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 #include "string-list.h"
  16 #include "line-log.h"
  17 #include "mailmap.h"
  18 #include "commit-slab.h"
  19 #include "dir.h"
  20 #include "cache-tree.h"
  21 #include "bisect.h"
  22 #include "packfile.h"
  23 #include "worktree.h"
  24 #include "argv-array.h"
  25
  26 volatile show_early_output_fn_t show_early_output;
  27
  28 static const char *term_bad;
  29 static const char *term_good;
  30
  31 void show_object_with_name(FILE *out, struct object *obj, const char *name)
  32 {
  33         const char *p;
  34
  35         fprintf(out, "%s ", oid_to_hex(&obj->oid));
  36         for (p = name; *p && *p != '\n'; p++)
  37                 fputc(*p, out);
  38         fputc('\n', out);
  39 }
  40
  41 static void mark_blob_uninteresting(struct blob *blob)
  42 {
  43         if (!blob)
  44                 return;
  45         if (blob->object.flags & UNINTERESTING)
  46                 return;
  47         blob->object.flags |= UNINTERESTING;
  48 }
  49
  50 static void mark_tree_contents_uninteresting(struct tree *tree)
  51 {
  52         struct tree_desc desc;
  53         struct name_entry entry;
  54         struct object *obj = &tree->object;
  55
  56         if (!has_object_file(&obj->oid))
  57                 return;
  58         if (parse_tree(tree) < 0)
  59                 die("bad tree %s", oid_to_hex(&obj->oid));
  60
  61         init_tree_desc(&desc, tree->buffer, tree->size);
  62         while (tree_entry(&desc, &entry)) {
  63                 switch (object_type(entry.mode)) {
  64                 case OBJ_TREE:
  65                         mark_tree_uninteresting(lookup_tree(entry.oid));
  66                         break;
  67                 case OBJ_BLOB:
  68                         mark_blob_uninteresting(lookup_blob(entry.oid));
  69                         break;
  70                 default:
  71                         /* Subproject commit - not in this repository */
  72                         break;
  73                 }
  74         }
  75
  76         /*
  77          * We don't care about the tree any more
  78          * after it has been marked uninteresting.
  79          */
  80         free_tree_buffer(tree);
  81 }
  82
  83 void mark_tree_uninteresting(struct tree *tree)
  84 {
  85         struct object *obj;
  86
  87         if (!tree)
  88                 return;
  89
  90         obj = &tree->object;
  91         if (obj->flags & UNINTERESTING)
  92                 return;
  93         obj->flags |= UNINTERESTING;
  94         mark_tree_contents_uninteresting(tree);
  95 }
  96
  97 void mark_parents_uninteresting(struct commit *commit)
  98 {
  99         struct commit_list *parents = NULL, *l;
 100
 101         for (l = commit->parents; l; l = l->next)
 102                 commit_list_insert(l->item, &parents);
 103
 104         while (parents) {
 105                 struct commit *commit = pop_commit(&parents);
 106
 107                 while (commit) {
 108                         /*
 109                          * A missing commit is ok iff its parent is marked
 110                          * uninteresting.
 111                          *
 112                          * We just mark such a thing parsed, so that when
 113                          * it is popped next time around, we won't be trying
 114                          * to parse it and get an error.
 115                          */
 116                         if (!has_object_file(&commit->object.oid))
 117                                 commit->object.parsed = 1;
 118
 119                         if (commit->object.flags & UNINTERESTING)
 120                                 break;
 121
 122                         commit->object.flags |= UNINTERESTING;
 123
 124                         /*
 125                          * Normally we haven't parsed the parent
 126                          * yet, so we won't have a parent of a parent
 127                          * here. However, it may turn out that we've
 128                          * reached this commit some other way (where it
 129                          * wasn't uninteresting), in which case we need
 130                          * to mark its parents recursively too..
 131                          */
 132                         if (!commit->parents)
 133                                 break;
 134
 135                         for (l = commit->parents->next; l; l = l->next)
 136                                 commit_list_insert(l->item, &parents);
 137                         commit = commit->parents->item;
 138                 }
 139         }
 140 }
 141
 142 static void add_pending_object_with_path(struct rev_info *revs,
 143                                          struct object *obj,
 144                                          const char *name, unsigned mode,
 145                                          const char *path)
 146 {
 147         if (!obj)
 148                 return;
 149         if (revs->no_walk && (obj->flags & UNINTERESTING))
 150                 revs->no_walk = 0;
 151         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 152                 struct strbuf buf = STRBUF_INIT;
 153                 int len = interpret_branch_name(name, 0, &buf, 0);
 154
 155                 if (0 < len && name[len] && buf.len)
 156                         strbuf_addstr(&buf, name + len);
 157                 add_reflog_for_walk(revs->reflog_info,
 158                                     (struct commit *)obj,
 159                                     buf.buf[0] ? buf.buf: name);
 160                 strbuf_release(&buf);
 161                 return; /* do not add the commit itself */
 162         }
 163         add_object_array_with_path(obj, name, &revs->pending, mode, path);
 164 }
 165
 166 static void add_pending_object_with_mode(struct rev_info *revs,
 167                                          struct object *obj,
 168                                          const char *name, unsigned mode)
 169 {
 170         add_pending_object_with_path(revs, obj, name, mode, NULL);
 171 }
 172
 173 void add_pending_object(struct rev_info *revs,
 174                         struct object *obj, const char *name)
 175 {
 176         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 177 }
 178
 179 void add_head_to_pending(struct rev_info *revs)
 180 {
 181         struct object_id oid;
 182         struct object *obj;
 183         if (get_oid("HEAD", &oid))
 184                 return;
 185         obj = parse_object(&oid);
 186         if (!obj)
 187                 return;
 188         add_pending_object(revs, obj, "HEAD");
 189 }
 190
 191 static struct object *get_reference(struct rev_info *revs, const char *name,
 192                                     const struct object_id *oid,
 193                                     unsigned int flags)
 194 {
 195         struct object *object;
 196
 197         object = parse_object(oid);
 198         if (!object) {
 199                 if (revs->ignore_missing)
 200                         return object;
 201                 die("bad object %s", name);
 202         }
 203         object->flags |= flags;
 204         return object;
 205 }
 206
 207 void add_pending_oid(struct rev_info *revs, const char *name,
 208                       const struct object_id *oid, unsigned int flags)
 209 {
 210         struct object *object = get_reference(revs, name, oid, flags);
 211         add_pending_object(revs, object, name);
 212 }
 213
 214 static struct commit *handle_commit(struct rev_info *revs,
 215                                     struct object_array_entry *entry)
 216 {
 217         struct object *object = entry->item;
 218         const char *name = entry->name;
 219         const char *path = entry->path;
 220         unsigned int mode = entry->mode;
 221         unsigned long flags = object->flags;
 222
 223         /*
 224          * Tag object? Look what it points to..
 225          */
 226         while (object->type == OBJ_TAG) {
 227                 struct tag *tag = (struct tag *) object;
 228                 if (revs->tag_objects && !(flags & UNINTERESTING))
 229                         add_pending_object(revs, object, tag->tag);
 230                 if (!tag->tagged)
 231                         die("bad tag");
 232                 object = parse_object(&tag->tagged->oid);
 233                 if (!object) {
 234                         if (revs->ignore_missing_links || (flags & UNINTERESTING))
 235                                 return NULL;
 236                         die("bad object %s", oid_to_hex(&tag->tagged->oid));
 237                 }
 238                 object->flags |= flags;
 239                 /*
 240                  * We'll handle the tagged object by looping or dropping
 241                  * through to the non-tag handlers below. Do not
 242                  * propagate path data from the tag's pending entry.
 243                  */
 244                 path = NULL;
 245                 mode = 0;
 246         }
 247
 248         /*
 249          * Commit object? Just return it, we'll do all the complex
 250          * reachability crud.
 251          */
 252         if (object->type == OBJ_COMMIT) {
 253                 struct commit *commit = (struct commit *)object;
 254                 if (parse_commit(commit) < 0)
 255                         die("unable to parse commit %s", name);
 256                 if (flags & UNINTERESTING) {
 257                         mark_parents_uninteresting(commit);
 258                         revs->limited = 1;
 259                 }
 260                 if (revs->show_source && !commit->util)
 261                         commit->util = xstrdup(name);
 262                 return commit;
 263         }
 264
 265         /*
 266          * Tree object? Either mark it uninteresting, or add it
 267          * to the list of objects to look at later..
 268          */
 269         if (object->type == OBJ_TREE) {
 270                 struct tree *tree = (struct tree *)object;
 271                 if (!revs->tree_objects)
 272                         return NULL;
 273                 if (flags & UNINTERESTING) {
 274                         mark_tree_contents_uninteresting(tree);
 275                         return NULL;
 276                 }
 277                 add_pending_object_with_path(revs, object, name, mode, path);
 278                 return NULL;
 279         }
 280
 281         /*
 282          * Blob object? You know the drill by now..
 283          */
 284         if (object->type == OBJ_BLOB) {
 285                 if (!revs->blob_objects)
 286                         return NULL;
 287                 if (flags & UNINTERESTING)
 288                         return NULL;
 289                 add_pending_object_with_path(revs, object, name, mode, path);
 290                 return NULL;
 291         }
 292         die("%s is unknown object", name);
 293 }
 294
 295 static int everybody_uninteresting(struct commit_list *orig,
 296                                    struct commit **interesting_cache)
 297 {
 298         struct commit_list *list = orig;
 299
 300         if (*interesting_cache) {
 301                 struct commit *commit = *interesting_cache;
 302                 if (!(commit->object.flags & UNINTERESTING))
 303                         return 0;
 304         }
 305
 306         while (list) {
 307                 struct commit *commit = list->item;
 308                 list = list->next;
 309                 if (commit->object.flags & UNINTERESTING)
 310                         continue;
 311
 312                 *interesting_cache = commit;
 313                 return 0;
 314         }
 315         return 1;
 316 }
 317
 318 /*
 319  * A definition of "relevant" commit that we can use to simplify limited graphs
 320  * by eliminating side branches.
 321  *
 322  * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
 323  * in our list), or that is a specified BOTTOM commit. Then after computing
 324  * a limited list, during processing we can generally ignore boundary merges
 325  * coming from outside the graph, (ie from irrelevant parents), and treat
 326  * those merges as if they were single-parent. TREESAME is defined to consider
 327  * only relevant parents, if any. If we are TREESAME to our on-graph parents,
 328  * we don't care if we were !TREESAME to non-graph parents.
 329  *
 330  * Treating bottom commits as relevant ensures that a limited graph's
 331  * connection to the actual bottom commit is not viewed as a side branch, but
 332  * treated as part of the graph. For example:
 333  *
 334  *   ....Z...A---X---o---o---B
 335  *        .     /
 336  *         W---Y
 337  *
 338  * When computing "A..B", the A-X connection is at least as important as
 339  * Y-X, despite A being flagged UNINTERESTING.
 340  *
 341  * And when computing --ancestry-path "A..B", the A-X connection is more
 342  * important than Y-X, despite both A and Y being flagged UNINTERESTING.
 343  */
 344 static inline int relevant_commit(struct commit *commit)
 345 {
 346         return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
 347 }
 348
 349 /*
 350  * Return a single relevant commit from a parent list. If we are a TREESAME
 351  * commit, and this selects one of our parents, then we can safely simplify to
 352  * that parent.
 353  */
 354 static struct commit *one_relevant_parent(const struct rev_info *revs,
 355                                           struct commit_list *orig)
 356 {
 357         struct commit_list *list = orig;
 358         struct commit *relevant = NULL;
 359
 360         if (!orig)
 361                 return NULL;
 362
 363         /*
 364          * For 1-parent commits, or if first-parent-only, then return that
 365          * first parent (even if not "relevant" by the above definition).
 366          * TREESAME will have been set purely on that parent.
 367          */
 368         if (revs->first_parent_only || !orig->next)
 369                 return orig->item;
 370
 371         /*
 372          * For multi-parent commits, identify a sole relevant parent, if any.
 373          * If we have only one relevant parent, then TREESAME will be set purely
 374          * with regard to that parent, and we can simplify accordingly.
 375          *
 376          * If we have more than one relevant parent, or no relevant parents
 377          * (and multiple irrelevant ones), then we can't select a parent here
 378          * and return NULL.
 379          */
 380         while (list) {
 381                 struct commit *commit = list->item;
 382                 list = list->next;
 383                 if (relevant_commit(commit)) {
 384                         if (relevant)
 385                                 return NULL;
 386                         relevant = commit;
 387                 }
 388         }
 389         return relevant;
 390 }
 391
 392 /*
 393  * The goal is to get REV_TREE_NEW as the result only if the
 394  * diff consists of all '+' (and no other changes), REV_TREE_OLD
 395  * if the whole diff is removal of old data, and otherwise
 396  * REV_TREE_DIFFERENT (of course if the trees are the same we
 397  * want REV_TREE_SAME).
 398  * That means that once we get to REV_TREE_DIFFERENT, we do not
 399  * have to look any further.
 400  */
 401 static int tree_difference = REV_TREE_SAME;
 402
 403 static void file_add_remove(struct diff_options *options,
 404                     int addremove, unsigned mode,
 405                     const struct object_id *oid,
 406                     int oid_valid,
 407                     const char *fullpath, unsigned dirty_submodule)
 408 {
 409         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 410
 411         tree_difference |= diff;
 412         if (tree_difference == REV_TREE_DIFFERENT)
 413                 DIFF_OPT_SET(options, HAS_CHANGES);
 414 }
 415
 416 static void file_change(struct diff_options *options,
 417                  unsigned old_mode, unsigned new_mode,
 418                  const struct object_id *old_oid,
 419                  const struct object_id *new_oid,
 420                  int old_oid_valid, int new_oid_valid,
 421                  const char *fullpath,
 422                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 423 {
 424         tree_difference = REV_TREE_DIFFERENT;
 425         DIFF_OPT_SET(options, HAS_CHANGES);
 426 }
 427
 428 static int rev_compare_tree(struct rev_info *revs,
 429                             struct commit *parent, struct commit *commit)
 430 {
 431         struct tree *t1 = parent->tree;
 432         struct tree *t2 = commit->tree;
 433
 434         if (!t1)
 435                 return REV_TREE_NEW;
 436         if (!t2)
 437                 return REV_TREE_OLD;
 438
 439         if (revs->simplify_by_decoration) {
 440                 /*
 441                  * If we are simplifying by decoration, then the commit
 442                  * is worth showing if it has a tag pointing at it.
 443                  */
 444                 if (get_name_decoration(&commit->object))
 445                         return REV_TREE_DIFFERENT;
 446                 /*
 447                  * A commit that is not pointed by a tag is uninteresting
 448                  * if we are not limited by path.  This means that you will
 449                  * see the usual "commits that touch the paths" plus any
 450                  * tagged commit by specifying both --simplify-by-decoration
 451                  * and pathspec.
 452                  */
 453                 if (!revs->prune_data.nr)
 454                         return REV_TREE_SAME;
 455         }
 456
 457         tree_difference = REV_TREE_SAME;
 458         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 459         if (diff_tree_oid(&t1->object.oid, &t2->object.oid, "",
 460                            &revs->pruning) < 0)
 461                 return REV_TREE_DIFFERENT;
 462         return tree_difference;
 463 }
 464
 465 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 466 {
 467         int retval;
 468         struct tree *t1 = commit->tree;
 469
 470         if (!t1)
 471                 return 0;
 472
 473         tree_difference = REV_TREE_SAME;
 474         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 475         retval = diff_tree_oid(NULL, &t1->object.oid, "", &revs->pruning);
 476
 477         return retval >= 0 && (tree_difference == REV_TREE_SAME);
 478 }
 479
 480 struct treesame_state {
 481         unsigned int nparents;
 482         unsigned char treesame[FLEX_ARRAY];
 483 };
 484
 485 static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
 486 {
 487         unsigned n = commit_list_count(commit->parents);
 488         struct treesame_state *st = xcalloc(1, st_add(sizeof(*st), n));
 489         st->nparents = n;
 490         add_decoration(&revs->treesame, &commit->object, st);
 491         return st;
 492 }
 493
 494 /*
 495  * Must be called immediately after removing the nth_parent from a commit's
 496  * parent list, if we are maintaining the per-parent treesame[] decoration.
 497  * This does not recalculate the master TREESAME flag - update_treesame()
 498  * should be called to update it after a sequence of treesame[] modifications
 499  * that may have affected it.
 500  */
 501 static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
 502 {
 503         struct treesame_state *st;
 504         int old_same;
 505
 506         if (!commit->parents) {
 507                 /*
 508                  * Have just removed the only parent from a non-merge.
 509                  * Different handling, as we lack decoration.
 510                  */
 511                 if (nth_parent != 0)
 512                         die("compact_treesame %u", nth_parent);
 513                 old_same = !!(commit->object.flags & TREESAME);
 514                 if (rev_same_tree_as_empty(revs, commit))
 515                         commit->object.flags |= TREESAME;
 516                 else
 517                         commit->object.flags &= ~TREESAME;
 518                 return old_same;
 519         }
 520
 521         st = lookup_decoration(&revs->treesame, &commit->object);
 522         if (!st || nth_parent >= st->nparents)
 523                 die("compact_treesame %u", nth_parent);
 524
 525         old_same = st->treesame[nth_parent];
 526         memmove(st->treesame + nth_parent,
 527                 st->treesame + nth_parent + 1,
 528                 st->nparents - nth_parent - 1);
 529
 530         /*
 531          * If we've just become a non-merge commit, update TREESAME
 532          * immediately, and remove the no-longer-needed decoration.
 533          * If still a merge, defer update until update_treesame().
 534          */
 535         if (--st->nparents == 1) {
 536                 if (commit->parents->next)
 537                         die("compact_treesame parents mismatch");
 538                 if (st->treesame[0] && revs->dense)
 539                         commit->object.flags |= TREESAME;
 540                 else
 541                         commit->object.flags &= ~TREESAME;
 542                 free(add_decoration(&revs->treesame, &commit->object, NULL));
 543         }
 544
 545         return old_same;
 546 }
 547
 548 static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
 549 {
 550         if (commit->parents && commit->parents->next) {
 551                 unsigned n;
 552                 struct treesame_state *st;
 553                 struct commit_list *p;
 554                 unsigned relevant_parents;
 555                 unsigned relevant_change, irrelevant_change;
 556
 557                 st = lookup_decoration(&revs->treesame, &commit->object);
 558                 if (!st)
 559                         die("update_treesame %s", oid_to_hex(&commit->object.oid));
 560                 relevant_parents = 0;
 561                 relevant_change = irrelevant_change = 0;
 562                 for (p = commit->parents, n = 0; p; n++, p = p->next) {
 563                         if (relevant_commit(p->item)) {
 564                                 relevant_change |= !st->treesame[n];
 565                                 relevant_parents++;
 566                         } else
 567                                 irrelevant_change |= !st->treesame[n];
 568                 }
 569                 if (relevant_parents ? relevant_change : irrelevant_change)
 570                         commit->object.flags &= ~TREESAME;
 571                 else
 572                         commit->object.flags |= TREESAME;
 573         }
 574
 575         return commit->object.flags & TREESAME;
 576 }
 577
 578 static inline int limiting_can_increase_treesame(const struct rev_info *revs)
 579 {
 580         /*
 581          * TREESAME is irrelevant unless prune && dense;
 582          * if simplify_history is set, we can't have a mixture of TREESAME and
 583          *    !TREESAME INTERESTING parents (and we don't have treesame[]
 584          *    decoration anyway);
 585          * if first_parent_only is set, then the TREESAME flag is locked
 586          *    against the first parent (and again we lack treesame[] decoration).
 587          */
 588         return revs->prune && revs->dense &&
 589                !revs->simplify_history &&
 590                !revs->first_parent_only;
 591 }
 592
 593 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 594 {
 595         struct commit_list **pp, *parent;
 596         struct treesame_state *ts = NULL;
 597         int relevant_change = 0, irrelevant_change = 0;
 598         int relevant_parents, nth_parent;
 599
 600         /*
 601          * If we don't do pruning, everything is interesting
 602          */
 603         if (!revs->prune)
 604                 return;
 605
 606         if (!commit->tree)
 607                 return;
 608
 609         if (!commit->parents) {
 610                 if (rev_same_tree_as_empty(revs, commit))
 611                         commit->object.flags |= TREESAME;
 612                 return;
 613         }
 614
 615         /*
 616          * Normal non-merge commit? If we don't want to make the
 617          * history dense, we consider it always to be a change..
 618          */
 619         if (!revs->dense && !commit->parents->next)
 620                 return;
 621
 622         for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
 623              (parent = *pp) != NULL;
 624              pp = &parent->next, nth_parent++) {
 625                 struct commit *p = parent->item;
 626                 if (relevant_commit(p))
 627                         relevant_parents++;
 628
 629                 if (nth_parent == 1) {
 630                         /*
 631                          * This our second loop iteration - so we now know
 632                          * we're dealing with a merge.
 633                          *
 634                          * Do not compare with later parents when we care only about
 635                          * the first parent chain, in order to avoid derailing the
 636                          * traversal to follow a side branch that brought everything
 637                          * in the path we are limited to by the pathspec.
 638                          */
 639                         if (revs->first_parent_only)
 640                                 break;
 641                         /*
 642                          * If this will remain a potentially-simplifiable
 643                          * merge, remember per-parent treesame if needed.
 644                          * Initialise the array with the comparison from our
 645                          * first iteration.
 646                          */
 647                         if (revs->treesame.name &&
 648                             !revs->simplify_history &&
 649                             !(commit->object.flags & UNINTERESTING)) {
 650                                 ts = initialise_treesame(revs, commit);
 651                                 if (!(irrelevant_change || relevant_change))
 652                                         ts->treesame[0] = 1;
 653                         }
 654                 }
 655                 if (parse_commit(p) < 0)
 656                         die("cannot simplify commit %s (because of %s)",
 657                             oid_to_hex(&commit->object.oid),
 658                             oid_to_hex(&p->object.oid));
 659                 switch (rev_compare_tree(revs, p, commit)) {
 660                 case REV_TREE_SAME:
 661                         if (!revs->simplify_history || !relevant_commit(p)) {
 662                                 /* Even if a merge with an uninteresting
 663                                  * side branch brought the entire change
 664                                  * we are interested in, we do not want
 665                                  * to lose the other branches of this
 666                                  * merge, so we just keep going.
 667                                  */
 668                                 if (ts)
 669                                         ts->treesame[nth_parent] = 1;
 670                                 continue;
 671                         }
 672                         parent->next = NULL;
 673                         commit->parents = parent;
 674                         commit->object.flags |= TREESAME;
 675                         return;
 676
 677                 case REV_TREE_NEW:
 678                         if (revs->remove_empty_trees &&
 679                             rev_same_tree_as_empty(revs, p)) {
 680                                 /* We are adding all the specified
 681                                  * paths from this parent, so the
 682                                  * history beyond this parent is not
 683                                  * interesting.  Remove its parents
 684                                  * (they are grandparents for us).
 685                                  * IOW, we pretend this parent is a
 686                                  * "root" commit.
 687                                  */
 688                                 if (parse_commit(p) < 0)
 689                                         die("cannot simplify commit %s (invalid %s)",
 690                                             oid_to_hex(&commit->object.oid),
 691                                             oid_to_hex(&p->object.oid));
 692                                 p->parents = NULL;
 693                         }
 694                 /* fallthrough */
 695                 case REV_TREE_OLD:
 696                 case REV_TREE_DIFFERENT:
 697                         if (relevant_commit(p))
 698                                 relevant_change = 1;
 699                         else
 700                                 irrelevant_change = 1;
 701                         continue;
 702                 }
 703                 die("bad tree compare for commit %s", oid_to_hex(&commit->object.oid));
 704         }
 705
 706         /*
 707          * TREESAME is straightforward for single-parent commits. For merge
 708          * commits, it is most useful to define it so that "irrelevant"
 709          * parents cannot make us !TREESAME - if we have any relevant
 710          * parents, then we only consider TREESAMEness with respect to them,
 711          * allowing irrelevant merges from uninteresting branches to be
 712          * simplified away. Only if we have only irrelevant parents do we
 713          * base TREESAME on them. Note that this logic is replicated in
 714          * update_treesame, which should be kept in sync.
 715          */
 716         if (relevant_parents ? !relevant_change : !irrelevant_change)
 717                 commit->object.flags |= TREESAME;
 718 }
 719
 720 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 721                     struct commit_list *cached_base, struct commit_list **cache)
 722 {
 723         struct commit_list *new_entry;
 724
 725         if (cached_base && p->date < cached_base->item->date)
 726                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
 727         else
 728                 new_entry = commit_list_insert_by_date(p, head);
 729
 730         if (cache && (!*cache || p->date < (*cache)->item->date))
 731                 *cache = new_entry;
 732 }
 733
 734 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 735                     struct commit_list **list, struct commit_list **cache_ptr)
 736 {
 737         struct commit_list *parent = commit->parents;
 738         unsigned left_flag;
 739         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 740
 741         if (commit->object.flags & ADDED)
 742                 return 0;
 743         commit->object.flags |= ADDED;
 744
 745         if (revs->include_check &&
 746             !revs->include_check(commit, revs->include_check_data))
 747                 return 0;
 748
 749         /*
 750          * If the commit is uninteresting, don't try to
 751          * prune parents - we want the maximal uninteresting
 752          * set.
 753          *
 754          * Normally we haven't parsed the parent
 755          * yet, so we won't have a parent of a parent
 756          * here. However, it may turn out that we've
 757          * reached this commit some other way (where it
 758          * wasn't uninteresting), in which case we need
 759          * to mark its parents recursively too..
 760          */
 761         if (commit->object.flags & UNINTERESTING) {
 762                 while (parent) {
 763                         struct commit *p = parent->item;
 764                         parent = parent->next;
 765                         if (p)
 766                                 p->object.flags |= UNINTERESTING;
 767                         if (parse_commit_gently(p, 1) < 0)
 768                                 continue;
 769                         if (p->parents)
 770                                 mark_parents_uninteresting(p);
 771                         if (p->object.flags & SEEN)
 772                                 continue;
 773                         p->object.flags |= SEEN;
 774                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 775                 }
 776                 return 0;
 777         }
 778
 779         /*
 780          * Ok, the commit wasn't uninteresting. Try to
 781          * simplify the commit history and find the parent
 782          * that has no differences in the path set if one exists.
 783          */
 784         try_to_simplify_commit(revs, commit);
 785
 786         if (revs->no_walk)
 787                 return 0;
 788
 789         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 790
 791         for (parent = commit->parents; parent; parent = parent->next) {
 792                 struct commit *p = parent->item;
 793
 794                 if (parse_commit_gently(p, revs->ignore_missing_links) < 0)
 795                         return -1;
 796                 if (revs->show_source && !p->util)
 797                         p->util = commit->util;
 798                 p->object.flags |= left_flag;
 799                 if (!(p->object.flags & SEEN)) {
 800                         p->object.flags |= SEEN;
 801                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 802                 }
 803                 if (revs->first_parent_only)
 804                         break;
 805         }
 806         return 0;
 807 }
 808
 809 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 810 {
 811         struct commit_list *p;
 812         int left_count = 0, right_count = 0;
 813         int left_first;
 814         struct patch_ids ids;
 815         unsigned cherry_flag;
 816
 817         /* First count the commits on the left and on the right */
 818         for (p = list; p; p = p->next) {
 819                 struct commit *commit = p->item;
 820                 unsigned flags = commit->object.flags;
 821                 if (flags & BOUNDARY)
 822                         ;
 823                 else if (flags & SYMMETRIC_LEFT)
 824                         left_count++;
 825                 else
 826                         right_count++;
 827         }
 828
 829         if (!left_count || !right_count)
 830                 return;
 831
 832         left_first = left_count < right_count;
 833         init_patch_ids(&ids);
 834         ids.diffopts.pathspec = revs->diffopt.pathspec;
 835
 836         /* Compute patch-ids for one side */
 837         for (p = list; p; p = p->next) {
 838                 struct commit *commit = p->item;
 839                 unsigned flags = commit->object.flags;
 840
 841                 if (flags & BOUNDARY)
 842                         continue;
 843                 /*
 844                  * If we have fewer left, left_first is set and we omit
 845                  * commits on the right branch in this loop.  If we have
 846                  * fewer right, we skip the left ones.
 847                  */
 848                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 849                         continue;
 850                 add_commit_patch_id(commit, &ids);
 851         }
 852
 853         /* either cherry_mark or cherry_pick are true */
 854         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 855
 856         /* Check the other side */
 857         for (p = list; p; p = p->next) {
 858                 struct commit *commit = p->item;
 859                 struct patch_id *id;
 860                 unsigned flags = commit->object.flags;
 861
 862                 if (flags & BOUNDARY)
 863                         continue;
 864                 /*
 865                  * If we have fewer left, left_first is set and we omit
 866                  * commits on the left branch in this loop.
 867                  */
 868                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 869                         continue;
 870
 871                 /*
 872                  * Have we seen the same patch id?
 873                  */
 874                 id = has_commit_patch_id(commit, &ids);
 875                 if (!id)
 876                         continue;
 877
 878                 commit->object.flags |= cherry_flag;
 879                 id->commit->object.flags |= cherry_flag;
 880         }
 881
 882         free_patch_ids(&ids);
 883 }
 884
 885 /* How many extra uninteresting commits we want to see.. */
 886 #define SLOP 5
 887
 888 static int still_interesting(struct commit_list *src, timestamp_t date, int slop,
 889                              struct commit **interesting_cache)
 890 {
 891         /*
 892          * No source list at all? We're definitely done..
 893          */
 894         if (!src)
 895                 return 0;
 896
 897         /*
 898          * Does the destination list contain entries with a date
 899          * before the source list? Definitely _not_ done.
 900          */
 901         if (date <= src->item->date)
 902                 return SLOP;
 903
 904         /*
 905          * Does the source list still have interesting commits in
 906          * it? Definitely not done..
 907          */
 908         if (!everybody_uninteresting(src, interesting_cache))
 909                 return SLOP;
 910
 911         /* Ok, we're closing in.. */
 912         return slop-1;
 913 }
 914
 915 /*
 916  * "rev-list --ancestry-path A..B" computes commits that are ancestors
 917  * of B but not ancestors of A but further limits the result to those
 918  * that are descendants of A.  This takes the list of bottom commits and
 919  * the result of "A..B" without --ancestry-path, and limits the latter
 920  * further to the ones that can reach one of the commits in "bottom".
 921  */
 922 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 923 {
 924         struct commit_list *p;
 925         struct commit_list *rlist = NULL;
 926         int made_progress;
 927
 928         /*
 929          * Reverse the list so that it will be likely that we would
 930          * process parents before children.
 931          */
 932         for (p = list; p; p = p->next)
 933                 commit_list_insert(p->item, &rlist);
 934
 935         for (p = bottom; p; p = p->next)
 936                 p->item->object.flags |= TMP_MARK;
 937
 938         /*
 939          * Mark the ones that can reach bottom commits in "list",
 940          * in a bottom-up fashion.
 941          */
 942         do {
 943                 made_progress = 0;
 944                 for (p = rlist; p; p = p->next) {
 945                         struct commit *c = p->item;
 946                         struct commit_list *parents;
 947                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
 948                                 continue;
 949                         for (parents = c->parents;
 950                              parents;
 951                              parents = parents->next) {
 952                                 if (!(parents->item->object.flags & TMP_MARK))
 953                                         continue;
 954                                 c->object.flags |= TMP_MARK;
 955                                 made_progress = 1;
 956                                 break;
 957                         }
 958                 }
 959         } while (made_progress);
 960
 961         /*
 962          * NEEDSWORK: decide if we want to remove parents that are
 963          * not marked with TMP_MARK from commit->parents for commits
 964          * in the resulting list.  We may not want to do that, though.
 965          */
 966
 967         /*
 968          * The ones that are not marked with TMP_MARK are uninteresting
 969          */
 970         for (p = list; p; p = p->next) {
 971                 struct commit *c = p->item;
 972                 if (c->object.flags & TMP_MARK)
 973                         continue;
 974                 c->object.flags |= UNINTERESTING;
 975         }
 976
 977         /* We are done with the TMP_MARK */
 978         for (p = list; p; p = p->next)
 979                 p->item->object.flags &= ~TMP_MARK;
 980         for (p = bottom; p; p = p->next)
 981                 p->item->object.flags &= ~TMP_MARK;
 982         free_commit_list(rlist);
 983 }
 984
 985 /*
 986  * Before walking the history, keep the set of "negative" refs the
 987  * caller has asked to exclude.
 988  *
 989  * This is used to compute "rev-list --ancestry-path A..B", as we need
 990  * to filter the result of "A..B" further to the ones that can actually
 991  * reach A.
 992  */
 993 static struct commit_list *collect_bottom_commits(struct commit_list *list)
 994 {
 995         struct commit_list *elem, *bottom = NULL;
 996         for (elem = list; elem; elem = elem->next)
 997                 if (elem->item->object.flags & BOTTOM)
 998                         commit_list_insert(elem->item, &bottom);
 999         return bottom;
1000 }
1001
1002 /* Assumes either left_only or right_only is set */
1003 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1004 {
1005         struct commit_list *p;
1006
1007         for (p = list; p; p = p->next) {
1008                 struct commit *commit = p->item;
1009
1010                 if (revs->right_only) {
1011                         if (commit->object.flags & SYMMETRIC_LEFT)
1012                                 commit->object.flags |= SHOWN;
1013                 } else  /* revs->left_only is set */
1014                         if (!(commit->object.flags & SYMMETRIC_LEFT))
1015                                 commit->object.flags |= SHOWN;
1016         }
1017 }
1018
1019 static int limit_list(struct rev_info *revs)
1020 {
1021         int slop = SLOP;
1022         timestamp_t date = TIME_MAX;
1023         struct commit_list *list = revs->commits;
1024         struct commit_list *newlist = NULL;
1025         struct commit_list **p = &newlist;
1026         struct commit_list *bottom = NULL;
1027         struct commit *interesting_cache = NULL;
1028
1029         if (revs->ancestry_path) {
1030                 bottom = collect_bottom_commits(list);
1031                 if (!bottom)
1032                         die("--ancestry-path given but there are no bottom commits");
1033         }
1034
1035         while (list) {
1036                 struct commit *commit = pop_commit(&list);
1037                 struct object *obj = &commit->object;
1038                 show_early_output_fn_t show;
1039
1040                 if (commit == interesting_cache)
1041                         interesting_cache = NULL;
1042
1043                 if (revs->max_age != -1 && (commit->date < revs->max_age))
1044                         obj->flags |= UNINTERESTING;
1045                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
1046                         return -1;
1047                 if (obj->flags & UNINTERESTING) {
1048                         mark_parents_uninteresting(commit);
1049                         if (revs->show_all)
1050                                 p = &commit_list_insert(commit, p)->next;
1051                         slop = still_interesting(list, date, slop, &interesting_cache);
1052                         if (slop)
1053                                 continue;
1054                         /* If showing all, add the whole pending list to the end */
1055                         if (revs->show_all)
1056                                 *p = list;
1057                         break;
1058                 }
1059                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1060                         continue;
1061                 date = commit->date;
1062                 p = &commit_list_insert(commit, p)->next;
1063
1064                 show = show_early_output;
1065                 if (!show)
1066                         continue;
1067
1068                 show(revs, newlist);
1069                 show_early_output = NULL;
1070         }
1071         if (revs->cherry_pick || revs->cherry_mark)
1072                 cherry_pick_list(newlist, revs);
1073
1074         if (revs->left_only || revs->right_only)
1075                 limit_left_right(newlist, revs);
1076
1077         if (bottom) {
1078                 limit_to_ancestry(bottom, newlist);
1079                 free_commit_list(bottom);
1080         }
1081
1082         /*
1083          * Check if any commits have become TREESAME by some of their parents
1084          * becoming UNINTERESTING.
1085          */
1086         if (limiting_can_increase_treesame(revs))
1087                 for (list = newlist; list; list = list->next) {
1088                         struct commit *c = list->item;
1089                         if (c->object.flags & (UNINTERESTING | TREESAME))
1090                                 continue;
1091                         update_treesame(revs, c);
1092                 }
1093
1094         revs->commits = newlist;
1095         return 0;
1096 }
1097
1098 /*
1099  * Add an entry to refs->cmdline with the specified information.
1100  * *name is copied.
1101  */
1102 static void add_rev_cmdline(struct rev_info *revs,
1103                             struct object *item,
1104                             const char *name,
1105                             int whence,
1106                             unsigned flags)
1107 {
1108         struct rev_cmdline_info *info = &revs->cmdline;
1109         int nr = info->nr;
1110
1111         ALLOC_GROW(info->rev, nr + 1, info->alloc);
1112         info->rev[nr].item = item;
1113         info->rev[nr].name = xstrdup(name);
1114         info->rev[nr].whence = whence;
1115         info->rev[nr].flags = flags;
1116         info->nr++;
1117 }
1118
1119 static void add_rev_cmdline_list(struct rev_info *revs,
1120                                  struct commit_list *commit_list,
1121                                  int whence,
1122                                  unsigned flags)
1123 {
1124         while (commit_list) {
1125                 struct object *object = &commit_list->item->object;
1126                 add_rev_cmdline(revs, object, oid_to_hex(&object->oid),
1127                                 whence, flags);
1128                 commit_list = commit_list->next;
1129         }
1130 }
1131
1132 struct all_refs_cb {
1133         int all_flags;
1134         int warned_bad_reflog;
1135         struct rev_info *all_revs;
1136         const char *name_for_errormsg;
1137         struct ref_store *refs;
1138 };
1139
1140 int ref_excluded(struct string_list *ref_excludes, const char *path)
1141 {
1142         struct string_list_item *item;
1143
1144         if (!ref_excludes)
1145                 return 0;
1146         for_each_string_list_item(item, ref_excludes) {
1147                 if (!wildmatch(item->string, path, 0))
1148                         return 1;
1149         }
1150         return 0;
1151 }
1152
1153 static int handle_one_ref(const char *path, const struct object_id *oid,
1154                           int flag, void *cb_data)
1155 {
1156         struct all_refs_cb *cb = cb_data;
1157         struct object *object;
1158
1159         if (ref_excluded(cb->all_revs->ref_excludes, path))
1160             return 0;
1161
1162         object = get_reference(cb->all_revs, path, oid, cb->all_flags);
1163         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1164         add_pending_oid(cb->all_revs, path, oid, cb->all_flags);
1165         return 0;
1166 }
1167
1168 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1169         unsigned flags)
1170 {
1171         cb->all_revs = revs;
1172         cb->all_flags = flags;
1173         revs->rev_input_given = 1;
1174         cb->refs = NULL;
1175 }
1176
1177 void clear_ref_exclusion(struct string_list **ref_excludes_p)
1178 {
1179         if (*ref_excludes_p) {
1180                 string_list_clear(*ref_excludes_p, 0);
1181                 free(*ref_excludes_p);
1182         }
1183         *ref_excludes_p = NULL;
1184 }
1185
1186 void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1187 {
1188         if (!*ref_excludes_p) {
1189                 *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1190                 (*ref_excludes_p)->strdup_strings = 1;
1191         }
1192         string_list_append(*ref_excludes_p, exclude);
1193 }
1194
1195 static void handle_refs(struct ref_store *refs,
1196                         struct rev_info *revs, unsigned flags,
1197                         int (*for_each)(struct ref_store *, each_ref_fn, void *))
1198 {
1199         struct all_refs_cb cb;
1200
1201         if (!refs) {
1202                 /* this could happen with uninitialized submodules */
1203                 return;
1204         }
1205
1206         init_all_refs_cb(&cb, revs, flags);
1207         for_each(refs, handle_one_ref, &cb);
1208 }
1209
1210 static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
1211 {
1212         struct all_refs_cb *cb = cb_data;
1213         if (!is_null_oid(oid)) {
1214                 struct object *o = parse_object(oid);
1215                 if (o) {
1216                         o->flags |= cb->all_flags;
1217                         /* ??? CMDLINEFLAGS ??? */
1218                         add_pending_object(cb->all_revs, o, "");
1219                 }
1220                 else if (!cb->warned_bad_reflog) {
1221                         warning("reflog of '%s' references pruned commits",
1222                                 cb->name_for_errormsg);
1223                         cb->warned_bad_reflog = 1;
1224                 }
1225         }
1226 }
1227
1228 static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
1229                 const char *email, timestamp_t timestamp, int tz,
1230                 const char *message, void *cb_data)
1231 {
1232         handle_one_reflog_commit(ooid, cb_data);
1233         handle_one_reflog_commit(noid, cb_data);
1234         return 0;
1235 }
1236
1237 static int handle_one_reflog(const char *path, const struct object_id *oid,
1238                              int flag, void *cb_data)
1239 {
1240         struct all_refs_cb *cb = cb_data;
1241         cb->warned_bad_reflog = 0;
1242         cb->name_for_errormsg = path;
1243         refs_for_each_reflog_ent(cb->refs, path,
1244                                  handle_one_reflog_ent, cb_data);
1245         return 0;
1246 }
1247
1248 static void add_other_reflogs_to_pending(struct all_refs_cb *cb)
1249 {
1250         struct worktree **worktrees, **p;
1251
1252         worktrees = get_worktrees(0);
1253         for (p = worktrees; *p; p++) {
1254                 struct worktree *wt = *p;
1255
1256                 if (wt->is_current)
1257                         continue;
1258
1259                 cb->refs = get_worktree_ref_store(wt);
1260                 refs_for_each_reflog(cb->refs,
1261                                      handle_one_reflog,
1262                                      cb);
1263         }
1264         free_worktrees(worktrees);
1265 }
1266
1267 void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1268 {
1269         struct all_refs_cb cb;
1270
1271         cb.all_revs = revs;
1272         cb.all_flags = flags;
1273         cb.refs = get_main_ref_store();
1274         for_each_reflog(handle_one_reflog, &cb);
1275
1276         if (!revs->single_worktree)
1277                 add_other_reflogs_to_pending(&cb);
1278 }
1279
1280 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1281                            struct strbuf *path)
1282 {
1283         size_t baselen = path->len;
1284         int i;
1285
1286         if (it->entry_count >= 0) {
1287                 struct tree *tree = lookup_tree(&it->oid);
1288                 add_pending_object_with_path(revs, &tree->object, "",
1289                                              040000, path->buf);
1290         }
1291
1292         for (i = 0; i < it->subtree_nr; i++) {
1293                 struct cache_tree_sub *sub = it->down[i];
1294                 strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1295                 add_cache_tree(sub->cache_tree, revs, path);
1296                 strbuf_setlen(path, baselen);
1297         }
1298
1299 }
1300
1301 static void do_add_index_objects_to_pending(struct rev_info *revs,
1302                                             struct index_state *istate)
1303 {
1304         int i;
1305
1306         for (i = 0; i < istate->cache_nr; i++) {
1307                 struct cache_entry *ce = istate->cache[i];
1308                 struct blob *blob;
1309
1310                 if (S_ISGITLINK(ce->ce_mode))
1311                         continue;
1312
1313                 blob = lookup_blob(&ce->oid);
1314                 if (!blob)
1315                         die("unable to add index blob to traversal");
1316                 add_pending_object_with_path(revs, &blob->object, "",
1317                                              ce->ce_mode, ce->name);
1318         }
1319
1320         if (istate->cache_tree) {
1321                 struct strbuf path = STRBUF_INIT;
1322                 add_cache_tree(istate->cache_tree, revs, &path);
1323                 strbuf_release(&path);
1324         }
1325 }
1326
1327 void add_index_objects_to_pending(struct rev_info *revs, unsigned int flags)
1328 {
1329         struct worktree **worktrees, **p;
1330
1331         read_cache();
1332         do_add_index_objects_to_pending(revs, &the_index);
1333
1334         if (revs->single_worktree)
1335                 return;
1336
1337         worktrees = get_worktrees(0);
1338         for (p = worktrees; *p; p++) {
1339                 struct worktree *wt = *p;
1340                 struct index_state istate = { NULL };
1341
1342                 if (wt->is_current)
1343                         continue; /* current index already taken care of */
1344
1345                 if (read_index_from(&istate,
1346                                     worktree_git_path(wt, "index")) > 0)
1347                         do_add_index_objects_to_pending(revs, &istate);
1348                 discard_index(&istate);
1349         }
1350         free_worktrees(worktrees);
1351 }
1352
1353 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
1354                             int exclude_parent)
1355 {
1356         struct object_id oid;
1357         struct object *it;
1358         struct commit *commit;
1359         struct commit_list *parents;
1360         int parent_number;
1361         const char *arg = arg_;
1362
1363         if (*arg == '^') {
1364                 flags ^= UNINTERESTING | BOTTOM;
1365                 arg++;
1366         }
1367         if (get_oid_committish(arg, &oid))
1368                 return 0;
1369         while (1) {
1370                 it = get_reference(revs, arg, &oid, 0);
1371                 if (!it && revs->ignore_missing)
1372                         return 0;
1373                 if (it->type != OBJ_TAG)
1374                         break;
1375                 if (!((struct tag*)it)->tagged)
1376                         return 0;
1377                 oidcpy(&oid, &((struct tag*)it)->tagged->oid);
1378         }
1379         if (it->type != OBJ_COMMIT)
1380                 return 0;
1381         commit = (struct commit *)it;
1382         if (exclude_parent &&
1383             exclude_parent > commit_list_count(commit->parents))
1384                 return 0;
1385         for (parents = commit->parents, parent_number = 1;
1386              parents;
1387              parents = parents->next, parent_number++) {
1388                 if (exclude_parent && parent_number != exclude_parent)
1389                         continue;
1390
1391                 it = &parents->item->object;
1392                 it->flags |= flags;
1393                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1394                 add_pending_object(revs, it, arg);
1395         }
1396         return 1;
1397 }
1398
1399 void init_revisions(struct rev_info *revs, const char *prefix)
1400 {
1401         memset(revs, 0, sizeof(*revs));
1402
1403         revs->abbrev = DEFAULT_ABBREV;
1404         revs->ignore_merges = 1;
1405         revs->simplify_history = 1;
1406         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1407         DIFF_OPT_SET(&revs->pruning, QUICK);
1408         revs->pruning.add_remove = file_add_remove;
1409         revs->pruning.change = file_change;
1410         revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1411         revs->dense = 1;
1412         revs->prefix = prefix;
1413         revs->max_age = -1;
1414         revs->min_age = -1;
1415         revs->skip_count = -1;
1416         revs->max_count = -1;
1417         revs->max_parents = -1;
1418         revs->expand_tabs_in_log = -1;
1419
1420         revs->commit_format = CMIT_FMT_DEFAULT;
1421         revs->expand_tabs_in_log_default = 8;
1422
1423         init_grep_defaults();
1424         grep_init(&revs->grep_filter, prefix);
1425         revs->grep_filter.status_only = 1;
1426
1427         diff_setup(&revs->diffopt);
1428         if (prefix && !revs->diffopt.prefix) {
1429                 revs->diffopt.prefix = prefix;
1430                 revs->diffopt.prefix_length = strlen(prefix);
1431         }
1432
1433         revs->notes_opt.use_default_notes = -1;
1434 }
1435
1436 static void add_pending_commit_list(struct rev_info *revs,
1437                                     struct commit_list *commit_list,
1438                                     unsigned int flags)
1439 {
1440         while (commit_list) {
1441                 struct object *object = &commit_list->item->object;
1442                 object->flags |= flags;
1443                 add_pending_object(revs, object, oid_to_hex(&object->oid));
1444                 commit_list = commit_list->next;
1445         }
1446 }
1447
1448 static void prepare_show_merge(struct rev_info *revs)
1449 {
1450         struct commit_list *bases;
1451         struct commit *head, *other;
1452         struct object_id oid;
1453         const char **prune = NULL;
1454         int i, prune_num = 1; /* counting terminating NULL */
1455
1456         if (get_oid("HEAD", &oid))
1457                 die("--merge without HEAD?");
1458         head = lookup_commit_or_die(&oid, "HEAD");
1459         if (get_oid("MERGE_HEAD", &oid))
1460                 die("--merge without MERGE_HEAD?");
1461         other = lookup_commit_or_die(&oid, "MERGE_HEAD");
1462         add_pending_object(revs, &head->object, "HEAD");
1463         add_pending_object(revs, &other->object, "MERGE_HEAD");
1464         bases = get_merge_bases(head, other);
1465         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1466         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1467         free_commit_list(bases);
1468         head->object.flags |= SYMMETRIC_LEFT;
1469
1470         if (!active_nr)
1471                 read_cache();
1472         for (i = 0; i < active_nr; i++) {
1473                 const struct cache_entry *ce = active_cache[i];
1474                 if (!ce_stage(ce))
1475                         continue;
1476                 if (ce_path_match(ce, &revs->prune_data, NULL)) {
1477                         prune_num++;
1478                         REALLOC_ARRAY(prune, prune_num);
1479                         prune[prune_num-2] = ce->name;
1480                         prune[prune_num-1] = NULL;
1481                 }
1482                 while ((i+1 < active_nr) &&
1483                        ce_same_name(ce, active_cache[i+1]))
1484                         i++;
1485         }
1486         clear_pathspec(&revs->prune_data);
1487         parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1488                        PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1489         revs->limited = 1;
1490 }
1491
1492 static int dotdot_missing(const char *arg, char *dotdot,
1493                           struct rev_info *revs, int symmetric)
1494 {
1495         if (revs->ignore_missing)
1496                 return 0;
1497         /* de-munge so we report the full argument */
1498         *dotdot = '.';
1499         die(symmetric
1500             ? "Invalid symmetric difference expression %s"
1501             : "Invalid revision range %s", arg);
1502 }
1503
1504 static int handle_dotdot_1(const char *arg, char *dotdot,
1505                            struct rev_info *revs, int flags,
1506                            int cant_be_filename,
1507                            struct object_context *a_oc,
1508                            struct object_context *b_oc)
1509 {
1510         const char *a_name, *b_name;
1511         struct object_id a_oid, b_oid;
1512         struct object *a_obj, *b_obj;
1513         unsigned int a_flags, b_flags;
1514         int symmetric = 0;
1515         unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1516         unsigned int oc_flags = GET_OID_COMMITTISH | GET_OID_RECORD_PATH;
1517
1518         a_name = arg;
1519         if (!*a_name)
1520                 a_name = "HEAD";
1521
1522         b_name = dotdot + 2;
1523         if (*b_name == '.') {
1524                 symmetric = 1;
1525                 b_name++;
1526         }
1527         if (!*b_name)
1528                 b_name = "HEAD";
1529
1530         if (get_oid_with_context(a_name, oc_flags, &a_oid, a_oc) ||
1531             get_oid_with_context(b_name, oc_flags, &b_oid, b_oc))
1532                 return -1;
1533
1534         if (!cant_be_filename) {
1535                 *dotdot = '.';
1536                 verify_non_filename(revs->prefix, arg);
1537                 *dotdot = '\0';
1538         }
1539
1540         a_obj = parse_object(&a_oid);
1541         b_obj = parse_object(&b_oid);
1542         if (!a_obj || !b_obj)
1543                 return dotdot_missing(arg, dotdot, revs, symmetric);
1544
1545         if (!symmetric) {
1546                 /* just A..B */
1547                 b_flags = flags;
1548                 a_flags = flags_exclude;
1549         } else {
1550                 /* A...B -- find merge bases between the two */
1551                 struct commit *a, *b;
1552                 struct commit_list *exclude;
1553
1554                 a = lookup_commit_reference(&a_obj->oid);
1555                 b = lookup_commit_reference(&b_obj->oid);
1556                 if (!a || !b)
1557                         return dotdot_missing(arg, dotdot, revs, symmetric);
1558
1559                 exclude = get_merge_bases(a, b);
1560                 add_rev_cmdline_list(revs, exclude, REV_CMD_MERGE_BASE,
1561                                      flags_exclude);
1562                 add_pending_commit_list(revs, exclude, flags_exclude);
1563                 free_commit_list(exclude);
1564
1565                 b_flags = flags;
1566                 a_flags = flags | SYMMETRIC_LEFT;
1567         }
1568
1569         a_obj->flags |= a_flags;
1570         b_obj->flags |= b_flags;
1571         add_rev_cmdline(revs, a_obj, a_name, REV_CMD_LEFT, a_flags);
1572         add_rev_cmdline(revs, b_obj, b_name, REV_CMD_RIGHT, b_flags);
1573         add_pending_object_with_path(revs, a_obj, a_name, a_oc->mode, a_oc->path);
1574         add_pending_object_with_path(revs, b_obj, b_name, b_oc->mode, b_oc->path);
1575         return 0;
1576 }
1577
1578 static int handle_dotdot(const char *arg,
1579                          struct rev_info *revs, int flags,
1580                          int cant_be_filename)
1581 {
1582         struct object_context a_oc, b_oc;
1583         char *dotdot = strstr(arg, "..");
1584         int ret;
1585
1586         if (!dotdot)
1587                 return -1;
1588
1589         memset(&a_oc, 0, sizeof(a_oc));
1590         memset(&b_oc, 0, sizeof(b_oc));
1591
1592         *dotdot = '\0';
1593         ret = handle_dotdot_1(arg, dotdot, revs, flags, cant_be_filename,
1594                               &a_oc, &b_oc);
1595         *dotdot = '.';
1596
1597         free(a_oc.path);
1598         free(b_oc.path);
1599
1600         return ret;
1601 }
1602
1603 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1604 {
1605         struct object_context oc;
1606         char *mark;
1607         struct object *object;
1608         struct object_id oid;
1609         int local_flags;
1610         const char *arg = arg_;
1611         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1612         unsigned get_sha1_flags = GET_OID_RECORD_PATH;
1613
1614         flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1615
1616         if (!cant_be_filename && !strcmp(arg, "..")) {
1617                 /*
1618                  * Just ".."?  That is not a range but the
1619                  * pathspec for the parent directory.
1620                  */
1621                 return -1;
1622         }
1623
1624         if (!handle_dotdot(arg, revs, flags, revarg_opt))
1625                 return 0;
1626
1627         mark = strstr(arg, "^@");
1628         if (mark && !mark[2]) {
1629                 *mark = 0;
1630                 if (add_parents_only(revs, arg, flags, 0))
1631                         return 0;
1632                 *mark = '^';
1633         }
1634         mark = strstr(arg, "^!");
1635         if (mark && !mark[2]) {
1636                 *mark = 0;
1637                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
1638                         *mark = '^';
1639         }
1640         mark = strstr(arg, "^-");
1641         if (mark) {
1642                 int exclude_parent = 1;
1643
1644                 if (mark[2]) {
1645                         char *end;
1646                         exclude_parent = strtoul(mark + 2, &end, 10);
1647                         if (*end != '\0' || !exclude_parent)
1648                                 return -1;
1649                 }
1650
1651                 *mark = 0;
1652                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
1653                         *mark = '^';
1654         }
1655
1656         local_flags = 0;
1657         if (*arg == '^') {
1658                 local_flags = UNINTERESTING | BOTTOM;
1659                 arg++;
1660         }
1661
1662         if (revarg_opt & REVARG_COMMITTISH)
1663                 get_sha1_flags |= GET_OID_COMMITTISH;
1664
1665         if (get_oid_with_context(arg, get_sha1_flags, &oid, &oc))
1666                 return revs->ignore_missing ? 0 : -1;
1667         if (!cant_be_filename)
1668                 verify_non_filename(revs->prefix, arg);
1669         object = get_reference(revs, arg, &oid, flags ^ local_flags);
1670         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1671         add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
1672         free(oc.path);
1673         return 0;
1674 }
1675
1676 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1677                                      struct argv_array *prune)
1678 {
1679         while (strbuf_getline(sb, stdin) != EOF)
1680                 argv_array_push(prune, sb->buf);
1681 }
1682
1683 static void read_revisions_from_stdin(struct rev_info *revs,
1684                                       struct argv_array *prune)
1685 {
1686         struct strbuf sb;
1687         int seen_dashdash = 0;
1688         int save_warning;
1689
1690         save_warning = warn_on_object_refname_ambiguity;
1691         warn_on_object_refname_ambiguity = 0;
1692
1693         strbuf_init(&sb, 1000);
1694         while (strbuf_getline(&sb, stdin) != EOF) {
1695                 int len = sb.len;
1696                 if (!len)
1697                         break;
1698                 if (sb.buf[0] == '-') {
1699                         if (len == 2 && sb.buf[1] == '-') {
1700                                 seen_dashdash = 1;
1701                                 break;
1702                         }
1703                         die("options not supported in --stdin mode");
1704                 }
1705                 if (handle_revision_arg(sb.buf, revs, 0,
1706                                         REVARG_CANNOT_BE_FILENAME))
1707                         die("bad revision '%s'", sb.buf);
1708         }
1709         if (seen_dashdash)
1710                 read_pathspec_from_stdin(revs, &sb, prune);
1711
1712         strbuf_release(&sb);
1713         warn_on_object_refname_ambiguity = save_warning;
1714 }
1715
1716 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1717 {
1718         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1719 }
1720
1721 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1722 {
1723         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1724 }
1725
1726 static void add_message_grep(struct rev_info *revs, const char *pattern)
1727 {
1728         add_grep(revs, pattern, GREP_PATTERN_BODY);
1729 }
1730
1731 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1732                                int *unkc, const char **unkv)
1733 {
1734         const char *arg = argv[0];
1735         const char *optarg;
1736         int argcount;
1737
1738         /* pseudo revision arguments */
1739         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1740             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1741             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1742             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1743             !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
1744             !strcmp(arg, "--indexed-objects") ||
1745             starts_with(arg, "--exclude=") ||
1746             starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
1747             starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
1748         {
1749                 unkv[(*unkc)++] = arg;
1750                 return 1;
1751         }
1752
1753         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1754                 revs->max_count = atoi(optarg);
1755                 revs->no_walk = 0;
1756                 return argcount;
1757         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1758                 revs->skip_count = atoi(optarg);
1759                 return argcount;
1760         } else if ((*arg == '-') && isdigit(arg[1])) {
1761                 /* accept -<digit>, like traditional "head" */
1762                 if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
1763                     revs->max_count < 0)
1764                         die("'%s': not a non-negative integer", arg + 1);
1765                 revs->no_walk = 0;
1766         } else if (!strcmp(arg, "-n")) {
1767                 if (argc <= 1)
1768                         return error("-n requires an argument");
1769                 revs->max_count = atoi(argv[1]);
1770                 revs->no_walk = 0;
1771                 return 2;
1772         } else if (skip_prefix(arg, "-n", &optarg)) {
1773                 revs->max_count = atoi(optarg);
1774                 revs->no_walk = 0;
1775         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1776                 revs->max_age = atoi(optarg);
1777                 return argcount;
1778         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1779                 revs->max_age = approxidate(optarg);
1780                 return argcount;
1781         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1782                 revs->max_age = approxidate(optarg);
1783                 return argcount;
1784         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1785                 revs->min_age = atoi(optarg);
1786                 return argcount;
1787         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1788                 revs->min_age = approxidate(optarg);
1789                 return argcount;
1790         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1791                 revs->min_age = approxidate(optarg);
1792                 return argcount;
1793         } else if (!strcmp(arg, "--first-parent")) {
1794                 revs->first_parent_only = 1;
1795         } else if (!strcmp(arg, "--ancestry-path")) {
1796                 revs->ancestry_path = 1;
1797                 revs->simplify_history = 0;
1798                 revs->limited = 1;
1799         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1800                 init_reflog_walk(&revs->reflog_info);
1801         } else if (!strcmp(arg, "--default")) {
1802                 if (argc <= 1)
1803                         return error("bad --default argument");
1804                 revs->def = argv[1];
1805                 return 2;
1806         } else if (!strcmp(arg, "--merge")) {
1807                 revs->show_merge = 1;
1808         } else if (!strcmp(arg, "--topo-order")) {
1809                 revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1810                 revs->topo_order = 1;
1811         } else if (!strcmp(arg, "--simplify-merges")) {
1812                 revs->simplify_merges = 1;
1813                 revs->topo_order = 1;
1814                 revs->rewrite_parents = 1;
1815                 revs->simplify_history = 0;
1816                 revs->limited = 1;
1817         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1818                 revs->simplify_merges = 1;
1819                 revs->topo_order = 1;
1820                 revs->rewrite_parents = 1;
1821                 revs->simplify_history = 0;
1822                 revs->simplify_by_decoration = 1;
1823                 revs->limited = 1;
1824                 revs->prune = 1;
1825                 load_ref_decorations(DECORATE_SHORT_REFS);
1826         } else if (!strcmp(arg, "--date-order")) {
1827                 revs->sort_order = REV_SORT_BY_COMMIT_DATE;
1828                 revs->topo_order = 1;
1829         } else if (!strcmp(arg, "--author-date-order")) {
1830                 revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
1831                 revs->topo_order = 1;
1832         } else if (!strcmp(arg, "--early-output")) {
1833                 revs->early_output = 100;
1834                 revs->topo_order = 1;
1835         } else if (skip_prefix(arg, "--early-output=", &optarg)) {
1836                 if (strtoul_ui(optarg, 10, &revs->early_output) < 0)
1837                         die("'%s': not a non-negative integer", optarg);
1838                 revs->topo_order = 1;
1839         } else if (!strcmp(arg, "--parents")) {
1840                 revs->rewrite_parents = 1;
1841                 revs->print_parents = 1;
1842         } else if (!strcmp(arg, "--dense")) {
1843                 revs->dense = 1;
1844         } else if (!strcmp(arg, "--sparse")) {
1845                 revs->dense = 0;
1846         } else if (!strcmp(arg, "--show-all")) {
1847                 revs->show_all = 1;
1848         } else if (!strcmp(arg, "--remove-empty")) {
1849                 revs->remove_empty_trees = 1;
1850         } else if (!strcmp(arg, "--merges")) {
1851                 revs->min_parents = 2;
1852         } else if (!strcmp(arg, "--no-merges")) {
1853                 revs->max_parents = 1;
1854         } else if (skip_prefix(arg, "--min-parents=", &optarg)) {
1855                 revs->min_parents = atoi(optarg);
1856         } else if (!strcmp(arg, "--no-min-parents")) {
1857                 revs->min_parents = 0;
1858         } else if (skip_prefix(arg, "--max-parents=", &optarg)) {
1859                 revs->max_parents = atoi(optarg);
1860         } else if (!strcmp(arg, "--no-max-parents")) {
1861                 revs->max_parents = -1;
1862         } else if (!strcmp(arg, "--boundary")) {
1863                 revs->boundary = 1;
1864         } else if (!strcmp(arg, "--left-right")) {
1865                 revs->left_right = 1;
1866         } else if (!strcmp(arg, "--left-only")) {
1867                 if (revs->right_only)
1868                         die("--left-only is incompatible with --right-only"
1869                             " or --cherry");
1870                 revs->left_only = 1;
1871         } else if (!strcmp(arg, "--right-only")) {
1872                 if (revs->left_only)
1873                         die("--right-only is incompatible with --left-only");
1874                 revs->right_only = 1;
1875         } else if (!strcmp(arg, "--cherry")) {
1876                 if (revs->left_only)
1877                         die("--cherry is incompatible with --left-only");
1878                 revs->cherry_mark = 1;
1879                 revs->right_only = 1;
1880                 revs->max_parents = 1;
1881                 revs->limited = 1;
1882         } else if (!strcmp(arg, "--count")) {
1883                 revs->count = 1;
1884         } else if (!strcmp(arg, "--cherry-mark")) {
1885                 if (revs->cherry_pick)
1886                         die("--cherry-mark is incompatible with --cherry-pick");
1887                 revs->cherry_mark = 1;
1888                 revs->limited = 1; /* needs limit_list() */
1889         } else if (!strcmp(arg, "--cherry-pick")) {
1890                 if (revs->cherry_mark)
1891                         die("--cherry-pick is incompatible with --cherry-mark");
1892                 revs->cherry_pick = 1;
1893                 revs->limited = 1;
1894         } else if (!strcmp(arg, "--objects")) {
1895                 revs->tag_objects = 1;
1896                 revs->tree_objects = 1;
1897                 revs->blob_objects = 1;
1898         } else if (!strcmp(arg, "--objects-edge")) {
1899                 revs->tag_objects = 1;
1900                 revs->tree_objects = 1;
1901                 revs->blob_objects = 1;
1902                 revs->edge_hint = 1;
1903         } else if (!strcmp(arg, "--objects-edge-aggressive")) {
1904                 revs->tag_objects = 1;
1905                 revs->tree_objects = 1;
1906                 revs->blob_objects = 1;
1907                 revs->edge_hint = 1;
1908                 revs->edge_hint_aggressive = 1;
1909         } else if (!strcmp(arg, "--verify-objects")) {
1910                 revs->tag_objects = 1;
1911                 revs->tree_objects = 1;
1912                 revs->blob_objects = 1;
1913                 revs->verify_objects = 1;
1914         } else if (!strcmp(arg, "--unpacked")) {
1915                 revs->unpacked = 1;
1916         } else if (starts_with(arg, "--unpacked=")) {
1917                 die("--unpacked=<packfile> no longer supported.");
1918         } else if (!strcmp(arg, "-r")) {
1919                 revs->diff = 1;
1920                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1921         } else if (!strcmp(arg, "-t")) {
1922                 revs->diff = 1;
1923                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1924                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1925         } else if (!strcmp(arg, "-m")) {
1926                 revs->ignore_merges = 0;
1927         } else if (!strcmp(arg, "-c")) {
1928                 revs->diff = 1;
1929                 revs->dense_combined_merges = 0;
1930                 revs->combine_merges = 1;
1931         } else if (!strcmp(arg, "--cc")) {
1932                 revs->diff = 1;
1933                 revs->dense_combined_merges = 1;
1934                 revs->combine_merges = 1;
1935         } else if (!strcmp(arg, "-v")) {
1936                 revs->verbose_header = 1;
1937         } else if (!strcmp(arg, "--pretty")) {
1938                 revs->verbose_header = 1;
1939                 revs->pretty_given = 1;
1940                 get_commit_format(NULL, revs);
1941         } else if (skip_prefix(arg, "--pretty=", &optarg) ||
1942                    skip_prefix(arg, "--format=", &optarg)) {
1943                 /*
1944                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1945                  * not allowed, since the argument is optional.
1946                  */
1947                 revs->verbose_header = 1;
1948                 revs->pretty_given = 1;
1949                 get_commit_format(optarg, revs);
1950         } else if (!strcmp(arg, "--expand-tabs")) {
1951                 revs->expand_tabs_in_log = 8;
1952         } else if (!strcmp(arg, "--no-expand-tabs")) {
1953                 revs->expand_tabs_in_log = 0;
1954         } else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
1955                 int val;
1956                 if (strtol_i(arg, 10, &val) < 0 || val < 0)
1957                         die("'%s': not a non-negative integer", arg);
1958                 revs->expand_tabs_in_log = val;
1959         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1960                 revs->show_notes = 1;
1961                 revs->show_notes_given = 1;
1962                 revs->notes_opt.use_default_notes = 1;
1963         } else if (!strcmp(arg, "--show-signature")) {
1964                 revs->show_signature = 1;
1965         } else if (!strcmp(arg, "--no-show-signature")) {
1966                 revs->show_signature = 0;
1967         } else if (!strcmp(arg, "--show-linear-break")) {
1968                 revs->break_bar = "                    ..........";
1969                 revs->track_linear = 1;
1970                 revs->track_first_time = 1;
1971         } else if (skip_prefix(arg, "--show-linear-break=", &optarg)) {
1972                 revs->break_bar = xstrdup(optarg);
1973                 revs->track_linear = 1;
1974                 revs->track_first_time = 1;
1975         } else if (skip_prefix(arg, "--show-notes=", &optarg) ||
1976                    skip_prefix(arg, "--notes=", &optarg)) {
1977                 struct strbuf buf = STRBUF_INIT;
1978                 revs->show_notes = 1;
1979                 revs->show_notes_given = 1;
1980                 if (starts_with(arg, "--show-notes=") &&
1981                     revs->notes_opt.use_default_notes < 0)
1982                         revs->notes_opt.use_default_notes = 1;
1983                 strbuf_addstr(&buf, optarg);
1984                 expand_notes_ref(&buf);
1985                 string_list_append(&revs->notes_opt.extra_notes_refs,
1986                                    strbuf_detach(&buf, NULL));
1987         } else if (!strcmp(arg, "--no-notes")) {
1988                 revs->show_notes = 0;
1989                 revs->show_notes_given = 1;
1990                 revs->notes_opt.use_default_notes = -1;
1991                 /* we have been strdup'ing ourselves, so trick
1992                  * string_list into free()ing strings */
1993                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1994                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1995                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1996         } else if (!strcmp(arg, "--standard-notes")) {
1997                 revs->show_notes_given = 1;
1998                 revs->notes_opt.use_default_notes = 1;
1999         } else if (!strcmp(arg, "--no-standard-notes")) {
2000                 revs->notes_opt.use_default_notes = 0;
2001         } else if (!strcmp(arg, "--oneline")) {
2002                 revs->verbose_header = 1;
2003                 get_commit_format("oneline", revs);
2004                 revs->pretty_given = 1;
2005                 revs->abbrev_commit = 1;
2006         } else if (!strcmp(arg, "--graph")) {
2007                 revs->topo_order = 1;
2008                 revs->rewrite_parents = 1;
2009                 revs->graph = graph_init(revs);
2010         } else if (!strcmp(arg, "--root")) {
2011                 revs->show_root_diff = 1;
2012         } else if (!strcmp(arg, "--no-commit-id")) {
2013                 revs->no_commit_id = 1;
2014         } else if (!strcmp(arg, "--always")) {
2015                 revs->always_show_header = 1;
2016         } else if (!strcmp(arg, "--no-abbrev")) {
2017                 revs->abbrev = 0;
2018         } else if (!strcmp(arg, "--abbrev")) {
2019                 revs->abbrev = DEFAULT_ABBREV;
2020         } else if (skip_prefix(arg, "--abbrev=", &optarg)) {
2021                 revs->abbrev = strtoul(optarg, NULL, 10);
2022                 if (revs->abbrev < MINIMUM_ABBREV)
2023                         revs->abbrev = MINIMUM_ABBREV;
2024                 else if (revs->abbrev > 40)
2025                         revs->abbrev = 40;
2026         } else if (!strcmp(arg, "--abbrev-commit")) {
2027                 revs->abbrev_commit = 1;
2028                 revs->abbrev_commit_given = 1;
2029         } else if (!strcmp(arg, "--no-abbrev-commit")) {
2030                 revs->abbrev_commit = 0;
2031         } else if (!strcmp(arg, "--full-diff")) {
2032                 revs->diff = 1;
2033                 revs->full_diff = 1;
2034         } else if (!strcmp(arg, "--full-history")) {
2035                 revs->simplify_history = 0;
2036         } else if (!strcmp(arg, "--relative-date")) {
2037                 revs->date_mode.type = DATE_RELATIVE;
2038                 revs->date_mode_explicit = 1;
2039         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
2040                 parse_date_format(optarg, &revs->date_mode);
2041                 revs->date_mode_explicit = 1;
2042                 return argcount;
2043         } else if (!strcmp(arg, "--log-size")) {
2044                 revs->show_log_size = 1;
2045         }
2046         /*
2047          * Grepping the commit log
2048          */
2049         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
2050                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
2051                 return argcount;
2052         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
2053                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
2054                 return argcount;
2055         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
2056                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
2057                 return argcount;
2058         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
2059                 add_message_grep(revs, optarg);
2060                 return argcount;
2061         } else if (!strcmp(arg, "--grep-debug")) {
2062                 revs->grep_filter.debug = 1;
2063         } else if (!strcmp(arg, "--basic-regexp")) {
2064                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_BRE;
2065         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
2066                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
2067         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
2068                 revs->grep_filter.ignore_case = 1;
2069                 DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
2070         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
2071                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
2072         } else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
2073                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_PCRE;
2074         } else if (!strcmp(arg, "--all-match")) {
2075                 revs->grep_filter.all_match = 1;
2076         } else if (!strcmp(arg, "--invert-grep")) {
2077                 revs->invert_grep = 1;
2078         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2079                 if (strcmp(optarg, "none"))
2080                         git_log_output_encoding = xstrdup(optarg);
2081                 else
2082                         git_log_output_encoding = "";
2083                 return argcount;
2084         } else if (!strcmp(arg, "--reverse")) {
2085                 revs->reverse ^= 1;
2086         } else if (!strcmp(arg, "--children")) {
2087                 revs->children.name = "children";
2088                 revs->limited = 1;
2089         } else if (!strcmp(arg, "--ignore-missing")) {
2090                 revs->ignore_missing = 1;
2091         } else {
2092                 int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
2093                 if (!opts)
2094                         unkv[(*unkc)++] = arg;
2095                 return opts;
2096         }
2097         if (revs->graph && revs->track_linear)
2098                 die("--show-linear-break and --graph are incompatible");
2099
2100         return 1;
2101 }
2102
2103 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2104                         const struct option *options,
2105                         const char * const usagestr[])
2106 {
2107         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2108                                     &ctx->cpidx, ctx->out);
2109         if (n <= 0) {
2110                 error("unknown option `%s'", ctx->argv[0]);
2111                 usage_with_options(usagestr, options);
2112         }
2113         ctx->argv += n;
2114         ctx->argc -= n;
2115 }
2116
2117 static int for_each_bisect_ref(struct ref_store *refs, each_ref_fn fn,
2118                                void *cb_data, const char *term)
2119 {
2120         struct strbuf bisect_refs = STRBUF_INIT;
2121         int status;
2122         strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2123         status = refs_for_each_fullref_in(refs, bisect_refs.buf, fn, cb_data, 0);
2124         strbuf_release(&bisect_refs);
2125         return status;
2126 }
2127
2128 static int for_each_bad_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2129 {
2130         return for_each_bisect_ref(refs, fn, cb_data, term_bad);
2131 }
2132
2133 static int for_each_good_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2134 {
2135         return for_each_bisect_ref(refs, fn, cb_data, term_good);
2136 }
2137
2138 static int handle_revision_pseudo_opt(const char *submodule,
2139                                 struct rev_info *revs,
2140                                 int argc, const char **argv, int *flags)
2141 {
2142         const char *arg = argv[0];
2143         const char *optarg;
2144         struct ref_store *refs;
2145         int argcount;
2146
2147         if (submodule) {
2148                 /*
2149                  * We need some something like get_submodule_worktrees()
2150                  * before we can go through all worktrees of a submodule,
2151                  * .e.g with adding all HEADs from --all, which is not
2152                  * supported right now, so stick to single worktree.
2153                  */
2154                 if (!revs->single_worktree)
2155                         die("BUG: --single-worktree cannot be used together with submodule");
2156                 refs = get_submodule_ref_store(submodule);
2157         } else
2158                 refs = get_main_ref_store();
2159
2160         /*
2161          * NOTE!
2162          *
2163          * Commands like "git shortlog" will not accept the options below
2164          * unless parse_revision_opt queues them (as opposed to erroring
2165          * out).
2166          *
2167          * When implementing your new pseudo-option, remember to
2168          * register it in the list at the top of handle_revision_opt.
2169          */
2170         if (!strcmp(arg, "--all")) {
2171                 handle_refs(refs, revs, *flags, refs_for_each_ref);
2172                 handle_refs(refs, revs, *flags, refs_head_ref);
2173                 if (!revs->single_worktree) {
2174                         struct all_refs_cb cb;
2175
2176                         init_all_refs_cb(&cb, revs, *flags);
2177                         other_head_refs(handle_one_ref, &cb);
2178                 }
2179                 clear_ref_exclusion(&revs->ref_excludes);
2180         } else if (!strcmp(arg, "--branches")) {
2181                 handle_refs(refs, revs, *flags, refs_for_each_branch_ref);
2182                 clear_ref_exclusion(&revs->ref_excludes);
2183         } else if (!strcmp(arg, "--bisect")) {
2184                 read_bisect_terms(&term_bad, &term_good);
2185                 handle_refs(refs, revs, *flags, for_each_bad_bisect_ref);
2186                 handle_refs(refs, revs, *flags ^ (UNINTERESTING | BOTTOM),
2187                             for_each_good_bisect_ref);
2188                 revs->bisect = 1;
2189         } else if (!strcmp(arg, "--tags")) {
2190                 handle_refs(refs, revs, *flags, refs_for_each_tag_ref);
2191                 clear_ref_exclusion(&revs->ref_excludes);
2192         } else if (!strcmp(arg, "--remotes")) {
2193                 handle_refs(refs, revs, *flags, refs_for_each_remote_ref);
2194                 clear_ref_exclusion(&revs->ref_excludes);
2195         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2196                 struct all_refs_cb cb;
2197                 init_all_refs_cb(&cb, revs, *flags);
2198                 for_each_glob_ref(handle_one_ref, optarg, &cb);
2199                 clear_ref_exclusion(&revs->ref_excludes);
2200                 return argcount;
2201         } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2202                 add_ref_exclusion(&revs->ref_excludes, optarg);
2203                 return argcount;
2204         } else if (skip_prefix(arg, "--branches=", &optarg)) {
2205                 struct all_refs_cb cb;
2206                 init_all_refs_cb(&cb, revs, *flags);
2207                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/heads/", &cb);
2208                 clear_ref_exclusion(&revs->ref_excludes);
2209         } else if (skip_prefix(arg, "--tags=", &optarg)) {
2210                 struct all_refs_cb cb;
2211                 init_all_refs_cb(&cb, revs, *flags);
2212                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/tags/", &cb);
2213                 clear_ref_exclusion(&revs->ref_excludes);
2214         } else if (skip_prefix(arg, "--remotes=", &optarg)) {
2215                 struct all_refs_cb cb;
2216                 init_all_refs_cb(&cb, revs, *flags);
2217                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/remotes/", &cb);
2218                 clear_ref_exclusion(&revs->ref_excludes);
2219         } else if (!strcmp(arg, "--reflog")) {
2220                 add_reflogs_to_pending(revs, *flags);
2221         } else if (!strcmp(arg, "--indexed-objects")) {
2222                 add_index_objects_to_pending(revs, *flags);
2223         } else if (!strcmp(arg, "--not")) {
2224                 *flags ^= UNINTERESTING | BOTTOM;
2225         } else if (!strcmp(arg, "--no-walk")) {
2226                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2227         } else if (skip_prefix(arg, "--no-walk=", &optarg)) {
2228                 /*
2229                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2230                  * not allowed, since the argument is optional.
2231                  */
2232                 if (!strcmp(optarg, "sorted"))
2233                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2234                 else if (!strcmp(optarg, "unsorted"))
2235                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2236                 else
2237                         return error("invalid argument to --no-walk");
2238         } else if (!strcmp(arg, "--do-walk")) {
2239                 revs->no_walk = 0;
2240         } else if (!strcmp(arg, "--single-worktree")) {
2241                 revs->single_worktree = 1;
2242         } else {
2243                 return 0;
2244         }
2245
2246         return 1;
2247 }
2248
2249 static void NORETURN diagnose_missing_default(const char *def)
2250 {
2251         unsigned char sha1[20];
2252         int flags;
2253         const char *refname;
2254
2255         refname = resolve_ref_unsafe(def, 0, sha1, &flags);
2256         if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2257                 die(_("your current branch appears to be broken"));
2258
2259         skip_prefix(refname, "refs/heads/", &refname);
2260         die(_("your current branch '%s' does not have any commits yet"),
2261             refname);
2262 }
2263
2264 /*
2265  * Parse revision information, filling in the "rev_info" structure,
2266  * and removing the used arguments from the argument list.
2267  *
2268  * Returns the number of arguments left that weren't recognized
2269  * (which are also moved to the head of the argument list)
2270  */
2271 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2272 {
2273         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
2274         struct argv_array prune_data = ARGV_ARRAY_INIT;
2275         const char *submodule = NULL;
2276
2277         if (opt)
2278                 submodule = opt->submodule;
2279
2280         /* First, search for "--" */
2281         if (opt && opt->assume_dashdash) {
2282                 seen_dashdash = 1;
2283         } else {
2284                 seen_dashdash = 0;
2285                 for (i = 1; i < argc; i++) {
2286                         const char *arg = argv[i];
2287                         if (strcmp(arg, "--"))
2288                                 continue;
2289                         argv[i] = NULL;
2290                         argc = i;
2291                         if (argv[i + 1])
2292                                 argv_array_pushv(&prune_data, argv + i + 1);
2293                         seen_dashdash = 1;
2294                         break;
2295                 }
2296         }
2297
2298         /* Second, deal with arguments and options */
2299         flags = 0;
2300         revarg_opt = opt ? opt->revarg_opt : 0;
2301         if (seen_dashdash)
2302                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2303         read_from_stdin = 0;
2304         for (left = i = 1; i < argc; i++) {
2305                 const char *arg = argv[i];
2306                 if (*arg == '-') {
2307                         int opts;
2308
2309                         opts = handle_revision_pseudo_opt(submodule,
2310                                                 revs, argc - i, argv + i,
2311                                                 &flags);
2312                         if (opts > 0) {
2313                                 i += opts - 1;
2314                                 continue;
2315                         }
2316
2317                         if (!strcmp(arg, "--stdin")) {
2318                                 if (revs->disable_stdin) {
2319                                         argv[left++] = arg;
2320                                         continue;
2321                                 }
2322                                 if (read_from_stdin++)
2323                                         die("--stdin given twice?");
2324                                 read_revisions_from_stdin(revs, &prune_data);
2325                                 continue;
2326                         }
2327
2328                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
2329                         if (opts > 0) {
2330                                 i += opts - 1;
2331                                 continue;
2332                         }
2333                         if (opts < 0)
2334                                 exit(128);
2335                         continue;
2336                 }
2337
2338
2339                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2340                         int j;
2341                         if (seen_dashdash || *arg == '^')
2342                                 die("bad revision '%s'", arg);
2343
2344                         /* If we didn't have a "--":
2345                          * (1) all filenames must exist;
2346                          * (2) all rev-args must not be interpretable
2347                          *     as a valid filename.
2348                          * but the latter we have checked in the main loop.
2349                          */
2350                         for (j = i; j < argc; j++)
2351                                 verify_filename(revs->prefix, argv[j], j == i);
2352
2353                         argv_array_pushv(&prune_data, argv + i);
2354                         break;
2355                 }
2356                 else
2357                         got_rev_arg = 1;
2358         }
2359
2360         if (prune_data.argc) {
2361                 /*
2362                  * If we need to introduce the magic "a lone ':' means no
2363                  * pathspec whatsoever", here is the place to do so.
2364                  *
2365                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2366                  *      prune_data.nr = 0;
2367                  *      prune_data.alloc = 0;
2368                  *      free(prune_data.path);
2369                  *      prune_data.path = NULL;
2370                  * } else {
2371                  *      terminate prune_data.alloc with NULL and
2372                  *      call init_pathspec() to set revs->prune_data here.
2373                  * }
2374                  */
2375                 parse_pathspec(&revs->prune_data, 0, 0,
2376                                revs->prefix, prune_data.argv);
2377         }
2378         argv_array_clear(&prune_data);
2379
2380         if (revs->def == NULL)
2381                 revs->def = opt ? opt->def : NULL;
2382         if (opt && opt->tweak)
2383                 opt->tweak(revs, opt);
2384         if (revs->show_merge)
2385                 prepare_show_merge(revs);
2386         if (revs->def && !revs->pending.nr && !revs->rev_input_given && !got_rev_arg) {
2387                 struct object_id oid;
2388                 struct object *object;
2389                 struct object_context oc;
2390                 if (get_oid_with_context(revs->def, 0, &oid, &oc))
2391                         diagnose_missing_default(revs->def);
2392                 object = get_reference(revs, revs->def, &oid, 0);
2393                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2394         }
2395
2396         /* Did the user ask for any diff output? Run the diff! */
2397         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2398                 revs->diff = 1;
2399
2400         /* Pickaxe, diff-filter and rename following need diffs */
2401         if (revs->diffopt.pickaxe ||
2402             revs->diffopt.filter ||
2403             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2404                 revs->diff = 1;
2405
2406         if (revs->topo_order)
2407                 revs->limited = 1;
2408
2409         if (revs->prune_data.nr) {
2410                 copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2411                 /* Can't prune commits with rename following: the paths change.. */
2412                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2413                         revs->prune = 1;
2414                 if (!revs->full_diff)
2415                         copy_pathspec(&revs->diffopt.pathspec,
2416                                       &revs->prune_data);
2417         }
2418         if (revs->combine_merges)
2419                 revs->ignore_merges = 0;
2420         revs->diffopt.abbrev = revs->abbrev;
2421
2422         if (revs->line_level_traverse) {
2423                 revs->limited = 1;
2424                 revs->topo_order = 1;
2425         }
2426
2427         diff_setup_done(&revs->diffopt);
2428
2429         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2430                                  &revs->grep_filter);
2431         compile_grep_patterns(&revs->grep_filter);
2432
2433         if (revs->reverse && revs->reflog_info)
2434                 die("cannot combine --reverse with --walk-reflogs");
2435         if (revs->reflog_info && revs->limited)
2436                 die("cannot combine --walk-reflogs with history-limiting options");
2437         if (revs->rewrite_parents && revs->children.name)
2438                 die("cannot combine --parents and --children");
2439
2440         /*
2441          * Limitations on the graph functionality
2442          */
2443         if (revs->reverse && revs->graph)
2444                 die("cannot combine --reverse with --graph");
2445
2446         if (revs->reflog_info && revs->graph)
2447                 die("cannot combine --walk-reflogs with --graph");
2448         if (revs->no_walk && revs->graph)
2449                 die("cannot combine --no-walk with --graph");
2450         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2451                 die("cannot use --grep-reflog without --walk-reflogs");
2452
2453         if (revs->first_parent_only && revs->bisect)
2454                 die(_("--first-parent is incompatible with --bisect"));
2455
2456         if (revs->expand_tabs_in_log < 0)
2457                 revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
2458
2459         return left;
2460 }
2461
2462 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2463 {
2464         struct commit_list *l = xcalloc(1, sizeof(*l));
2465
2466         l->item = child;
2467         l->next = add_decoration(&revs->children, &parent->object, l);
2468 }
2469
2470 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2471 {
2472         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2473         struct commit_list **pp, *p;
2474         int surviving_parents;
2475
2476         /* Examine existing parents while marking ones we have seen... */
2477         pp = &commit->parents;
2478         surviving_parents = 0;
2479         while ((p = *pp) != NULL) {
2480                 struct commit *parent = p->item;
2481                 if (parent->object.flags & TMP_MARK) {
2482                         *pp = p->next;
2483                         if (ts)
2484                                 compact_treesame(revs, commit, surviving_parents);
2485                         continue;
2486                 }
2487                 parent->object.flags |= TMP_MARK;
2488                 surviving_parents++;
2489                 pp = &p->next;
2490         }
2491         /* clear the temporary mark */
2492         for (p = commit->parents; p; p = p->next) {
2493                 p->item->object.flags &= ~TMP_MARK;
2494         }
2495         /* no update_treesame() - removing duplicates can't affect TREESAME */
2496         return surviving_parents;
2497 }
2498
2499 struct merge_simplify_state {
2500         struct commit *simplified;
2501 };
2502
2503 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2504 {
2505         struct merge_simplify_state *st;
2506
2507         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2508         if (!st) {
2509                 st = xcalloc(1, sizeof(*st));
2510                 add_decoration(&revs->merge_simplification, &commit->object, st);
2511         }
2512         return st;
2513 }
2514
2515 static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2516 {
2517         struct commit_list *h = reduce_heads(commit->parents);
2518         int i = 0, marked = 0;
2519         struct commit_list *po, *pn;
2520
2521         /* Want these for sanity-checking only */
2522         int orig_cnt = commit_list_count(commit->parents);
2523         int cnt = commit_list_count(h);
2524
2525         /*
2526          * Not ready to remove items yet, just mark them for now, based
2527          * on the output of reduce_heads(). reduce_heads outputs the reduced
2528          * set in its original order, so this isn't too hard.
2529          */
2530         po = commit->parents;
2531         pn = h;
2532         while (po) {
2533                 if (pn && po->item == pn->item) {
2534                         pn = pn->next;
2535                         i++;
2536                 } else {
2537                         po->item->object.flags |= TMP_MARK;
2538                         marked++;
2539                 }
2540                 po=po->next;
2541         }
2542
2543         if (i != cnt || cnt+marked != orig_cnt)
2544                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2545
2546         free_commit_list(h);
2547
2548         return marked;
2549 }
2550
2551 static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2552 {
2553         struct commit_list *p;
2554         int marked = 0;
2555
2556         for (p = commit->parents; p; p = p->next) {
2557                 struct commit *parent = p->item;
2558                 if (!parent->parents && (parent->object.flags & TREESAME)) {
2559                         parent->object.flags |= TMP_MARK;
2560                         marked++;
2561                 }
2562         }
2563
2564         return marked;
2565 }
2566
2567 /*
2568  * Awkward naming - this means one parent we are TREESAME to.
2569  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2570  * empty tree). Better name suggestions?
2571  */
2572 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2573 {
2574         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2575         struct commit *unmarked = NULL, *marked = NULL;
2576         struct commit_list *p;
2577         unsigned n;
2578
2579         for (p = commit->parents, n = 0; p; p = p->next, n++) {
2580                 if (ts->treesame[n]) {
2581                         if (p->item->object.flags & TMP_MARK) {
2582                                 if (!marked)
2583                                         marked = p->item;
2584                         } else {
2585                                 if (!unmarked) {
2586                                         unmarked = p->item;
2587                                         break;
2588                                 }
2589                         }
2590                 }
2591         }
2592
2593         /*
2594          * If we are TREESAME to a marked-for-deletion parent, but not to any
2595          * unmarked parents, unmark the first TREESAME parent. This is the
2596          * parent that the default simplify_history==1 scan would have followed,
2597          * and it doesn't make sense to omit that path when asking for a
2598          * simplified full history. Retaining it improves the chances of
2599          * understanding odd missed merges that took an old version of a file.
2600          *
2601          * Example:
2602          *
2603          *   I--------*X       A modified the file, but mainline merge X used
2604          *    \       /        "-s ours", so took the version from I. X is
2605          *     `-*A--'         TREESAME to I and !TREESAME to A.
2606          *
2607          * Default log from X would produce "I". Without this check,
2608          * --full-history --simplify-merges would produce "I-A-X", showing
2609          * the merge commit X and that it changed A, but not making clear that
2610          * it had just taken the I version. With this check, the topology above
2611          * is retained.
2612          *
2613          * Note that it is possible that the simplification chooses a different
2614          * TREESAME parent from the default, in which case this test doesn't
2615          * activate, and we _do_ drop the default parent. Example:
2616          *
2617          *   I------X         A modified the file, but it was reverted in B,
2618          *    \    /          meaning mainline merge X is TREESAME to both
2619          *    *A-*B           parents.
2620          *
2621          * Default log would produce "I" by following the first parent;
2622          * --full-history --simplify-merges will produce "I-A-B". But this is a
2623          * reasonable result - it presents a logical full history leading from
2624          * I to X, and X is not an important merge.
2625          */
2626         if (!unmarked && marked) {
2627                 marked->object.flags &= ~TMP_MARK;
2628                 return 1;
2629         }
2630
2631         return 0;
2632 }
2633
2634 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2635 {
2636         struct commit_list **pp, *p;
2637         int nth_parent, removed = 0;
2638
2639         pp = &commit->parents;
2640         nth_parent = 0;
2641         while ((p = *pp) != NULL) {
2642                 struct commit *parent = p->item;
2643                 if (parent->object.flags & TMP_MARK) {
2644                         parent->object.flags &= ~TMP_MARK;
2645                         *pp = p->next;
2646                         free(p);
2647                         removed++;
2648                         compact_treesame(revs, commit, nth_parent);
2649                         continue;
2650                 }
2651                 pp = &p->next;
2652                 nth_parent++;
2653         }
2654
2655         /* Removing parents can only increase TREESAMEness */
2656         if (removed && !(commit->object.flags & TREESAME))
2657                 update_treesame(revs, commit);
2658
2659         return nth_parent;
2660 }
2661
2662 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2663 {
2664         struct commit_list *p;
2665         struct commit *parent;
2666         struct merge_simplify_state *st, *pst;
2667         int cnt;
2668
2669         st = locate_simplify_state(revs, commit);
2670
2671         /*
2672          * Have we handled this one?
2673          */
2674         if (st->simplified)
2675                 return tail;
2676
2677         /*
2678          * An UNINTERESTING commit simplifies to itself, so does a
2679          * root commit.  We do not rewrite parents of such commit
2680          * anyway.
2681          */
2682         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2683                 st->simplified = commit;
2684                 return tail;
2685         }
2686
2687         /*
2688          * Do we know what commit all of our parents that matter
2689          * should be rewritten to?  Otherwise we are not ready to
2690          * rewrite this one yet.
2691          */
2692         for (cnt = 0, p = commit->parents; p; p = p->next) {
2693                 pst = locate_simplify_state(revs, p->item);
2694                 if (!pst->simplified) {
2695                         tail = &commit_list_insert(p->item, tail)->next;
2696                         cnt++;
2697                 }
2698                 if (revs->first_parent_only)
2699                         break;
2700         }
2701         if (cnt) {
2702                 tail = &commit_list_insert(commit, tail)->next;
2703                 return tail;
2704         }
2705
2706         /*
2707          * Rewrite our list of parents. Note that this cannot
2708          * affect our TREESAME flags in any way - a commit is
2709          * always TREESAME to its simplification.
2710          */
2711         for (p = commit->parents; p; p = p->next) {
2712                 pst = locate_simplify_state(revs, p->item);
2713                 p->item = pst->simplified;
2714                 if (revs->first_parent_only)
2715                         break;
2716         }
2717
2718         if (revs->first_parent_only)
2719                 cnt = 1;
2720         else
2721                 cnt = remove_duplicate_parents(revs, commit);
2722
2723         /*
2724          * It is possible that we are a merge and one side branch
2725          * does not have any commit that touches the given paths;
2726          * in such a case, the immediate parent from that branch
2727          * will be rewritten to be the merge base.
2728          *
2729          *      o----X          X: the commit we are looking at;
2730          *     /    /           o: a commit that touches the paths;
2731          * ---o----'
2732          *
2733          * Further, a merge of an independent branch that doesn't
2734          * touch the path will reduce to a treesame root parent:
2735          *
2736          *  ----o----X          X: the commit we are looking at;
2737          *          /           o: a commit that touches the paths;
2738          *         r            r: a root commit not touching the paths
2739          *
2740          * Detect and simplify both cases.
2741          */
2742         if (1 < cnt) {
2743                 int marked = mark_redundant_parents(revs, commit);
2744                 marked += mark_treesame_root_parents(revs, commit);
2745                 if (marked)
2746                         marked -= leave_one_treesame_to_parent(revs, commit);
2747                 if (marked)
2748                         cnt = remove_marked_parents(revs, commit);
2749         }
2750
2751         /*
2752          * A commit simplifies to itself if it is a root, if it is
2753          * UNINTERESTING, if it touches the given paths, or if it is a
2754          * merge and its parents don't simplify to one relevant commit
2755          * (the first two cases are already handled at the beginning of
2756          * this function).
2757          *
2758          * Otherwise, it simplifies to what its sole relevant parent
2759          * simplifies to.
2760          */
2761         if (!cnt ||
2762             (commit->object.flags & UNINTERESTING) ||
2763             !(commit->object.flags & TREESAME) ||
2764             (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2765                 st->simplified = commit;
2766         else {
2767                 pst = locate_simplify_state(revs, parent);
2768                 st->simplified = pst->simplified;
2769         }
2770         return tail;
2771 }
2772
2773 static void simplify_merges(struct rev_info *revs)
2774 {
2775         struct commit_list *list, *next;
2776         struct commit_list *yet_to_do, **tail;
2777         struct commit *commit;
2778
2779         if (!revs->prune)
2780                 return;
2781
2782         /* feed the list reversed */
2783         yet_to_do = NULL;
2784         for (list = revs->commits; list; list = next) {
2785                 commit = list->item;
2786                 next = list->next;
2787                 /*
2788                  * Do not free(list) here yet; the original list
2789                  * is used later in this function.
2790                  */
2791                 commit_list_insert(commit, &yet_to_do);
2792         }
2793         while (yet_to_do) {
2794                 list = yet_to_do;
2795                 yet_to_do = NULL;
2796                 tail = &yet_to_do;
2797                 while (list) {
2798                         commit = pop_commit(&list);
2799                         tail = simplify_one(revs, commit, tail);
2800                 }
2801         }
2802
2803         /* clean up the result, removing the simplified ones */
2804         list = revs->commits;
2805         revs->commits = NULL;
2806         tail = &revs->commits;
2807         while (list) {
2808                 struct merge_simplify_state *st;
2809
2810                 commit = pop_commit(&list);
2811                 st = locate_simplify_state(revs, commit);
2812                 if (st->simplified == commit)
2813                         tail = &commit_list_insert(commit, tail)->next;
2814         }
2815 }
2816
2817 static void set_children(struct rev_info *revs)
2818 {
2819         struct commit_list *l;
2820         for (l = revs->commits; l; l = l->next) {
2821                 struct commit *commit = l->item;
2822                 struct commit_list *p;
2823
2824                 for (p = commit->parents; p; p = p->next)
2825                         add_child(revs, p->item, commit);
2826         }
2827 }
2828
2829 void reset_revision_walk(void)
2830 {
2831         clear_object_flags(SEEN | ADDED | SHOWN);
2832 }
2833
2834 int prepare_revision_walk(struct rev_info *revs)
2835 {
2836         int i;
2837         struct object_array old_pending;
2838         struct commit_list **next = &revs->commits;
2839
2840         memcpy(&old_pending, &revs->pending, sizeof(old_pending));
2841         revs->pending.nr = 0;
2842         revs->pending.alloc = 0;
2843         revs->pending.objects = NULL;
2844         for (i = 0; i < old_pending.nr; i++) {
2845                 struct object_array_entry *e = old_pending.objects + i;
2846                 struct commit *commit = handle_commit(revs, e);
2847                 if (commit) {
2848                         if (!(commit->object.flags & SEEN)) {
2849                                 commit->object.flags |= SEEN;
2850                                 next = commit_list_append(commit, next);
2851                         }
2852                 }
2853         }
2854         if (!revs->leak_pending)
2855                 object_array_clear(&old_pending);
2856
2857         /* Signal whether we need per-parent treesame decoration */
2858         if (revs->simplify_merges ||
2859             (revs->limited && limiting_can_increase_treesame(revs)))
2860                 revs->treesame.name = "treesame";
2861
2862         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2863                 commit_list_sort_by_date(&revs->commits);
2864         if (revs->no_walk)
2865                 return 0;
2866         if (revs->limited)
2867                 if (limit_list(revs) < 0)
2868                         return -1;
2869         if (revs->topo_order)
2870                 sort_in_topological_order(&revs->commits, revs->sort_order);
2871         if (revs->line_level_traverse)
2872                 line_log_filter(revs);
2873         if (revs->simplify_merges)
2874                 simplify_merges(revs);
2875         if (revs->children.name)
2876                 set_children(revs);
2877         return 0;
2878 }
2879
2880 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2881 {
2882         struct commit_list *cache = NULL;
2883
2884         for (;;) {
2885                 struct commit *p = *pp;
2886                 if (!revs->limited)
2887                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2888                                 return rewrite_one_error;
2889                 if (p->object.flags & UNINTERESTING)
2890                         return rewrite_one_ok;
2891                 if (!(p->object.flags & TREESAME))
2892                         return rewrite_one_ok;
2893                 if (!p->parents)
2894                         return rewrite_one_noparents;
2895                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2896                         return rewrite_one_ok;
2897                 *pp = p;
2898         }
2899 }
2900
2901 int rewrite_parents(struct rev_info *revs, struct commit *commit,
2902         rewrite_parent_fn_t rewrite_parent)
2903 {
2904         struct commit_list **pp = &commit->parents;
2905         while (*pp) {
2906                 struct commit_list *parent = *pp;
2907                 switch (rewrite_parent(revs, &parent->item)) {
2908                 case rewrite_one_ok:
2909                         break;
2910                 case rewrite_one_noparents:
2911                         *pp = parent->next;
2912                         continue;
2913                 case rewrite_one_error:
2914                         return -1;
2915                 }
2916                 pp = &parent->next;
2917         }
2918         remove_duplicate_parents(revs, commit);
2919         return 0;
2920 }
2921
2922 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2923 {
2924         char *person, *endp;
2925         size_t len, namelen, maillen;
2926         const char *name;
2927         const char *mail;
2928         struct ident_split ident;
2929
2930         person = strstr(buf->buf, what);
2931         if (!person)
2932                 return 0;
2933
2934         person += strlen(what);
2935         endp = strchr(person, '\n');
2936         if (!endp)
2937                 return 0;
2938
2939         len = endp - person;
2940
2941         if (split_ident_line(&ident, person, len))
2942                 return 0;
2943
2944         mail = ident.mail_begin;
2945         maillen = ident.mail_end - ident.mail_begin;
2946         name = ident.name_begin;
2947         namelen = ident.name_end - ident.name_begin;
2948
2949         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2950                 struct strbuf namemail = STRBUF_INIT;
2951
2952                 strbuf_addf(&namemail, "%.*s <%.*s>",
2953                             (int)namelen, name, (int)maillen, mail);
2954
2955                 strbuf_splice(buf, ident.name_begin - buf->buf,
2956                               ident.mail_end - ident.name_begin + 1,
2957                               namemail.buf, namemail.len);
2958
2959                 strbuf_release(&namemail);
2960
2961                 return 1;
2962         }
2963
2964         return 0;
2965 }
2966
2967 static int commit_match(struct commit *commit, struct rev_info *opt)
2968 {
2969         int retval;
2970         const char *encoding;
2971         const char *message;
2972         struct strbuf buf = STRBUF_INIT;
2973
2974         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2975                 return 1;
2976
2977         /* Prepend "fake" headers as needed */
2978         if (opt->grep_filter.use_reflog_filter) {
2979                 strbuf_addstr(&buf, "reflog ");
2980                 get_reflog_message(&buf, opt->reflog_info);
2981                 strbuf_addch(&buf, '\n');
2982         }
2983
2984         /*
2985          * We grep in the user's output encoding, under the assumption that it
2986          * is the encoding they are most likely to write their grep pattern
2987          * for. In addition, it means we will match the "notes" encoding below,
2988          * so we will not end up with a buffer that has two different encodings
2989          * in it.
2990          */
2991         encoding = get_log_output_encoding();
2992         message = logmsg_reencode(commit, NULL, encoding);
2993
2994         /* Copy the commit to temporary if we are using "fake" headers */
2995         if (buf.len)
2996                 strbuf_addstr(&buf, message);
2997
2998         if (opt->grep_filter.header_list && opt->mailmap) {
2999                 if (!buf.len)
3000                         strbuf_addstr(&buf, message);
3001
3002                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
3003                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
3004         }
3005
3006         /* Append "fake" message parts as needed */
3007         if (opt->show_notes) {
3008                 if (!buf.len)
3009                         strbuf_addstr(&buf, message);
3010                 format_display_notes(&commit->object.oid, &buf, encoding, 1);
3011         }
3012
3013         /*
3014          * Find either in the original commit message, or in the temporary.
3015          * Note that we cast away the constness of "message" here. It is
3016          * const because it may come from the cached commit buffer. That's OK,
3017          * because we know that it is modifiable heap memory, and that while
3018          * grep_buffer may modify it for speed, it will restore any
3019          * changes before returning.
3020          */
3021         if (buf.len)
3022                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
3023         else
3024                 retval = grep_buffer(&opt->grep_filter,
3025                                      (char *)message, strlen(message));
3026         strbuf_release(&buf);
3027         unuse_commit_buffer(commit, message);
3028         return opt->invert_grep ? !retval : retval;
3029 }
3030
3031 static inline int want_ancestry(const struct rev_info *revs)
3032 {
3033         return (revs->rewrite_parents || revs->children.name);
3034 }
3035
3036 /*
3037  * Return a timestamp to be used for --since/--until comparisons for this
3038  * commit, based on the revision options.
3039  */
3040 static timestamp_t comparison_date(const struct rev_info *revs,
3041                                    struct commit *commit)
3042 {
3043         return revs->reflog_info ?
3044                 get_reflog_timestamp(revs->reflog_info) :
3045                 commit->date;
3046 }
3047
3048 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
3049 {
3050         if (commit->object.flags & SHOWN)
3051                 return commit_ignore;
3052         if (revs->unpacked && has_sha1_pack(commit->object.oid.hash))
3053                 return commit_ignore;
3054         if (revs->show_all)
3055                 return commit_show;
3056         if (commit->object.flags & UNINTERESTING)
3057                 return commit_ignore;
3058         if (revs->min_age != -1 &&
3059             comparison_date(revs, commit) > revs->min_age)
3060                         return commit_ignore;
3061         if (revs->min_parents || (revs->max_parents >= 0)) {
3062                 int n = commit_list_count(commit->parents);
3063                 if ((n < revs->min_parents) ||
3064                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
3065                         return commit_ignore;
3066         }
3067         if (!commit_match(commit, revs))
3068                 return commit_ignore;
3069         if (revs->prune && revs->dense) {
3070                 /* Commit without changes? */
3071                 if (commit->object.flags & TREESAME) {
3072                         int n;
3073                         struct commit_list *p;
3074                         /* drop merges unless we want parenthood */
3075                         if (!want_ancestry(revs))
3076                                 return commit_ignore;
3077                         /*
3078                          * If we want ancestry, then need to keep any merges
3079                          * between relevant commits to tie together topology.
3080                          * For consistency with TREESAME and simplification
3081                          * use "relevant" here rather than just INTERESTING,
3082                          * to treat bottom commit(s) as part of the topology.
3083                          */
3084                         for (n = 0, p = commit->parents; p; p = p->next)
3085                                 if (relevant_commit(p->item))
3086                                         if (++n >= 2)
3087                                                 return commit_show;
3088                         return commit_ignore;
3089                 }
3090         }
3091         return commit_show;
3092 }
3093
3094 define_commit_slab(saved_parents, struct commit_list *);
3095
3096 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3097
3098 /*
3099  * You may only call save_parents() once per commit (this is checked
3100  * for non-root commits).
3101  */
3102 static void save_parents(struct rev_info *revs, struct commit *commit)
3103 {
3104         struct commit_list **pp;
3105
3106         if (!revs->saved_parents_slab) {
3107                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3108                 init_saved_parents(revs->saved_parents_slab);
3109         }
3110
3111         pp = saved_parents_at(revs->saved_parents_slab, commit);
3112
3113         /*
3114          * When walking with reflogs, we may visit the same commit
3115          * several times: once for each appearance in the reflog.
3116          *
3117          * In this case, save_parents() will be called multiple times.
3118          * We want to keep only the first set of parents.  We need to
3119          * store a sentinel value for an empty (i.e., NULL) parent
3120          * list to distinguish it from a not-yet-saved list, however.
3121          */
3122         if (*pp)
3123                 return;
3124         if (commit->parents)
3125                 *pp = copy_commit_list(commit->parents);
3126         else
3127                 *pp = EMPTY_PARENT_LIST;
3128 }
3129
3130 static void free_saved_parents(struct rev_info *revs)
3131 {
3132         if (revs->saved_parents_slab)
3133                 clear_saved_parents(revs->saved_parents_slab);
3134 }
3135
3136 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3137 {
3138         struct commit_list *parents;
3139
3140         if (!revs->saved_parents_slab)
3141                 return commit->parents;
3142
3143         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3144         if (parents == EMPTY_PARENT_LIST)
3145                 return NULL;
3146         return parents;
3147 }
3148
3149 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3150 {
3151         enum commit_action action = get_commit_action(revs, commit);
3152
3153         if (action == commit_show &&
3154             !revs->show_all &&
3155             revs->prune && revs->dense && want_ancestry(revs)) {
3156                 /*
3157                  * --full-diff on simplified parents is no good: it
3158                  * will show spurious changes from the commits that
3159                  * were elided.  So we save the parents on the side
3160                  * when --full-diff is in effect.
3161                  */
3162                 if (revs->full_diff)
3163                         save_parents(revs, commit);
3164                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
3165                         return commit_error;
3166         }
3167         return action;
3168 }
3169
3170 static void track_linear(struct rev_info *revs, struct commit *commit)
3171 {
3172         if (revs->track_first_time) {
3173                 revs->linear = 1;
3174                 revs->track_first_time = 0;
3175         } else {
3176                 struct commit_list *p;
3177                 for (p = revs->previous_parents; p; p = p->next)
3178                         if (p->item == NULL || /* first commit */
3179                             !oidcmp(&p->item->object.oid, &commit->object.oid))
3180                                 break;
3181                 revs->linear = p != NULL;
3182         }
3183         if (revs->reverse) {
3184                 if (revs->linear)
3185                         commit->object.flags |= TRACK_LINEAR;
3186         }
3187         free_commit_list(revs->previous_parents);
3188         revs->previous_parents = copy_commit_list(commit->parents);
3189 }
3190
3191 static struct commit *get_revision_1(struct rev_info *revs)
3192 {
3193         while (1) {
3194                 struct commit *commit;
3195
3196                 if (revs->reflog_info)
3197                         commit = next_reflog_entry(revs->reflog_info);
3198                 else
3199                         commit = pop_commit(&revs->commits);
3200
3201                 if (!commit)
3202                         return NULL;
3203
3204                 if (revs->reflog_info)
3205                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3206
3207                 /*
3208                  * If we haven't done the list limiting, we need to look at
3209                  * the parents here. We also need to do the date-based limiting
3210                  * that we'd otherwise have done in limit_list().
3211                  */
3212                 if (!revs->limited) {
3213                         if (revs->max_age != -1 &&
3214                             comparison_date(revs, commit) < revs->max_age)
3215                                 continue;
3216
3217                         if (revs->reflog_info)
3218                                 try_to_simplify_commit(revs, commit);
3219                         else if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
3220                                 if (!revs->ignore_missing_links)
3221                                         die("Failed to traverse parents of commit %s",
3222                                                 oid_to_hex(&commit->object.oid));
3223                         }
3224                 }
3225
3226                 switch (simplify_commit(revs, commit)) {
3227                 case commit_ignore:
3228                         continue;
3229                 case commit_error:
3230                         die("Failed to simplify parents of commit %s",
3231                             oid_to_hex(&commit->object.oid));
3232                 default:
3233                         if (revs->track_linear)
3234                                 track_linear(revs, commit);
3235                         return commit;
3236                 }
3237         }
3238 }
3239
3240 /*
3241  * Return true for entries that have not yet been shown.  (This is an
3242  * object_array_each_func_t.)
3243  */
3244 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3245 {
3246         return !(entry->item->flags & SHOWN);
3247 }
3248
3249 /*
3250  * If array is on the verge of a realloc, garbage-collect any entries
3251  * that have already been shown to try to free up some space.
3252  */
3253 static void gc_boundary(struct object_array *array)
3254 {
3255         if (array->nr == array->alloc)
3256                 object_array_filter(array, entry_unshown, NULL);
3257 }
3258
3259 static void create_boundary_commit_list(struct rev_info *revs)
3260 {
3261         unsigned i;
3262         struct commit *c;
3263         struct object_array *array = &revs->boundary_commits;
3264         struct object_array_entry *objects = array->objects;
3265
3266         /*
3267          * If revs->commits is non-NULL at this point, an error occurred in
3268          * get_revision_1().  Ignore the error and continue printing the
3269          * boundary commits anyway.  (This is what the code has always
3270          * done.)
3271          */
3272         if (revs->commits) {
3273                 free_commit_list(revs->commits);
3274                 revs->commits = NULL;
3275         }
3276
3277         /*
3278          * Put all of the actual boundary commits from revs->boundary_commits
3279          * into revs->commits
3280          */
3281         for (i = 0; i < array->nr; i++) {
3282                 c = (struct commit *)(objects[i].item);
3283                 if (!c)
3284                         continue;
3285                 if (!(c->object.flags & CHILD_SHOWN))
3286                         continue;
3287                 if (c->object.flags & (SHOWN | BOUNDARY))
3288                         continue;
3289                 c->object.flags |= BOUNDARY;
3290                 commit_list_insert(c, &revs->commits);
3291         }
3292
3293         /*
3294          * If revs->topo_order is set, sort the boundary commits
3295          * in topological order
3296          */
3297         sort_in_topological_order(&revs->commits, revs->sort_order);
3298 }
3299
3300 static struct commit *get_revision_internal(struct rev_info *revs)
3301 {
3302         struct commit *c = NULL;
3303         struct commit_list *l;
3304
3305         if (revs->boundary == 2) {
3306                 /*
3307                  * All of the normal commits have already been returned,
3308                  * and we are now returning boundary commits.
3309                  * create_boundary_commit_list() has populated
3310                  * revs->commits with the remaining commits to return.
3311                  */
3312                 c = pop_commit(&revs->commits);
3313                 if (c)
3314                         c->object.flags |= SHOWN;
3315                 return c;
3316         }
3317
3318         /*
3319          * If our max_count counter has reached zero, then we are done. We
3320          * don't simply return NULL because we still might need to show
3321          * boundary commits. But we want to avoid calling get_revision_1, which
3322          * might do a considerable amount of work finding the next commit only
3323          * for us to throw it away.
3324          *
3325          * If it is non-zero, then either we don't have a max_count at all
3326          * (-1), or it is still counting, in which case we decrement.
3327          */
3328         if (revs->max_count) {
3329                 c = get_revision_1(revs);
3330                 if (c) {
3331                         while (revs->skip_count > 0) {
3332                                 revs->skip_count--;
3333                                 c = get_revision_1(revs);
3334                                 if (!c)
3335                                         break;
3336                         }
3337                 }
3338
3339                 if (revs->max_count > 0)
3340                         revs->max_count--;
3341         }
3342
3343         if (c)
3344                 c->object.flags |= SHOWN;
3345
3346         if (!revs->boundary)
3347                 return c;
3348
3349         if (!c) {
3350                 /*
3351                  * get_revision_1() runs out the commits, and
3352                  * we are done computing the boundaries.
3353                  * switch to boundary commits output mode.
3354                  */
3355                 revs->boundary = 2;
3356
3357                 /*
3358                  * Update revs->commits to contain the list of
3359                  * boundary commits.
3360                  */
3361                 create_boundary_commit_list(revs);
3362
3363                 return get_revision_internal(revs);
3364         }
3365
3366         /*
3367          * boundary commits are the commits that are parents of the
3368          * ones we got from get_revision_1() but they themselves are
3369          * not returned from get_revision_1().  Before returning
3370          * 'c', we need to mark its parents that they could be boundaries.
3371          */
3372
3373         for (l = c->parents; l; l = l->next) {
3374                 struct object *p;
3375                 p = &(l->item->object);
3376                 if (p->flags & (CHILD_SHOWN | SHOWN))
3377                         continue;
3378                 p->flags |= CHILD_SHOWN;
3379                 gc_boundary(&revs->boundary_commits);
3380                 add_object_array(p, NULL, &revs->boundary_commits);
3381         }
3382
3383         return c;
3384 }
3385
3386 struct commit *get_revision(struct rev_info *revs)
3387 {
3388         struct commit *c;
3389         struct commit_list *reversed;
3390
3391         if (revs->reverse) {
3392                 reversed = NULL;
3393                 while ((c = get_revision_internal(revs)))
3394                         commit_list_insert(c, &reversed);
3395                 revs->commits = reversed;
3396                 revs->reverse = 0;
3397                 revs->reverse_output_stage = 1;
3398         }
3399
3400         if (revs->reverse_output_stage) {
3401                 c = pop_commit(&revs->commits);
3402                 if (revs->track_linear)
3403                         revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
3404                 return c;
3405         }
3406
3407         c = get_revision_internal(revs);
3408         if (c && revs->graph)
3409                 graph_update(revs->graph, c);
3410         if (!c) {
3411                 free_saved_parents(revs);
3412                 if (revs->previous_parents) {
3413                         free_commit_list(revs->previous_parents);
3414                         revs->previous_parents = NULL;
3415                 }
3416         }
3417         return c;
3418 }
3419
3420 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3421 {
3422         if (commit->object.flags & BOUNDARY)
3423                 return "-";
3424         else if (commit->object.flags & UNINTERESTING)
3425                 return "^";
3426         else if (commit->object.flags & PATCHSAME)
3427                 return "=";
3428         else if (!revs || revs->left_right) {
3429                 if (commit->object.flags & SYMMETRIC_LEFT)
3430                         return "<";
3431                 else
3432                         return ">";
3433         } else if (revs->graph)
3434                 return "*";
3435         else if (revs->cherry_mark)
3436                 return "+";
3437         return "";
3438 }
3439
3440 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3441 {
3442         char *mark = get_revision_mark(revs, commit);
3443         if (!strlen(mark))
3444                 return;
3445         fputs(mark, stdout);
3446         putchar(' ');
3447 }