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
  22 volatile show_early_output_fn_t show_early_output;
  23
  24 char *path_name(const struct name_path *path, const char *name)
  25 {
  26         const struct name_path *p;
  27         char *n, *m;
  28         int nlen = strlen(name);
  29         int len = nlen + 1;
  30
  31         for (p = path; p; p = p->up) {
  32                 if (p->elem_len)
  33                         len += p->elem_len + 1;
  34         }
  35         n = xmalloc(len);
  36         m = n + len - (nlen + 1);
  37         strcpy(m, name);
  38         for (p = path; p; p = p->up) {
  39                 if (p->elem_len) {
  40                         m -= p->elem_len + 1;
  41                         memcpy(m, p->elem, p->elem_len);
  42                         m[p->elem_len] = '/';
  43                 }
  44         }
  45         return n;
  46 }
  47
  48 static int show_path_component_truncated(FILE *out, const char *name, int len)
  49 {
  50         int cnt;
  51         for (cnt = 0; cnt < len; cnt++) {
  52                 int ch = name[cnt];
  53                 if (!ch || ch == '\n')
  54                         return -1;
  55                 fputc(ch, out);
  56         }
  57         return len;
  58 }
  59
  60 static int show_path_truncated(FILE *out, const struct name_path *path)
  61 {
  62         int emitted, ours;
  63
  64         if (!path)
  65                 return 0;
  66         emitted = show_path_truncated(out, path->up);
  67         if (emitted < 0)
  68                 return emitted;
  69         if (emitted)
  70                 fputc('/', out);
  71         ours = show_path_component_truncated(out, path->elem, path->elem_len);
  72         if (ours < 0)
  73                 return ours;
  74         return ours || emitted;
  75 }
  76
  77 void show_object_with_name(FILE *out, struct object *obj,
  78                            const struct name_path *path, const char *component)
  79 {
  80         struct name_path leaf;
  81         leaf.up = (struct name_path *)path;
  82         leaf.elem = component;
  83         leaf.elem_len = strlen(component);
  84
  85         fprintf(out, "%s ", sha1_to_hex(obj->sha1));
  86         show_path_truncated(out, &leaf);
  87         fputc('\n', out);
  88 }
  89
  90 static void mark_blob_uninteresting(struct blob *blob)
  91 {
  92         if (!blob)
  93                 return;
  94         if (blob->object.flags & UNINTERESTING)
  95                 return;
  96         blob->object.flags |= UNINTERESTING;
  97 }
  98
  99 static void mark_tree_contents_uninteresting(struct tree *tree)
 100 {
 101         struct tree_desc desc;
 102         struct name_entry entry;
 103         struct object *obj = &tree->object;
 104
 105         if (!has_sha1_file(obj->sha1))
 106                 return;
 107         if (parse_tree(tree) < 0)
 108                 die("bad tree %s", sha1_to_hex(obj->sha1));
 109
 110         init_tree_desc(&desc, tree->buffer, tree->size);
 111         while (tree_entry(&desc, &entry)) {
 112                 switch (object_type(entry.mode)) {
 113                 case OBJ_TREE:
 114                         mark_tree_uninteresting(lookup_tree(entry.sha1));
 115                         break;
 116                 case OBJ_BLOB:
 117                         mark_blob_uninteresting(lookup_blob(entry.sha1));
 118                         break;
 119                 default:
 120                         /* Subproject commit - not in this repository */
 121                         break;
 122                 }
 123         }
 124
 125         /*
 126          * We don't care about the tree any more
 127          * after it has been marked uninteresting.
 128          */
 129         free_tree_buffer(tree);
 130 }
 131
 132 void mark_tree_uninteresting(struct tree *tree)
 133 {
 134         struct object *obj = &tree->object;
 135
 136         if (!tree)
 137                 return;
 138         if (obj->flags & UNINTERESTING)
 139                 return;
 140         obj->flags |= UNINTERESTING;
 141         mark_tree_contents_uninteresting(tree);
 142 }
 143
 144 void mark_parents_uninteresting(struct commit *commit)
 145 {
 146         struct commit_list *parents = NULL, *l;
 147
 148         for (l = commit->parents; l; l = l->next)
 149                 commit_list_insert(l->item, &parents);
 150
 151         while (parents) {
 152                 struct commit *commit = parents->item;
 153                 l = parents;
 154                 parents = parents->next;
 155                 free(l);
 156
 157                 while (commit) {
 158                         /*
 159                          * A missing commit is ok iff its parent is marked
 160                          * uninteresting.
 161                          *
 162                          * We just mark such a thing parsed, so that when
 163                          * it is popped next time around, we won't be trying
 164                          * to parse it and get an error.
 165                          */
 166                         if (!has_sha1_file(commit->object.sha1))
 167                                 commit->object.parsed = 1;
 168
 169                         if (commit->object.flags & UNINTERESTING)
 170                                 break;
 171
 172                         commit->object.flags |= UNINTERESTING;
 173
 174                         /*
 175                          * Normally we haven't parsed the parent
 176                          * yet, so we won't have a parent of a parent
 177                          * here. However, it may turn out that we've
 178                          * reached this commit some other way (where it
 179                          * wasn't uninteresting), in which case we need
 180                          * to mark its parents recursively too..
 181                          */
 182                         if (!commit->parents)
 183                                 break;
 184
 185                         for (l = commit->parents->next; l; l = l->next)
 186                                 commit_list_insert(l->item, &parents);
 187                         commit = commit->parents->item;
 188                 }
 189         }
 190 }
 191
 192 static void add_pending_object_with_path(struct rev_info *revs,
 193                                          struct object *obj,
 194                                          const char *name, unsigned mode,
 195                                          const char *path)
 196 {
 197         if (!obj)
 198                 return;
 199         if (revs->no_walk && (obj->flags & UNINTERESTING))
 200                 revs->no_walk = 0;
 201         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 202                 struct strbuf buf = STRBUF_INIT;
 203                 int len = interpret_branch_name(name, 0, &buf);
 204                 int st;
 205
 206                 if (0 < len && name[len] && buf.len)
 207                         strbuf_addstr(&buf, name + len);
 208                 st = add_reflog_for_walk(revs->reflog_info,
 209                                          (struct commit *)obj,
 210                                          buf.buf[0] ? buf.buf: name);
 211                 strbuf_release(&buf);
 212                 if (st)
 213                         return;
 214         }
 215         add_object_array_with_path(obj, name, &revs->pending, mode, path);
 216 }
 217
 218 static void add_pending_object_with_mode(struct rev_info *revs,
 219                                          struct object *obj,
 220                                          const char *name, unsigned mode)
 221 {
 222         add_pending_object_with_path(revs, obj, name, mode, NULL);
 223 }
 224
 225 void add_pending_object(struct rev_info *revs,
 226                         struct object *obj, const char *name)
 227 {
 228         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 229 }
 230
 231 void add_head_to_pending(struct rev_info *revs)
 232 {
 233         unsigned char sha1[20];
 234         struct object *obj;
 235         if (get_sha1("HEAD", sha1))
 236                 return;
 237         obj = parse_object(sha1);
 238         if (!obj)
 239                 return;
 240         add_pending_object(revs, obj, "HEAD");
 241 }
 242
 243 static struct object *get_reference(struct rev_info *revs, const char *name,
 244                                     const unsigned char *sha1,
 245                                     unsigned int flags)
 246 {
 247         struct object *object;
 248
 249         object = parse_object(sha1);
 250         if (!object) {
 251                 if (revs->ignore_missing)
 252                         return object;
 253                 die("bad object %s", name);
 254         }
 255         object->flags |= flags;
 256         return object;
 257 }
 258
 259 void add_pending_sha1(struct rev_info *revs, const char *name,
 260                       const unsigned char *sha1, unsigned int flags)
 261 {
 262         struct object *object = get_reference(revs, name, sha1, flags);
 263         add_pending_object(revs, object, name);
 264 }
 265
 266 static struct commit *handle_commit(struct rev_info *revs,
 267                                     struct object_array_entry *entry)
 268 {
 269         struct object *object = entry->item;
 270         const char *name = entry->name;
 271         const char *path = entry->path;
 272         unsigned int mode = entry->mode;
 273         unsigned long flags = object->flags;
 274
 275         /*
 276          * Tag object? Look what it points to..
 277          */
 278         while (object->type == OBJ_TAG) {
 279                 struct tag *tag = (struct tag *) object;
 280                 if (revs->tag_objects && !(flags & UNINTERESTING))
 281                         add_pending_object(revs, object, tag->tag);
 282                 if (!tag->tagged)
 283                         die("bad tag");
 284                 object = parse_object(tag->tagged->sha1);
 285                 if (!object) {
 286                         if (flags & UNINTERESTING)
 287                                 return NULL;
 288                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 289                 }
 290                 object->flags |= flags;
 291                 /*
 292                  * We'll handle the tagged object by looping or dropping
 293                  * through to the non-tag handlers below. Do not
 294                  * propagate data from the tag's pending entry.
 295                  */
 296                 name = "";
 297                 path = NULL;
 298                 mode = 0;
 299         }
 300
 301         /*
 302          * Commit object? Just return it, we'll do all the complex
 303          * reachability crud.
 304          */
 305         if (object->type == OBJ_COMMIT) {
 306                 struct commit *commit = (struct commit *)object;
 307                 if (parse_commit(commit) < 0)
 308                         die("unable to parse commit %s", name);
 309                 if (flags & UNINTERESTING) {
 310                         mark_parents_uninteresting(commit);
 311                         revs->limited = 1;
 312                 }
 313                 if (revs->show_source && !commit->util)
 314                         commit->util = xstrdup(name);
 315                 return commit;
 316         }
 317
 318         /*
 319          * Tree object? Either mark it uninteresting, or add it
 320          * to the list of objects to look at later..
 321          */
 322         if (object->type == OBJ_TREE) {
 323                 struct tree *tree = (struct tree *)object;
 324                 if (!revs->tree_objects)
 325                         return NULL;
 326                 if (flags & UNINTERESTING) {
 327                         mark_tree_contents_uninteresting(tree);
 328                         return NULL;
 329                 }
 330                 add_pending_object_with_path(revs, object, name, mode, path);
 331                 return NULL;
 332         }
 333
 334         /*
 335          * Blob object? You know the drill by now..
 336          */
 337         if (object->type == OBJ_BLOB) {
 338                 if (!revs->blob_objects)
 339                         return NULL;
 340                 if (flags & UNINTERESTING)
 341                         return NULL;
 342                 add_pending_object_with_path(revs, object, name, mode, path);
 343                 return NULL;
 344         }
 345         die("%s is unknown object", name);
 346 }
 347
 348 static int everybody_uninteresting(struct commit_list *orig,
 349                                    struct commit **interesting_cache)
 350 {
 351         struct commit_list *list = orig;
 352
 353         if (*interesting_cache) {
 354                 struct commit *commit = *interesting_cache;
 355                 if (!(commit->object.flags & UNINTERESTING))
 356                         return 0;
 357         }
 358
 359         while (list) {
 360                 struct commit *commit = list->item;
 361                 list = list->next;
 362                 if (commit->object.flags & UNINTERESTING)
 363                         continue;
 364                 if (interesting_cache)
 365                         *interesting_cache = commit;
 366                 return 0;
 367         }
 368         return 1;
 369 }
 370
 371 /*
 372  * A definition of "relevant" commit that we can use to simplify limited graphs
 373  * by eliminating side branches.
 374  *
 375  * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
 376  * in our list), or that is a specified BOTTOM commit. Then after computing
 377  * a limited list, during processing we can generally ignore boundary merges
 378  * coming from outside the graph, (ie from irrelevant parents), and treat
 379  * those merges as if they were single-parent. TREESAME is defined to consider
 380  * only relevant parents, if any. If we are TREESAME to our on-graph parents,
 381  * we don't care if we were !TREESAME to non-graph parents.
 382  *
 383  * Treating bottom commits as relevant ensures that a limited graph's
 384  * connection to the actual bottom commit is not viewed as a side branch, but
 385  * treated as part of the graph. For example:
 386  *
 387  *   ....Z...A---X---o---o---B
 388  *        .     /
 389  *         W---Y
 390  *
 391  * When computing "A..B", the A-X connection is at least as important as
 392  * Y-X, despite A being flagged UNINTERESTING.
 393  *
 394  * And when computing --ancestry-path "A..B", the A-X connection is more
 395  * important than Y-X, despite both A and Y being flagged UNINTERESTING.
 396  */
 397 static inline int relevant_commit(struct commit *commit)
 398 {
 399         return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
 400 }
 401
 402 /*
 403  * Return a single relevant commit from a parent list. If we are a TREESAME
 404  * commit, and this selects one of our parents, then we can safely simplify to
 405  * that parent.
 406  */
 407 static struct commit *one_relevant_parent(const struct rev_info *revs,
 408                                           struct commit_list *orig)
 409 {
 410         struct commit_list *list = orig;
 411         struct commit *relevant = NULL;
 412
 413         if (!orig)
 414                 return NULL;
 415
 416         /*
 417          * For 1-parent commits, or if first-parent-only, then return that
 418          * first parent (even if not "relevant" by the above definition).
 419          * TREESAME will have been set purely on that parent.
 420          */
 421         if (revs->first_parent_only || !orig->next)
 422                 return orig->item;
 423
 424         /*
 425          * For multi-parent commits, identify a sole relevant parent, if any.
 426          * If we have only one relevant parent, then TREESAME will be set purely
 427          * with regard to that parent, and we can simplify accordingly.
 428          *
 429          * If we have more than one relevant parent, or no relevant parents
 430          * (and multiple irrelevant ones), then we can't select a parent here
 431          * and return NULL.
 432          */
 433         while (list) {
 434                 struct commit *commit = list->item;
 435                 list = list->next;
 436                 if (relevant_commit(commit)) {
 437                         if (relevant)
 438                                 return NULL;
 439                         relevant = commit;
 440                 }
 441         }
 442         return relevant;
 443 }
 444
 445 /*
 446  * The goal is to get REV_TREE_NEW as the result only if the
 447  * diff consists of all '+' (and no other changes), REV_TREE_OLD
 448  * if the whole diff is removal of old data, and otherwise
 449  * REV_TREE_DIFFERENT (of course if the trees are the same we
 450  * want REV_TREE_SAME).
 451  * That means that once we get to REV_TREE_DIFFERENT, we do not
 452  * have to look any further.
 453  */
 454 static int tree_difference = REV_TREE_SAME;
 455
 456 static void file_add_remove(struct diff_options *options,
 457                     int addremove, unsigned mode,
 458                     const unsigned char *sha1,
 459                     int sha1_valid,
 460                     const char *fullpath, unsigned dirty_submodule)
 461 {
 462         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 463
 464         tree_difference |= diff;
 465         if (tree_difference == REV_TREE_DIFFERENT)
 466                 DIFF_OPT_SET(options, HAS_CHANGES);
 467 }
 468
 469 static void file_change(struct diff_options *options,
 470                  unsigned old_mode, unsigned new_mode,
 471                  const unsigned char *old_sha1,
 472                  const unsigned char *new_sha1,
 473                  int old_sha1_valid, int new_sha1_valid,
 474                  const char *fullpath,
 475                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 476 {
 477         tree_difference = REV_TREE_DIFFERENT;
 478         DIFF_OPT_SET(options, HAS_CHANGES);
 479 }
 480
 481 static int rev_compare_tree(struct rev_info *revs,
 482                             struct commit *parent, struct commit *commit)
 483 {
 484         struct tree *t1 = parent->tree;
 485         struct tree *t2 = commit->tree;
 486
 487         if (!t1)
 488                 return REV_TREE_NEW;
 489         if (!t2)
 490                 return REV_TREE_OLD;
 491
 492         if (revs->simplify_by_decoration) {
 493                 /*
 494                  * If we are simplifying by decoration, then the commit
 495                  * is worth showing if it has a tag pointing at it.
 496                  */
 497                 if (get_name_decoration(&commit->object))
 498                         return REV_TREE_DIFFERENT;
 499                 /*
 500                  * A commit that is not pointed by a tag is uninteresting
 501                  * if we are not limited by path.  This means that you will
 502                  * see the usual "commits that touch the paths" plus any
 503                  * tagged commit by specifying both --simplify-by-decoration
 504                  * and pathspec.
 505                  */
 506                 if (!revs->prune_data.nr)
 507                         return REV_TREE_SAME;
 508         }
 509
 510         tree_difference = REV_TREE_SAME;
 511         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 512         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 513                            &revs->pruning) < 0)
 514                 return REV_TREE_DIFFERENT;
 515         return tree_difference;
 516 }
 517
 518 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 519 {
 520         int retval;
 521         struct tree *t1 = commit->tree;
 522
 523         if (!t1)
 524                 return 0;
 525
 526         tree_difference = REV_TREE_SAME;
 527         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 528         retval = diff_tree_sha1(NULL, t1->object.sha1, "", &revs->pruning);
 529
 530         return retval >= 0 && (tree_difference == REV_TREE_SAME);
 531 }
 532
 533 struct treesame_state {
 534         unsigned int nparents;
 535         unsigned char treesame[FLEX_ARRAY];
 536 };
 537
 538 static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
 539 {
 540         unsigned n = commit_list_count(commit->parents);
 541         struct treesame_state *st = xcalloc(1, sizeof(*st) + n);
 542         st->nparents = n;
 543         add_decoration(&revs->treesame, &commit->object, st);
 544         return st;
 545 }
 546
 547 /*
 548  * Must be called immediately after removing the nth_parent from a commit's
 549  * parent list, if we are maintaining the per-parent treesame[] decoration.
 550  * This does not recalculate the master TREESAME flag - update_treesame()
 551  * should be called to update it after a sequence of treesame[] modifications
 552  * that may have affected it.
 553  */
 554 static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
 555 {
 556         struct treesame_state *st;
 557         int old_same;
 558
 559         if (!commit->parents) {
 560                 /*
 561                  * Have just removed the only parent from a non-merge.
 562                  * Different handling, as we lack decoration.
 563                  */
 564                 if (nth_parent != 0)
 565                         die("compact_treesame %u", nth_parent);
 566                 old_same = !!(commit->object.flags & TREESAME);
 567                 if (rev_same_tree_as_empty(revs, commit))
 568                         commit->object.flags |= TREESAME;
 569                 else
 570                         commit->object.flags &= ~TREESAME;
 571                 return old_same;
 572         }
 573
 574         st = lookup_decoration(&revs->treesame, &commit->object);
 575         if (!st || nth_parent >= st->nparents)
 576                 die("compact_treesame %u", nth_parent);
 577
 578         old_same = st->treesame[nth_parent];
 579         memmove(st->treesame + nth_parent,
 580                 st->treesame + nth_parent + 1,
 581                 st->nparents - nth_parent - 1);
 582
 583         /*
 584          * If we've just become a non-merge commit, update TREESAME
 585          * immediately, and remove the no-longer-needed decoration.
 586          * If still a merge, defer update until update_treesame().
 587          */
 588         if (--st->nparents == 1) {
 589                 if (commit->parents->next)
 590                         die("compact_treesame parents mismatch");
 591                 if (st->treesame[0] && revs->dense)
 592                         commit->object.flags |= TREESAME;
 593                 else
 594                         commit->object.flags &= ~TREESAME;
 595                 free(add_decoration(&revs->treesame, &commit->object, NULL));
 596         }
 597
 598         return old_same;
 599 }
 600
 601 static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
 602 {
 603         if (commit->parents && commit->parents->next) {
 604                 unsigned n;
 605                 struct treesame_state *st;
 606                 struct commit_list *p;
 607                 unsigned relevant_parents;
 608                 unsigned relevant_change, irrelevant_change;
 609
 610                 st = lookup_decoration(&revs->treesame, &commit->object);
 611                 if (!st)
 612                         die("update_treesame %s", sha1_to_hex(commit->object.sha1));
 613                 relevant_parents = 0;
 614                 relevant_change = irrelevant_change = 0;
 615                 for (p = commit->parents, n = 0; p; n++, p = p->next) {
 616                         if (relevant_commit(p->item)) {
 617                                 relevant_change |= !st->treesame[n];
 618                                 relevant_parents++;
 619                         } else
 620                                 irrelevant_change |= !st->treesame[n];
 621                 }
 622                 if (relevant_parents ? relevant_change : irrelevant_change)
 623                         commit->object.flags &= ~TREESAME;
 624                 else
 625                         commit->object.flags |= TREESAME;
 626         }
 627
 628         return commit->object.flags & TREESAME;
 629 }
 630
 631 static inline int limiting_can_increase_treesame(const struct rev_info *revs)
 632 {
 633         /*
 634          * TREESAME is irrelevant unless prune && dense;
 635          * if simplify_history is set, we can't have a mixture of TREESAME and
 636          *    !TREESAME INTERESTING parents (and we don't have treesame[]
 637          *    decoration anyway);
 638          * if first_parent_only is set, then the TREESAME flag is locked
 639          *    against the first parent (and again we lack treesame[] decoration).
 640          */
 641         return revs->prune && revs->dense &&
 642                !revs->simplify_history &&
 643                !revs->first_parent_only;
 644 }
 645
 646 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 647 {
 648         struct commit_list **pp, *parent;
 649         struct treesame_state *ts = NULL;
 650         int relevant_change = 0, irrelevant_change = 0;
 651         int relevant_parents, nth_parent;
 652
 653         /*
 654          * If we don't do pruning, everything is interesting
 655          */
 656         if (!revs->prune)
 657                 return;
 658
 659         if (!commit->tree)
 660                 return;
 661
 662         if (!commit->parents) {
 663                 if (rev_same_tree_as_empty(revs, commit))
 664                         commit->object.flags |= TREESAME;
 665                 return;
 666         }
 667
 668         /*
 669          * Normal non-merge commit? If we don't want to make the
 670          * history dense, we consider it always to be a change..
 671          */
 672         if (!revs->dense && !commit->parents->next)
 673                 return;
 674
 675         for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
 676              (parent = *pp) != NULL;
 677              pp = &parent->next, nth_parent++) {
 678                 struct commit *p = parent->item;
 679                 if (relevant_commit(p))
 680                         relevant_parents++;
 681
 682                 if (nth_parent == 1) {
 683                         /*
 684                          * This our second loop iteration - so we now know
 685                          * we're dealing with a merge.
 686                          *
 687                          * Do not compare with later parents when we care only about
 688                          * the first parent chain, in order to avoid derailing the
 689                          * traversal to follow a side branch that brought everything
 690                          * in the path we are limited to by the pathspec.
 691                          */
 692                         if (revs->first_parent_only)
 693                                 break;
 694                         /*
 695                          * If this will remain a potentially-simplifiable
 696                          * merge, remember per-parent treesame if needed.
 697                          * Initialise the array with the comparison from our
 698                          * first iteration.
 699                          */
 700                         if (revs->treesame.name &&
 701                             !revs->simplify_history &&
 702                             !(commit->object.flags & UNINTERESTING)) {
 703                                 ts = initialise_treesame(revs, commit);
 704                                 if (!(irrelevant_change || relevant_change))
 705                                         ts->treesame[0] = 1;
 706                         }
 707                 }
 708                 if (parse_commit(p) < 0)
 709                         die("cannot simplify commit %s (because of %s)",
 710                             sha1_to_hex(commit->object.sha1),
 711                             sha1_to_hex(p->object.sha1));
 712                 switch (rev_compare_tree(revs, p, commit)) {
 713                 case REV_TREE_SAME:
 714                         if (!revs->simplify_history || !relevant_commit(p)) {
 715                                 /* Even if a merge with an uninteresting
 716                                  * side branch brought the entire change
 717                                  * we are interested in, we do not want
 718                                  * to lose the other branches of this
 719                                  * merge, so we just keep going.
 720                                  */
 721                                 if (ts)
 722                                         ts->treesame[nth_parent] = 1;
 723                                 continue;
 724                         }
 725                         parent->next = NULL;
 726                         commit->parents = parent;
 727                         commit->object.flags |= TREESAME;
 728                         return;
 729
 730                 case REV_TREE_NEW:
 731                         if (revs->remove_empty_trees &&
 732                             rev_same_tree_as_empty(revs, p)) {
 733                                 /* We are adding all the specified
 734                                  * paths from this parent, so the
 735                                  * history beyond this parent is not
 736                                  * interesting.  Remove its parents
 737                                  * (they are grandparents for us).
 738                                  * IOW, we pretend this parent is a
 739                                  * "root" commit.
 740                                  */
 741                                 if (parse_commit(p) < 0)
 742                                         die("cannot simplify commit %s (invalid %s)",
 743                                             sha1_to_hex(commit->object.sha1),
 744                                             sha1_to_hex(p->object.sha1));
 745                                 p->parents = NULL;
 746                         }
 747                 /* fallthrough */
 748                 case REV_TREE_OLD:
 749                 case REV_TREE_DIFFERENT:
 750                         if (relevant_commit(p))
 751                                 relevant_change = 1;
 752                         else
 753                                 irrelevant_change = 1;
 754                         continue;
 755                 }
 756                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 757         }
 758
 759         /*
 760          * TREESAME is straightforward for single-parent commits. For merge
 761          * commits, it is most useful to define it so that "irrelevant"
 762          * parents cannot make us !TREESAME - if we have any relevant
 763          * parents, then we only consider TREESAMEness with respect to them,
 764          * allowing irrelevant merges from uninteresting branches to be
 765          * simplified away. Only if we have only irrelevant parents do we
 766          * base TREESAME on them. Note that this logic is replicated in
 767          * update_treesame, which should be kept in sync.
 768          */
 769         if (relevant_parents ? !relevant_change : !irrelevant_change)
 770                 commit->object.flags |= TREESAME;
 771 }
 772
 773 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 774                     struct commit_list *cached_base, struct commit_list **cache)
 775 {
 776         struct commit_list *new_entry;
 777
 778         if (cached_base && p->date < cached_base->item->date)
 779                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
 780         else
 781                 new_entry = commit_list_insert_by_date(p, head);
 782
 783         if (cache && (!*cache || p->date < (*cache)->item->date))
 784                 *cache = new_entry;
 785 }
 786
 787 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 788                     struct commit_list **list, struct commit_list **cache_ptr)
 789 {
 790         struct commit_list *parent = commit->parents;
 791         unsigned left_flag;
 792         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 793
 794         if (commit->object.flags & ADDED)
 795                 return 0;
 796         commit->object.flags |= ADDED;
 797
 798         if (revs->include_check &&
 799             !revs->include_check(commit, revs->include_check_data))
 800                 return 0;
 801
 802         /*
 803          * If the commit is uninteresting, don't try to
 804          * prune parents - we want the maximal uninteresting
 805          * set.
 806          *
 807          * Normally we haven't parsed the parent
 808          * yet, so we won't have a parent of a parent
 809          * here. However, it may turn out that we've
 810          * reached this commit some other way (where it
 811          * wasn't uninteresting), in which case we need
 812          * to mark its parents recursively too..
 813          */
 814         if (commit->object.flags & UNINTERESTING) {
 815                 while (parent) {
 816                         struct commit *p = parent->item;
 817                         parent = parent->next;
 818                         if (p)
 819                                 p->object.flags |= UNINTERESTING;
 820                         if (parse_commit_gently(p, 1) < 0)
 821                                 continue;
 822                         if (p->parents)
 823                                 mark_parents_uninteresting(p);
 824                         if (p->object.flags & SEEN)
 825                                 continue;
 826                         p->object.flags |= SEEN;
 827                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 828                 }
 829                 return 0;
 830         }
 831
 832         /*
 833          * Ok, the commit wasn't uninteresting. Try to
 834          * simplify the commit history and find the parent
 835          * that has no differences in the path set if one exists.
 836          */
 837         try_to_simplify_commit(revs, commit);
 838
 839         if (revs->no_walk)
 840                 return 0;
 841
 842         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 843
 844         for (parent = commit->parents; parent; parent = parent->next) {
 845                 struct commit *p = parent->item;
 846
 847                 if (parse_commit_gently(p, revs->ignore_missing_links) < 0)
 848                         return -1;
 849                 if (revs->show_source && !p->util)
 850                         p->util = commit->util;
 851                 p->object.flags |= left_flag;
 852                 if (!(p->object.flags & SEEN)) {
 853                         p->object.flags |= SEEN;
 854                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 855                 }
 856                 if (revs->first_parent_only)
 857                         break;
 858         }
 859         return 0;
 860 }
 861
 862 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 863 {
 864         struct commit_list *p;
 865         int left_count = 0, right_count = 0;
 866         int left_first;
 867         struct patch_ids ids;
 868         unsigned cherry_flag;
 869
 870         /* First count the commits on the left and on the right */
 871         for (p = list; p; p = p->next) {
 872                 struct commit *commit = p->item;
 873                 unsigned flags = commit->object.flags;
 874                 if (flags & BOUNDARY)
 875                         ;
 876                 else if (flags & SYMMETRIC_LEFT)
 877                         left_count++;
 878                 else
 879                         right_count++;
 880         }
 881
 882         if (!left_count || !right_count)
 883                 return;
 884
 885         left_first = left_count < right_count;
 886         init_patch_ids(&ids);
 887         ids.diffopts.pathspec = revs->diffopt.pathspec;
 888
 889         /* Compute patch-ids for one side */
 890         for (p = list; p; p = p->next) {
 891                 struct commit *commit = p->item;
 892                 unsigned flags = commit->object.flags;
 893
 894                 if (flags & BOUNDARY)
 895                         continue;
 896                 /*
 897                  * If we have fewer left, left_first is set and we omit
 898                  * commits on the right branch in this loop.  If we have
 899                  * fewer right, we skip the left ones.
 900                  */
 901                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 902                         continue;
 903                 commit->util = add_commit_patch_id(commit, &ids);
 904         }
 905
 906         /* either cherry_mark or cherry_pick are true */
 907         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 908
 909         /* Check the other side */
 910         for (p = list; p; p = p->next) {
 911                 struct commit *commit = p->item;
 912                 struct patch_id *id;
 913                 unsigned flags = commit->object.flags;
 914
 915                 if (flags & BOUNDARY)
 916                         continue;
 917                 /*
 918                  * If we have fewer left, left_first is set and we omit
 919                  * commits on the left branch in this loop.
 920                  */
 921                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 922                         continue;
 923
 924                 /*
 925                  * Have we seen the same patch id?
 926                  */
 927                 id = has_commit_patch_id(commit, &ids);
 928                 if (!id)
 929                         continue;
 930                 id->seen = 1;
 931                 commit->object.flags |= cherry_flag;
 932         }
 933
 934         /* Now check the original side for seen ones */
 935         for (p = list; p; p = p->next) {
 936                 struct commit *commit = p->item;
 937                 struct patch_id *ent;
 938
 939                 ent = commit->util;
 940                 if (!ent)
 941                         continue;
 942                 if (ent->seen)
 943                         commit->object.flags |= cherry_flag;
 944                 commit->util = NULL;
 945         }
 946
 947         free_patch_ids(&ids);
 948 }
 949
 950 /* How many extra uninteresting commits we want to see.. */
 951 #define SLOP 5
 952
 953 static int still_interesting(struct commit_list *src, unsigned long date, int slop,
 954                              struct commit **interesting_cache)
 955 {
 956         /*
 957          * No source list at all? We're definitely done..
 958          */
 959         if (!src)
 960                 return 0;
 961
 962         /*
 963          * Does the destination list contain entries with a date
 964          * before the source list? Definitely _not_ done.
 965          */
 966         if (date <= src->item->date)
 967                 return SLOP;
 968
 969         /*
 970          * Does the source list still have interesting commits in
 971          * it? Definitely not done..
 972          */
 973         if (!everybody_uninteresting(src, interesting_cache))
 974                 return SLOP;
 975
 976         /* Ok, we're closing in.. */
 977         return slop-1;
 978 }
 979
 980 /*
 981  * "rev-list --ancestry-path A..B" computes commits that are ancestors
 982  * of B but not ancestors of A but further limits the result to those
 983  * that are descendants of A.  This takes the list of bottom commits and
 984  * the result of "A..B" without --ancestry-path, and limits the latter
 985  * further to the ones that can reach one of the commits in "bottom".
 986  */
 987 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 988 {
 989         struct commit_list *p;
 990         struct commit_list *rlist = NULL;
 991         int made_progress;
 992
 993         /*
 994          * Reverse the list so that it will be likely that we would
 995          * process parents before children.
 996          */
 997         for (p = list; p; p = p->next)
 998                 commit_list_insert(p->item, &rlist);
 999
1000         for (p = bottom; p; p = p->next)
1001                 p->item->object.flags |= TMP_MARK;
1002
1003         /*
1004          * Mark the ones that can reach bottom commits in "list",
1005          * in a bottom-up fashion.
1006          */
1007         do {
1008                 made_progress = 0;
1009                 for (p = rlist; p; p = p->next) {
1010                         struct commit *c = p->item;
1011                         struct commit_list *parents;
1012                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
1013                                 continue;
1014                         for (parents = c->parents;
1015                              parents;
1016                              parents = parents->next) {
1017                                 if (!(parents->item->object.flags & TMP_MARK))
1018                                         continue;
1019                                 c->object.flags |= TMP_MARK;
1020                                 made_progress = 1;
1021                                 break;
1022                         }
1023                 }
1024         } while (made_progress);
1025
1026         /*
1027          * NEEDSWORK: decide if we want to remove parents that are
1028          * not marked with TMP_MARK from commit->parents for commits
1029          * in the resulting list.  We may not want to do that, though.
1030          */
1031
1032         /*
1033          * The ones that are not marked with TMP_MARK are uninteresting
1034          */
1035         for (p = list; p; p = p->next) {
1036                 struct commit *c = p->item;
1037                 if (c->object.flags & TMP_MARK)
1038                         continue;
1039                 c->object.flags |= UNINTERESTING;
1040         }
1041
1042         /* We are done with the TMP_MARK */
1043         for (p = list; p; p = p->next)
1044                 p->item->object.flags &= ~TMP_MARK;
1045         for (p = bottom; p; p = p->next)
1046                 p->item->object.flags &= ~TMP_MARK;
1047         free_commit_list(rlist);
1048 }
1049
1050 /*
1051  * Before walking the history, keep the set of "negative" refs the
1052  * caller has asked to exclude.
1053  *
1054  * This is used to compute "rev-list --ancestry-path A..B", as we need
1055  * to filter the result of "A..B" further to the ones that can actually
1056  * reach A.
1057  */
1058 static struct commit_list *collect_bottom_commits(struct commit_list *list)
1059 {
1060         struct commit_list *elem, *bottom = NULL;
1061         for (elem = list; elem; elem = elem->next)
1062                 if (elem->item->object.flags & BOTTOM)
1063                         commit_list_insert(elem->item, &bottom);
1064         return bottom;
1065 }
1066
1067 /* Assumes either left_only or right_only is set */
1068 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1069 {
1070         struct commit_list *p;
1071
1072         for (p = list; p; p = p->next) {
1073                 struct commit *commit = p->item;
1074
1075                 if (revs->right_only) {
1076                         if (commit->object.flags & SYMMETRIC_LEFT)
1077                                 commit->object.flags |= SHOWN;
1078                 } else  /* revs->left_only is set */
1079                         if (!(commit->object.flags & SYMMETRIC_LEFT))
1080                                 commit->object.flags |= SHOWN;
1081         }
1082 }
1083
1084 static int limit_list(struct rev_info *revs)
1085 {
1086         int slop = SLOP;
1087         unsigned long date = ~0ul;
1088         struct commit_list *list = revs->commits;
1089         struct commit_list *newlist = NULL;
1090         struct commit_list **p = &newlist;
1091         struct commit_list *bottom = NULL;
1092         struct commit *interesting_cache = NULL;
1093
1094         if (revs->ancestry_path) {
1095                 bottom = collect_bottom_commits(list);
1096                 if (!bottom)
1097                         die("--ancestry-path given but there are no bottom commits");
1098         }
1099
1100         while (list) {
1101                 struct commit_list *entry = list;
1102                 struct commit *commit = list->item;
1103                 struct object *obj = &commit->object;
1104                 show_early_output_fn_t show;
1105
1106                 list = list->next;
1107                 free(entry);
1108
1109                 if (commit == interesting_cache)
1110                         interesting_cache = NULL;
1111
1112                 if (revs->max_age != -1 && (commit->date < revs->max_age))
1113                         obj->flags |= UNINTERESTING;
1114                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
1115                         return -1;
1116                 if (obj->flags & UNINTERESTING) {
1117                         mark_parents_uninteresting(commit);
1118                         if (revs->show_all)
1119                                 p = &commit_list_insert(commit, p)->next;
1120                         slop = still_interesting(list, date, slop, &interesting_cache);
1121                         if (slop)
1122                                 continue;
1123                         /* If showing all, add the whole pending list to the end */
1124                         if (revs->show_all)
1125                                 *p = list;
1126                         break;
1127                 }
1128                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1129                         continue;
1130                 date = commit->date;
1131                 p = &commit_list_insert(commit, p)->next;
1132
1133                 show = show_early_output;
1134                 if (!show)
1135                         continue;
1136
1137                 show(revs, newlist);
1138                 show_early_output = NULL;
1139         }
1140         if (revs->cherry_pick || revs->cherry_mark)
1141                 cherry_pick_list(newlist, revs);
1142
1143         if (revs->left_only || revs->right_only)
1144                 limit_left_right(newlist, revs);
1145
1146         if (bottom) {
1147                 limit_to_ancestry(bottom, newlist);
1148                 free_commit_list(bottom);
1149         }
1150
1151         /*
1152          * Check if any commits have become TREESAME by some of their parents
1153          * becoming UNINTERESTING.
1154          */
1155         if (limiting_can_increase_treesame(revs))
1156                 for (list = newlist; list; list = list->next) {
1157                         struct commit *c = list->item;
1158                         if (c->object.flags & (UNINTERESTING | TREESAME))
1159                                 continue;
1160                         update_treesame(revs, c);
1161                 }
1162
1163         revs->commits = newlist;
1164         return 0;
1165 }
1166
1167 /*
1168  * Add an entry to refs->cmdline with the specified information.
1169  * *name is copied.
1170  */
1171 static void add_rev_cmdline(struct rev_info *revs,
1172                             struct object *item,
1173                             const char *name,
1174                             int whence,
1175                             unsigned flags)
1176 {
1177         struct rev_cmdline_info *info = &revs->cmdline;
1178         int nr = info->nr;
1179
1180         ALLOC_GROW(info->rev, nr + 1, info->alloc);
1181         info->rev[nr].item = item;
1182         info->rev[nr].name = xstrdup(name);
1183         info->rev[nr].whence = whence;
1184         info->rev[nr].flags = flags;
1185         info->nr++;
1186 }
1187
1188 static void add_rev_cmdline_list(struct rev_info *revs,
1189                                  struct commit_list *commit_list,
1190                                  int whence,
1191                                  unsigned flags)
1192 {
1193         while (commit_list) {
1194                 struct object *object = &commit_list->item->object;
1195                 add_rev_cmdline(revs, object, sha1_to_hex(object->sha1),
1196                                 whence, flags);
1197                 commit_list = commit_list->next;
1198         }
1199 }
1200
1201 struct all_refs_cb {
1202         int all_flags;
1203         int warned_bad_reflog;
1204         struct rev_info *all_revs;
1205         const char *name_for_errormsg;
1206 };
1207
1208 int ref_excluded(struct string_list *ref_excludes, const char *path)
1209 {
1210         struct string_list_item *item;
1211
1212         if (!ref_excludes)
1213                 return 0;
1214         for_each_string_list_item(item, ref_excludes) {
1215                 if (!wildmatch(item->string, path, 0, NULL))
1216                         return 1;
1217         }
1218         return 0;
1219 }
1220
1221 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1222 {
1223         struct all_refs_cb *cb = cb_data;
1224         struct object *object;
1225
1226         if (ref_excluded(cb->all_revs->ref_excludes, path))
1227             return 0;
1228
1229         object = get_reference(cb->all_revs, path, sha1, cb->all_flags);
1230         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1231         add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
1232         return 0;
1233 }
1234
1235 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1236         unsigned flags)
1237 {
1238         cb->all_revs = revs;
1239         cb->all_flags = flags;
1240 }
1241
1242 void clear_ref_exclusion(struct string_list **ref_excludes_p)
1243 {
1244         if (*ref_excludes_p) {
1245                 string_list_clear(*ref_excludes_p, 0);
1246                 free(*ref_excludes_p);
1247         }
1248         *ref_excludes_p = NULL;
1249 }
1250
1251 void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1252 {
1253         if (!*ref_excludes_p) {
1254                 *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1255                 (*ref_excludes_p)->strdup_strings = 1;
1256         }
1257         string_list_append(*ref_excludes_p, exclude);
1258 }
1259
1260 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
1261                 int (*for_each)(const char *, each_ref_fn, void *))
1262 {
1263         struct all_refs_cb cb;
1264         init_all_refs_cb(&cb, revs, flags);
1265         for_each(submodule, handle_one_ref, &cb);
1266 }
1267
1268 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
1269 {
1270         struct all_refs_cb *cb = cb_data;
1271         if (!is_null_sha1(sha1)) {
1272                 struct object *o = parse_object(sha1);
1273                 if (o) {
1274                         o->flags |= cb->all_flags;
1275                         /* ??? CMDLINEFLAGS ??? */
1276                         add_pending_object(cb->all_revs, o, "");
1277                 }
1278                 else if (!cb->warned_bad_reflog) {
1279                         warning("reflog of '%s' references pruned commits",
1280                                 cb->name_for_errormsg);
1281                         cb->warned_bad_reflog = 1;
1282                 }
1283         }
1284 }
1285
1286 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
1287                 const char *email, unsigned long timestamp, int tz,
1288                 const char *message, void *cb_data)
1289 {
1290         handle_one_reflog_commit(osha1, cb_data);
1291         handle_one_reflog_commit(nsha1, cb_data);
1292         return 0;
1293 }
1294
1295 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1296 {
1297         struct all_refs_cb *cb = cb_data;
1298         cb->warned_bad_reflog = 0;
1299         cb->name_for_errormsg = path;
1300         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
1301         return 0;
1302 }
1303
1304 void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1305 {
1306         struct all_refs_cb cb;
1307         cb.all_revs = revs;
1308         cb.all_flags = flags;
1309         for_each_reflog(handle_one_reflog, &cb);
1310 }
1311
1312 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1313                            struct strbuf *path)
1314 {
1315         size_t baselen = path->len;
1316         int i;
1317
1318         if (it->entry_count >= 0) {
1319                 struct tree *tree = lookup_tree(it->sha1);
1320                 add_pending_object_with_path(revs, &tree->object, "",
1321                                              040000, path->buf);
1322         }
1323
1324         for (i = 0; i < it->subtree_nr; i++) {
1325                 struct cache_tree_sub *sub = it->down[i];
1326                 strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1327                 add_cache_tree(sub->cache_tree, revs, path);
1328                 strbuf_setlen(path, baselen);
1329         }
1330
1331 }
1332
1333 void add_index_objects_to_pending(struct rev_info *revs, unsigned flags)
1334 {
1335         int i;
1336
1337         read_cache();
1338         for (i = 0; i < active_nr; i++) {
1339                 struct cache_entry *ce = active_cache[i];
1340                 struct blob *blob;
1341
1342                 if (S_ISGITLINK(ce->ce_mode))
1343                         continue;
1344
1345                 blob = lookup_blob(ce->sha1);
1346                 if (!blob)
1347                         die("unable to add index blob to traversal");
1348                 add_pending_object_with_path(revs, &blob->object, "",
1349                                              ce->ce_mode, ce->name);
1350         }
1351
1352         if (active_cache_tree) {
1353                 struct strbuf path = STRBUF_INIT;
1354                 add_cache_tree(active_cache_tree, revs, &path);
1355                 strbuf_release(&path);
1356         }
1357 }
1358
1359 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
1360 {
1361         unsigned char sha1[20];
1362         struct object *it;
1363         struct commit *commit;
1364         struct commit_list *parents;
1365         const char *arg = arg_;
1366
1367         if (*arg == '^') {
1368                 flags ^= UNINTERESTING | BOTTOM;
1369                 arg++;
1370         }
1371         if (get_sha1_committish(arg, sha1))
1372                 return 0;
1373         while (1) {
1374                 it = get_reference(revs, arg, sha1, 0);
1375                 if (!it && revs->ignore_missing)
1376                         return 0;
1377                 if (it->type != OBJ_TAG)
1378                         break;
1379                 if (!((struct tag*)it)->tagged)
1380                         return 0;
1381                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1382         }
1383         if (it->type != OBJ_COMMIT)
1384                 return 0;
1385         commit = (struct commit *)it;
1386         for (parents = commit->parents; parents; parents = parents->next) {
1387                 it = &parents->item->object;
1388                 it->flags |= flags;
1389                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1390                 add_pending_object(revs, it, arg);
1391         }
1392         return 1;
1393 }
1394
1395 void init_revisions(struct rev_info *revs, const char *prefix)
1396 {
1397         memset(revs, 0, sizeof(*revs));
1398
1399         revs->abbrev = DEFAULT_ABBREV;
1400         revs->ignore_merges = 1;
1401         revs->simplify_history = 1;
1402         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1403         DIFF_OPT_SET(&revs->pruning, QUICK);
1404         revs->pruning.add_remove = file_add_remove;
1405         revs->pruning.change = file_change;
1406         revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1407         revs->dense = 1;
1408         revs->prefix = prefix;
1409         revs->max_age = -1;
1410         revs->min_age = -1;
1411         revs->skip_count = -1;
1412         revs->max_count = -1;
1413         revs->max_parents = -1;
1414
1415         revs->commit_format = CMIT_FMT_DEFAULT;
1416
1417         init_grep_defaults();
1418         grep_init(&revs->grep_filter, prefix);
1419         revs->grep_filter.status_only = 1;
1420         revs->grep_filter.regflags = REG_NEWLINE;
1421
1422         diff_setup(&revs->diffopt);
1423         if (prefix && !revs->diffopt.prefix) {
1424                 revs->diffopt.prefix = prefix;
1425                 revs->diffopt.prefix_length = strlen(prefix);
1426         }
1427
1428         revs->notes_opt.use_default_notes = -1;
1429 }
1430
1431 static void add_pending_commit_list(struct rev_info *revs,
1432                                     struct commit_list *commit_list,
1433                                     unsigned int flags)
1434 {
1435         while (commit_list) {
1436                 struct object *object = &commit_list->item->object;
1437                 object->flags |= flags;
1438                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
1439                 commit_list = commit_list->next;
1440         }
1441 }
1442
1443 static void prepare_show_merge(struct rev_info *revs)
1444 {
1445         struct commit_list *bases;
1446         struct commit *head, *other;
1447         unsigned char sha1[20];
1448         const char **prune = NULL;
1449         int i, prune_num = 1; /* counting terminating NULL */
1450
1451         if (get_sha1("HEAD", sha1))
1452                 die("--merge without HEAD?");
1453         head = lookup_commit_or_die(sha1, "HEAD");
1454         if (get_sha1("MERGE_HEAD", sha1))
1455                 die("--merge without MERGE_HEAD?");
1456         other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1457         add_pending_object(revs, &head->object, "HEAD");
1458         add_pending_object(revs, &other->object, "MERGE_HEAD");
1459         bases = get_merge_bases(head, other);
1460         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1461         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1462         free_commit_list(bases);
1463         head->object.flags |= SYMMETRIC_LEFT;
1464
1465         if (!active_nr)
1466                 read_cache();
1467         for (i = 0; i < active_nr; i++) {
1468                 const struct cache_entry *ce = active_cache[i];
1469                 if (!ce_stage(ce))
1470                         continue;
1471                 if (ce_path_match(ce, &revs->prune_data, NULL)) {
1472                         prune_num++;
1473                         REALLOC_ARRAY(prune, prune_num);
1474                         prune[prune_num-2] = ce->name;
1475                         prune[prune_num-1] = NULL;
1476                 }
1477                 while ((i+1 < active_nr) &&
1478                        ce_same_name(ce, active_cache[i+1]))
1479                         i++;
1480         }
1481         free_pathspec(&revs->prune_data);
1482         parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1483                        PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1484         revs->limited = 1;
1485 }
1486
1487 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1488 {
1489         struct object_context oc;
1490         char *dotdot;
1491         struct object *object;
1492         unsigned char sha1[20];
1493         int local_flags;
1494         const char *arg = arg_;
1495         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1496         unsigned get_sha1_flags = 0;
1497
1498         flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1499
1500         dotdot = strstr(arg, "..");
1501         if (dotdot) {
1502                 unsigned char from_sha1[20];
1503                 const char *next = dotdot + 2;
1504                 const char *this = arg;
1505                 int symmetric = *next == '.';
1506                 unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1507                 static const char head_by_default[] = "HEAD";
1508                 unsigned int a_flags;
1509
1510                 *dotdot = 0;
1511                 next += symmetric;
1512
1513                 if (!*next)
1514                         next = head_by_default;
1515                 if (dotdot == arg)
1516                         this = head_by_default;
1517                 if (this == head_by_default && next == head_by_default &&
1518                     !symmetric) {
1519                         /*
1520                          * Just ".."?  That is not a range but the
1521                          * pathspec for the parent directory.
1522                          */
1523                         if (!cant_be_filename) {
1524                                 *dotdot = '.';
1525                                 return -1;
1526                         }
1527                 }
1528                 if (!get_sha1_committish(this, from_sha1) &&
1529                     !get_sha1_committish(next, sha1)) {
1530                         struct object *a_obj, *b_obj;
1531
1532                         if (!cant_be_filename) {
1533                                 *dotdot = '.';
1534                                 verify_non_filename(revs->prefix, arg);
1535                         }
1536
1537                         a_obj = parse_object(from_sha1);
1538                         b_obj = parse_object(sha1);
1539                         if (!a_obj || !b_obj) {
1540                         missing:
1541                                 if (revs->ignore_missing)
1542                                         return 0;
1543                                 die(symmetric
1544                                     ? "Invalid symmetric difference expression %s"
1545                                     : "Invalid revision range %s", arg);
1546                         }
1547
1548                         if (!symmetric) {
1549                                 /* just A..B */
1550                                 a_flags = flags_exclude;
1551                         } else {
1552                                 /* A...B -- find merge bases between the two */
1553                                 struct commit *a, *b;
1554                                 struct commit_list *exclude;
1555
1556                                 a = (a_obj->type == OBJ_COMMIT
1557                                      ? (struct commit *)a_obj
1558                                      : lookup_commit_reference(a_obj->sha1));
1559                                 b = (b_obj->type == OBJ_COMMIT
1560                                      ? (struct commit *)b_obj
1561                                      : lookup_commit_reference(b_obj->sha1));
1562                                 if (!a || !b)
1563                                         goto missing;
1564                                 exclude = get_merge_bases(a, b);
1565                                 add_rev_cmdline_list(revs, exclude,
1566                                                      REV_CMD_MERGE_BASE,
1567                                                      flags_exclude);
1568                                 add_pending_commit_list(revs, exclude,
1569                                                         flags_exclude);
1570                                 free_commit_list(exclude);
1571
1572                                 a_flags = flags | SYMMETRIC_LEFT;
1573                         }
1574
1575                         a_obj->flags |= a_flags;
1576                         b_obj->flags |= flags;
1577                         add_rev_cmdline(revs, a_obj, this,
1578                                         REV_CMD_LEFT, a_flags);
1579                         add_rev_cmdline(revs, b_obj, next,
1580                                         REV_CMD_RIGHT, flags);
1581                         add_pending_object(revs, a_obj, this);
1582                         add_pending_object(revs, b_obj, next);
1583                         return 0;
1584                 }
1585                 *dotdot = '.';
1586         }
1587         dotdot = strstr(arg, "^@");
1588         if (dotdot && !dotdot[2]) {
1589                 *dotdot = 0;
1590                 if (add_parents_only(revs, arg, flags))
1591                         return 0;
1592                 *dotdot = '^';
1593         }
1594         dotdot = strstr(arg, "^!");
1595         if (dotdot && !dotdot[2]) {
1596                 *dotdot = 0;
1597                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM)))
1598                         *dotdot = '^';
1599         }
1600
1601         local_flags = 0;
1602         if (*arg == '^') {
1603                 local_flags = UNINTERESTING | BOTTOM;
1604                 arg++;
1605         }
1606
1607         if (revarg_opt & REVARG_COMMITTISH)
1608                 get_sha1_flags = GET_SHA1_COMMITTISH;
1609
1610         if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1611                 return revs->ignore_missing ? 0 : -1;
1612         if (!cant_be_filename)
1613                 verify_non_filename(revs->prefix, arg);
1614         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1615         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1616         add_pending_object_with_mode(revs, object, arg, oc.mode);
1617         return 0;
1618 }
1619
1620 struct cmdline_pathspec {
1621         int alloc;
1622         int nr;
1623         const char **path;
1624 };
1625
1626 static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1627 {
1628         while (*av) {
1629                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1630                 prune->path[prune->nr++] = *(av++);
1631         }
1632 }
1633
1634 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1635                                      struct cmdline_pathspec *prune)
1636 {
1637         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1638                 int len = sb->len;
1639                 if (len && sb->buf[len - 1] == '\n')
1640                         sb->buf[--len] = '\0';
1641                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1642                 prune->path[prune->nr++] = xstrdup(sb->buf);
1643         }
1644 }
1645
1646 static void read_revisions_from_stdin(struct rev_info *revs,
1647                                       struct cmdline_pathspec *prune)
1648 {
1649         struct strbuf sb;
1650         int seen_dashdash = 0;
1651         int save_warning;
1652
1653         save_warning = warn_on_object_refname_ambiguity;
1654         warn_on_object_refname_ambiguity = 0;
1655
1656         strbuf_init(&sb, 1000);
1657         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1658                 int len = sb.len;
1659                 if (len && sb.buf[len - 1] == '\n')
1660                         sb.buf[--len] = '\0';
1661                 if (!len)
1662                         break;
1663                 if (sb.buf[0] == '-') {
1664                         if (len == 2 && sb.buf[1] == '-') {
1665                                 seen_dashdash = 1;
1666                                 break;
1667                         }
1668                         die("options not supported in --stdin mode");
1669                 }
1670                 if (handle_revision_arg(sb.buf, revs, 0,
1671                                         REVARG_CANNOT_BE_FILENAME))
1672                         die("bad revision '%s'", sb.buf);
1673         }
1674         if (seen_dashdash)
1675                 read_pathspec_from_stdin(revs, &sb, prune);
1676
1677         strbuf_release(&sb);
1678         warn_on_object_refname_ambiguity = save_warning;
1679 }
1680
1681 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1682 {
1683         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1684 }
1685
1686 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1687 {
1688         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1689 }
1690
1691 static void add_message_grep(struct rev_info *revs, const char *pattern)
1692 {
1693         add_grep(revs, pattern, GREP_PATTERN_BODY);
1694 }
1695
1696 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1697                                int *unkc, const char **unkv)
1698 {
1699         const char *arg = argv[0];
1700         const char *optarg;
1701         int argcount;
1702
1703         /* pseudo revision arguments */
1704         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1705             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1706             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1707             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1708             !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
1709             !strcmp(arg, "--indexed-objects") ||
1710             starts_with(arg, "--exclude=") ||
1711             starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
1712             starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
1713         {
1714                 unkv[(*unkc)++] = arg;
1715                 return 1;
1716         }
1717
1718         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1719                 revs->max_count = atoi(optarg);
1720                 revs->no_walk = 0;
1721                 return argcount;
1722         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1723                 revs->skip_count = atoi(optarg);
1724                 return argcount;
1725         } else if ((*arg == '-') && isdigit(arg[1])) {
1726                 /* accept -<digit>, like traditional "head" */
1727                 if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
1728                     revs->max_count < 0)
1729                         die("'%s': not a non-negative integer", arg + 1);
1730                 revs->no_walk = 0;
1731         } else if (!strcmp(arg, "-n")) {
1732                 if (argc <= 1)
1733                         return error("-n requires an argument");
1734                 revs->max_count = atoi(argv[1]);
1735                 revs->no_walk = 0;
1736                 return 2;
1737         } else if (starts_with(arg, "-n")) {
1738                 revs->max_count = atoi(arg + 2);
1739                 revs->no_walk = 0;
1740         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1741                 revs->max_age = atoi(optarg);
1742                 return argcount;
1743         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1744                 revs->max_age = approxidate(optarg);
1745                 return argcount;
1746         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1747                 revs->max_age = approxidate(optarg);
1748                 return argcount;
1749         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1750                 revs->min_age = atoi(optarg);
1751                 return argcount;
1752         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1753                 revs->min_age = approxidate(optarg);
1754                 return argcount;
1755         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1756                 revs->min_age = approxidate(optarg);
1757                 return argcount;
1758         } else if (!strcmp(arg, "--first-parent")) {
1759                 revs->first_parent_only = 1;
1760         } else if (!strcmp(arg, "--ancestry-path")) {
1761                 revs->ancestry_path = 1;
1762                 revs->simplify_history = 0;
1763                 revs->limited = 1;
1764         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1765                 init_reflog_walk(&revs->reflog_info);
1766         } else if (!strcmp(arg, "--default")) {
1767                 if (argc <= 1)
1768                         return error("bad --default argument");
1769                 revs->def = argv[1];
1770                 return 2;
1771         } else if (!strcmp(arg, "--merge")) {
1772                 revs->show_merge = 1;
1773         } else if (!strcmp(arg, "--topo-order")) {
1774                 revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1775                 revs->topo_order = 1;
1776         } else if (!strcmp(arg, "--simplify-merges")) {
1777                 revs->simplify_merges = 1;
1778                 revs->topo_order = 1;
1779                 revs->rewrite_parents = 1;
1780                 revs->simplify_history = 0;
1781                 revs->limited = 1;
1782         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1783                 revs->simplify_merges = 1;
1784                 revs->topo_order = 1;
1785                 revs->rewrite_parents = 1;
1786                 revs->simplify_history = 0;
1787                 revs->simplify_by_decoration = 1;
1788                 revs->limited = 1;
1789                 revs->prune = 1;
1790                 load_ref_decorations(DECORATE_SHORT_REFS);
1791         } else if (!strcmp(arg, "--date-order")) {
1792                 revs->sort_order = REV_SORT_BY_COMMIT_DATE;
1793                 revs->topo_order = 1;
1794         } else if (!strcmp(arg, "--author-date-order")) {
1795                 revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
1796                 revs->topo_order = 1;
1797         } else if (starts_with(arg, "--early-output")) {
1798                 int count = 100;
1799                 switch (arg[14]) {
1800                 case '=':
1801                         count = atoi(arg+15);
1802                         /* Fallthrough */
1803                 case 0:
1804                         revs->topo_order = 1;
1805                        revs->early_output = count;
1806                 }
1807         } else if (!strcmp(arg, "--parents")) {
1808                 revs->rewrite_parents = 1;
1809                 revs->print_parents = 1;
1810         } else if (!strcmp(arg, "--dense")) {
1811                 revs->dense = 1;
1812         } else if (!strcmp(arg, "--sparse")) {
1813                 revs->dense = 0;
1814         } else if (!strcmp(arg, "--show-all")) {
1815                 revs->show_all = 1;
1816         } else if (!strcmp(arg, "--remove-empty")) {
1817                 revs->remove_empty_trees = 1;
1818         } else if (!strcmp(arg, "--merges")) {
1819                 revs->min_parents = 2;
1820         } else if (!strcmp(arg, "--no-merges")) {
1821                 revs->max_parents = 1;
1822         } else if (starts_with(arg, "--min-parents=")) {
1823                 revs->min_parents = atoi(arg+14);
1824         } else if (starts_with(arg, "--no-min-parents")) {
1825                 revs->min_parents = 0;
1826         } else if (starts_with(arg, "--max-parents=")) {
1827                 revs->max_parents = atoi(arg+14);
1828         } else if (starts_with(arg, "--no-max-parents")) {
1829                 revs->max_parents = -1;
1830         } else if (!strcmp(arg, "--boundary")) {
1831                 revs->boundary = 1;
1832         } else if (!strcmp(arg, "--left-right")) {
1833                 revs->left_right = 1;
1834         } else if (!strcmp(arg, "--left-only")) {
1835                 if (revs->right_only)
1836                         die("--left-only is incompatible with --right-only"
1837                             " or --cherry");
1838                 revs->left_only = 1;
1839         } else if (!strcmp(arg, "--right-only")) {
1840                 if (revs->left_only)
1841                         die("--right-only is incompatible with --left-only");
1842                 revs->right_only = 1;
1843         } else if (!strcmp(arg, "--cherry")) {
1844                 if (revs->left_only)
1845                         die("--cherry is incompatible with --left-only");
1846                 revs->cherry_mark = 1;
1847                 revs->right_only = 1;
1848                 revs->max_parents = 1;
1849                 revs->limited = 1;
1850         } else if (!strcmp(arg, "--count")) {
1851                 revs->count = 1;
1852         } else if (!strcmp(arg, "--cherry-mark")) {
1853                 if (revs->cherry_pick)
1854                         die("--cherry-mark is incompatible with --cherry-pick");
1855                 revs->cherry_mark = 1;
1856                 revs->limited = 1; /* needs limit_list() */
1857         } else if (!strcmp(arg, "--cherry-pick")) {
1858                 if (revs->cherry_mark)
1859                         die("--cherry-pick is incompatible with --cherry-mark");
1860                 revs->cherry_pick = 1;
1861                 revs->limited = 1;
1862         } else if (!strcmp(arg, "--objects")) {
1863                 revs->tag_objects = 1;
1864                 revs->tree_objects = 1;
1865                 revs->blob_objects = 1;
1866         } else if (!strcmp(arg, "--objects-edge")) {
1867                 revs->tag_objects = 1;
1868                 revs->tree_objects = 1;
1869                 revs->blob_objects = 1;
1870                 revs->edge_hint = 1;
1871         } else if (!strcmp(arg, "--objects-edge-aggressive")) {
1872                 revs->tag_objects = 1;
1873                 revs->tree_objects = 1;
1874                 revs->blob_objects = 1;
1875                 revs->edge_hint = 1;
1876                 revs->edge_hint_aggressive = 1;
1877         } else if (!strcmp(arg, "--verify-objects")) {
1878                 revs->tag_objects = 1;
1879                 revs->tree_objects = 1;
1880                 revs->blob_objects = 1;
1881                 revs->verify_objects = 1;
1882         } else if (!strcmp(arg, "--unpacked")) {
1883                 revs->unpacked = 1;
1884         } else if (starts_with(arg, "--unpacked=")) {
1885                 die("--unpacked=<packfile> no longer supported.");
1886         } else if (!strcmp(arg, "-r")) {
1887                 revs->diff = 1;
1888                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1889         } else if (!strcmp(arg, "-t")) {
1890                 revs->diff = 1;
1891                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1892                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1893         } else if (!strcmp(arg, "-m")) {
1894                 revs->ignore_merges = 0;
1895         } else if (!strcmp(arg, "-c")) {
1896                 revs->diff = 1;
1897                 revs->dense_combined_merges = 0;
1898                 revs->combine_merges = 1;
1899         } else if (!strcmp(arg, "--cc")) {
1900                 revs->diff = 1;
1901                 revs->dense_combined_merges = 1;
1902                 revs->combine_merges = 1;
1903         } else if (!strcmp(arg, "-v")) {
1904                 revs->verbose_header = 1;
1905         } else if (!strcmp(arg, "--pretty")) {
1906                 revs->verbose_header = 1;
1907                 revs->pretty_given = 1;
1908                 get_commit_format(NULL, revs);
1909         } else if (starts_with(arg, "--pretty=") || starts_with(arg, "--format=")) {
1910                 /*
1911                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1912                  * not allowed, since the argument is optional.
1913                  */
1914                 revs->verbose_header = 1;
1915                 revs->pretty_given = 1;
1916                 get_commit_format(arg+9, revs);
1917         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1918                 revs->show_notes = 1;
1919                 revs->show_notes_given = 1;
1920                 revs->notes_opt.use_default_notes = 1;
1921         } else if (!strcmp(arg, "--show-signature")) {
1922                 revs->show_signature = 1;
1923         } else if (!strcmp(arg, "--show-linear-break") ||
1924                    starts_with(arg, "--show-linear-break=")) {
1925                 if (starts_with(arg, "--show-linear-break="))
1926                         revs->break_bar = xstrdup(arg + 20);
1927                 else
1928                         revs->break_bar = "                    ..........";
1929                 revs->track_linear = 1;
1930                 revs->track_first_time = 1;
1931         } else if (starts_with(arg, "--show-notes=") ||
1932                    starts_with(arg, "--notes=")) {
1933                 struct strbuf buf = STRBUF_INIT;
1934                 revs->show_notes = 1;
1935                 revs->show_notes_given = 1;
1936                 if (starts_with(arg, "--show-notes")) {
1937                         if (revs->notes_opt.use_default_notes < 0)
1938                                 revs->notes_opt.use_default_notes = 1;
1939                         strbuf_addstr(&buf, arg+13);
1940                 }
1941                 else
1942                         strbuf_addstr(&buf, arg+8);
1943                 expand_notes_ref(&buf);
1944                 string_list_append(&revs->notes_opt.extra_notes_refs,
1945                                    strbuf_detach(&buf, NULL));
1946         } else if (!strcmp(arg, "--no-notes")) {
1947                 revs->show_notes = 0;
1948                 revs->show_notes_given = 1;
1949                 revs->notes_opt.use_default_notes = -1;
1950                 /* we have been strdup'ing ourselves, so trick
1951                  * string_list into free()ing strings */
1952                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1953                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1954                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1955         } else if (!strcmp(arg, "--standard-notes")) {
1956                 revs->show_notes_given = 1;
1957                 revs->notes_opt.use_default_notes = 1;
1958         } else if (!strcmp(arg, "--no-standard-notes")) {
1959                 revs->notes_opt.use_default_notes = 0;
1960         } else if (!strcmp(arg, "--oneline")) {
1961                 revs->verbose_header = 1;
1962                 get_commit_format("oneline", revs);
1963                 revs->pretty_given = 1;
1964                 revs->abbrev_commit = 1;
1965         } else if (!strcmp(arg, "--graph")) {
1966                 revs->topo_order = 1;
1967                 revs->rewrite_parents = 1;
1968                 revs->graph = graph_init(revs);
1969         } else if (!strcmp(arg, "--root")) {
1970                 revs->show_root_diff = 1;
1971         } else if (!strcmp(arg, "--no-commit-id")) {
1972                 revs->no_commit_id = 1;
1973         } else if (!strcmp(arg, "--always")) {
1974                 revs->always_show_header = 1;
1975         } else if (!strcmp(arg, "--no-abbrev")) {
1976                 revs->abbrev = 0;
1977         } else if (!strcmp(arg, "--abbrev")) {
1978                 revs->abbrev = DEFAULT_ABBREV;
1979         } else if (starts_with(arg, "--abbrev=")) {
1980                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1981                 if (revs->abbrev < MINIMUM_ABBREV)
1982                         revs->abbrev = MINIMUM_ABBREV;
1983                 else if (revs->abbrev > 40)
1984                         revs->abbrev = 40;
1985         } else if (!strcmp(arg, "--abbrev-commit")) {
1986                 revs->abbrev_commit = 1;
1987                 revs->abbrev_commit_given = 1;
1988         } else if (!strcmp(arg, "--no-abbrev-commit")) {
1989                 revs->abbrev_commit = 0;
1990         } else if (!strcmp(arg, "--full-diff")) {
1991                 revs->diff = 1;
1992                 revs->full_diff = 1;
1993         } else if (!strcmp(arg, "--full-history")) {
1994                 revs->simplify_history = 0;
1995         } else if (!strcmp(arg, "--relative-date")) {
1996                 revs->date_mode = DATE_RELATIVE;
1997                 revs->date_mode_explicit = 1;
1998         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1999                 revs->date_mode = parse_date_format(optarg);
2000                 revs->date_mode_explicit = 1;
2001                 return argcount;
2002         } else if (!strcmp(arg, "--log-size")) {
2003                 revs->show_log_size = 1;
2004         }
2005         /*
2006          * Grepping the commit log
2007          */
2008         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
2009                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
2010                 return argcount;
2011         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
2012                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
2013                 return argcount;
2014         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
2015                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
2016                 return argcount;
2017         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
2018                 add_message_grep(revs, optarg);
2019                 return argcount;
2020         } else if (!strcmp(arg, "--grep-debug")) {
2021                 revs->grep_filter.debug = 1;
2022         } else if (!strcmp(arg, "--basic-regexp")) {
2023                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_BRE, &revs->grep_filter);
2024         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
2025                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, &revs->grep_filter);
2026         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
2027                 revs->grep_filter.regflags |= REG_ICASE;
2028                 DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
2029         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
2030                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_FIXED, &revs->grep_filter);
2031         } else if (!strcmp(arg, "--perl-regexp")) {
2032                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_PCRE, &revs->grep_filter);
2033         } else if (!strcmp(arg, "--all-match")) {
2034                 revs->grep_filter.all_match = 1;
2035         } else if (!strcmp(arg, "--invert-grep")) {
2036                 revs->invert_grep = 1;
2037         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2038                 if (strcmp(optarg, "none"))
2039                         git_log_output_encoding = xstrdup(optarg);
2040                 else
2041                         git_log_output_encoding = "";
2042                 return argcount;
2043         } else if (!strcmp(arg, "--reverse")) {
2044                 revs->reverse ^= 1;
2045         } else if (!strcmp(arg, "--children")) {
2046                 revs->children.name = "children";
2047                 revs->limited = 1;
2048         } else if (!strcmp(arg, "--ignore-missing")) {
2049                 revs->ignore_missing = 1;
2050         } else {
2051                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
2052                 if (!opts)
2053                         unkv[(*unkc)++] = arg;
2054                 return opts;
2055         }
2056         if (revs->graph && revs->track_linear)
2057                 die("--show-linear-break and --graph are incompatible");
2058
2059         return 1;
2060 }
2061
2062 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2063                         const struct option *options,
2064                         const char * const usagestr[])
2065 {
2066         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2067                                     &ctx->cpidx, ctx->out);
2068         if (n <= 0) {
2069                 error("unknown option `%s'", ctx->argv[0]);
2070                 usage_with_options(usagestr, options);
2071         }
2072         ctx->argv += n;
2073         ctx->argc -= n;
2074 }
2075
2076 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2077 {
2078         return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
2079 }
2080
2081 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2082 {
2083         return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
2084 }
2085
2086 static int handle_revision_pseudo_opt(const char *submodule,
2087                                 struct rev_info *revs,
2088                                 int argc, const char **argv, int *flags)
2089 {
2090         const char *arg = argv[0];
2091         const char *optarg;
2092         int argcount;
2093
2094         /*
2095          * NOTE!
2096          *
2097          * Commands like "git shortlog" will not accept the options below
2098          * unless parse_revision_opt queues them (as opposed to erroring
2099          * out).
2100          *
2101          * When implementing your new pseudo-option, remember to
2102          * register it in the list at the top of handle_revision_opt.
2103          */
2104         if (!strcmp(arg, "--all")) {
2105                 handle_refs(submodule, revs, *flags, for_each_ref_submodule);
2106                 handle_refs(submodule, revs, *flags, head_ref_submodule);
2107                 clear_ref_exclusion(&revs->ref_excludes);
2108         } else if (!strcmp(arg, "--branches")) {
2109                 handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
2110                 clear_ref_exclusion(&revs->ref_excludes);
2111         } else if (!strcmp(arg, "--bisect")) {
2112                 handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
2113                 handle_refs(submodule, revs, *flags ^ (UNINTERESTING | BOTTOM), for_each_good_bisect_ref);
2114                 revs->bisect = 1;
2115         } else if (!strcmp(arg, "--tags")) {
2116                 handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
2117                 clear_ref_exclusion(&revs->ref_excludes);
2118         } else if (!strcmp(arg, "--remotes")) {
2119                 handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
2120                 clear_ref_exclusion(&revs->ref_excludes);
2121         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2122                 struct all_refs_cb cb;
2123                 init_all_refs_cb(&cb, revs, *flags);
2124                 for_each_glob_ref(handle_one_ref, optarg, &cb);
2125                 clear_ref_exclusion(&revs->ref_excludes);
2126                 return argcount;
2127         } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2128                 add_ref_exclusion(&revs->ref_excludes, optarg);
2129                 return argcount;
2130         } else if (starts_with(arg, "--branches=")) {
2131                 struct all_refs_cb cb;
2132                 init_all_refs_cb(&cb, revs, *flags);
2133                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
2134                 clear_ref_exclusion(&revs->ref_excludes);
2135         } else if (starts_with(arg, "--tags=")) {
2136                 struct all_refs_cb cb;
2137                 init_all_refs_cb(&cb, revs, *flags);
2138                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
2139                 clear_ref_exclusion(&revs->ref_excludes);
2140         } else if (starts_with(arg, "--remotes=")) {
2141                 struct all_refs_cb cb;
2142                 init_all_refs_cb(&cb, revs, *flags);
2143                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
2144                 clear_ref_exclusion(&revs->ref_excludes);
2145         } else if (!strcmp(arg, "--reflog")) {
2146                 add_reflogs_to_pending(revs, *flags);
2147         } else if (!strcmp(arg, "--indexed-objects")) {
2148                 add_index_objects_to_pending(revs, *flags);
2149         } else if (!strcmp(arg, "--not")) {
2150                 *flags ^= UNINTERESTING | BOTTOM;
2151         } else if (!strcmp(arg, "--no-walk")) {
2152                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2153         } else if (starts_with(arg, "--no-walk=")) {
2154                 /*
2155                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2156                  * not allowed, since the argument is optional.
2157                  */
2158                 if (!strcmp(arg + 10, "sorted"))
2159                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2160                 else if (!strcmp(arg + 10, "unsorted"))
2161                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2162                 else
2163                         return error("invalid argument to --no-walk");
2164         } else if (!strcmp(arg, "--do-walk")) {
2165                 revs->no_walk = 0;
2166         } else {
2167                 return 0;
2168         }
2169
2170         return 1;
2171 }
2172
2173 /*
2174  * Parse revision information, filling in the "rev_info" structure,
2175  * and removing the used arguments from the argument list.
2176  *
2177  * Returns the number of arguments left that weren't recognized
2178  * (which are also moved to the head of the argument list)
2179  */
2180 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2181 {
2182         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
2183         struct cmdline_pathspec prune_data;
2184         const char *submodule = NULL;
2185
2186         memset(&prune_data, 0, sizeof(prune_data));
2187         if (opt)
2188                 submodule = opt->submodule;
2189
2190         /* First, search for "--" */
2191         if (opt && opt->assume_dashdash) {
2192                 seen_dashdash = 1;
2193         } else {
2194                 seen_dashdash = 0;
2195                 for (i = 1; i < argc; i++) {
2196                         const char *arg = argv[i];
2197                         if (strcmp(arg, "--"))
2198                                 continue;
2199                         argv[i] = NULL;
2200                         argc = i;
2201                         if (argv[i + 1])
2202                                 append_prune_data(&prune_data, argv + i + 1);
2203                         seen_dashdash = 1;
2204                         break;
2205                 }
2206         }
2207
2208         /* Second, deal with arguments and options */
2209         flags = 0;
2210         revarg_opt = opt ? opt->revarg_opt : 0;
2211         if (seen_dashdash)
2212                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2213         read_from_stdin = 0;
2214         for (left = i = 1; i < argc; i++) {
2215                 const char *arg = argv[i];
2216                 if (*arg == '-') {
2217                         int opts;
2218
2219                         opts = handle_revision_pseudo_opt(submodule,
2220                                                 revs, argc - i, argv + i,
2221                                                 &flags);
2222                         if (opts > 0) {
2223                                 i += opts - 1;
2224                                 continue;
2225                         }
2226
2227                         if (!strcmp(arg, "--stdin")) {
2228                                 if (revs->disable_stdin) {
2229                                         argv[left++] = arg;
2230                                         continue;
2231                                 }
2232                                 if (read_from_stdin++)
2233                                         die("--stdin given twice?");
2234                                 read_revisions_from_stdin(revs, &prune_data);
2235                                 continue;
2236                         }
2237
2238                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
2239                         if (opts > 0) {
2240                                 i += opts - 1;
2241                                 continue;
2242                         }
2243                         if (opts < 0)
2244                                 exit(128);
2245                         continue;
2246                 }
2247
2248
2249                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2250                         int j;
2251                         if (seen_dashdash || *arg == '^')
2252                                 die("bad revision '%s'", arg);
2253
2254                         /* If we didn't have a "--":
2255                          * (1) all filenames must exist;
2256                          * (2) all rev-args must not be interpretable
2257                          *     as a valid filename.
2258                          * but the latter we have checked in the main loop.
2259                          */
2260                         for (j = i; j < argc; j++)
2261                                 verify_filename(revs->prefix, argv[j], j == i);
2262
2263                         append_prune_data(&prune_data, argv + i);
2264                         break;
2265                 }
2266                 else
2267                         got_rev_arg = 1;
2268         }
2269
2270         if (prune_data.nr) {
2271                 /*
2272                  * If we need to introduce the magic "a lone ':' means no
2273                  * pathspec whatsoever", here is the place to do so.
2274                  *
2275                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2276                  *      prune_data.nr = 0;
2277                  *      prune_data.alloc = 0;
2278                  *      free(prune_data.path);
2279                  *      prune_data.path = NULL;
2280                  * } else {
2281                  *      terminate prune_data.alloc with NULL and
2282                  *      call init_pathspec() to set revs->prune_data here.
2283                  * }
2284                  */
2285                 ALLOC_GROW(prune_data.path, prune_data.nr + 1, prune_data.alloc);
2286                 prune_data.path[prune_data.nr++] = NULL;
2287                 parse_pathspec(&revs->prune_data, 0, 0,
2288                                revs->prefix, prune_data.path);
2289         }
2290
2291         if (revs->def == NULL)
2292                 revs->def = opt ? opt->def : NULL;
2293         if (opt && opt->tweak)
2294                 opt->tweak(revs, opt);
2295         if (revs->show_merge)
2296                 prepare_show_merge(revs);
2297         if (revs->def && !revs->pending.nr && !got_rev_arg) {
2298                 unsigned char sha1[20];
2299                 struct object *object;
2300                 struct object_context oc;
2301                 if (get_sha1_with_context(revs->def, 0, sha1, &oc))
2302                         die("bad default revision '%s'", revs->def);
2303                 object = get_reference(revs, revs->def, sha1, 0);
2304                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2305         }
2306
2307         /* Did the user ask for any diff output? Run the diff! */
2308         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2309                 revs->diff = 1;
2310
2311         /* Pickaxe, diff-filter and rename following need diffs */
2312         if (revs->diffopt.pickaxe ||
2313             revs->diffopt.filter ||
2314             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2315                 revs->diff = 1;
2316
2317         if (revs->topo_order)
2318                 revs->limited = 1;
2319
2320         if (revs->prune_data.nr) {
2321                 copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2322                 /* Can't prune commits with rename following: the paths change.. */
2323                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2324                         revs->prune = 1;
2325                 if (!revs->full_diff)
2326                         copy_pathspec(&revs->diffopt.pathspec,
2327                                       &revs->prune_data);
2328         }
2329         if (revs->combine_merges)
2330                 revs->ignore_merges = 0;
2331         revs->diffopt.abbrev = revs->abbrev;
2332
2333         if (revs->line_level_traverse) {
2334                 revs->limited = 1;
2335                 revs->topo_order = 1;
2336         }
2337
2338         diff_setup_done(&revs->diffopt);
2339
2340         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2341                                  &revs->grep_filter);
2342         compile_grep_patterns(&revs->grep_filter);
2343
2344         if (revs->reverse && revs->reflog_info)
2345                 die("cannot combine --reverse with --walk-reflogs");
2346         if (revs->rewrite_parents && revs->children.name)
2347                 die("cannot combine --parents and --children");
2348
2349         /*
2350          * Limitations on the graph functionality
2351          */
2352         if (revs->reverse && revs->graph)
2353                 die("cannot combine --reverse with --graph");
2354
2355         if (revs->reflog_info && revs->graph)
2356                 die("cannot combine --walk-reflogs with --graph");
2357         if (revs->no_walk && revs->graph)
2358                 die("cannot combine --no-walk with --graph");
2359         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2360                 die("cannot use --grep-reflog without --walk-reflogs");
2361
2362         if (revs->first_parent_only && revs->bisect)
2363                 die(_("--first-parent is incompatible with --bisect"));
2364
2365         return left;
2366 }
2367
2368 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2369 {
2370         struct commit_list *l = xcalloc(1, sizeof(*l));
2371
2372         l->item = child;
2373         l->next = add_decoration(&revs->children, &parent->object, l);
2374 }
2375
2376 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2377 {
2378         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2379         struct commit_list **pp, *p;
2380         int surviving_parents;
2381
2382         /* Examine existing parents while marking ones we have seen... */
2383         pp = &commit->parents;
2384         surviving_parents = 0;
2385         while ((p = *pp) != NULL) {
2386                 struct commit *parent = p->item;
2387                 if (parent->object.flags & TMP_MARK) {
2388                         *pp = p->next;
2389                         if (ts)
2390                                 compact_treesame(revs, commit, surviving_parents);
2391                         continue;
2392                 }
2393                 parent->object.flags |= TMP_MARK;
2394                 surviving_parents++;
2395                 pp = &p->next;
2396         }
2397         /* clear the temporary mark */
2398         for (p = commit->parents; p; p = p->next) {
2399                 p->item->object.flags &= ~TMP_MARK;
2400         }
2401         /* no update_treesame() - removing duplicates can't affect TREESAME */
2402         return surviving_parents;
2403 }
2404
2405 struct merge_simplify_state {
2406         struct commit *simplified;
2407 };
2408
2409 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2410 {
2411         struct merge_simplify_state *st;
2412
2413         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2414         if (!st) {
2415                 st = xcalloc(1, sizeof(*st));
2416                 add_decoration(&revs->merge_simplification, &commit->object, st);
2417         }
2418         return st;
2419 }
2420
2421 static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2422 {
2423         struct commit_list *h = reduce_heads(commit->parents);
2424         int i = 0, marked = 0;
2425         struct commit_list *po, *pn;
2426
2427         /* Want these for sanity-checking only */
2428         int orig_cnt = commit_list_count(commit->parents);
2429         int cnt = commit_list_count(h);
2430
2431         /*
2432          * Not ready to remove items yet, just mark them for now, based
2433          * on the output of reduce_heads(). reduce_heads outputs the reduced
2434          * set in its original order, so this isn't too hard.
2435          */
2436         po = commit->parents;
2437         pn = h;
2438         while (po) {
2439                 if (pn && po->item == pn->item) {
2440                         pn = pn->next;
2441                         i++;
2442                 } else {
2443                         po->item->object.flags |= TMP_MARK;
2444                         marked++;
2445                 }
2446                 po=po->next;
2447         }
2448
2449         if (i != cnt || cnt+marked != orig_cnt)
2450                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2451
2452         free_commit_list(h);
2453
2454         return marked;
2455 }
2456
2457 static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2458 {
2459         struct commit_list *p;
2460         int marked = 0;
2461
2462         for (p = commit->parents; p; p = p->next) {
2463                 struct commit *parent = p->item;
2464                 if (!parent->parents && (parent->object.flags & TREESAME)) {
2465                         parent->object.flags |= TMP_MARK;
2466                         marked++;
2467                 }
2468         }
2469
2470         return marked;
2471 }
2472
2473 /*
2474  * Awkward naming - this means one parent we are TREESAME to.
2475  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2476  * empty tree). Better name suggestions?
2477  */
2478 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2479 {
2480         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2481         struct commit *unmarked = NULL, *marked = NULL;
2482         struct commit_list *p;
2483         unsigned n;
2484
2485         for (p = commit->parents, n = 0; p; p = p->next, n++) {
2486                 if (ts->treesame[n]) {
2487                         if (p->item->object.flags & TMP_MARK) {
2488                                 if (!marked)
2489                                         marked = p->item;
2490                         } else {
2491                                 if (!unmarked) {
2492                                         unmarked = p->item;
2493                                         break;
2494                                 }
2495                         }
2496                 }
2497         }
2498
2499         /*
2500          * If we are TREESAME to a marked-for-deletion parent, but not to any
2501          * unmarked parents, unmark the first TREESAME parent. This is the
2502          * parent that the default simplify_history==1 scan would have followed,
2503          * and it doesn't make sense to omit that path when asking for a
2504          * simplified full history. Retaining it improves the chances of
2505          * understanding odd missed merges that took an old version of a file.
2506          *
2507          * Example:
2508          *
2509          *   I--------*X       A modified the file, but mainline merge X used
2510          *    \       /        "-s ours", so took the version from I. X is
2511          *     `-*A--'         TREESAME to I and !TREESAME to A.
2512          *
2513          * Default log from X would produce "I". Without this check,
2514          * --full-history --simplify-merges would produce "I-A-X", showing
2515          * the merge commit X and that it changed A, but not making clear that
2516          * it had just taken the I version. With this check, the topology above
2517          * is retained.
2518          *
2519          * Note that it is possible that the simplification chooses a different
2520          * TREESAME parent from the default, in which case this test doesn't
2521          * activate, and we _do_ drop the default parent. Example:
2522          *
2523          *   I------X         A modified the file, but it was reverted in B,
2524          *    \    /          meaning mainline merge X is TREESAME to both
2525          *    *A-*B           parents.
2526          *
2527          * Default log would produce "I" by following the first parent;
2528          * --full-history --simplify-merges will produce "I-A-B". But this is a
2529          * reasonable result - it presents a logical full history leading from
2530          * I to X, and X is not an important merge.
2531          */
2532         if (!unmarked && marked) {
2533                 marked->object.flags &= ~TMP_MARK;
2534                 return 1;
2535         }
2536
2537         return 0;
2538 }
2539
2540 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2541 {
2542         struct commit_list **pp, *p;
2543         int nth_parent, removed = 0;
2544
2545         pp = &commit->parents;
2546         nth_parent = 0;
2547         while ((p = *pp) != NULL) {
2548                 struct commit *parent = p->item;
2549                 if (parent->object.flags & TMP_MARK) {
2550                         parent->object.flags &= ~TMP_MARK;
2551                         *pp = p->next;
2552                         free(p);
2553                         removed++;
2554                         compact_treesame(revs, commit, nth_parent);
2555                         continue;
2556                 }
2557                 pp = &p->next;
2558                 nth_parent++;
2559         }
2560
2561         /* Removing parents can only increase TREESAMEness */
2562         if (removed && !(commit->object.flags & TREESAME))
2563                 update_treesame(revs, commit);
2564
2565         return nth_parent;
2566 }
2567
2568 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2569 {
2570         struct commit_list *p;
2571         struct commit *parent;
2572         struct merge_simplify_state *st, *pst;
2573         int cnt;
2574
2575         st = locate_simplify_state(revs, commit);
2576
2577         /*
2578          * Have we handled this one?
2579          */
2580         if (st->simplified)
2581                 return tail;
2582
2583         /*
2584          * An UNINTERESTING commit simplifies to itself, so does a
2585          * root commit.  We do not rewrite parents of such commit
2586          * anyway.
2587          */
2588         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2589                 st->simplified = commit;
2590                 return tail;
2591         }
2592
2593         /*
2594          * Do we know what commit all of our parents that matter
2595          * should be rewritten to?  Otherwise we are not ready to
2596          * rewrite this one yet.
2597          */
2598         for (cnt = 0, p = commit->parents; p; p = p->next) {
2599                 pst = locate_simplify_state(revs, p->item);
2600                 if (!pst->simplified) {
2601                         tail = &commit_list_insert(p->item, tail)->next;
2602                         cnt++;
2603                 }
2604                 if (revs->first_parent_only)
2605                         break;
2606         }
2607         if (cnt) {
2608                 tail = &commit_list_insert(commit, tail)->next;
2609                 return tail;
2610         }
2611
2612         /*
2613          * Rewrite our list of parents. Note that this cannot
2614          * affect our TREESAME flags in any way - a commit is
2615          * always TREESAME to its simplification.
2616          */
2617         for (p = commit->parents; p; p = p->next) {
2618                 pst = locate_simplify_state(revs, p->item);
2619                 p->item = pst->simplified;
2620                 if (revs->first_parent_only)
2621                         break;
2622         }
2623
2624         if (revs->first_parent_only)
2625                 cnt = 1;
2626         else
2627                 cnt = remove_duplicate_parents(revs, commit);
2628
2629         /*
2630          * It is possible that we are a merge and one side branch
2631          * does not have any commit that touches the given paths;
2632          * in such a case, the immediate parent from that branch
2633          * will be rewritten to be the merge base.
2634          *
2635          *      o----X          X: the commit we are looking at;
2636          *     /    /           o: a commit that touches the paths;
2637          * ---o----'
2638          *
2639          * Further, a merge of an independent branch that doesn't
2640          * touch the path will reduce to a treesame root parent:
2641          *
2642          *  ----o----X          X: the commit we are looking at;
2643          *          /           o: a commit that touches the paths;
2644          *         r            r: a root commit not touching the paths
2645          *
2646          * Detect and simplify both cases.
2647          */
2648         if (1 < cnt) {
2649                 int marked = mark_redundant_parents(revs, commit);
2650                 marked += mark_treesame_root_parents(revs, commit);
2651                 if (marked)
2652                         marked -= leave_one_treesame_to_parent(revs, commit);
2653                 if (marked)
2654                         cnt = remove_marked_parents(revs, commit);
2655         }
2656
2657         /*
2658          * A commit simplifies to itself if it is a root, if it is
2659          * UNINTERESTING, if it touches the given paths, or if it is a
2660          * merge and its parents don't simplify to one relevant commit
2661          * (the first two cases are already handled at the beginning of
2662          * this function).
2663          *
2664          * Otherwise, it simplifies to what its sole relevant parent
2665          * simplifies to.
2666          */
2667         if (!cnt ||
2668             (commit->object.flags & UNINTERESTING) ||
2669             !(commit->object.flags & TREESAME) ||
2670             (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2671                 st->simplified = commit;
2672         else {
2673                 pst = locate_simplify_state(revs, parent);
2674                 st->simplified = pst->simplified;
2675         }
2676         return tail;
2677 }
2678
2679 static void simplify_merges(struct rev_info *revs)
2680 {
2681         struct commit_list *list, *next;
2682         struct commit_list *yet_to_do, **tail;
2683         struct commit *commit;
2684
2685         if (!revs->prune)
2686                 return;
2687
2688         /* feed the list reversed */
2689         yet_to_do = NULL;
2690         for (list = revs->commits; list; list = next) {
2691                 commit = list->item;
2692                 next = list->next;
2693                 /*
2694                  * Do not free(list) here yet; the original list
2695                  * is used later in this function.
2696                  */
2697                 commit_list_insert(commit, &yet_to_do);
2698         }
2699         while (yet_to_do) {
2700                 list = yet_to_do;
2701                 yet_to_do = NULL;
2702                 tail = &yet_to_do;
2703                 while (list) {
2704                         commit = list->item;
2705                         next = list->next;
2706                         free(list);
2707                         list = next;
2708                         tail = simplify_one(revs, commit, tail);
2709                 }
2710         }
2711
2712         /* clean up the result, removing the simplified ones */
2713         list = revs->commits;
2714         revs->commits = NULL;
2715         tail = &revs->commits;
2716         while (list) {
2717                 struct merge_simplify_state *st;
2718
2719                 commit = list->item;
2720                 next = list->next;
2721                 free(list);
2722                 list = next;
2723                 st = locate_simplify_state(revs, commit);
2724                 if (st->simplified == commit)
2725                         tail = &commit_list_insert(commit, tail)->next;
2726         }
2727 }
2728
2729 static void set_children(struct rev_info *revs)
2730 {
2731         struct commit_list *l;
2732         for (l = revs->commits; l; l = l->next) {
2733                 struct commit *commit = l->item;
2734                 struct commit_list *p;
2735
2736                 for (p = commit->parents; p; p = p->next)
2737                         add_child(revs, p->item, commit);
2738         }
2739 }
2740
2741 void reset_revision_walk(void)
2742 {
2743         clear_object_flags(SEEN | ADDED | SHOWN);
2744 }
2745
2746 int prepare_revision_walk(struct rev_info *revs)
2747 {
2748         int i;
2749         struct object_array old_pending;
2750         struct commit_list **next = &revs->commits;
2751
2752         memcpy(&old_pending, &revs->pending, sizeof(old_pending));
2753         revs->pending.nr = 0;
2754         revs->pending.alloc = 0;
2755         revs->pending.objects = NULL;
2756         for (i = 0; i < old_pending.nr; i++) {
2757                 struct object_array_entry *e = old_pending.objects + i;
2758                 struct commit *commit = handle_commit(revs, e);
2759                 if (commit) {
2760                         if (!(commit->object.flags & SEEN)) {
2761                                 commit->object.flags |= SEEN;
2762                                 next = commit_list_append(commit, next);
2763                         }
2764                 }
2765         }
2766         if (!revs->leak_pending)
2767                 object_array_clear(&old_pending);
2768
2769         /* Signal whether we need per-parent treesame decoration */
2770         if (revs->simplify_merges ||
2771             (revs->limited && limiting_can_increase_treesame(revs)))
2772                 revs->treesame.name = "treesame";
2773
2774         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2775                 commit_list_sort_by_date(&revs->commits);
2776         if (revs->no_walk)
2777                 return 0;
2778         if (revs->limited)
2779                 if (limit_list(revs) < 0)
2780                         return -1;
2781         if (revs->topo_order)
2782                 sort_in_topological_order(&revs->commits, revs->sort_order);
2783         if (revs->line_level_traverse)
2784                 line_log_filter(revs);
2785         if (revs->simplify_merges)
2786                 simplify_merges(revs);
2787         if (revs->children.name)
2788                 set_children(revs);
2789         return 0;
2790 }
2791
2792 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2793 {
2794         struct commit_list *cache = NULL;
2795
2796         for (;;) {
2797                 struct commit *p = *pp;
2798                 if (!revs->limited)
2799                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2800                                 return rewrite_one_error;
2801                 if (p->object.flags & UNINTERESTING)
2802                         return rewrite_one_ok;
2803                 if (!(p->object.flags & TREESAME))
2804                         return rewrite_one_ok;
2805                 if (!p->parents)
2806                         return rewrite_one_noparents;
2807                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2808                         return rewrite_one_ok;
2809                 *pp = p;
2810         }
2811 }
2812
2813 int rewrite_parents(struct rev_info *revs, struct commit *commit,
2814         rewrite_parent_fn_t rewrite_parent)
2815 {
2816         struct commit_list **pp = &commit->parents;
2817         while (*pp) {
2818                 struct commit_list *parent = *pp;
2819                 switch (rewrite_parent(revs, &parent->item)) {
2820                 case rewrite_one_ok:
2821                         break;
2822                 case rewrite_one_noparents:
2823                         *pp = parent->next;
2824                         continue;
2825                 case rewrite_one_error:
2826                         return -1;
2827                 }
2828                 pp = &parent->next;
2829         }
2830         remove_duplicate_parents(revs, commit);
2831         return 0;
2832 }
2833
2834 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2835 {
2836         char *person, *endp;
2837         size_t len, namelen, maillen;
2838         const char *name;
2839         const char *mail;
2840         struct ident_split ident;
2841
2842         person = strstr(buf->buf, what);
2843         if (!person)
2844                 return 0;
2845
2846         person += strlen(what);
2847         endp = strchr(person, '\n');
2848         if (!endp)
2849                 return 0;
2850
2851         len = endp - person;
2852
2853         if (split_ident_line(&ident, person, len))
2854                 return 0;
2855
2856         mail = ident.mail_begin;
2857         maillen = ident.mail_end - ident.mail_begin;
2858         name = ident.name_begin;
2859         namelen = ident.name_end - ident.name_begin;
2860
2861         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2862                 struct strbuf namemail = STRBUF_INIT;
2863
2864                 strbuf_addf(&namemail, "%.*s <%.*s>",
2865                             (int)namelen, name, (int)maillen, mail);
2866
2867                 strbuf_splice(buf, ident.name_begin - buf->buf,
2868                               ident.mail_end - ident.name_begin + 1,
2869                               namemail.buf, namemail.len);
2870
2871                 strbuf_release(&namemail);
2872
2873                 return 1;
2874         }
2875
2876         return 0;
2877 }
2878
2879 static int commit_match(struct commit *commit, struct rev_info *opt)
2880 {
2881         int retval;
2882         const char *encoding;
2883         const char *message;
2884         struct strbuf buf = STRBUF_INIT;
2885
2886         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2887                 return 1;
2888
2889         /* Prepend "fake" headers as needed */
2890         if (opt->grep_filter.use_reflog_filter) {
2891                 strbuf_addstr(&buf, "reflog ");
2892                 get_reflog_message(&buf, opt->reflog_info);
2893                 strbuf_addch(&buf, '\n');
2894         }
2895
2896         /*
2897          * We grep in the user's output encoding, under the assumption that it
2898          * is the encoding they are most likely to write their grep pattern
2899          * for. In addition, it means we will match the "notes" encoding below,
2900          * so we will not end up with a buffer that has two different encodings
2901          * in it.
2902          */
2903         encoding = get_log_output_encoding();
2904         message = logmsg_reencode(commit, NULL, encoding);
2905
2906         /* Copy the commit to temporary if we are using "fake" headers */
2907         if (buf.len)
2908                 strbuf_addstr(&buf, message);
2909
2910         if (opt->grep_filter.header_list && opt->mailmap) {
2911                 if (!buf.len)
2912                         strbuf_addstr(&buf, message);
2913
2914                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2915                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2916         }
2917
2918         /* Append "fake" message parts as needed */
2919         if (opt->show_notes) {
2920                 if (!buf.len)
2921                         strbuf_addstr(&buf, message);
2922                 format_display_notes(commit->object.sha1, &buf, encoding, 1);
2923         }
2924
2925         /*
2926          * Find either in the original commit message, or in the temporary.
2927          * Note that we cast away the constness of "message" here. It is
2928          * const because it may come from the cached commit buffer. That's OK,
2929          * because we know that it is modifiable heap memory, and that while
2930          * grep_buffer may modify it for speed, it will restore any
2931          * changes before returning.
2932          */
2933         if (buf.len)
2934                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2935         else
2936                 retval = grep_buffer(&opt->grep_filter,
2937                                      (char *)message, strlen(message));
2938         strbuf_release(&buf);
2939         unuse_commit_buffer(commit, message);
2940         return opt->invert_grep ? !retval : retval;
2941 }
2942
2943 static inline int want_ancestry(const struct rev_info *revs)
2944 {
2945         return (revs->rewrite_parents || revs->children.name);
2946 }
2947
2948 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2949 {
2950         if (commit->object.flags & SHOWN)
2951                 return commit_ignore;
2952         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2953                 return commit_ignore;
2954         if (revs->show_all)
2955                 return commit_show;
2956         if (commit->object.flags & UNINTERESTING)
2957                 return commit_ignore;
2958         if (revs->min_age != -1 && (commit->date > revs->min_age))
2959                 return commit_ignore;
2960         if (revs->min_parents || (revs->max_parents >= 0)) {
2961                 int n = commit_list_count(commit->parents);
2962                 if ((n < revs->min_parents) ||
2963                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2964                         return commit_ignore;
2965         }
2966         if (!commit_match(commit, revs))
2967                 return commit_ignore;
2968         if (revs->prune && revs->dense) {
2969                 /* Commit without changes? */
2970                 if (commit->object.flags & TREESAME) {
2971                         int n;
2972                         struct commit_list *p;
2973                         /* drop merges unless we want parenthood */
2974                         if (!want_ancestry(revs))
2975                                 return commit_ignore;
2976                         /*
2977                          * If we want ancestry, then need to keep any merges
2978                          * between relevant commits to tie together topology.
2979                          * For consistency with TREESAME and simplification
2980                          * use "relevant" here rather than just INTERESTING,
2981                          * to treat bottom commit(s) as part of the topology.
2982                          */
2983                         for (n = 0, p = commit->parents; p; p = p->next)
2984                                 if (relevant_commit(p->item))
2985                                         if (++n >= 2)
2986                                                 return commit_show;
2987                         return commit_ignore;
2988                 }
2989         }
2990         return commit_show;
2991 }
2992
2993 define_commit_slab(saved_parents, struct commit_list *);
2994
2995 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
2996
2997 /*
2998  * You may only call save_parents() once per commit (this is checked
2999  * for non-root commits).
3000  */
3001 static void save_parents(struct rev_info *revs, struct commit *commit)
3002 {
3003         struct commit_list **pp;
3004
3005         if (!revs->saved_parents_slab) {
3006                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3007                 init_saved_parents(revs->saved_parents_slab);
3008         }
3009
3010         pp = saved_parents_at(revs->saved_parents_slab, commit);
3011
3012         /*
3013          * When walking with reflogs, we may visit the same commit
3014          * several times: once for each appearance in the reflog.
3015          *
3016          * In this case, save_parents() will be called multiple times.
3017          * We want to keep only the first set of parents.  We need to
3018          * store a sentinel value for an empty (i.e., NULL) parent
3019          * list to distinguish it from a not-yet-saved list, however.
3020          */
3021         if (*pp)
3022                 return;
3023         if (commit->parents)
3024                 *pp = copy_commit_list(commit->parents);
3025         else
3026                 *pp = EMPTY_PARENT_LIST;
3027 }
3028
3029 static void free_saved_parents(struct rev_info *revs)
3030 {
3031         if (revs->saved_parents_slab)
3032                 clear_saved_parents(revs->saved_parents_slab);
3033 }
3034
3035 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3036 {
3037         struct commit_list *parents;
3038
3039         if (!revs->saved_parents_slab)
3040                 return commit->parents;
3041
3042         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3043         if (parents == EMPTY_PARENT_LIST)
3044                 return NULL;
3045         return parents;
3046 }
3047
3048 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3049 {
3050         enum commit_action action = get_commit_action(revs, commit);
3051
3052         if (action == commit_show &&
3053             !revs->show_all &&
3054             revs->prune && revs->dense && want_ancestry(revs)) {
3055                 /*
3056                  * --full-diff on simplified parents is no good: it
3057                  * will show spurious changes from the commits that
3058                  * were elided.  So we save the parents on the side
3059                  * when --full-diff is in effect.
3060                  */
3061                 if (revs->full_diff)
3062                         save_parents(revs, commit);
3063                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
3064                         return commit_error;
3065         }
3066         return action;
3067 }
3068
3069 static void track_linear(struct rev_info *revs, struct commit *commit)
3070 {
3071         if (revs->track_first_time) {
3072                 revs->linear = 1;
3073                 revs->track_first_time = 0;
3074         } else {
3075                 struct commit_list *p;
3076                 for (p = revs->previous_parents; p; p = p->next)
3077                         if (p->item == NULL || /* first commit */
3078                             !hashcmp(p->item->object.sha1, commit->object.sha1))
3079                                 break;
3080                 revs->linear = p != NULL;
3081         }
3082         if (revs->reverse) {
3083                 if (revs->linear)
3084                         commit->object.flags |= TRACK_LINEAR;
3085         }
3086         free_commit_list(revs->previous_parents);
3087         revs->previous_parents = copy_commit_list(commit->parents);
3088 }
3089
3090 static struct commit *get_revision_1(struct rev_info *revs)
3091 {
3092         if (!revs->commits)
3093                 return NULL;
3094
3095         do {
3096                 struct commit_list *entry = revs->commits;
3097                 struct commit *commit = entry->item;
3098
3099                 revs->commits = entry->next;
3100                 free(entry);
3101
3102                 if (revs->reflog_info) {
3103                         save_parents(revs, commit);
3104                         fake_reflog_parent(revs->reflog_info, commit);
3105                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3106                 }
3107
3108                 /*
3109                  * If we haven't done the list limiting, we need to look at
3110                  * the parents here. We also need to do the date-based limiting
3111                  * that we'd otherwise have done in limit_list().
3112                  */
3113                 if (!revs->limited) {
3114                         if (revs->max_age != -1 &&
3115                             (commit->date < revs->max_age))
3116                                 continue;
3117                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
3118                                 if (!revs->ignore_missing_links)
3119                                         die("Failed to traverse parents of commit %s",
3120                                                 sha1_to_hex(commit->object.sha1));
3121                         }
3122                 }
3123
3124                 switch (simplify_commit(revs, commit)) {
3125                 case commit_ignore:
3126                         continue;
3127                 case commit_error:
3128                         die("Failed to simplify parents of commit %s",
3129                             sha1_to_hex(commit->object.sha1));
3130                 default:
3131                         if (revs->track_linear)
3132                                 track_linear(revs, commit);
3133                         return commit;
3134                 }
3135         } while (revs->commits);
3136         return NULL;
3137 }
3138
3139 /*
3140  * Return true for entries that have not yet been shown.  (This is an
3141  * object_array_each_func_t.)
3142  */
3143 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3144 {
3145         return !(entry->item->flags & SHOWN);
3146 }
3147
3148 /*
3149  * If array is on the verge of a realloc, garbage-collect any entries
3150  * that have already been shown to try to free up some space.
3151  */
3152 static void gc_boundary(struct object_array *array)
3153 {
3154         if (array->nr == array->alloc)
3155                 object_array_filter(array, entry_unshown, NULL);
3156 }
3157
3158 static void create_boundary_commit_list(struct rev_info *revs)
3159 {
3160         unsigned i;
3161         struct commit *c;
3162         struct object_array *array = &revs->boundary_commits;
3163         struct object_array_entry *objects = array->objects;
3164
3165         /*
3166          * If revs->commits is non-NULL at this point, an error occurred in
3167          * get_revision_1().  Ignore the error and continue printing the
3168          * boundary commits anyway.  (This is what the code has always
3169          * done.)
3170          */
3171         if (revs->commits) {
3172                 free_commit_list(revs->commits);
3173                 revs->commits = NULL;
3174         }
3175
3176         /*
3177          * Put all of the actual boundary commits from revs->boundary_commits
3178          * into revs->commits
3179          */
3180         for (i = 0; i < array->nr; i++) {
3181                 c = (struct commit *)(objects[i].item);
3182                 if (!c)
3183                         continue;
3184                 if (!(c->object.flags & CHILD_SHOWN))
3185                         continue;
3186                 if (c->object.flags & (SHOWN | BOUNDARY))
3187                         continue;
3188                 c->object.flags |= BOUNDARY;
3189                 commit_list_insert(c, &revs->commits);
3190         }
3191
3192         /*
3193          * If revs->topo_order is set, sort the boundary commits
3194          * in topological order
3195          */
3196         sort_in_topological_order(&revs->commits, revs->sort_order);
3197 }
3198
3199 static struct commit *get_revision_internal(struct rev_info *revs)
3200 {
3201         struct commit *c = NULL;
3202         struct commit_list *l;
3203
3204         if (revs->boundary == 2) {
3205                 /*
3206                  * All of the normal commits have already been returned,
3207                  * and we are now returning boundary commits.
3208                  * create_boundary_commit_list() has populated
3209                  * revs->commits with the remaining commits to return.
3210                  */
3211                 c = pop_commit(&revs->commits);
3212                 if (c)
3213                         c->object.flags |= SHOWN;
3214                 return c;
3215         }
3216
3217         /*
3218          * If our max_count counter has reached zero, then we are done. We
3219          * don't simply return NULL because we still might need to show
3220          * boundary commits. But we want to avoid calling get_revision_1, which
3221          * might do a considerable amount of work finding the next commit only
3222          * for us to throw it away.
3223          *
3224          * If it is non-zero, then either we don't have a max_count at all
3225          * (-1), or it is still counting, in which case we decrement.
3226          */
3227         if (revs->max_count) {
3228                 c = get_revision_1(revs);
3229                 if (c) {
3230                         while (revs->skip_count > 0) {
3231                                 revs->skip_count--;
3232                                 c = get_revision_1(revs);
3233                                 if (!c)
3234                                         break;
3235                         }
3236                 }
3237
3238                 if (revs->max_count > 0)
3239                         revs->max_count--;
3240         }
3241
3242         if (c)
3243                 c->object.flags |= SHOWN;
3244
3245         if (!revs->boundary)
3246                 return c;
3247
3248         if (!c) {
3249                 /*
3250                  * get_revision_1() runs out the commits, and
3251                  * we are done computing the boundaries.
3252                  * switch to boundary commits output mode.
3253                  */
3254                 revs->boundary = 2;
3255
3256                 /*
3257                  * Update revs->commits to contain the list of
3258                  * boundary commits.
3259                  */
3260                 create_boundary_commit_list(revs);
3261
3262                 return get_revision_internal(revs);
3263         }
3264
3265         /*
3266          * boundary commits are the commits that are parents of the
3267          * ones we got from get_revision_1() but they themselves are
3268          * not returned from get_revision_1().  Before returning
3269          * 'c', we need to mark its parents that they could be boundaries.
3270          */
3271
3272         for (l = c->parents; l; l = l->next) {
3273                 struct object *p;
3274                 p = &(l->item->object);
3275                 if (p->flags & (CHILD_SHOWN | SHOWN))
3276                         continue;
3277                 p->flags |= CHILD_SHOWN;
3278                 gc_boundary(&revs->boundary_commits);
3279                 add_object_array(p, NULL, &revs->boundary_commits);
3280         }
3281
3282         return c;
3283 }
3284
3285 struct commit *get_revision(struct rev_info *revs)
3286 {
3287         struct commit *c;
3288         struct commit_list *reversed;
3289
3290         if (revs->reverse) {
3291                 reversed = NULL;
3292                 while ((c = get_revision_internal(revs)))
3293                         commit_list_insert(c, &reversed);
3294                 revs->commits = reversed;
3295                 revs->reverse = 0;
3296                 revs->reverse_output_stage = 1;
3297         }
3298
3299         if (revs->reverse_output_stage) {
3300                 c = pop_commit(&revs->commits);
3301                 if (revs->track_linear)
3302                         revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
3303                 return c;
3304         }
3305
3306         c = get_revision_internal(revs);
3307         if (c && revs->graph)
3308                 graph_update(revs->graph, c);
3309         if (!c) {
3310                 free_saved_parents(revs);
3311                 if (revs->previous_parents) {
3312                         free_commit_list(revs->previous_parents);
3313                         revs->previous_parents = NULL;
3314                 }
3315         }
3316         return c;
3317 }
3318
3319 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3320 {
3321         if (commit->object.flags & BOUNDARY)
3322                 return "-";
3323         else if (commit->object.flags & UNINTERESTING)
3324                 return "^";
3325         else if (commit->object.flags & PATCHSAME)
3326                 return "=";
3327         else if (!revs || revs->left_right) {
3328                 if (commit->object.flags & SYMMETRIC_LEFT)
3329                         return "<";
3330                 else
3331                         return ">";
3332         } else if (revs->graph)
3333                 return "*";
3334         else if (revs->cherry_mark)
3335                 return "+";
3336         return "";
3337 }
3338
3339 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3340 {
3341         char *mark = get_revision_mark(revs, commit);
3342         if (!strlen(mark))
3343                 return;
3344         fputs(mark, stdout);
3345         putchar(' ');
3346 }