant parents.
1639          */
1640         if (1 < cnt) {
1641                 struct commit_list *h = reduce_heads(commit->parents);
1642                 cnt = commit_list_count(h);
1643                 free_commit_list(commit->parents);
1644                 commit->parents = h;
1645         }
1646
1647         /*
1648          * A commit simplifies to itself if it is a root, if it is
1649          * UNINTERESTING, if it touches the given paths, or if it is a
1650          * merge and its parents simplifies to more than one commits
1651          * (the first two cases are already handled at the beginning of
1652          * this function).
1653          *
1654          * Otherwise, it simplifies to what its sole parent simplifies to.
1655          */
1656         if (!cnt ||
1657             (commit->object.flags & UNINTERESTING) ||
1658             !(commit->object.flags & TREESAME) ||
1659             (1 < cnt))
1660                 st->simplified = commit;
1661         else {
1662                 pst = locate_simplify_state(revs, commit->parents->item);
1663                 st->simplified = pst->simplified;
1664         }
1665         return tail;
1666 }
1667
1668 static void simplify_merges(struct rev_info *revs)
1669 {
1670         struct commit_list *list;
1671         struct commit_list *yet_to_do, **tail;
1672
1673         if (!revs->topo_order)
1674                 sort_in_topological_order(&revs->commits, revs->lifo);
1675         if (!revs->prune)
1676                 return;
1677
1678         /* feed the list reversed */
1679         yet_to_do = NULL;
1680         for (list = revs->commits; list; list = list->next)
1681                 commit_list_insert(list->item, &yet_to_do);
1682         while (yet_to_do) {
1683                 list = yet_to_do;
1684                 yet_to_do = NULL;
1685                 tail = &yet_to_do;
1686                 while (list) {
1687                         struct commit *commit = list->item;
1688                         struct commit_list *next = list->next;
1689                         free(list);
1690                         list = next;
1691                         tail = simplify_one(revs, commit, tail);
1692                 }
1693         }
1694
1695         /* clean up the result, removing the simplified ones */
1696         list = revs->commits;
1697         revs->commits = NULL;
1698         tail = &revs->commits;
1699         while (list) {
1700                 struct commit *commit = list->item;
1701                 struct commit_list *next = list->next;
1702                 struct merge_simplify_state *st;
1703                 free(list);
1704                 list = next;
1705                 st = locate_simplify_state(revs, commit);
1706                 if (st->simplified == commit)
1707                         tail = &commit_list_insert(commit, tail)->next;
1708         }
1709 }
1710
1711 static void set_children(struct rev_info *revs)
1712 {
1713         struct commit_list *l;
1714         for (l = revs->commits; l; l = l->next) {
1715                 struct commit *commit = l->item;
1716                 struct commit_list *p;
1717
1718                 for (p = commit->parents; p; p = p->next)
1719                         add_child(revs, p->item, commit);
1720         }
1721 }
1722
1723 int prepare_revision_walk(struct rev_info *revs)
1724 {
1725         int nr = revs->pending.nr;
1726         struct object_array_entry *e, *list;
1727
1728         e = list = revs->pending.objects;
1729         revs->pending.nr = 0;
1730         revs->pending.alloc = 0;
1731         revs->pending.objects = NULL;
1732         while (--nr >= 0) {
1733                 struct commit *commit = handle_commit(revs, e->item, e->name);
1734                 if (commit) {
1735                         if (!(commit->object.flags & SEEN)) {
1736                                 commit->object.flags |= SEEN;
1737                                 insert_by_date(commit, &revs->commits);
1738                         }
1739                 }
1740                 e++;
1741         }
1742         free(list);
1743
1744         if (revs->no_walk)
1745                 return 0;
1746         if (revs->limited)
1747                 if (limit_list(revs) < 0)
1748                         return -1;
1749         if (revs->topo_order)
1750                 sort_in_topological_order(&revs->commits, revs->lifo);
1751         if (revs->simplify_merges)
1752                 simplify_merges(revs);
1753         if (revs->children.name)
1754                 set_children(revs);
1755         return 0;
1756 }
1757
1758 enum rewrite_result {
1759         rewrite_one_ok,
1760         rewrite_one_noparents,
1761         rewrite_one_error,
1762 };
1763
1764 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1765 {
1766         struct commit_list *cache = NULL;
1767
1768         for (;;) {
1769                 struct commit *p = *pp;
1770                 if (!revs->limited)
1771                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
1772                                 return rewrite_one_error;
1773                 if (p->parents && p->parents->next)
1774                         return rewrite_one_ok;
1775                 if (p->object.flags & UNINTERESTING)
1776                         return rewrite_one_ok;
1777                 if (!(p->object.flags & TREESAME))
1778                         return rewrite_one_ok;
1779                 if (!p->parents)
1780                         return rewrite_one_noparents;
1781                 *pp = p->parents->item;
1782         }
1783 }
1784
1785 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1786 {
1787         struct commit_list **pp = &commit->parents;
1788         while (*pp) {
1789                 struct commit_list *parent = *pp;
1790                 switch (rewrite_one(revs, &parent->item)) {
1791                 case rewrite_one_ok:
1792                         break;
1793                 case rewrite_one_noparents:
1794                         *pp = parent->next;
1795                         continue;
1796                 case rewrite_one_error:
1797                         return -1;
1798                 }
1799                 pp = &parent->next;
1800         }
1801         remove_duplicate_parents(commit);
1802         return 0;
1803 }
1804
1805 static int commit_match(struct commit *commit, struct rev_info *opt)
1806 {
1807         if (!opt->grep_filter.pattern_list)
1808                 return 1;
1809         return grep_buffer(&opt->grep_filter,
1810                            NULL, /* we say nothing, not even filename */
1811                            commit->buffer, strlen(commit->buffer));
1812 }
1813
1814 static inline int want_ancestry(struct rev_info *revs)
1815 {
1816         return (revs->rewrite_parents || revs->children.name);
1817 }
1818
1819 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
1820 {
1821         if (commit->object.flags & SHOWN)
1822                 return commit_ignore;
1823         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
1824                 return commit_ignore;
1825         if (revs->show_all)
1826                 return commit_show;
1827         if (commit->object.flags & UNINTERESTING)
1828                 return commit_ignore;
1829         if (revs->min_age != -1 && (commit->date > revs->min_age))
1830                 return commit_ignore;
1831         if (revs->no_merges && commit->parents && commit->parents->next)
1832                 return commit_ignore;
1833         if (revs->merges_only && !(commit->parents && commit->parents->next))
1834                 return commit_ignore;
1835         if (!commit_match(commit, revs))
1836                 return commit_ignore;
1837         if (revs->prune && revs->dense) {
1838                 /* Commit without changes? */
1839                 if (commit->object.flags & TREESAME) {
1840                         /* drop merges unless we want parenthood */
1841                         if (!want_ancestry(revs))
1842                                 return commit_ignore;
1843                         /* non-merge - always ignore it */
1844                         if (!commit->parents || !commit->parents->next)
1845                                 return commit_ignore;
1846                 }
1847         }
1848         return commit_show;
1849 }
1850
1851 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1852 {
1853         enum commit_action action = get_commit_action(revs, commit);
1854
1855         if (action == commit_show &&
1856             !revs->show_all &&
1857             revs->prune && revs->dense && want_ancestry(revs)) {
1858                 if (rewrite_parents(revs, commit) < 0)
1859                         return commit_error;
1860         }
1861         return action;
1862 }
1863
1864 static struct commit *get_revision_1(struct rev_info *revs)
1865 {
1866         if (!revs->commits)
1867                 return NULL;
1868
1869         do {
1870                 struct commit_list *entry = revs->commits;
1871                 struct commit *commit = entry->item;
1872
1873                 revs->commits = entry->next;
1874                 free(entry);
1875
1876                 if (revs->reflog_info)
1877                         fake_reflog_parent(revs->reflog_info, commit);
1878
1879                 /*
1880                  * If we haven't done the list limiting, we need to look at
1881                  * the parents here. We also need to do the date-based limiting
1882                  * that we'd otherwise have done in limit_list().
1883                  */
1884                 if (!revs->limited) {
1885                         if (revs->max_age != -1 &&
1886                             (commit->date < revs->max_age))
1887                                 continue;
1888                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
1889                                 die("Failed to traverse parents of commit %s",
1890                                     sha1_to_hex(commit->object.sha1));
1891                 }
1892
1893                 switch (simplify_commit(revs, commit)) {
1894                 case commit_ignore:
1895                         continue;
1896                 case commit_error:
1897                         die("Failed to simplify parents of commit %s",
1898                             sha1_to_hex(commit->object.sha1));
1899                 default:
1900                         return commit;
1901                 }
1902         } while (revs->commits);
1903         return NULL;
1904 }
1905
1906 static void gc_boundary(struct object_array *array)
1907 {
1908         unsigned nr = array->nr;
1909         unsigned alloc = array->alloc;
1910         struct object_array_entry *objects = array->objects;
1911
1912         if (alloc <= nr) {
1913                 unsigned i, j;
1914                 for (i = j = 0; i < nr; i++) {
1915                         if (objects[i].item->flags & SHOWN)
1916                                 continue;
1917                         if (i != j)
1918                                 objects[j] = objects[i];
1919                         j++;
1920                 }
1921                 for (i = j; i < nr; i++)
1922                         objects[i].item = NULL;
1923                 array->nr = j;
1924         }
1925 }
1926
1927 static void create_boundary_commit_list(struct rev_info *revs)
1928 {
1929         unsigned i;
1930         struct commit *c;
1931         struct object_array *array = &revs->boundary_commits;
1932         struct object_array_entry *objects = array->objects;
1933
1934         /*
1935          * If revs->commits is non-NULL at this point, an error occurred in
1936          * get_revision_1().  Ignore the error and continue printing the
1937          * boundary commits anyway.  (This is what the code has always
1938          * done.)
1939          */
1940         if (revs->commits) {
1941                 free_commit_list(revs->commits);
1942                 revs->commits = NULL;
1943         }
1944
1945         /*
1946          * Put all of the actual boundary commits from revs->boundary_commits
1947          * into revs->commits
1948          */
1949         for (i = 0; i < array->nr; i++) {
1950                 c = (struct commit *)(objects[i].item);
1951                 if (!c)
1952                         continue;
1953                 if (!(c->object.flags & CHILD_SHOWN))
1954                         continue;
1955                 if (c->object.flags & (SHOWN | BOUNDARY))
1956                         continue;
1957                 c->object.flags |= BOUNDARY;
1958                 commit_list_insert(c, &revs->commits);
1959         }
1960
1961         /*
1962          * If revs->topo_order is set, sort the boundary commits
1963          * in topological order
1964          */
1965         sort_in_topological_order(&revs->commits, revs->lifo);
1966 }
1967
1968 static struct commit *get_revision_internal(struct rev_info *revs)
1969 {
1970         struct commit *c = NULL;
1971         struct commit_list *l;
1972
1973         if (revs->boundary == 2) {
1974                 /*
1975                  * All of the normal commits have already been returned,
1976                  * and we are now returning boundary commits.
1977                  * create_boundary_commit_list() has populated
1978                  * revs->commits with the remaining commits to return.
1979                  */
1980                 c = pop_commit(&revs->commits);
1981                 if (c)
1982                         c->object.flags |= SHOWN;
1983                 return c;
1984         }
1985
1986         /*
1987          * Now pick up what they want to give us
1988          */
1989         c = get_revision_1(revs);
1990         if (c) {
1991                 while (0 < revs->skip_count) {
1992                         revs->skip_count--;
1993                         c = get_revision_1(revs);
1994                         if (!c)
1995                                 break;
1996                 }
1997         }
1998
1999         /*
2000          * Check the max_count.
2001          */
2002         switch (revs->max_count) {
2003         case -1:
2004                 break;
2005         case 0:
2006                 c = NULL;
2007                 break;
2008         default:
2009                 revs->max_count--;
2010         }
2011
2012         if (c)
2013                 c->object.flags |= SHOWN;
2014
2015         if (!revs->boundary) {
2016                 return c;
2017         }
2018
2019         if (!c) {
2020                 /*
2021                  * get_revision_1() runs out the commits, and
2022                  * we are done computing the boundaries.
2023                  * switch to boundary commits output mode.
2024                  */
2025                 revs->boundary = 2;
2026
2027                 /*
2028                  * Update revs->commits to contain the list of
2029                  * boundary commits.
2030                  */
2031                 create_boundary_commit_list(revs);
2032
2033                 return get_revision_internal(revs);
2034         }
2035
2036         /*
2037          * boundary commits are the commits that are parents of the
2038          * ones we got from get_revision_1() but they themselves are
2039          * not returned from get_revision_1().  Before returning
2040          * 'c', we need to mark its parents that they could be boundaries.
2041          */
2042
2043         for (l = c->parents; l; l = l->next) {
2044                 struct object *p;
2045                 p = &(l->item->object);
2046                 if (p->flags & (CHILD_SHOWN | SHOWN))
2047                         continue;
2048                 p->flags |= CHILD_SHOWN;
2049                 gc_boundary(&revs->boundary_commits);
2050                 add_object_array(p, NULL, &revs->boundary_commits);
2051         }
2052
2053         return c;
2054 }
2055
2056 struct commit *get_revision(struct rev_info *revs)
2057 {
2058         struct commit *c;
2059         struct commit_list *reversed;
2060
2061         if (revs->reverse) {
2062                 reversed = NULL;
2063                 while ((c = get_revision_internal(revs))) {
2064                         commit_list_insert(c, &reversed);
2065                 }
2066                 revs->commits = reversed;
2067                 revs->reverse = 0;
2068                 revs->reverse_output_stage = 1;
2069         }
2070
2071         if (revs->reverse_output_stage)
2072                 return pop_commit(&revs->commits);
2073
2074         c = get_revision_internal(revs);
2075         if (c && revs->graph)
2076                 graph_update(revs->graph, c);
2077         return c;
2078 }