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         left_first = left_count < right_count;
 551         init_patch_ids(&ids);
 552         if (revs->diffopt.nr_paths) {
 553                 ids.diffopts.nr_paths = revs->diffopt.nr_paths;
 554                 ids.diffopts.paths = revs->diffopt.paths;
 555                 ids.diffopts.pathlens = revs->diffopt.pathlens;
 556         }
 557
 558         /* Compute patch-ids for one side */
 559         for (p = list; p; p = p->next) {
 560                 struct commit *commit = p->item;
 561                 unsigned flags = commit->object.flags;
 562
 563                 if (flags & BOUNDARY)
 564                         continue;
 565                 /*
 566                  * If we have fewer left, left_first is set and we omit
 567                  * commits on the right branch in this loop.  If we have
 568                  * fewer right, we skip the left ones.
 569                  */
 570                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 571                         continue;
 572                 commit->util = add_commit_patch_id(commit, &ids);
 573         }
 574
 575         /* Check the other side */
 576         for (p = list; p; p = p->next) {
 577                 struct commit *commit = p->item;
 578                 struct patch_id *id;
 579                 unsigned flags = commit->object.flags;
 580
 581                 if (flags & BOUNDARY)
 582                         continue;
 583                 /*
 584                  * If we have fewer left, left_first is set and we omit
 585                  * commits on the left branch in this loop.
 586                  */
 587                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 588                         continue;
 589
 590                 /*
 591                  * Have we seen the same patch id?
 592                  */
 593                 id = has_commit_patch_id(commit, &ids);
 594                 if (!id)
 595                         continue;
 596                 id->seen = 1;
 597                 commit->object.flags |= SHOWN;
 598         }
 599
 600         /* Now check the original side for seen ones */
 601         for (p = list; p; p = p->next) {
 602                 struct commit *commit = p->item;
 603                 struct patch_id *ent;
 604
 605                 ent = commit->util;
 606                 if (!ent)
 607                         continue;
 608                 if (ent->seen)
 609                         commit->object.flags |= SHOWN;
 610                 commit->util = NULL;
 611         }
 612
 613         free_patch_ids(&ids);
 614 }
 615
 616 /* How many extra uninteresting commits we want to see.. */
 617 #define SLOP 5
 618
 619 static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 620 {
 621         /*
 622          * No source list at all? We're definitely done..
 623          */
 624         if (!src)
 625                 return 0;
 626
 627         /*
 628          * Does the destination list contain entries with a date
 629          * before the source list? Definitely _not_ done.
 630          */
 631         if (date < src->item->date)
 632                 return SLOP;
 633
 634         /*
 635          * Does the source list still have interesting commits in
 636          * it? Definitely not done..
 637          */
 638         if (!everybody_uninteresting(src))
 639                 return SLOP;
 640
 641         /* Ok, we're closing in.. */
 642         return slop-1;
 643 }
 644
 645 static int limit_list(struct rev_info *revs)
 646 {
 647         int slop = SLOP;
 648         unsigned long date = ~0ul;
 649         struct commit_list *list = revs->commits;
 650         struct commit_list *newlist = NULL;
 651         struct commit_list **p = &newlist;
 652
 653         while (list) {
 654                 struct commit_list *entry = list;
 655                 struct commit *commit = list->item;
 656                 struct object *obj = &commit->object;
 657                 show_early_output_fn_t show;
 658
 659                 list = list->next;
 660                 free(entry);
 661
 662                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 663                         obj->flags |= UNINTERESTING;
 664                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 665                         return -1;
 666                 if (obj->flags & UNINTERESTING) {
 667                         mark_parents_uninteresting(commit);
 668                         if (revs->show_all)
 669                                 p = &commit_list_insert(commit, p)->next;
 670                         slop = still_interesting(list, date, slop);
 671                         if (slop)
 672                                 continue;
 673                         /* If showing all, add the whole pending list to the end */
 674                         if (revs->show_all)
 675                                 *p = list;
 676                         break;
 677                 }
 678                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 679                         continue;
 680                 date = commit->date;
 681                 p = &commit_list_insert(commit, p)->next;
 682
 683                 show = show_early_output;
 684                 if (!show)
 685                         continue;
 686
 687                 show(revs, newlist);
 688                 show_early_output = NULL;
 689         }
 690         if (revs->cherry_pick)
 691                 cherry_pick_list(newlist, revs);
 692
 693         revs->commits = newlist;
 694         return 0;
 695 }
 696
 697 struct all_refs_cb {
 698         int all_flags;
 699         int warned_bad_reflog;
 700         struct rev_info *all_revs;
 701         const char *name_for_errormsg;
 702 };
 703
 704 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 705 {
 706         struct all_refs_cb *cb = cb_data;
 707         struct object *object = get_reference(cb->all_revs, path, sha1,
 708                                               cb->all_flags);
 709         add_pending_object(cb->all_revs, object, path);
 710         return 0;
 711 }
 712
 713 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
 714         unsigned flags)
 715 {
 716         cb->all_revs = revs;
 717         cb->all_flags = flags;
 718 }
 719
 720 static void handle_refs(struct rev_info *revs, unsigned flags,
 721                 int (*for_each)(each_ref_fn, void *))
 722 {
 723         struct all_refs_cb cb;
 724         init_all_refs_cb(&cb, revs, flags);
 725         for_each(handle_one_ref, &cb);
 726 }
 727
 728 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 729 {
 730         struct all_refs_cb *cb = cb_data;
 731         if (!is_null_sha1(sha1)) {
 732                 struct object *o = parse_object(sha1);
 733                 if (o) {
 734                         o->flags |= cb->all_flags;
 735                         add_pending_object(cb->all_revs, o, "");
 736                 }
 737                 else if (!cb->warned_bad_reflog) {
 738                         warning("reflog of '%s' references pruned commits",
 739                                 cb->name_for_errormsg);
 740                         cb->warned_bad_reflog = 1;
 741                 }
 742         }
 743 }
 744
 745 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 746                 const char *email, unsigned long timestamp, int tz,
 747                 const char *message, void *cb_data)
 748 {
 749         handle_one_reflog_commit(osha1, cb_data);
 750         handle_one_reflog_commit(nsha1, cb_data);
 751         return 0;
 752 }
 753
 754 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 755 {
 756         struct all_refs_cb *cb = cb_data;
 757         cb->warned_bad_reflog = 0;
 758         cb->name_for_errormsg = path;
 759         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 760         return 0;
 761 }
 762
 763 static void handle_reflog(struct rev_info *revs, unsigned flags)
 764 {
 765         struct all_refs_cb cb;
 766         cb.all_revs = revs;
 767         cb.all_flags = flags;
 768         for_each_reflog(handle_one_reflog, &cb);
 769 }
 770
 771 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 772 {
 773         unsigned char sha1[20];
 774         struct object *it;
 775         struct commit *commit;
 776         struct commit_list *parents;
 777
 778         if (*arg == '^') {
 779                 flags ^= UNINTERESTING;
 780                 arg++;
 781         }
 782         if (get_sha1(arg, sha1))
 783                 return 0;
 784         while (1) {
 785                 it = get_reference(revs, arg, sha1, 0);
 786                 if (it->type != OBJ_TAG)
 787                         break;
 788                 if (!((struct tag*)it)->tagged)
 789                         return 0;
 790                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 791         }
 792         if (it->type != OBJ_COMMIT)
 793                 return 0;
 794         commit = (struct commit *)it;
 795         for (parents = commit->parents; parents; parents = parents->next) {
 796                 it = &parents->item->object;
 797                 it->flags |= flags;
 798                 add_pending_object(revs, it, arg);
 799         }
 800         return 1;
 801 }
 802
 803 void init_revisions(struct rev_info *revs, const char *prefix)
 804 {
 805         memset(revs, 0, sizeof(*revs));
 806
 807         revs->abbrev = DEFAULT_ABBREV;
 808         revs->ignore_merges = 1;
 809         revs->simplify_history = 1;
 810         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 811         DIFF_OPT_SET(&revs->pruning, QUICK);
 812         revs->pruning.add_remove = file_add_remove;
 813         revs->pruning.change = file_change;
 814         revs->lifo = 1;
 815         revs->dense = 1;
 816         revs->prefix = prefix;
 817         revs->max_age = -1;
 818         revs->min_age = -1;
 819         revs->skip_count = -1;
 820         revs->max_count = -1;
 821
 822         revs->commit_format = CMIT_FMT_DEFAULT;
 823
 824         revs->grep_filter.status_only = 1;
 825         revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
 826         revs->grep_filter.header_tail = &(revs->grep_filter.header_list);
 827         revs->grep_filter.regflags = REG_NEWLINE;
 828
 829         diff_setup(&revs->diffopt);
 830         if (prefix && !revs->diffopt.prefix) {
 831                 revs->diffopt.prefix = prefix;
 832                 revs->diffopt.prefix_length = strlen(prefix);
 833         }
 834 }
 835
 836 static void add_pending_commit_list(struct rev_info *revs,
 837                                     struct commit_list *commit_list,
 838                                     unsigned int flags)
 839 {
 840         while (commit_list) {
 841                 struct object *object = &commit_list->item->object;
 842                 object->flags |= flags;
 843                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
 844                 commit_list = commit_list->next;
 845         }
 846 }
 847
 848 static void prepare_show_merge(struct rev_info *revs)
 849 {
 850         struct commit_list *bases;
 851         struct commit *head, *other;
 852         unsigned char sha1[20];
 853         const char **prune = NULL;
 854         int i, prune_num = 1; /* counting terminating NULL */
 855
 856         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 857                 die("--merge without HEAD?");
 858         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 859                 die("--merge without MERGE_HEAD?");
 860         add_pending_object(revs, &head->object, "HEAD");
 861         add_pending_object(revs, &other->object, "MERGE_HEAD");
 862         bases = get_merge_bases(head, other, 1);
 863         add_pending_commit_list(revs, bases, UNINTERESTING);
 864         free_commit_list(bases);
 865         head->object.flags |= SYMMETRIC_LEFT;
 866
 867         if (!active_nr)
 868                 read_cache();
 869         for (i = 0; i < active_nr; i++) {
 870                 struct cache_entry *ce = active_cache[i];
 871                 if (!ce_stage(ce))
 872                         continue;
 873                 if (ce_path_match(ce, revs->prune_data)) {
 874                         prune_num++;
 875                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
 876                         prune[prune_num-2] = ce->name;
 877                         prune[prune_num-1] = NULL;
 878                 }
 879                 while ((i+1 < active_nr) &&
 880                        ce_same_name(ce, active_cache[i+1]))
 881                         i++;
 882         }
 883         revs->prune_data = prune;
 884         revs->limited = 1;
 885 }
 886
 887 int handle_revision_arg(const char *arg, struct rev_info *revs,
 888                         int flags,
 889                         int cant_be_filename)
 890 {
 891         unsigned mode;
 892         char *dotdot;
 893         struct object *object;
 894         unsigned char sha1[20];
 895         int local_flags;
 896
 897         dotdot = strstr(arg, "..");
 898         if (dotdot) {
 899                 unsigned char from_sha1[20];
 900                 const char *next = dotdot + 2;
 901                 const char *this = arg;
 902                 int symmetric = *next == '.';
 903                 unsigned int flags_exclude = flags ^ UNINTERESTING;
 904
 905                 *dotdot = 0;
 906                 next += symmetric;
 907
 908                 if (!*next)
 909                         next = "HEAD";
 910                 if (dotdot == arg)
 911                         this = "HEAD";
 912                 if (!get_sha1(this, from_sha1) &&
 913                     !get_sha1(next, sha1)) {
 914                         struct commit *a, *b;
 915                         struct commit_list *exclude;
 916
 917                         a = lookup_commit_reference(from_sha1);
 918                         b = lookup_commit_reference(sha1);
 919                         if (!a || !b) {
 920                                 die(symmetric ?
 921                                     "Invalid symmetric difference expression %s...%s" :
 922                                     "Invalid revision range %s..%s",
 923                                     arg, next);
 924                         }
 925
 926                         if (!cant_be_filename) {
 927                                 *dotdot = '.';
 928                                 verify_non_filename(revs->prefix, arg);
 929                         }
 930
 931                         if (symmetric) {
 932                                 exclude = get_merge_bases(a, b, 1);
 933                                 add_pending_commit_list(revs, exclude,
 934                                                         flags_exclude);
 935                                 free_commit_list(exclude);
 936                                 a->object.flags |= flags | SYMMETRIC_LEFT;
 937                         } else
 938                                 a->object.flags |= flags_exclude;
 939                         b->object.flags |= flags;
 940                         add_pending_object(revs, &a->object, this);
 941                         add_pending_object(revs, &b->object, next);
 942                         return 0;
 943                 }
 944                 *dotdot = '.';
 945         }
 946         dotdot = strstr(arg, "^@");
 947         if (dotdot && !dotdot[2]) {
 948                 *dotdot = 0;
 949                 if (add_parents_only(revs, arg, flags))
 950                         return 0;
 951                 *dotdot = '^';
 952         }
 953         dotdot = strstr(arg, "^!");
 954         if (dotdot && !dotdot[2]) {
 955                 *dotdot = 0;
 956                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 957                         *dotdot = '^';
 958         }
 959
 960         local_flags = 0;
 961         if (*arg == '^') {
 962                 local_flags = UNINTERESTING;
 963                 arg++;
 964         }
 965         if (get_sha1_with_mode(arg, sha1, &mode))
 966                 return -1;
 967         if (!cant_be_filename)
 968                 verify_non_filename(revs->prefix, arg);
 969         object = get_reference(revs, arg, sha1, flags ^ local_flags);
 970         add_pending_object_with_mode(revs, object, arg, mode);
 971         return 0;
 972 }
 973
 974 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb, const char ***prune_data)
 975 {
 976         const char **prune = *prune_data;
 977         int prune_nr;
 978         int prune_alloc;
 979
 980         /* count existing ones */
 981         if (!prune)
 982                 prune_nr = 0;
 983         else
 984                 for (prune_nr = 0; prune[prune_nr]; prune_nr++)
 985                         ;
 986         prune_alloc = prune_nr; /* not really, but we do not know */
 987
 988         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
 989                 int len = sb->len;
 990                 if (len && sb->buf[len - 1] == '\n')
 991                         sb->buf[--len] = '\0';
 992                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
 993                 prune[prune_nr++] = xstrdup(sb->buf);
 994         }
 995         if (prune) {
 996                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
 997                 prune[prune_nr] = NULL;
 998         }
 999         *prune_data = prune;
1000 }
1001
1002 static void read_revisions_from_stdin(struct rev_info *revs, const char ***prune)
1003 {
1004         struct strbuf sb;
1005         int seen_dashdash = 0;
1006
1007         strbuf_init(&sb, 1000);
1008         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1009                 int len = sb.len;
1010                 if (len && sb.buf[len - 1] == '\n')
1011                         sb.buf[--len] = '\0';
1012                 if (!len)
1013                         break;
1014                 if (sb.buf[0] == '-') {
1015                         if (len == 2 && sb.buf[1] == '-') {
1016                                 seen_dashdash = 1;
1017                                 break;
1018                         }
1019                         die("options not supported in --stdin mode");
1020                 }
1021                 if (handle_revision_arg(sb.buf, revs, 0, 1))
1022                         die("bad revision '%s'", sb.buf);
1023         }
1024         if (seen_dashdash)
1025                 read_pathspec_from_stdin(revs, &sb, prune);
1026         strbuf_release(&sb);
1027 }
1028
1029 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1030 {
1031         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1032 }
1033
1034 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1035 {
1036         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1037 }
1038
1039 static void add_message_grep(struct rev_info *revs, const char *pattern)
1040 {
1041         add_grep(revs, pattern, GREP_PATTERN_BODY);
1042 }
1043
1044 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1045                                int *unkc, const char **unkv)
1046 {
1047         const char *arg = argv[0];
1048
1049         /* pseudo revision arguments */
1050         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1051             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1052             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1053             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1054             !strcmp(arg, "--bisect"))
1055         {
1056                 unkv[(*unkc)++] = arg;
1057                 return 1;
1058         }
1059
1060         if (!prefixcmp(arg, "--max-count=")) {
1061                 revs->max_count = atoi(arg + 12);
1062         } else if (!prefixcmp(arg, "--skip=")) {
1063                 revs->skip_count = atoi(arg + 7);
1064         } else if ((*arg == '-') && isdigit(arg[1])) {
1065         /* accept -<digit>, like traditional "head" */
1066                 revs->max_count = atoi(arg + 1);
1067         } else if (!strcmp(arg, "-n")) {
1068                 if (argc <= 1)
1069                         return error("-n requires an argument");
1070                 revs->max_count = atoi(argv[1]);
1071                 return 2;
1072         } else if (!prefixcmp(arg, "-n")) {
1073                 revs->max_count = atoi(arg + 2);
1074         } else if (!prefixcmp(arg, "--max-age=")) {
1075                 revs->max_age = atoi(arg + 10);
1076         } else if (!prefixcmp(arg, "--since=")) {
1077                 revs->max_age = approxidate(arg + 8);
1078         } else if (!prefixcmp(arg, "--after=")) {
1079                 revs->max_age = approxidate(arg + 8);
1080         } else if (!prefixcmp(arg, "--min-age=")) {
1081                 revs->min_age = atoi(arg + 10);
1082         } else if (!prefixcmp(arg, "--before=")) {
1083                 revs->min_age = approxidate(arg + 9);
1084         } else if (!prefixcmp(arg, "--until=")) {
1085                 revs->min_age = approxidate(arg + 8);
1086         } else if (!strcmp(arg, "--first-parent")) {
1087                 revs->first_parent_only = 1;
1088         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1089                 init_reflog_walk(&revs->reflog_info);
1090         } else if (!strcmp(arg, "--default")) {
1091                 if (argc <= 1)
1092                         return error("bad --default argument");
1093                 revs->def = argv[1];
1094                 return 2;
1095         } else if (!strcmp(arg, "--merge")) {
1096                 revs->show_merge = 1;
1097         } else if (!strcmp(arg, "--topo-order")) {
1098                 revs->lifo = 1;
1099                 revs->topo_order = 1;
1100         } else if (!strcmp(arg, "--simplify-merges")) {
1101                 revs->simplify_merges = 1;
1102                 revs->rewrite_parents = 1;
1103                 revs->simplify_history = 0;
1104                 revs->limited = 1;
1105         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1106                 revs->simplify_merges = 1;
1107                 revs->rewrite_parents = 1;
1108                 revs->simplify_history = 0;
1109                 revs->simplify_by_decoration = 1;
1110                 revs->limited = 1;
1111                 revs->prune = 1;
1112                 load_ref_decorations(DECORATE_SHORT_REFS);
1113         } else if (!strcmp(arg, "--date-order")) {
1114                 revs->lifo = 0;
1115                 revs->topo_order = 1;
1116         } else if (!prefixcmp(arg, "--early-output")) {
1117                 int count = 100;
1118                 switch (arg[14]) {
1119                 case '=':
1120                         count = atoi(arg+15);
1121                         /* Fallthrough */
1122                 case 0:
1123                         revs->topo_order = 1;
1124                        revs->early_output = count;
1125                 }
1126         } else if (!strcmp(arg, "--parents")) {
1127                 revs->rewrite_parents = 1;
1128                 revs->print_parents = 1;
1129         } else if (!strcmp(arg, "--dense")) {
1130                 revs->dense = 1;
1131         } else if (!strcmp(arg, "--sparse")) {
1132                 revs->dense = 0;
1133         } else if (!strcmp(arg, "--show-all")) {
1134                 revs->show_all = 1;
1135         } else if (!strcmp(arg, "--remove-empty")) {
1136                 revs->remove_empty_trees = 1;
1137         } else if (!strcmp(arg, "--merges")) {
1138                 revs->merges_only = 1;
1139         } else if (!strcmp(arg, "--no-merges")) {
1140                 revs->no_merges = 1;
1141         } else if (!strcmp(arg, "--boundary")) {
1142                 revs->boundary = 1;
1143         } else if (!strcmp(arg, "--left-right")) {
1144                 revs->left_right = 1;
1145         } else if (!strcmp(arg, "--cherry-pick")) {
1146                 revs->cherry_pick = 1;
1147                 revs->limited = 1;
1148         } else if (!strcmp(arg, "--objects")) {
1149                 revs->tag_objects = 1;
1150                 revs->tree_objects = 1;
1151                 revs->blob_objects = 1;
1152         } else if (!strcmp(arg, "--objects-edge")) {
1153                 revs->tag_objects = 1;
1154                 revs->tree_objects = 1;
1155                 revs->blob_objects = 1;
1156                 revs->edge_hint = 1;
1157         } else if (!strcmp(arg, "--unpacked")) {
1158                 revs->unpacked = 1;
1159         } else if (!prefixcmp(arg, "--unpacked=")) {
1160                 die("--unpacked=<packfile> no longer supported.");
1161         } else if (!strcmp(arg, "-r")) {
1162                 revs->diff = 1;
1163                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1164         } else if (!strcmp(arg, "-t")) {
1165                 revs->diff = 1;
1166                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1167                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1168         } else if (!strcmp(arg, "-m")) {
1169                 revs->ignore_merges = 0;
1170         } else if (!strcmp(arg, "-c")) {
1171                 revs->diff = 1;
1172                 revs->dense_combined_merges = 0;
1173                 revs->combine_merges = 1;
1174         } else if (!strcmp(arg, "--cc")) {
1175                 revs->diff = 1;
1176                 revs->dense_combined_merges = 1;
1177                 revs->combine_merges = 1;
1178         } else if (!strcmp(arg, "-v")) {
1179                 revs->verbose_header = 1;
1180         } else if (!strcmp(arg, "--pretty")) {
1181                 revs->verbose_header = 1;
1182                 revs->pretty_given = 1;
1183                 get_commit_format(arg+8, revs);
1184         } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1185                 revs->verbose_header = 1;
1186                 revs->pretty_given = 1;
1187                 get_commit_format(arg+9, revs);
1188         } else if (!strcmp(arg, "--show-notes")) {
1189                 revs->show_notes = 1;
1190                 revs->show_notes_given = 1;
1191         } else if (!strcmp(arg, "--no-notes")) {
1192                 revs->show_notes = 0;
1193                 revs->show_notes_given = 1;
1194         } else if (!strcmp(arg, "--oneline")) {
1195                 revs->verbose_header = 1;
1196                 get_commit_format("oneline", revs);
1197                 revs->pretty_given = 1;
1198                 revs->abbrev_commit = 1;
1199         } else if (!strcmp(arg, "--graph")) {
1200                 revs->topo_order = 1;
1201                 revs->rewrite_parents = 1;
1202                 revs->graph = graph_init(revs);
1203         } else if (!strcmp(arg, "--root")) {
1204                 revs->show_root_diff = 1;
1205         } else if (!strcmp(arg, "--no-commit-id")) {
1206                 revs->no_commit_id = 1;
1207         } else if (!strcmp(arg, "--always")) {
1208                 revs->always_show_header = 1;
1209         } else if (!strcmp(arg, "--no-abbrev")) {
1210                 revs->abbrev = 0;
1211         } else if (!strcmp(arg, "--abbrev")) {
1212                 revs->abbrev = DEFAULT_ABBREV;
1213         } else if (!prefixcmp(arg, "--abbrev=")) {
1214                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1215                 if (revs->abbrev < MINIMUM_ABBREV)
1216                         revs->abbrev = MINIMUM_ABBREV;
1217                 else if (revs->abbrev > 40)
1218                         revs->abbrev = 40;
1219         } else if (!strcmp(arg, "--abbrev-commit")) {
1220                 revs->abbrev_commit = 1;
1221         } else if (!strcmp(arg, "--full-diff")) {
1222                 revs->diff = 1;
1223                 revs->full_diff = 1;
1224         } else if (!strcmp(arg, "--full-history")) {
1225                 revs->simplify_history = 0;
1226         } else if (!strcmp(arg, "--relative-date")) {
1227                 revs->date_mode = DATE_RELATIVE;
1228                 revs->date_mode_explicit = 1;
1229         } else if (!strncmp(arg, "--date=", 7)) {
1230                 revs->date_mode = parse_date_format(arg + 7);
1231                 revs->date_mode_explicit = 1;
1232         } else if (!strcmp(arg, "--log-size")) {
1233                 revs->show_log_size = 1;
1234         }
1235         /*
1236          * Grepping the commit log
1237          */
1238         else if (!prefixcmp(arg, "--author=")) {
1239                 add_header_grep(revs, GREP_HEADER_AUTHOR, arg+9);
1240         } else if (!prefixcmp(arg, "--committer=")) {
1241                 add_header_grep(revs, GREP_HEADER_COMMITTER, arg+12);
1242         } else if (!prefixcmp(arg, "--grep=")) {
1243                 add_message_grep(revs, arg+7);
1244         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1245                 revs->grep_filter.regflags |= REG_EXTENDED;
1246         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1247                 revs->grep_filter.regflags |= REG_ICASE;
1248         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1249                 revs->grep_filter.fixed = 1;
1250         } else if (!strcmp(arg, "--all-match")) {
1251                 revs->grep_filter.all_match = 1;
1252         } else if (!prefixcmp(arg, "--encoding=")) {
1253                 arg += 11;
1254                 if (strcmp(arg, "none"))
1255                         git_log_output_encoding = xstrdup(arg);
1256                 else
1257                         git_log_output_encoding = "";
1258         } else if (!strcmp(arg, "--reverse")) {
1259                 revs->reverse ^= 1;
1260         } else if (!strcmp(arg, "--children")) {
1261                 revs->children.name = "children";
1262                 revs->limited = 1;
1263         } else {
1264                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1265                 if (!opts)
1266                         unkv[(*unkc)++] = arg;
1267                 return opts;
1268         }
1269
1270         return 1;
1271 }
1272
1273 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1274                         const struct option *options,
1275                         const char * const usagestr[])
1276 {
1277         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1278                                     &ctx->cpidx, ctx->out);
1279         if (n <= 0) {
1280                 error("unknown option `%s'", ctx->argv[0]);
1281                 usage_with_options(usagestr, options);
1282         }
1283         ctx->argv += n;
1284         ctx->argc -= n;
1285 }
1286
1287 static int for_each_bad_bisect_ref(each_ref_fn fn, void *cb_data)
1288 {
1289         return for_each_ref_in("refs/bisect/bad", fn, cb_data);
1290 }
1291
1292 static int for_each_good_bisect_ref(each_ref_fn fn, void *cb_data)
1293 {
1294         return for_each_ref_in("refs/bisect/good", fn, cb_data);
1295 }
1296
1297 static void append_prune_data(const char ***prune_data, const char **av)
1298 {
1299         const char **prune = *prune_data;
1300         int prune_nr;
1301         int prune_alloc;
1302
1303         if (!prune) {
1304                 *prune_data = av;
1305                 return;
1306         }
1307
1308         /* count existing ones */
1309         for (prune_nr = 0; prune[prune_nr]; prune_nr++)
1310                 ;
1311         prune_alloc = prune_nr; /* not really, but we do not know */
1312
1313         while (*av) {
1314                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1315                 prune[prune_nr++] = *av;
1316                 av++;
1317         }
1318         if (prune) {
1319                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1320                 prune[prune_nr] = NULL;
1321         }
1322         *prune_data = prune;
1323 }
1324
1325 /*
1326  * Parse revision information, filling in the "rev_info" structure,
1327  * and removing the used arguments from the argument list.
1328  *
1329  * Returns the number of arguments left that weren't recognized
1330  * (which are also moved to the head of the argument list)
1331  */
1332 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
1333 {
1334         int i, flags, left, seen_dashdash, read_from_stdin;
1335         const char **prune_data = NULL;
1336
1337         /* First, search for "--" */
1338         seen_dashdash = 0;
1339         for (i = 1; i < argc; i++) {
1340                 const char *arg = argv[i];
1341                 if (strcmp(arg, "--"))
1342                         continue;
1343                 argv[i] = NULL;
1344                 argc = i;
1345                 if (argv[i + 1])
1346                         prune_data = argv + i + 1;
1347                 seen_dashdash = 1;
1348                 break;
1349         }
1350
1351         /* Second, deal with arguments and options */
1352         flags = 0;
1353         read_from_stdin = 0;
1354         for (left = i = 1; i < argc; i++) {
1355                 const char *arg = argv[i];
1356                 if (*arg == '-') {
1357                         int opts;
1358
1359                         if (!strcmp(arg, "--all")) {
1360                                 handle_refs(revs, flags, for_each_ref);
1361                                 handle_refs(revs, flags, head_ref);
1362                                 continue;
1363                         }
1364                         if (!strcmp(arg, "--branches")) {
1365                                 handle_refs(revs, flags, for_each_branch_ref);
1366                                 continue;
1367                         }
1368                         if (!strcmp(arg, "--bisect")) {
1369                                 handle_refs(revs, flags, for_each_bad_bisect_ref);
1370                                 handle_refs(revs, flags ^ UNINTERESTING, for_each_good_bisect_ref);
1371                                 revs->bisect = 1;
1372                                 continue;
1373                         }
1374                         if (!strcmp(arg, "--tags")) {
1375                                 handle_refs(revs, flags, for_each_tag_ref);
1376                                 continue;
1377                         }
1378                         if (!strcmp(arg, "--remotes")) {
1379                                 handle_refs(revs, flags, for_each_remote_ref);
1380                                 continue;
1381                         }
1382                         if (!prefixcmp(arg, "--glob=")) {
1383                                 struct all_refs_cb cb;
1384                                 init_all_refs_cb(&cb, revs, flags);
1385                                 for_each_glob_ref(handle_one_ref, arg + 7, &cb);
1386                                 continue;
1387                         }
1388                         if (!prefixcmp(arg, "--branches=")) {
1389                                 struct all_refs_cb cb;
1390                                 init_all_refs_cb(&cb, revs, flags);
1391                                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1392                                 continue;
1393                         }
1394                         if (!prefixcmp(arg, "--tags=")) {
1395                                 struct all_refs_cb cb;
1396                                 init_all_refs_cb(&cb, revs, flags);
1397                                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1398                                 continue;
1399                         }
1400                         if (!prefixcmp(arg, "--remotes=")) {
1401                                 struct all_refs_cb cb;
1402                                 init_all_refs_cb(&cb, revs, flags);
1403                                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1404                                 continue;
1405                         }
1406                         if (!strcmp(arg, "--reflog")) {
1407                                 handle_reflog(revs, flags);
1408                                 continue;
1409                         }
1410                         if (!strcmp(arg, "--not")) {
1411                                 flags ^= UNINTERESTING;
1412                                 continue;
1413                         }
1414                         if (!strcmp(arg, "--no-walk")) {
1415                                 revs->no_walk = 1;
1416                                 continue;
1417                         }
1418                         if (!strcmp(arg, "--do-walk")) {
1419                                 revs->no_walk = 0;
1420                                 continue;
1421                         }
1422                         if (!strcmp(arg, "--stdin")) {
1423                                 if (revs->disable_stdin) {
1424                                         argv[left++] = arg;
1425                                         continue;
1426                                 }
1427                                 if (read_from_stdin++)
1428                                         die("--stdin given twice?");
1429                                 read_revisions_from_stdin(revs, &prune_data);
1430                                 continue;
1431                         }
1432
1433                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1434                         if (opts > 0) {
1435                                 i += opts - 1;
1436                                 continue;
1437                         }
1438                         if (opts < 0)
1439                                 exit(128);
1440                         continue;
1441                 }
1442
1443                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1444                         int j;
1445                         if (seen_dashdash || *arg == '^')
1446                                 die("bad revision '%s'", arg);
1447
1448                         /* If we didn't have a "--":
1449                          * (1) all filenames must exist;
1450                          * (2) all rev-args must not be interpretable
1451                          *     as a valid filename.
1452                          * but the latter we have checked in the main loop.
1453                          */
1454                         for (j = i; j < argc; j++)
1455                                 verify_filename(revs->prefix, argv[j]);
1456
1457                         append_prune_data(&prune_data, argv + i);
1458                         break;
1459                 }
1460         }
1461
1462         if (prune_data)
1463                 revs->prune_data = get_pathspec(revs->prefix, prune_data);
1464
1465         if (revs->def == NULL)
1466                 revs->def = def;
1467         if (revs->show_merge)
1468                 prepare_show_merge(revs);
1469         if (revs->def && !revs->pending.nr) {
1470                 unsigned char sha1[20];
1471                 struct object *object;
1472                 unsigned mode;
1473                 if (get_sha1_with_mode(revs->def, sha1, &mode))
1474                         die("bad default revision '%s'", revs->def);
1475                 object = get_reference(revs, revs->def, sha1, 0);
1476                 add_pending_object_with_mode(revs, object, revs->def, mode);
1477         }
1478
1479         /* Did the user ask for any diff output? Run the diff! */
1480         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1481                 revs->diff = 1;
1482
1483         /* Pickaxe, diff-filter and rename following need diffs */
1484         if (revs->diffopt.pickaxe ||
1485             revs->diffopt.filter ||
1486             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1487                 revs->diff = 1;
1488
1489         if (revs->topo_order)
1490                 revs->limited = 1;
1491
1492         if (revs->prune_data) {
1493                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1494                 /* Can't prune commits with rename following: the paths change.. */
1495                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1496                         revs->prune = 1;
1497                 if (!revs->full_diff)
1498                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1499         }
1500         if (revs->combine_merges) {
1501                 revs->ignore_merges = 0;
1502                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1503                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1504         }
1505         revs->diffopt.abbrev = revs->abbrev;
1506         if (diff_setup_done(&revs->diffopt) < 0)
1507                 die("diff_setup_done failed");
1508
1509         compile_grep_patterns(&revs->grep_filter);
1510
1511         if (revs->reverse && revs->reflog_info)
1512                 die("cannot combine --reverse with --walk-reflogs");
1513         if (revs->rewrite_parents && revs->children.name)
1514                 die("cannot combine --parents and --children");
1515
1516         /*
1517          * Limitations on the graph functionality
1518          */
1519         if (revs->reverse && revs->graph)
1520                 die("cannot combine --reverse with --graph");
1521
1522         if (revs->reflog_info && revs->graph)
1523                 die("cannot combine --walk-reflogs with --graph");
1524
1525         return left;
1526 }
1527
1528 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1529 {
1530         struct commit_list *l = xcalloc(1, sizeof(*l));
1531
1532         l->item = child;
1533         l->next = add_decoration(&revs->children, &parent->object, l);
1534 }
1535
1536 static int remove_duplicate_parents(struct commit *commit)
1537 {
1538         struct commit_list **pp, *p;
1539         int surviving_parents;
1540
1541         /* Examine existing parents while marking ones we have seen... */
1542         pp = &commit->parents;
1543         while ((p = *pp) != NULL) {
1544                 struct commit *parent = p->item;
1545                 if (parent->object.flags & TMP_MARK) {
1546                         *pp = p->next;
1547                         continue;
1548                 }
1549                 parent->object.flags |= TMP_MARK;
1550                 pp = &p->next;
1551         }
1552         /* count them while clearing the temporary mark */
1553         surviving_parents = 0;
1554         for (p = commit->parents; p; p = p->next) {
1555                 p->item->object.flags &= ~TMP_MARK;
1556                 surviving_parents++;
1557         }
1558         return surviving_parents;
1559 }
1560
1561 struct merge_simplify_state {
1562         struct commit *simplified;
1563 };
1564
1565 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1566 {
1567         struct merge_simplify_state *st;
1568
1569         st = lookup_decoration(&revs->merge_simplification, &commit->object);
1570         if (!st) {
1571                 st = xcalloc(1, sizeof(*st));
1572                 add_decoration(&revs->merge_simplification, &commit->object, st);
1573         }
1574         return st;
1575 }
1576
1577 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1578 {
1579         struct commit_list *p;
1580         struct merge_simplify_state *st, *pst;
1581         int cnt;
1582
1583         st = locate_simplify_state(revs, commit);
1584
1585         /*
1586          * Have we handled this one?
1587          */
1588         if (st->simplified)
1589                 return tail;
1590
1591         /*
1592          * An UNINTERESTING commit simplifies to itself, so does a
1593          * root commit.  We do not rewrite parents of such commit
1594          * anyway.
1595          */
1596         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1597                 st->simplified = commit;
1598                 return tail;
1599         }
1600
1601         /*
1602          * Do we know what commit all of our parents should be rewritten to?
1603          * Otherwise we are not ready to rewrite this one yet.
1604          */
1605         for (cnt = 0, p = commit->parents; p; p = p->next) {
1606                 pst = locate_simplify_state(revs, p->item);
1607                 if (!pst->simplified) {
1608                         tail = &commit_list_insert(p->item, tail)->next;
1609                         cnt++;
1610                 }
1611         }
1612         if (cnt) {
1613                 tail = &commit_list_insert(commit, tail)->next;
1614                 return tail;
1615         }
1616
1617         /*
1618          * Rewrite our list of parents.
1619          */
1620         for (p = commit->parents; p; p = p->next) {
1621                 pst = locate_simplify_state(revs, p->item);
1622                 p->item = pst->simplified;
1623         }
1624         cnt = remove_duplicate_parents(commit);
1625
1626         /*
1627          * It is possible that we are a merge and one side branch
1628          * does not have any commit that touches the given paths;
1629          * in such a case, the immediate parents will be rewritten
1630          * to different commits.
1631          *
1632          *      o----X          X: the commit we are looking at;
1633          *     /    /           o: a commit that touches the paths;
1634          * ---o----'
1635          *
1636          * Further reduce the parents by removing redundant parents.
1637          */
1638         if (1 < cnt) {
1639                 struct commit_list *h = reduce_heads(commit->parents);
1640                 cnt = commit_list_count(h);
1641                 free_commit_list(commit->parents);
1642                 commit->parents = h;
1643         }
1644
1645         /*
1646          * A commit simplifies to itself if it is a root, if it is
1647          * UNINTERESTING, if it touches the given paths, or if it is a
1648          * merge and its parents simplifies to more than one commits
1649          * (the first two cases are already handled at the beginning of
1650          * this function).
1651          *
1652          * Otherwise, it simplifies to what its sole parent simplifies to.
1653          */
1654         if (!cnt ||
1655             (commit->object.flags & UNINTERESTING) ||
1656             !(commit->object.flags & TREESAME) ||
1657             (1 < cnt))
1658                 st->simplified = commit;
1659         else {
1660                 pst = locate_simplify_state(revs, commit->parents->item);
1661                 st->simplified = pst->simplified;
1662         }
1663         return tail;
1664 }
1665
1666 static void simplify_merges(struct rev_info *revs)
1667 {
1668         struct commit_list *list;
1669         struct commit_list *yet_to_do, **tail;
1670
1671         if (!revs->topo_order)
1672                 sort_in_topological_order(&revs->commits, revs->lifo);
1673         if (!revs->prune)
1674                 return;
1675
1676         /* feed the list reversed */
1677         yet_to_do = NULL;
1678         for (list = revs->commits; list; list = list->next)
1679                 commit_list_insert(list->item, &yet_to_do);
1680         while (yet_to_do) {
1681                 list = yet_to_do;
1682                 yet_to_do = NULL;
1683                 tail = &yet_to_do;
1684                 while (list) {
1685                         struct commit *commit = list->item;
1686                         struct commit_list *next = list->next;
1687                         free(list);
1688                         list = next;
1689                         tail = simplify_one(revs, commit, tail);
1690                 }
1691         }
1692
1693         /* clean up the result, removing the simplified ones */
1694         list = revs->commits;
1695         revs->commits = NULL;
1696         tail = &revs->commits;
1697         while (list) {
1698                 struct commit *commit = list->item;
1699                 struct commit_list *next = list->next;
1700                 struct merge_simplify_state *st;
1701                 free(list);
1702                 list = next;
1703                 st = locate_simplify_state(revs, commit);
1704                 if (st->simplified == commit)
1705                         tail = &commit_list_insert(commit, tail)->next;
1706         }
1707 }
1708
1709 static void set_children(struct rev_info *revs)
1710 {
1711         struct commit_list *l;
1712         for (l = revs->commits; l; l = l->next) {
1713                 struct commit *commit = l->item;
1714                 struct commit_list *p;
1715
1716                 for (p = commit->parents; p; p = p->next)
1717                         add_child(revs, p->item, commit);
1718         }
1719 }
1720
1721 int prepare_revision_walk(struct rev_info *revs)
1722 {
1723         int nr = revs->pending.nr;
1724         struct object_array_entry *e, *list;
1725
1726         e = list = revs->pending.objects;
1727         revs->pending.nr = 0;
1728         revs->pending.alloc = 0;
1729         revs->pending.objects = NULL;
1730         while (--nr >= 0) {
1731                 struct commit *commit = handle_commit(revs, e->item, e->name);
1732                 if (commit) {
1733                         if (!(commit->object.flags & SEEN)) {
1734                                 commit->object.flags |= SEEN;
1735                                 insert_by_date(commit, &revs->commits);
1736                         }
1737                 }
1738                 e++;
1739         }
1740         free(list);
1741
1742         if (revs->no_walk)
1743                 return 0;
1744         if (revs->limited)
1745                 if (limit_list(revs) < 0)
1746                         return -1;
1747         if (revs->topo_order)
1748                 sort_in_topological_order(&revs->commits, revs->lifo);
1749         if (revs->simplify_merges)
1750                 simplify_merges(revs);
1751         if (revs->children.name)
1752                 set_children(revs);
1753         return 0;
1754 }
1755
1756 enum rewrite_result {
1757         rewrite_one_ok,
1758         rewrite_one_noparents,
1759         rewrite_one_error,
1760 };
1761
1762 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1763 {
1764         struct commit_list *cache = NULL;
1765
1766         for (;;) {
1767                 struct commit *p = *pp;
1768                 if (!revs->limited)
1769                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
1770                                 return rewrite_one_error;
1771                 if (p->parents && p->parents->next)
1772                         return rewrite_one_ok;
1773                 if (p->object.flags & UNINTERESTING)
1774                         return rewrite_one_ok;
1775                 if (!(p->object.flags & TREESAME))
1776                         return rewrite_one_ok;
1777                 if (!p->parents)
1778                         return rewrite_one_noparents;
1779                 *pp = p->parents->item;
1780         }
1781 }
1782
1783 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1784 {
1785         struct commit_list **pp = &commit->parents;
1786         while (*pp) {
1787                 struct commit_list *parent = *pp;
1788                 switch (rewrite_one(revs, &parent->item)) {
1789                 case rewrite_one_ok:
1790                         break;
1791                 case rewrite_one_noparents:
1792                         *pp = parent->next;
1793                         continue;
1794                 case rewrite_one_error:
1795                         return -1;
1796                 }
1797                 pp = &parent->next;
1798         }
1799         remove_duplicate_parents(commit);
1800         return 0;
1801 }
1802
1803 static int commit_match(struct commit *commit, struct rev_info *opt)
1804 {
1805         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
1806                 return 1;
1807         return grep_buffer(&opt->grep_filter,
1808                            NULL, /* we say nothing, not even filename */
1809                            commit->buffer, strlen(commit->buffer));
1810 }
1811
1812 static inline int want_ancestry(struct rev_info *revs)
1813 {
1814         return (revs->rewrite_parents || revs->children.name);
1815 }
1816
1817 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
1818 {
1819         if (commit->object.flags & SHOWN)
1820                 return commit_ignore;
1821         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
1822                 return commit_ignore;
1823         if (revs->show_all)
1824                 return commit_show;
1825         if (commit->object.flags & UNINTERESTING)
1826                 return commit_ignore;
1827         if (revs->min_age != -1 && (commit->date > revs->min_age))
1828                 return commit_ignore;
1829         if (revs->no_merges && commit->parents && commit->parents->next)
1830                 return commit_ignore;
1831         if (revs->merges_only && !(commit->parents && commit->parents->next))
1832                 return commit_ignore;
1833         if (!commit_match(commit, revs))
1834                 return commit_ignore;
1835         if (revs->prune && revs->dense) {
1836                 /* Commit without changes? */
1837                 if (commit->object.flags & TREESAME) {
1838                         /* drop merges unless we want parenthood */
1839                         if (!want_ancestry(revs))
1840                                 return commit_ignore;
1841                         /* non-merge - always ignore it */
1842                         if (!commit->parents || !commit->parents->next)
1843                                 return commit_ignore;
1844                 }
1845         }
1846         return commit_show;
1847 }
1848
1849 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1850 {
1851         enum commit_action action = get_commit_action(revs, commit);
1852
1853         if (action == commit_show &&
1854             !revs->show_all &&
1855             revs->prune && revs->dense && want_ancestry(revs)) {
1856                 if (rewrite_parents(revs, commit) < 0)
1857                         return commit_error;
1858         }
1859         return action;
1860 }
1861
1862 static struct commit *get_revision_1(struct rev_info *revs)
1863 {
1864         if (!revs->commits)
1865                 return NULL;
1866
1867         do {
1868                 struct commit_list *entry = revs->commits;
1869                 struct commit *commit = entry->item;
1870
1871                 revs->commits = entry->next;
1872                 free(entry);
1873
1874                 if (revs->reflog_info)
1875                         fake_reflog_parent(revs->reflog_info, commit);
1876
1877                 /*
1878                  * If we haven't done the list limiting, we need to look at
1879                  * the parents here. We also need to do the date-based limiting
1880                  * that we'd otherwise have done in limit_list().
1881                  */
1882                 if (!revs->limited) {
1883                         if (revs->max_age != -1 &&
1884                             (commit->date < revs->max_age))
1885                                 continue;
1886                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
1887                                 die("Failed to traverse parents of commit %s",
1888                                     sha1_to_hex(commit->object.sha1));
1889                 }
1890
1891                 switch (simplify_commit(revs, commit)) {
1892                 case commit_ignore:
1893                         continue;
1894                 case commit_error:
1895                         die("Failed to simplify parents of commit %s",
1896                             sha1_to_hex(commit->object.sha1));
1897                 default:
1898                         return commit;
1899                 }
1900         } while (revs->commits);
1901         return NULL;
1902 }
1903
1904 static void gc_boundary(struct object_array *array)
1905 {
1906         unsigned nr = array->nr;
1907         unsigned alloc = array->alloc;
1908         struct object_array_entry *objects = array->objects;
1909
1910         if (alloc <= nr) {
1911                 unsigned i, j;
1912                 for (i = j = 0; i < nr; i++) {
1913                         if (objects[i].item->flags & SHOWN)
1914                                 continue;
1915                         if (i != j)
1916                                 objects[j] = objects[i];
1917                         j++;
1918                 }
1919                 for (i = j; i < nr; i++)
1920                         objects[i].item = NULL;
1921                 array->nr = j;
1922         }
1923 }
1924
1925 static void create_boundary_commit_list(struct rev_info *revs)
1926 {
1927         unsigned i;
1928         struct commit *c;
1929         struct object_array *array = &revs->boundary_commits;
1930         struct object_array_entry *objects = array->objects;
1931
1932         /*
1933          * If revs->commits is non-NULL at this point, an error occurred in
1934          * get_revision_1().  Ignore the error and continue printing the
1935          * boundary commits anyway.  (This is what the code has always
1936          * done.)
1937          */
1938         if (revs->commits) {
1939                 free_commit_list(revs->commits);
1940                 revs->commits = NULL;
1941         }
1942
1943         /*
1944          * Put all of the actual boundary commits from revs->boundary_commits
1945          * into revs->commits
1946          */
1947         for (i = 0; i < array->nr; i++) {
1948                 c = (struct commit *)(objects[i].item);
1949                 if (!c)
1950                         continue;
1951                 if (!(c->object.flags & CHILD_SHOWN))
1952                         continue;
1953                 if (c->object.flags & (SHOWN | BOUNDARY))
1954                         continue;
1955                 c->object.flags |= BOUNDARY;
1956                 commit_list_insert(c, &revs->commits);
1957         }
1958
1959         /*
1960          * If revs->topo_order is set, sort the boundary commits
1961          * in topological order
1962          */
1963         sort_in_topological_order(&revs->commits, revs->lifo);
1964 }
1965
1966 static struct commit *get_revision_internal(struct rev_info *revs)
1967 {
1968         struct commit *c = NULL;
1969         struct commit_list *l;
1970
1971         if (revs->boundary == 2) {
1972                 /*
1973                  * All of the normal commits have already been returned,
1974                  * and we are now returning boundary commits.
1975                  * create_boundary_commit_list() has populated
1976                  * revs->commits with the remaining commits to return.
1977                  */
1978                 c = pop_commit(&revs->commits);
1979                 if (c)
1980                         c->object.flags |= SHOWN;
1981                 return c;
1982         }
1983
1984         /*
1985          * Now pick up what they want to give us
1986          */
1987         c = get_revision_1(revs);
1988         if (c) {
1989                 while (0 < revs->skip_count) {
1990                         revs->skip_count--;
1991                         c = get_revision_1(revs);
1992                         if (!c)
1993                                 break;
1994                 }
1995         }
1996
1997         /*
1998          * Check the max_count.
1999          */
2000         switch (revs->max_count) {
2001         case -1:
2002                 break;
2003         case 0:
2004                 c = NULL;
2005                 break;
2006         default:
2007                 revs->max_count--;
2008         }
2009
2010         if (c)
2011                 c->object.flags |= SHOWN;
2012
2013         if (!revs->boundary) {
2014                 return c;
2015         }
2016
2017         if (!c) {
2018                 /*
2019                  * get_revision_1() runs out the commits, and
2020                  * we are done computing the boundaries.
2021                  * switch to boundary commits output mode.
2022                  */
2023                 revs->boundary = 2;
2024
2025                 /*
2026                  * Update revs->commits to contain the list of
2027                  * boundary commits.
2028                  */
2029                 create_boundary_commit_list(revs);
2030
2031                 return get_revision_internal(revs);
2032         }
2033
2034         /*
2035          * boundary commits are the commits that are parents of the
2036          * ones we got from get_revision_1() but they themselves are
2037          * not returned from get_revision_1().  Before returning
2038          * 'c', we need to mark its parents that they could be boundaries.
2039          */
2040
2041         for (l = c->parents; l; l = l->next) {
2042                 struct object *p;
2043                 p = &(l->item->object);
2044                 if (p->flags & (CHILD_SHOWN | SHOWN))
2045                         continue;
2046                 p->flags |= CHILD_SHOWN;
2047                 gc_boundary(&revs->boundary_commits);
2048                 add_object_array(p, NULL, &revs->boundary_commits);
2049         }
2050
2051         return c;
2052 }
2053
2054 struct commit *get_revision(struct rev_info *revs)
2055 {
2056         struct commit *c;
2057         struct commit_list *reversed;
2058
2059         if (revs->reverse) {
2060                 reversed = NULL;
2061                 while ((c = get_revision_internal(revs))) {
2062                         commit_list_insert(c, &reversed);
2063                 }
2064                 revs->commits = reversed;
2065                 revs->reverse = 0;
2066                 revs->reverse_output_stage = 1;
2067         }
2068
2069         if (revs->reverse_output_stage)
2070                 return pop_commit(&revs->commits);
2071
2072         c = get_revision_internal(revs);
2073         if (c && revs->graph)
2074                 graph_update(revs->graph, c);
2075         return c;
2076 }