Merge branch 'bp/merge-rename-config'
[git] / 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 "repository.h"
10 #include "graph.h"
11 #include "grep.h"
12 #include "reflog-walk.h"
13 #include "patch-ids.h"
14 #include "decorate.h"
15 #include "log-tree.h"
16 #include "string-list.h"
17 #include "line-log.h"
18 #include "mailmap.h"
19 #include "commit-slab.h"
20 #include "dir.h"
21 #include "cache-tree.h"
22 #include "bisect.h"
23 #include "packfile.h"
24 #include "worktree.h"
25 #include "argv-array.h"
26
27 volatile show_early_output_fn_t show_early_output;
28
29 static const char *term_bad;
30 static const char *term_good;
31
32 void show_object_with_name(FILE *out, struct object *obj, const char *name)
33 {
34         const char *p;
35
36         fprintf(out, "%s ", oid_to_hex(&obj->oid));
37         for (p = name; *p && *p != '\n'; p++)
38                 fputc(*p, out);
39         fputc('\n', out);
40 }
41
42 static void mark_blob_uninteresting(struct blob *blob)
43 {
44         if (!blob)
45                 return;
46         if (blob->object.flags & UNINTERESTING)
47                 return;
48         blob->object.flags |= UNINTERESTING;
49 }
50
51 static void mark_tree_contents_uninteresting(struct tree *tree)
52 {
53         struct tree_desc desc;
54         struct name_entry entry;
55         struct object *obj = &tree->object;
56
57         if (!has_object_file(&obj->oid))
58                 return;
59         if (parse_tree(tree) < 0)
60                 die("bad tree %s", oid_to_hex(&obj->oid));
61
62         init_tree_desc(&desc, tree->buffer, tree->size);
63         while (tree_entry(&desc, &entry)) {
64                 switch (object_type(entry.mode)) {
65                 case OBJ_TREE:
66                         mark_tree_uninteresting(lookup_tree(entry.oid));
67                         break;
68                 case OBJ_BLOB:
69                         mark_blob_uninteresting(lookup_blob(entry.oid));
70                         break;
71                 default:
72                         /* Subproject commit - not in this repository */
73                         break;
74                 }
75         }
76
77         /*
78          * We don't care about the tree any more
79          * after it has been marked uninteresting.
80          */
81         free_tree_buffer(tree);
82 }
83
84 void mark_tree_uninteresting(struct tree *tree)
85 {
86         struct object *obj;
87
88         if (!tree)
89                 return;
90
91         obj = &tree->object;
92         if (obj->flags & UNINTERESTING)
93                 return;
94         obj->flags |= UNINTERESTING;
95         mark_tree_contents_uninteresting(tree);
96 }
97
98 void mark_parents_uninteresting(struct commit *commit)
99 {
100         struct commit_list *parents = NULL, *l;
101
102         for (l = commit->parents; l; l = l->next)
103                 commit_list_insert(l->item, &parents);
104
105         while (parents) {
106                 struct commit *commit = pop_commit(&parents);
107
108                 while (commit) {
109                         /*
110                          * A missing commit is ok iff its parent is marked
111                          * uninteresting.
112                          *
113                          * We just mark such a thing parsed, so that when
114                          * it is popped next time around, we won't be trying
115                          * to parse it and get an error.
116                          */
117                         if (!commit->object.parsed &&
118                             !has_object_file(&commit->object.oid))
119                                 commit->object.parsed = 1;
120
121                         if (commit->object.flags & UNINTERESTING)
122                                 break;
123
124                         commit->object.flags |= UNINTERESTING;
125
126                         /*
127                          * Normally we haven't parsed the parent
128                          * yet, so we won't have a parent of a parent
129                          * here. However, it may turn out that we've
130                          * reached this commit some other way (where it
131                          * wasn't uninteresting), in which case we need
132                          * to mark its parents recursively too..
133                          */
134                         if (!commit->parents)
135                                 break;
136
137                         for (l = commit->parents->next; l; l = l->next)
138                                 commit_list_insert(l->item, &parents);
139                         commit = commit->parents->item;
140                 }
141         }
142 }
143
144 static void add_pending_object_with_path(struct rev_info *revs,
145                                          struct object *obj,
146                                          const char *name, unsigned mode,
147                                          const char *path)
148 {
149         if (!obj)
150                 return;
151         if (revs->no_walk && (obj->flags & UNINTERESTING))
152                 revs->no_walk = 0;
153         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
154                 struct strbuf buf = STRBUF_INIT;
155                 int len = interpret_branch_name(name, 0, &buf, 0);
156
157                 if (0 < len && name[len] && buf.len)
158                         strbuf_addstr(&buf, name + len);
159                 add_reflog_for_walk(revs->reflog_info,
160                                     (struct commit *)obj,
161                                     buf.buf[0] ? buf.buf: name);
162                 strbuf_release(&buf);
163                 return; /* do not add the commit itself */
164         }
165         add_object_array_with_path(obj, name, &revs->pending, mode, path);
166 }
167
168 static void add_pending_object_with_mode(struct rev_info *revs,
169                                          struct object *obj,
170                                          const char *name, unsigned mode)
171 {
172         add_pending_object_with_path(revs, obj, name, mode, NULL);
173 }
174
175 void add_pending_object(struct rev_info *revs,
176                         struct object *obj, const char *name)
177 {
178         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
179 }
180
181 void add_head_to_pending(struct rev_info *revs)
182 {
183         struct object_id oid;
184         struct object *obj;
185         if (get_oid("HEAD", &oid))
186                 return;
187         obj = parse_object(&oid);
188         if (!obj)
189                 return;
190         add_pending_object(revs, obj, "HEAD");
191 }
192
193 static struct object *get_reference(struct rev_info *revs, const char *name,
194                                     const struct object_id *oid,
195                                     unsigned int flags)
196 {
197         struct object *object;
198
199         object = parse_object(oid);
200         if (!object) {
201                 if (revs->ignore_missing)
202                         return object;
203                 if (revs->exclude_promisor_objects && is_promisor_object(oid))
204                         return NULL;
205                 die("bad object %s", name);
206         }
207         object->flags |= flags;
208         return object;
209 }
210
211 void add_pending_oid(struct rev_info *revs, const char *name,
212                       const struct object_id *oid, unsigned int flags)
213 {
214         struct object *object = get_reference(revs, name, oid, flags);
215         add_pending_object(revs, object, name);
216 }
217
218 static struct commit *handle_commit(struct rev_info *revs,
219                                     struct object_array_entry *entry)
220 {
221         struct object *object = entry->item;
222         const char *name = entry->name;
223         const char *path = entry->path;
224         unsigned int mode = entry->mode;
225         unsigned long flags = object->flags;
226
227         /*
228          * Tag object? Look what it points to..
229          */
230         while (object->type == OBJ_TAG) {
231                 struct tag *tag = (struct tag *) object;
232                 if (revs->tag_objects && !(flags & UNINTERESTING))
233                         add_pending_object(revs, object, tag->tag);
234                 if (!tag->tagged)
235                         die("bad tag");
236                 object = parse_object(&tag->tagged->oid);
237                 if (!object) {
238                         if (revs->ignore_missing_links || (flags & UNINTERESTING))
239                                 return NULL;
240                         die("bad object %s", oid_to_hex(&tag->tagged->oid));
241                 }
242                 object->flags |= flags;
243                 /*
244                  * We'll handle the tagged object by looping or dropping
245                  * through to the non-tag handlers below. Do not
246                  * propagate path data from the tag's pending entry.
247                  */
248                 path = NULL;
249                 mode = 0;
250         }
251
252         /*
253          * Commit object? Just return it, we'll do all the complex
254          * reachability crud.
255          */
256         if (object->type == OBJ_COMMIT) {
257                 struct commit *commit = (struct commit *)object;
258                 if (parse_commit(commit) < 0)
259                         die("unable to parse commit %s", name);
260                 if (flags & UNINTERESTING) {
261                         mark_parents_uninteresting(commit);
262                         revs->limited = 1;
263                 }
264                 if (revs->show_source && !commit->util)
265                         commit->util = xstrdup(name);
266                 return commit;
267         }
268
269         /*
270          * Tree object? Either mark it uninteresting, or add it
271          * to the list of objects to look at later..
272          */
273         if (object->type == OBJ_TREE) {
274                 struct tree *tree = (struct tree *)object;
275                 if (!revs->tree_objects)
276                         return NULL;
277                 if (flags & UNINTERESTING) {
278                         mark_tree_contents_uninteresting(tree);
279                         return NULL;
280                 }
281                 add_pending_object_with_path(revs, object, name, mode, path);
282                 return NULL;
283         }
284
285         /*
286          * Blob object? You know the drill by now..
287          */
288         if (object->type == OBJ_BLOB) {
289                 if (!revs->blob_objects)
290                         return NULL;
291                 if (flags & UNINTERESTING)
292                         return NULL;
293                 add_pending_object_with_path(revs, object, name, mode, path);
294                 return NULL;
295         }
296         die("%s is unknown object", name);
297 }
298
299 static int everybody_uninteresting(struct commit_list *orig,
300                                    struct commit **interesting_cache)
301 {
302         struct commit_list *list = orig;
303
304         if (*interesting_cache) {
305                 struct commit *commit = *interesting_cache;
306                 if (!(commit->object.flags & UNINTERESTING))
307                         return 0;
308         }
309
310         while (list) {
311                 struct commit *commit = list->item;
312                 list = list->next;
313                 if (commit->object.flags & UNINTERESTING)
314                         continue;
315
316                 *interesting_cache = commit;
317                 return 0;
318         }
319         return 1;
320 }
321
322 /*
323  * A definition of "relevant" commit that we can use to simplify limited graphs
324  * by eliminating side branches.
325  *
326  * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
327  * in our list), or that is a specified BOTTOM commit. Then after computing
328  * a limited list, during processing we can generally ignore boundary merges
329  * coming from outside the graph, (ie from irrelevant parents), and treat
330  * those merges as if they were single-parent. TREESAME is defined to consider
331  * only relevant parents, if any. If we are TREESAME to our on-graph parents,
332  * we don't care if we were !TREESAME to non-graph parents.
333  *
334  * Treating bottom commits as relevant ensures that a limited graph's
335  * connection to the actual bottom commit is not viewed as a side branch, but
336  * treated as part of the graph. For example:
337  *
338  *   ....Z...A---X---o---o---B
339  *        .     /
340  *         W---Y
341  *
342  * When computing "A..B", the A-X connection is at least as important as
343  * Y-X, despite A being flagged UNINTERESTING.
344  *
345  * And when computing --ancestry-path "A..B", the A-X connection is more
346  * important than Y-X, despite both A and Y being flagged UNINTERESTING.
347  */
348 static inline int relevant_commit(struct commit *commit)
349 {
350         return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
351 }
352
353 /*
354  * Return a single relevant commit from a parent list. If we are a TREESAME
355  * commit, and this selects one of our parents, then we can safely simplify to
356  * that parent.
357  */
358 static struct commit *one_relevant_parent(const struct rev_info *revs,
359                                           struct commit_list *orig)
360 {
361         struct commit_list *list = orig;
362         struct commit *relevant = NULL;
363
364         if (!orig)
365                 return NULL;
366
367         /*
368          * For 1-parent commits, or if first-parent-only, then return that
369          * first parent (even if not "relevant" by the above definition).
370          * TREESAME will have been set purely on that parent.
371          */
372         if (revs->first_parent_only || !orig->next)
373                 return orig->item;
374
375         /*
376          * For multi-parent commits, identify a sole relevant parent, if any.
377          * If we have only one relevant parent, then TREESAME will be set purely
378          * with regard to that parent, and we can simplify accordingly.
379          *
380          * If we have more than one relevant parent, or no relevant parents
381          * (and multiple irrelevant ones), then we can't select a parent here
382          * and return NULL.
383          */
384         while (list) {
385                 struct commit *commit = list->item;
386                 list = list->next;
387                 if (relevant_commit(commit)) {
388                         if (relevant)
389                                 return NULL;
390                         relevant = commit;
391                 }
392         }
393         return relevant;
394 }
395
396 /*
397  * The goal is to get REV_TREE_NEW as the result only if the
398  * diff consists of all '+' (and no other changes), REV_TREE_OLD
399  * if the whole diff is removal of old data, and otherwise
400  * REV_TREE_DIFFERENT (of course if the trees are the same we
401  * want REV_TREE_SAME).
402  *
403  * The only time we care about the distinction is when
404  * remove_empty_trees is in effect, in which case we care only about
405  * whether the whole change is REV_TREE_NEW, or if there's another type
406  * of change. Which means we can stop the diff early in either of these
407  * cases:
408  *
409  *   1. We're not using remove_empty_trees at all.
410  *
411  *   2. We saw anything except REV_TREE_NEW.
412  */
413 static int tree_difference = REV_TREE_SAME;
414
415 static void file_add_remove(struct diff_options *options,
416                     int addremove, unsigned mode,
417                     const struct object_id *oid,
418                     int oid_valid,
419                     const char *fullpath, unsigned dirty_submodule)
420 {
421         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
422         struct rev_info *revs = options->change_fn_data;
423
424         tree_difference |= diff;
425         if (!revs->remove_empty_trees || tree_difference != REV_TREE_NEW)
426                 options->flags.has_changes = 1;
427 }
428
429 static void file_change(struct diff_options *options,
430                  unsigned old_mode, unsigned new_mode,
431                  const struct object_id *old_oid,
432                  const struct object_id *new_oid,
433                  int old_oid_valid, int new_oid_valid,
434                  const char *fullpath,
435                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
436 {
437         tree_difference = REV_TREE_DIFFERENT;
438         options->flags.has_changes = 1;
439 }
440
441 static int rev_compare_tree(struct rev_info *revs,
442                             struct commit *parent, struct commit *commit)
443 {
444         struct tree *t1 = get_commit_tree(parent);
445         struct tree *t2 = get_commit_tree(commit);
446
447         if (!t1)
448                 return REV_TREE_NEW;
449         if (!t2)
450                 return REV_TREE_OLD;
451
452         if (revs->simplify_by_decoration) {
453                 /*
454                  * If we are simplifying by decoration, then the commit
455                  * is worth showing if it has a tag pointing at it.
456                  */
457                 if (get_name_decoration(&commit->object))
458                         return REV_TREE_DIFFERENT;
459                 /*
460                  * A commit that is not pointed by a tag is uninteresting
461                  * if we are not limited by path.  This means that you will
462                  * see the usual "commits that touch the paths" plus any
463                  * tagged commit by specifying both --simplify-by-decoration
464                  * and pathspec.
465                  */
466                 if (!revs->prune_data.nr)
467                         return REV_TREE_SAME;
468         }
469
470         tree_difference = REV_TREE_SAME;
471         revs->pruning.flags.has_changes = 0;
472         if (diff_tree_oid(&t1->object.oid, &t2->object.oid, "",
473                            &revs->pruning) < 0)
474                 return REV_TREE_DIFFERENT;
475         return tree_difference;
476 }
477
478 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
479 {
480         int retval;
481         struct tree *t1 = get_commit_tree(commit);
482
483         if (!t1)
484                 return 0;
485
486         tree_difference = REV_TREE_SAME;
487         revs->pruning.flags.has_changes = 0;
488         retval = diff_tree_oid(NULL, &t1->object.oid, "", &revs->pruning);
489
490         return retval >= 0 && (tree_difference == REV_TREE_SAME);
491 }
492
493 struct treesame_state {
494         unsigned int nparents;
495         unsigned char treesame[FLEX_ARRAY];
496 };
497
498 static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
499 {
500         unsigned n = commit_list_count(commit->parents);
501         struct treesame_state *st = xcalloc(1, st_add(sizeof(*st), n));
502         st->nparents = n;
503         add_decoration(&revs->treesame, &commit->object, st);
504         return st;
505 }
506
507 /*
508  * Must be called immediately after removing the nth_parent from a commit's
509  * parent list, if we are maintaining the per-parent treesame[] decoration.
510  * This does not recalculate the master TREESAME flag - update_treesame()
511  * should be called to update it after a sequence of treesame[] modifications
512  * that may have affected it.
513  */
514 static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
515 {
516         struct treesame_state *st;
517         int old_same;
518
519         if (!commit->parents) {
520                 /*
521                  * Have just removed the only parent from a non-merge.
522                  * Different handling, as we lack decoration.
523                  */
524                 if (nth_parent != 0)
525                         die("compact_treesame %u", nth_parent);
526                 old_same = !!(commit->object.flags & TREESAME);
527                 if (rev_same_tree_as_empty(revs, commit))
528                         commit->object.flags |= TREESAME;
529                 else
530                         commit->object.flags &= ~TREESAME;
531                 return old_same;
532         }
533
534         st = lookup_decoration(&revs->treesame, &commit->object);
535         if (!st || nth_parent >= st->nparents)
536                 die("compact_treesame %u", nth_parent);
537
538         old_same = st->treesame[nth_parent];
539         memmove(st->treesame + nth_parent,
540                 st->treesame + nth_parent + 1,
541                 st->nparents - nth_parent - 1);
542
543         /*
544          * If we've just become a non-merge commit, update TREESAME
545          * immediately, and remove the no-longer-needed decoration.
546          * If still a merge, defer update until update_treesame().
547          */
548         if (--st->nparents == 1) {
549                 if (commit->parents->next)
550                         die("compact_treesame parents mismatch");
551                 if (st->treesame[0] && revs->dense)
552                         commit->object.flags |= TREESAME;
553                 else
554                         commit->object.flags &= ~TREESAME;
555                 free(add_decoration(&revs->treesame, &commit->object, NULL));
556         }
557
558         return old_same;
559 }
560
561 static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
562 {
563         if (commit->parents && commit->parents->next) {
564                 unsigned n;
565                 struct treesame_state *st;
566                 struct commit_list *p;
567                 unsigned relevant_parents;
568                 unsigned relevant_change, irrelevant_change;
569
570                 st = lookup_decoration(&revs->treesame, &commit->object);
571                 if (!st)
572                         die("update_treesame %s", oid_to_hex(&commit->object.oid));
573                 relevant_parents = 0;
574                 relevant_change = irrelevant_change = 0;
575                 for (p = commit->parents, n = 0; p; n++, p = p->next) {
576                         if (relevant_commit(p->item)) {
577                                 relevant_change |= !st->treesame[n];
578                                 relevant_parents++;
579                         } else
580                                 irrelevant_change |= !st->treesame[n];
581                 }
582                 if (relevant_parents ? relevant_change : irrelevant_change)
583                         commit->object.flags &= ~TREESAME;
584                 else
585                         commit->object.flags |= TREESAME;
586         }
587
588         return commit->object.flags & TREESAME;
589 }
590
591 static inline int limiting_can_increase_treesame(const struct rev_info *revs)
592 {
593         /*
594          * TREESAME is irrelevant unless prune && dense;
595          * if simplify_history is set, we can't have a mixture of TREESAME and
596          *    !TREESAME INTERESTING parents (and we don't have treesame[]
597          *    decoration anyway);
598          * if first_parent_only is set, then the TREESAME flag is locked
599          *    against the first parent (and again we lack treesame[] decoration).
600          */
601         return revs->prune && revs->dense &&
602                !revs->simplify_history &&
603                !revs->first_parent_only;
604 }
605
606 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
607 {
608         struct commit_list **pp, *parent;
609         struct treesame_state *ts = NULL;
610         int relevant_change = 0, irrelevant_change = 0;
611         int relevant_parents, nth_parent;
612
613         /*
614          * If we don't do pruning, everything is interesting
615          */
616         if (!revs->prune)
617                 return;
618
619         if (!get_commit_tree(commit))
620                 return;
621
622         if (!commit->parents) {
623                 if (rev_same_tree_as_empty(revs, commit))
624                         commit->object.flags |= TREESAME;
625                 return;
626         }
627
628         /*
629          * Normal non-merge commit? If we don't want to make the
630          * history dense, we consider it always to be a change..
631          */
632         if (!revs->dense && !commit->parents->next)
633                 return;
634
635         for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
636              (parent = *pp) != NULL;
637              pp = &parent->next, nth_parent++) {
638                 struct commit *p = parent->item;
639                 if (relevant_commit(p))
640                         relevant_parents++;
641
642                 if (nth_parent == 1) {
643                         /*
644                          * This our second loop iteration - so we now know
645                          * we're dealing with a merge.
646                          *
647                          * Do not compare with later parents when we care only about
648                          * the first parent chain, in order to avoid derailing the
649                          * traversal to follow a side branch that brought everything
650                          * in the path we are limited to by the pathspec.
651                          */
652                         if (revs->first_parent_only)
653                                 break;
654                         /*
655                          * If this will remain a potentially-simplifiable
656                          * merge, remember per-parent treesame if needed.
657                          * Initialise the array with the comparison from our
658                          * first iteration.
659                          */
660                         if (revs->treesame.name &&
661                             !revs->simplify_history &&
662                             !(commit->object.flags & UNINTERESTING)) {
663                                 ts = initialise_treesame(revs, commit);
664                                 if (!(irrelevant_change || relevant_change))
665                                         ts->treesame[0] = 1;
666                         }
667                 }
668                 if (parse_commit(p) < 0)
669                         die("cannot simplify commit %s (because of %s)",
670                             oid_to_hex(&commit->object.oid),
671                             oid_to_hex(&p->object.oid));
672                 switch (rev_compare_tree(revs, p, commit)) {
673                 case REV_TREE_SAME:
674                         if (!revs->simplify_history || !relevant_commit(p)) {
675                                 /* Even if a merge with an uninteresting
676                                  * side branch brought the entire change
677                                  * we are interested in, we do not want
678                                  * to lose the other branches of this
679                                  * merge, so we just keep going.
680                                  */
681                                 if (ts)
682                                         ts->treesame[nth_parent] = 1;
683                                 continue;
684                         }
685                         parent->next = NULL;
686                         commit->parents = parent;
687                         commit->object.flags |= TREESAME;
688                         return;
689
690                 case REV_TREE_NEW:
691                         if (revs->remove_empty_trees &&
692                             rev_same_tree_as_empty(revs, p)) {
693                                 /* We are adding all the specified
694                                  * paths from this parent, so the
695                                  * history beyond this parent is not
696                                  * interesting.  Remove its parents
697                                  * (they are grandparents for us).
698                                  * IOW, we pretend this parent is a
699                                  * "root" commit.
700                                  */
701                                 if (parse_commit(p) < 0)
702                                         die("cannot simplify commit %s (invalid %s)",
703                                             oid_to_hex(&commit->object.oid),
704                                             oid_to_hex(&p->object.oid));
705                                 p->parents = NULL;
706                         }
707                 /* fallthrough */
708                 case REV_TREE_OLD:
709                 case REV_TREE_DIFFERENT:
710                         if (relevant_commit(p))
711                                 relevant_change = 1;
712                         else
713                                 irrelevant_change = 1;
714                         continue;
715                 }
716                 die("bad tree compare for commit %s", oid_to_hex(&commit->object.oid));
717         }
718
719         /*
720          * TREESAME is straightforward for single-parent commits. For merge
721          * commits, it is most useful to define it so that "irrelevant"
722          * parents cannot make us !TREESAME - if we have any relevant
723          * parents, then we only consider TREESAMEness with respect to them,
724          * allowing irrelevant merges from uninteresting branches to be
725          * simplified away. Only if we have only irrelevant parents do we
726          * base TREESAME on them. Note that this logic is replicated in
727          * update_treesame, which should be kept in sync.
728          */
729         if (relevant_parents ? !relevant_change : !irrelevant_change)
730                 commit->object.flags |= TREESAME;
731 }
732
733 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
734                     struct commit_list *cached_base, struct commit_list **cache)
735 {
736         struct commit_list *new_entry;
737
738         if (cached_base && p->date < cached_base->item->date)
739                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
740         else
741                 new_entry = commit_list_insert_by_date(p, head);
742
743         if (cache && (!*cache || p->date < (*cache)->item->date))
744                 *cache = new_entry;
745 }
746
747 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
748                     struct commit_list **list, struct commit_list **cache_ptr)
749 {
750         struct commit_list *parent = commit->parents;
751         unsigned left_flag;
752         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
753
754         if (commit->object.flags & ADDED)
755                 return 0;
756         commit->object.flags |= ADDED;
757
758         if (revs->include_check &&
759             !revs->include_check(commit, revs->include_check_data))
760                 return 0;
761
762         /*
763          * If the commit is uninteresting, don't try to
764          * prune parents - we want the maximal uninteresting
765          * set.
766          *
767          * Normally we haven't parsed the parent
768          * yet, so we won't have a parent of a parent
769          * here. However, it may turn out that we've
770          * reached this commit some other way (where it
771          * wasn't uninteresting), in which case we need
772          * to mark its parents recursively too..
773          */
774         if (commit->object.flags & UNINTERESTING) {
775                 while (parent) {
776                         struct commit *p = parent->item;
777                         parent = parent->next;
778                         if (p)
779                                 p->object.flags |= UNINTERESTING;
780                         if (parse_commit_gently(p, 1) < 0)
781                                 continue;
782                         if (p->parents)
783                                 mark_parents_uninteresting(p);
784                         if (p->object.flags & SEEN)
785                                 continue;
786                         p->object.flags |= SEEN;
787                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
788                 }
789                 return 0;
790         }
791
792         /*
793          * Ok, the commit wasn't uninteresting. Try to
794          * simplify the commit history and find the parent
795          * that has no differences in the path set if one exists.
796          */
797         try_to_simplify_commit(revs, commit);
798
799         if (revs->no_walk)
800                 return 0;
801
802         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
803
804         for (parent = commit->parents; parent; parent = parent->next) {
805                 struct commit *p = parent->item;
806                 int gently = revs->ignore_missing_links ||
807                              revs->exclude_promisor_objects;
808                 if (parse_commit_gently(p, gently) < 0) {
809                         if (revs->exclude_promisor_objects &&
810                             is_promisor_object(&p->object.oid)) {
811                                 if (revs->first_parent_only)
812                                         break;
813                                 continue;
814                         }
815                         return -1;
816                 }
817                 if (revs->show_source && !p->util)
818                         p->util = commit->util;
819                 p->object.flags |= left_flag;
820                 if (!(p->object.flags & SEEN)) {
821                         p->object.flags |= SEEN;
822                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
823                 }
824                 if (revs->first_parent_only)
825                         break;
826         }
827         return 0;
828 }
829
830 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
831 {
832         struct commit_list *p;
833         int left_count = 0, right_count = 0;
834         int left_first;
835         struct patch_ids ids;
836         unsigned cherry_flag;
837
838         /* First count the commits on the left and on the right */
839         for (p = list; p; p = p->next) {
840                 struct commit *commit = p->item;
841                 unsigned flags = commit->object.flags;
842                 if (flags & BOUNDARY)
843                         ;
844                 else if (flags & SYMMETRIC_LEFT)
845                         left_count++;
846                 else
847                         right_count++;
848         }
849
850         if (!left_count || !right_count)
851                 return;
852
853         left_first = left_count < right_count;
854         init_patch_ids(&ids);
855         ids.diffopts.pathspec = revs->diffopt.pathspec;
856
857         /* Compute patch-ids for one side */
858         for (p = list; p; p = p->next) {
859                 struct commit *commit = p->item;
860                 unsigned flags = commit->object.flags;
861
862                 if (flags & BOUNDARY)
863                         continue;
864                 /*
865                  * If we have fewer left, left_first is set and we omit
866                  * commits on the right branch in this loop.  If we have
867                  * fewer right, we skip the left ones.
868                  */
869                 if (left_first != !!(flags & SYMMETRIC_LEFT))
870                         continue;
871                 add_commit_patch_id(commit, &ids);
872         }
873
874         /* either cherry_mark or cherry_pick are true */
875         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
876
877         /* Check the other side */
878         for (p = list; p; p = p->next) {
879                 struct commit *commit = p->item;
880                 struct patch_id *id;
881                 unsigned flags = commit->object.flags;
882
883                 if (flags & BOUNDARY)
884                         continue;
885                 /*
886                  * If we have fewer left, left_first is set and we omit
887                  * commits on the left branch in this loop.
888                  */
889                 if (left_first == !!(flags & SYMMETRIC_LEFT))
890                         continue;
891
892                 /*
893                  * Have we seen the same patch id?
894                  */
895                 id = has_commit_patch_id(commit, &ids);
896                 if (!id)
897                         continue;
898
899                 commit->object.flags |= cherry_flag;
900                 id->commit->object.flags |= cherry_flag;
901         }
902
903         free_patch_ids(&ids);
904 }
905
906 /* How many extra uninteresting commits we want to see.. */
907 #define SLOP 5
908
909 static int still_interesting(struct commit_list *src, timestamp_t date, int slop,
910                              struct commit **interesting_cache)
911 {
912         /*
913          * No source list at all? We're definitely done..
914          */
915         if (!src)
916                 return 0;
917
918         /*
919          * Does the destination list contain entries with a date
920          * before the source list? Definitely _not_ done.
921          */
922         if (date <= src->item->date)
923                 return SLOP;
924
925         /*
926          * Does the source list still have interesting commits in
927          * it? Definitely not done..
928          */
929         if (!everybody_uninteresting(src, interesting_cache))
930                 return SLOP;
931
932         /* Ok, we're closing in.. */
933         return slop-1;
934 }
935
936 /*
937  * "rev-list --ancestry-path A..B" computes commits that are ancestors
938  * of B but not ancestors of A but further limits the result to those
939  * that are descendants of A.  This takes the list of bottom commits and
940  * the result of "A..B" without --ancestry-path, and limits the latter
941  * further to the ones that can reach one of the commits in "bottom".
942  */
943 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
944 {
945         struct commit_list *p;
946         struct commit_list *rlist = NULL;
947         int made_progress;
948
949         /*
950          * Reverse the list so that it will be likely that we would
951          * process parents before children.
952          */
953         for (p = list; p; p = p->next)
954                 commit_list_insert(p->item, &rlist);
955
956         for (p = bottom; p; p = p->next)
957                 p->item->object.flags |= TMP_MARK;
958
959         /*
960          * Mark the ones that can reach bottom commits in "list",
961          * in a bottom-up fashion.
962          */
963         do {
964                 made_progress = 0;
965                 for (p = rlist; p; p = p->next) {
966                         struct commit *c = p->item;
967                         struct commit_list *parents;
968                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
969                                 continue;
970                         for (parents = c->parents;
971                              parents;
972                              parents = parents->next) {
973                                 if (!(parents->item->object.flags & TMP_MARK))
974                                         continue;
975                                 c->object.flags |= TMP_MARK;
976                                 made_progress = 1;
977                                 break;
978                         }
979                 }
980         } while (made_progress);
981
982         /*
983          * NEEDSWORK: decide if we want to remove parents that are
984          * not marked with TMP_MARK from commit->parents for commits
985          * in the resulting list.  We may not want to do that, though.
986          */
987
988         /*
989          * The ones that are not marked with TMP_MARK are uninteresting
990          */
991         for (p = list; p; p = p->next) {
992                 struct commit *c = p->item;
993                 if (c->object.flags & TMP_MARK)
994                         continue;
995                 c->object.flags |= UNINTERESTING;
996         }
997
998         /* We are done with the TMP_MARK */
999         for (p = list; p; p = p->next)
1000                 p->item->object.flags &= ~TMP_MARK;
1001         for (p = bottom; p; p = p->next)
1002                 p->item->object.flags &= ~TMP_MARK;
1003         free_commit_list(rlist);
1004 }
1005
1006 /*
1007  * Before walking the history, keep the set of "negative" refs the
1008  * caller has asked to exclude.
1009  *
1010  * This is used to compute "rev-list --ancestry-path A..B", as we need
1011  * to filter the result of "A..B" further to the ones that can actually
1012  * reach A.
1013  */
1014 static struct commit_list *collect_bottom_commits(struct commit_list *list)
1015 {
1016         struct commit_list *elem, *bottom = NULL;
1017         for (elem = list; elem; elem = elem->next)
1018                 if (elem->item->object.flags & BOTTOM)
1019                         commit_list_insert(elem->item, &bottom);
1020         return bottom;
1021 }
1022
1023 /* Assumes either left_only or right_only is set */
1024 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1025 {
1026         struct commit_list *p;
1027
1028         for (p = list; p; p = p->next) {
1029                 struct commit *commit = p->item;
1030
1031                 if (revs->right_only) {
1032                         if (commit->object.flags & SYMMETRIC_LEFT)
1033                                 commit->object.flags |= SHOWN;
1034                 } else  /* revs->left_only is set */
1035                         if (!(commit->object.flags & SYMMETRIC_LEFT))
1036                                 commit->object.flags |= SHOWN;
1037         }
1038 }
1039
1040 static int limit_list(struct rev_info *revs)
1041 {
1042         int slop = SLOP;
1043         timestamp_t date = TIME_MAX;
1044         struct commit_list *list = revs->commits;
1045         struct commit_list *newlist = NULL;
1046         struct commit_list **p = &newlist;
1047         struct commit_list *bottom = NULL;
1048         struct commit *interesting_cache = NULL;
1049
1050         if (revs->ancestry_path) {
1051                 bottom = collect_bottom_commits(list);
1052                 if (!bottom)
1053                         die("--ancestry-path given but there are no bottom commits");
1054         }
1055
1056         while (list) {
1057                 struct commit *commit = pop_commit(&list);
1058                 struct object *obj = &commit->object;
1059                 show_early_output_fn_t show;
1060
1061                 if (commit == interesting_cache)
1062                         interesting_cache = NULL;
1063
1064                 if (revs->max_age != -1 && (commit->date < revs->max_age))
1065                         obj->flags |= UNINTERESTING;
1066                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
1067                         return -1;
1068                 if (obj->flags & UNINTERESTING) {
1069                         mark_parents_uninteresting(commit);
1070                         slop = still_interesting(list, date, slop, &interesting_cache);
1071                         if (slop)
1072                                 continue;
1073                         break;
1074                 }
1075                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1076                         continue;
1077                 date = commit->date;
1078                 p = &commit_list_insert(commit, p)->next;
1079
1080                 show = show_early_output;
1081                 if (!show)
1082                         continue;
1083
1084                 show(revs, newlist);
1085                 show_early_output = NULL;
1086         }
1087         if (revs->cherry_pick || revs->cherry_mark)
1088                 cherry_pick_list(newlist, revs);
1089
1090         if (revs->left_only || revs->right_only)
1091                 limit_left_right(newlist, revs);
1092
1093         if (bottom) {
1094                 limit_to_ancestry(bottom, newlist);
1095                 free_commit_list(bottom);
1096         }
1097
1098         /*
1099          * Check if any commits have become TREESAME by some of their parents
1100          * becoming UNINTERESTING.
1101          */
1102         if (limiting_can_increase_treesame(revs))
1103                 for (list = newlist; list; list = list->next) {
1104                         struct commit *c = list->item;
1105                         if (c->object.flags & (UNINTERESTING | TREESAME))
1106                                 continue;
1107                         update_treesame(revs, c);
1108                 }
1109
1110         revs->commits = newlist;
1111         return 0;
1112 }
1113
1114 /*
1115  * Add an entry to refs->cmdline with the specified information.
1116  * *name is copied.
1117  */
1118 static void add_rev_cmdline(struct rev_info *revs,
1119                             struct object *item,
1120                             const char *name,
1121                             int whence,
1122                             unsigned flags)
1123 {
1124         struct rev_cmdline_info *info = &revs->cmdline;
1125         unsigned int nr = info->nr;
1126
1127         ALLOC_GROW(info->rev, nr + 1, info->alloc);
1128         info->rev[nr].item = item;
1129         info->rev[nr].name = xstrdup(name);
1130         info->rev[nr].whence = whence;
1131         info->rev[nr].flags = flags;
1132         info->nr++;
1133 }
1134
1135 static void add_rev_cmdline_list(struct rev_info *revs,
1136                                  struct commit_list *commit_list,
1137                                  int whence,
1138                                  unsigned flags)
1139 {
1140         while (commit_list) {
1141                 struct object *object = &commit_list->item->object;
1142                 add_rev_cmdline(revs, object, oid_to_hex(&object->oid),
1143                                 whence, flags);
1144                 commit_list = commit_list->next;
1145         }
1146 }
1147
1148 struct all_refs_cb {
1149         int all_flags;
1150         int warned_bad_reflog;
1151         struct rev_info *all_revs;
1152         const char *name_for_errormsg;
1153         struct ref_store *refs;
1154 };
1155
1156 int ref_excluded(struct string_list *ref_excludes, const char *path)
1157 {
1158         struct string_list_item *item;
1159
1160         if (!ref_excludes)
1161                 return 0;
1162         for_each_string_list_item(item, ref_excludes) {
1163                 if (!wildmatch(item->string, path, 0))
1164                         return 1;
1165         }
1166         return 0;
1167 }
1168
1169 static int handle_one_ref(const char *path, const struct object_id *oid,
1170                           int flag, void *cb_data)
1171 {
1172         struct all_refs_cb *cb = cb_data;
1173         struct object *object;
1174
1175         if (ref_excluded(cb->all_revs->ref_excludes, path))
1176             return 0;
1177
1178         object = get_reference(cb->all_revs, path, oid, cb->all_flags);
1179         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1180         add_pending_oid(cb->all_revs, path, oid, cb->all_flags);
1181         return 0;
1182 }
1183
1184 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1185         unsigned flags)
1186 {
1187         cb->all_revs = revs;
1188         cb->all_flags = flags;
1189         revs->rev_input_given = 1;
1190         cb->refs = NULL;
1191 }
1192
1193 void clear_ref_exclusion(struct string_list **ref_excludes_p)
1194 {
1195         if (*ref_excludes_p) {
1196                 string_list_clear(*ref_excludes_p, 0);
1197                 free(*ref_excludes_p);
1198         }
1199         *ref_excludes_p = NULL;
1200 }
1201
1202 void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1203 {
1204         if (!*ref_excludes_p) {
1205                 *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1206                 (*ref_excludes_p)->strdup_strings = 1;
1207         }
1208         string_list_append(*ref_excludes_p, exclude);
1209 }
1210
1211 static void handle_refs(struct ref_store *refs,
1212                         struct rev_info *revs, unsigned flags,
1213                         int (*for_each)(struct ref_store *, each_ref_fn, void *))
1214 {
1215         struct all_refs_cb cb;
1216
1217         if (!refs) {
1218                 /* this could happen with uninitialized submodules */
1219                 return;
1220         }
1221
1222         init_all_refs_cb(&cb, revs, flags);
1223         for_each(refs, handle_one_ref, &cb);
1224 }
1225
1226 static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
1227 {
1228         struct all_refs_cb *cb = cb_data;
1229         if (!is_null_oid(oid)) {
1230                 struct object *o = parse_object(oid);
1231                 if (o) {
1232                         o->flags |= cb->all_flags;
1233                         /* ??? CMDLINEFLAGS ??? */
1234                         add_pending_object(cb->all_revs, o, "");
1235                 }
1236                 else if (!cb->warned_bad_reflog) {
1237                         warning("reflog of '%s' references pruned commits",
1238                                 cb->name_for_errormsg);
1239                         cb->warned_bad_reflog = 1;
1240                 }
1241         }
1242 }
1243
1244 static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
1245                 const char *email, timestamp_t timestamp, int tz,
1246                 const char *message, void *cb_data)
1247 {
1248         handle_one_reflog_commit(ooid, cb_data);
1249         handle_one_reflog_commit(noid, cb_data);
1250         return 0;
1251 }
1252
1253 static int handle_one_reflog(const char *path, const struct object_id *oid,
1254                              int flag, void *cb_data)
1255 {
1256         struct all_refs_cb *cb = cb_data;
1257         cb->warned_bad_reflog = 0;
1258         cb->name_for_errormsg = path;
1259         refs_for_each_reflog_ent(cb->refs, path,
1260                                  handle_one_reflog_ent, cb_data);
1261         return 0;
1262 }
1263
1264 static void add_other_reflogs_to_pending(struct all_refs_cb *cb)
1265 {
1266         struct worktree **worktrees, **p;
1267
1268         worktrees = get_worktrees(0);
1269         for (p = worktrees; *p; p++) {
1270                 struct worktree *wt = *p;
1271
1272                 if (wt->is_current)
1273                         continue;
1274
1275                 cb->refs = get_worktree_ref_store(wt);
1276                 refs_for_each_reflog(cb->refs,
1277                                      handle_one_reflog,
1278                                      cb);
1279         }
1280         free_worktrees(worktrees);
1281 }
1282
1283 void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1284 {
1285         struct all_refs_cb cb;
1286
1287         cb.all_revs = revs;
1288         cb.all_flags = flags;
1289         cb.refs = get_main_ref_store(the_repository);
1290         for_each_reflog(handle_one_reflog, &cb);
1291
1292         if (!revs->single_worktree)
1293                 add_other_reflogs_to_pending(&cb);
1294 }
1295
1296 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1297                            struct strbuf *path)
1298 {
1299         size_t baselen = path->len;
1300         int i;
1301
1302         if (it->entry_count >= 0) {
1303                 struct tree *tree = lookup_tree(&it->oid);
1304                 add_pending_object_with_path(revs, &tree->object, "",
1305                                              040000, path->buf);
1306         }
1307
1308         for (i = 0; i < it->subtree_nr; i++) {
1309                 struct cache_tree_sub *sub = it->down[i];
1310                 strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1311                 add_cache_tree(sub->cache_tree, revs, path);
1312                 strbuf_setlen(path, baselen);
1313         }
1314
1315 }
1316
1317 static void do_add_index_objects_to_pending(struct rev_info *revs,
1318                                             struct index_state *istate)
1319 {
1320         int i;
1321
1322         for (i = 0; i < istate->cache_nr; i++) {
1323                 struct cache_entry *ce = istate->cache[i];
1324                 struct blob *blob;
1325
1326                 if (S_ISGITLINK(ce->ce_mode))
1327                         continue;
1328
1329                 blob = lookup_blob(&ce->oid);
1330                 if (!blob)
1331                         die("unable to add index blob to traversal");
1332                 add_pending_object_with_path(revs, &blob->object, "",
1333                                              ce->ce_mode, ce->name);
1334         }
1335
1336         if (istate->cache_tree) {
1337                 struct strbuf path = STRBUF_INIT;
1338                 add_cache_tree(istate->cache_tree, revs, &path);
1339                 strbuf_release(&path);
1340         }
1341 }
1342
1343 void add_index_objects_to_pending(struct rev_info *revs, unsigned int flags)
1344 {
1345         struct worktree **worktrees, **p;
1346
1347         read_cache();
1348         do_add_index_objects_to_pending(revs, &the_index);
1349
1350         if (revs->single_worktree)
1351                 return;
1352
1353         worktrees = get_worktrees(0);
1354         for (p = worktrees; *p; p++) {
1355                 struct worktree *wt = *p;
1356                 struct index_state istate = { NULL };
1357
1358                 if (wt->is_current)
1359                         continue; /* current index already taken care of */
1360
1361                 if (read_index_from(&istate,
1362                                     worktree_git_path(wt, "index"),
1363                                     get_worktree_git_dir(wt)) > 0)
1364                         do_add_index_objects_to_pending(revs, &istate);
1365                 discard_index(&istate);
1366         }
1367         free_worktrees(worktrees);
1368 }
1369
1370 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
1371                             int exclude_parent)
1372 {
1373         struct object_id oid;
1374         struct object *it;
1375         struct commit *commit;
1376         struct commit_list *parents;
1377         int parent_number;
1378         const char *arg = arg_;
1379
1380         if (*arg == '^') {
1381                 flags ^= UNINTERESTING | BOTTOM;
1382                 arg++;
1383         }
1384         if (get_oid_committish(arg, &oid))
1385                 return 0;
1386         while (1) {
1387                 it = get_reference(revs, arg, &oid, 0);
1388                 if (!it && revs->ignore_missing)
1389                         return 0;
1390                 if (it->type != OBJ_TAG)
1391                         break;
1392                 if (!((struct tag*)it)->tagged)
1393                         return 0;
1394                 oidcpy(&oid, &((struct tag*)it)->tagged->oid);
1395         }
1396         if (it->type != OBJ_COMMIT)
1397                 return 0;
1398         commit = (struct commit *)it;
1399         if (exclude_parent &&
1400             exclude_parent > commit_list_count(commit->parents))
1401                 return 0;
1402         for (parents = commit->parents, parent_number = 1;
1403              parents;
1404              parents = parents->next, parent_number++) {
1405                 if (exclude_parent && parent_number != exclude_parent)
1406                         continue;
1407
1408                 it = &parents->item->object;
1409                 it->flags |= flags;
1410                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1411                 add_pending_object(revs, it, arg);
1412         }
1413         return 1;
1414 }
1415
1416 void init_revisions(struct rev_info *revs, const char *prefix)
1417 {
1418         memset(revs, 0, sizeof(*revs));
1419
1420         revs->abbrev = DEFAULT_ABBREV;
1421         revs->ignore_merges = 1;
1422         revs->simplify_history = 1;
1423         revs->pruning.flags.recursive = 1;
1424         revs->pruning.flags.quick = 1;
1425         revs->pruning.add_remove = file_add_remove;
1426         revs->pruning.change = file_change;
1427         revs->pruning.change_fn_data = revs;
1428         revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1429         revs->dense = 1;
1430         revs->prefix = prefix;
1431         revs->max_age = -1;
1432         revs->min_age = -1;
1433         revs->skip_count = -1;
1434         revs->max_count = -1;
1435         revs->max_parents = -1;
1436         revs->expand_tabs_in_log = -1;
1437
1438         revs->commit_format = CMIT_FMT_DEFAULT;
1439         revs->expand_tabs_in_log_default = 8;
1440
1441         init_grep_defaults();
1442         grep_init(&revs->grep_filter, prefix);
1443         revs->grep_filter.status_only = 1;
1444
1445         diff_setup(&revs->diffopt);
1446         if (prefix && !revs->diffopt.prefix) {
1447                 revs->diffopt.prefix = prefix;
1448                 revs->diffopt.prefix_length = strlen(prefix);
1449         }
1450
1451         revs->notes_opt.use_default_notes = -1;
1452 }
1453
1454 static void add_pending_commit_list(struct rev_info *revs,
1455                                     struct commit_list *commit_list,
1456                                     unsigned int flags)
1457 {
1458         while (commit_list) {
1459                 struct object *object = &commit_list->item->object;
1460                 object->flags |= flags;
1461                 add_pending_object(revs, object, oid_to_hex(&object->oid));
1462                 commit_list = commit_list->next;
1463         }
1464 }
1465
1466 static void prepare_show_merge(struct rev_info *revs)
1467 {
1468         struct commit_list *bases;
1469         struct commit *head, *other;
1470         struct object_id oid;
1471         const char **prune = NULL;
1472         int i, prune_num = 1; /* counting terminating NULL */
1473
1474         if (get_oid("HEAD", &oid))
1475                 die("--merge without HEAD?");
1476         head = lookup_commit_or_die(&oid, "HEAD");
1477         if (get_oid("MERGE_HEAD", &oid))
1478                 die("--merge without MERGE_HEAD?");
1479         other = lookup_commit_or_die(&oid, "MERGE_HEAD");
1480         add_pending_object(revs, &head->object, "HEAD");
1481         add_pending_object(revs, &other->object, "MERGE_HEAD");
1482         bases = get_merge_bases(head, other);
1483         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1484         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1485         free_commit_list(bases);
1486         head->object.flags |= SYMMETRIC_LEFT;
1487
1488         if (!active_nr)
1489                 read_cache();
1490         for (i = 0; i < active_nr; i++) {
1491                 const struct cache_entry *ce = active_cache[i];
1492                 if (!ce_stage(ce))
1493                         continue;
1494                 if (ce_path_match(ce, &revs->prune_data, NULL)) {
1495                         prune_num++;
1496                         REALLOC_ARRAY(prune, prune_num);
1497                         prune[prune_num-2] = ce->name;
1498                         prune[prune_num-1] = NULL;
1499                 }
1500                 while ((i+1 < active_nr) &&
1501                        ce_same_name(ce, active_cache[i+1]))
1502                         i++;
1503         }
1504         clear_pathspec(&revs->prune_data);
1505         parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1506                        PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1507         revs->limited = 1;
1508 }
1509
1510 static int dotdot_missing(const char *arg, char *dotdot,
1511                           struct rev_info *revs, int symmetric)
1512 {
1513         if (revs->ignore_missing)
1514                 return 0;
1515         /* de-munge so we report the full argument */
1516         *dotdot = '.';
1517         die(symmetric
1518             ? "Invalid symmetric difference expression %s"
1519             : "Invalid revision range %s", arg);
1520 }
1521
1522 static int handle_dotdot_1(const char *arg, char *dotdot,
1523                            struct rev_info *revs, int flags,
1524                            int cant_be_filename,
1525                            struct object_context *a_oc,
1526                            struct object_context *b_oc)
1527 {
1528         const char *a_name, *b_name;
1529         struct object_id a_oid, b_oid;
1530         struct object *a_obj, *b_obj;
1531         unsigned int a_flags, b_flags;
1532         int symmetric = 0;
1533         unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1534         unsigned int oc_flags = GET_OID_COMMITTISH | GET_OID_RECORD_PATH;
1535
1536         a_name = arg;
1537         if (!*a_name)
1538                 a_name = "HEAD";
1539
1540         b_name = dotdot + 2;
1541         if (*b_name == '.') {
1542                 symmetric = 1;
1543                 b_name++;
1544         }
1545         if (!*b_name)
1546                 b_name = "HEAD";
1547
1548         if (get_oid_with_context(a_name, oc_flags, &a_oid, a_oc) ||
1549             get_oid_with_context(b_name, oc_flags, &b_oid, b_oc))
1550                 return -1;
1551
1552         if (!cant_be_filename) {
1553                 *dotdot = '.';
1554                 verify_non_filename(revs->prefix, arg);
1555                 *dotdot = '\0';
1556         }
1557
1558         a_obj = parse_object(&a_oid);
1559         b_obj = parse_object(&b_oid);
1560         if (!a_obj || !b_obj)
1561                 return dotdot_missing(arg, dotdot, revs, symmetric);
1562
1563         if (!symmetric) {
1564                 /* just A..B */
1565                 b_flags = flags;
1566                 a_flags = flags_exclude;
1567         } else {
1568                 /* A...B -- find merge bases between the two */
1569                 struct commit *a, *b;
1570                 struct commit_list *exclude;
1571
1572                 a = lookup_commit_reference(&a_obj->oid);
1573                 b = lookup_commit_reference(&b_obj->oid);
1574                 if (!a || !b)
1575                         return dotdot_missing(arg, dotdot, revs, symmetric);
1576
1577                 exclude = get_merge_bases(a, b);
1578                 add_rev_cmdline_list(revs, exclude, REV_CMD_MERGE_BASE,
1579                                      flags_exclude);
1580                 add_pending_commit_list(revs, exclude, flags_exclude);
1581                 free_commit_list(exclude);
1582
1583                 b_flags = flags;
1584                 a_flags = flags | SYMMETRIC_LEFT;
1585         }
1586
1587         a_obj->flags |= a_flags;
1588         b_obj->flags |= b_flags;
1589         add_rev_cmdline(revs, a_obj, a_name, REV_CMD_LEFT, a_flags);
1590         add_rev_cmdline(revs, b_obj, b_name, REV_CMD_RIGHT, b_flags);
1591         add_pending_object_with_path(revs, a_obj, a_name, a_oc->mode, a_oc->path);
1592         add_pending_object_with_path(revs, b_obj, b_name, b_oc->mode, b_oc->path);
1593         return 0;
1594 }
1595
1596 static int handle_dotdot(const char *arg,
1597                          struct rev_info *revs, int flags,
1598                          int cant_be_filename)
1599 {
1600         struct object_context a_oc, b_oc;
1601         char *dotdot = strstr(arg, "..");
1602         int ret;
1603
1604         if (!dotdot)
1605                 return -1;
1606
1607         memset(&a_oc, 0, sizeof(a_oc));
1608         memset(&b_oc, 0, sizeof(b_oc));
1609
1610         *dotdot = '\0';
1611         ret = handle_dotdot_1(arg, dotdot, revs, flags, cant_be_filename,
1612                               &a_oc, &b_oc);
1613         *dotdot = '.';
1614
1615         free(a_oc.path);
1616         free(b_oc.path);
1617
1618         return ret;
1619 }
1620
1621 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1622 {
1623         struct object_context oc;
1624         char *mark;
1625         struct object *object;
1626         struct object_id oid;
1627         int local_flags;
1628         const char *arg = arg_;
1629         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1630         unsigned get_sha1_flags = GET_OID_RECORD_PATH;
1631
1632         flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1633
1634         if (!cant_be_filename && !strcmp(arg, "..")) {
1635                 /*
1636                  * Just ".."?  That is not a range but the
1637                  * pathspec for the parent directory.
1638                  */
1639                 return -1;
1640         }
1641
1642         if (!handle_dotdot(arg, revs, flags, revarg_opt))
1643                 return 0;
1644
1645         mark = strstr(arg, "^@");
1646         if (mark && !mark[2]) {
1647                 *mark = 0;
1648                 if (add_parents_only(revs, arg, flags, 0))
1649                         return 0;
1650                 *mark = '^';
1651         }
1652         mark = strstr(arg, "^!");
1653         if (mark && !mark[2]) {
1654                 *mark = 0;
1655                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
1656                         *mark = '^';
1657         }
1658         mark = strstr(arg, "^-");
1659         if (mark) {
1660                 int exclude_parent = 1;
1661
1662                 if (mark[2]) {
1663                         char *end;
1664                         exclude_parent = strtoul(mark + 2, &end, 10);
1665                         if (*end != '\0' || !exclude_parent)
1666                                 return -1;
1667                 }
1668
1669                 *mark = 0;
1670                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
1671                         *mark = '^';
1672         }
1673
1674         local_flags = 0;
1675         if (*arg == '^') {
1676                 local_flags = UNINTERESTING | BOTTOM;
1677                 arg++;
1678         }
1679
1680         if (revarg_opt & REVARG_COMMITTISH)
1681                 get_sha1_flags |= GET_OID_COMMITTISH;
1682
1683         if (get_oid_with_context(arg, get_sha1_flags, &oid, &oc))
1684                 return revs->ignore_missing ? 0 : -1;
1685         if (!cant_be_filename)
1686                 verify_non_filename(revs->prefix, arg);
1687         object = get_reference(revs, arg, &oid, flags ^ local_flags);
1688         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1689         add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
1690         free(oc.path);
1691         return 0;
1692 }
1693
1694 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1695                                      struct argv_array *prune)
1696 {
1697         while (strbuf_getline(sb, stdin) != EOF)
1698                 argv_array_push(prune, sb->buf);
1699 }
1700
1701 static void read_revisions_from_stdin(struct rev_info *revs,
1702                                       struct argv_array *prune)
1703 {
1704         struct strbuf sb;
1705         int seen_dashdash = 0;
1706         int save_warning;
1707
1708         save_warning = warn_on_object_refname_ambiguity;
1709         warn_on_object_refname_ambiguity = 0;
1710
1711         strbuf_init(&sb, 1000);
1712         while (strbuf_getline(&sb, stdin) != EOF) {
1713                 int len = sb.len;
1714                 if (!len)
1715                         break;
1716                 if (sb.buf[0] == '-') {
1717                         if (len == 2 && sb.buf[1] == '-') {
1718                                 seen_dashdash = 1;
1719                                 break;
1720                         }
1721                         die("options not supported in --stdin mode");
1722                 }
1723                 if (handle_revision_arg(sb.buf, revs, 0,
1724                                         REVARG_CANNOT_BE_FILENAME))
1725                         die("bad revision '%s'", sb.buf);
1726         }
1727         if (seen_dashdash)
1728                 read_pathspec_from_stdin(revs, &sb, prune);
1729
1730         strbuf_release(&sb);
1731         warn_on_object_refname_ambiguity = save_warning;
1732 }
1733
1734 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1735 {
1736         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1737 }
1738
1739 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1740 {
1741         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1742 }
1743
1744 static void add_message_grep(struct rev_info *revs, const char *pattern)
1745 {
1746         add_grep(revs, pattern, GREP_PATTERN_BODY);
1747 }
1748
1749 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1750                                int *unkc, const char **unkv)
1751 {
1752         const char *arg = argv[0];
1753         const char *optarg;
1754         int argcount;
1755
1756         /* pseudo revision arguments */
1757         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1758             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1759             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1760             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1761             !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
1762             !strcmp(arg, "--indexed-objects") ||
1763             starts_with(arg, "--exclude=") ||
1764             starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
1765             starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
1766         {
1767                 unkv[(*unkc)++] = arg;
1768                 return 1;
1769         }
1770
1771         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1772                 revs->max_count = atoi(optarg);
1773                 revs->no_walk = 0;
1774                 return argcount;
1775         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1776                 revs->skip_count = atoi(optarg);
1777                 return argcount;
1778         } else if ((*arg == '-') && isdigit(arg[1])) {
1779                 /* accept -<digit>, like traditional "head" */
1780                 if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
1781                     revs->max_count < 0)
1782                         die("'%s': not a non-negative integer", arg + 1);
1783                 revs->no_walk = 0;
1784         } else if (!strcmp(arg, "-n")) {
1785                 if (argc <= 1)
1786                         return error("-n requires an argument");
1787                 revs->max_count = atoi(argv[1]);
1788                 revs->no_walk = 0;
1789                 return 2;
1790         } else if (skip_prefix(arg, "-n", &optarg)) {
1791                 revs->max_count = atoi(optarg);
1792                 revs->no_walk = 0;
1793         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1794                 revs->max_age = atoi(optarg);
1795                 return argcount;
1796         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1797                 revs->max_age = approxidate(optarg);
1798                 return argcount;
1799         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1800                 revs->max_age = approxidate(optarg);
1801                 return argcount;
1802         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1803                 revs->min_age = atoi(optarg);
1804                 return argcount;
1805         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1806                 revs->min_age = approxidate(optarg);
1807                 return argcount;
1808         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1809                 revs->min_age = approxidate(optarg);
1810                 return argcount;
1811         } else if (!strcmp(arg, "--first-parent")) {
1812                 revs->first_parent_only = 1;
1813         } else if (!strcmp(arg, "--ancestry-path")) {
1814                 revs->ancestry_path = 1;
1815                 revs->simplify_history = 0;
1816                 revs->limited = 1;
1817         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1818                 init_reflog_walk(&revs->reflog_info);
1819         } else if (!strcmp(arg, "--default")) {
1820                 if (argc <= 1)
1821                         return error("bad --default argument");
1822                 revs->def = argv[1];
1823                 return 2;
1824         } else if (!strcmp(arg, "--merge")) {
1825                 revs->show_merge = 1;
1826         } else if (!strcmp(arg, "--topo-order")) {
1827                 revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1828                 revs->topo_order = 1;
1829         } else if (!strcmp(arg, "--simplify-merges")) {
1830                 revs->simplify_merges = 1;
1831                 revs->topo_order = 1;
1832                 revs->rewrite_parents = 1;
1833                 revs->simplify_history = 0;
1834                 revs->limited = 1;
1835         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1836                 revs->simplify_merges = 1;
1837                 revs->topo_order = 1;
1838                 revs->rewrite_parents = 1;
1839                 revs->simplify_history = 0;
1840                 revs->simplify_by_decoration = 1;
1841                 revs->limited = 1;
1842                 revs->prune = 1;
1843                 load_ref_decorations(NULL, DECORATE_SHORT_REFS);
1844         } else if (!strcmp(arg, "--date-order")) {
1845                 revs->sort_order = REV_SORT_BY_COMMIT_DATE;
1846                 revs->topo_order = 1;
1847         } else if (!strcmp(arg, "--author-date-order")) {
1848                 revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
1849                 revs->topo_order = 1;
1850         } else if (!strcmp(arg, "--early-output")) {
1851                 revs->early_output = 100;
1852                 revs->topo_order = 1;
1853         } else if (skip_prefix(arg, "--early-output=", &optarg)) {
1854                 if (strtoul_ui(optarg, 10, &revs->early_output) < 0)
1855                         die("'%s': not a non-negative integer", optarg);
1856                 revs->topo_order = 1;
1857         } else if (!strcmp(arg, "--parents")) {
1858                 revs->rewrite_parents = 1;
1859                 revs->print_parents = 1;
1860         } else if (!strcmp(arg, "--dense")) {
1861                 revs->dense = 1;
1862         } else if (!strcmp(arg, "--sparse")) {
1863                 revs->dense = 0;
1864         } else if (!strcmp(arg, "--in-commit-order")) {
1865                 revs->tree_blobs_in_commit_order = 1;
1866         } else if (!strcmp(arg, "--remove-empty")) {
1867                 revs->remove_empty_trees = 1;
1868         } else if (!strcmp(arg, "--merges")) {
1869                 revs->min_parents = 2;
1870         } else if (!strcmp(arg, "--no-merges")) {
1871                 revs->max_parents = 1;
1872         } else if (skip_prefix(arg, "--min-parents=", &optarg)) {
1873                 revs->min_parents = atoi(optarg);
1874         } else if (!strcmp(arg, "--no-min-parents")) {
1875                 revs->min_parents = 0;
1876         } else if (skip_prefix(arg, "--max-parents=", &optarg)) {
1877                 revs->max_parents = atoi(optarg);
1878         } else if (!strcmp(arg, "--no-max-parents")) {
1879                 revs->max_parents = -1;
1880         } else if (!strcmp(arg, "--boundary")) {
1881                 revs->boundary = 1;
1882         } else if (!strcmp(arg, "--left-right")) {
1883                 revs->left_right = 1;
1884         } else if (!strcmp(arg, "--left-only")) {
1885                 if (revs->right_only)
1886                         die("--left-only is incompatible with --right-only"
1887                             " or --cherry");
1888                 revs->left_only = 1;
1889         } else if (!strcmp(arg, "--right-only")) {
1890                 if (revs->left_only)
1891                         die("--right-only is incompatible with --left-only");
1892                 revs->right_only = 1;
1893         } else if (!strcmp(arg, "--cherry")) {
1894                 if (revs->left_only)
1895                         die("--cherry is incompatible with --left-only");
1896                 revs->cherry_mark = 1;
1897                 revs->right_only = 1;
1898                 revs->max_parents = 1;
1899                 revs->limited = 1;
1900         } else if (!strcmp(arg, "--count")) {
1901                 revs->count = 1;
1902         } else if (!strcmp(arg, "--cherry-mark")) {
1903                 if (revs->cherry_pick)
1904                         die("--cherry-mark is incompatible with --cherry-pick");
1905                 revs->cherry_mark = 1;
1906                 revs->limited = 1; /* needs limit_list() */
1907         } else if (!strcmp(arg, "--cherry-pick")) {
1908                 if (revs->cherry_mark)
1909                         die("--cherry-pick is incompatible with --cherry-mark");
1910                 revs->cherry_pick = 1;
1911                 revs->limited = 1;
1912         } else if (!strcmp(arg, "--objects")) {
1913                 revs->tag_objects = 1;
1914                 revs->tree_objects = 1;
1915                 revs->blob_objects = 1;
1916         } else if (!strcmp(arg, "--objects-edge")) {
1917                 revs->tag_objects = 1;
1918                 revs->tree_objects = 1;
1919                 revs->blob_objects = 1;
1920                 revs->edge_hint = 1;
1921         } else if (!strcmp(arg, "--objects-edge-aggressive")) {
1922                 revs->tag_objects = 1;
1923                 revs->tree_objects = 1;
1924                 revs->blob_objects = 1;
1925                 revs->edge_hint = 1;
1926                 revs->edge_hint_aggressive = 1;
1927         } else if (!strcmp(arg, "--verify-objects")) {
1928                 revs->tag_objects = 1;
1929                 revs->tree_objects = 1;
1930                 revs->blob_objects = 1;
1931                 revs->verify_objects = 1;
1932         } else if (!strcmp(arg, "--unpacked")) {
1933                 revs->unpacked = 1;
1934         } else if (starts_with(arg, "--unpacked=")) {
1935                 die("--unpacked=<packfile> no longer supported.");
1936         } else if (!strcmp(arg, "-r")) {
1937                 revs->diff = 1;
1938                 revs->diffopt.flags.recursive = 1;
1939         } else if (!strcmp(arg, "-t")) {
1940                 revs->diff = 1;
1941                 revs->diffopt.flags.recursive = 1;
1942                 revs->diffopt.flags.tree_in_recursive = 1;
1943         } else if (!strcmp(arg, "-m")) {
1944                 revs->ignore_merges = 0;
1945         } else if (!strcmp(arg, "-c")) {
1946                 revs->diff = 1;
1947                 revs->dense_combined_merges = 0;
1948                 revs->combine_merges = 1;
1949         } else if (!strcmp(arg, "--cc")) {
1950                 revs->diff = 1;
1951                 revs->dense_combined_merges = 1;
1952                 revs->combine_merges = 1;
1953         } else if (!strcmp(arg, "-v")) {
1954                 revs->verbose_header = 1;
1955         } else if (!strcmp(arg, "--pretty")) {
1956                 revs->verbose_header = 1;
1957                 revs->pretty_given = 1;
1958                 get_commit_format(NULL, revs);
1959         } else if (skip_prefix(arg, "--pretty=", &optarg) ||
1960                    skip_prefix(arg, "--format=", &optarg)) {
1961                 /*
1962                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1963                  * not allowed, since the argument is optional.
1964                  */
1965                 revs->verbose_header = 1;
1966                 revs->pretty_given = 1;
1967                 get_commit_format(optarg, revs);
1968         } else if (!strcmp(arg, "--expand-tabs")) {
1969                 revs->expand_tabs_in_log = 8;
1970         } else if (!strcmp(arg, "--no-expand-tabs")) {
1971                 revs->expand_tabs_in_log = 0;
1972         } else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
1973                 int val;
1974                 if (strtol_i(arg, 10, &val) < 0 || val < 0)
1975                         die("'%s': not a non-negative integer", arg);
1976                 revs->expand_tabs_in_log = val;
1977         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1978                 revs->show_notes = 1;
1979                 revs->show_notes_given = 1;
1980                 revs->notes_opt.use_default_notes = 1;
1981         } else if (!strcmp(arg, "--show-signature")) {
1982                 revs->show_signature = 1;
1983         } else if (!strcmp(arg, "--no-show-signature")) {
1984                 revs->show_signature = 0;
1985         } else if (!strcmp(arg, "--show-linear-break")) {
1986                 revs->break_bar = "                    ..........";
1987                 revs->track_linear = 1;
1988                 revs->track_first_time = 1;
1989         } else if (skip_prefix(arg, "--show-linear-break=", &optarg)) {
1990                 revs->break_bar = xstrdup(optarg);
1991                 revs->track_linear = 1;
1992                 revs->track_first_time = 1;
1993         } else if (skip_prefix(arg, "--show-notes=", &optarg) ||
1994                    skip_prefix(arg, "--notes=", &optarg)) {
1995                 struct strbuf buf = STRBUF_INIT;
1996                 revs->show_notes = 1;
1997                 revs->show_notes_given = 1;
1998                 if (starts_with(arg, "--show-notes=") &&
1999                     revs->notes_opt.use_default_notes < 0)
2000                         revs->notes_opt.use_default_notes = 1;
2001                 strbuf_addstr(&buf, optarg);
2002                 expand_notes_ref(&buf);
2003                 string_list_append(&revs->notes_opt.extra_notes_refs,
2004                                    strbuf_detach(&buf, NULL));
2005         } else if (!strcmp(arg, "--no-notes")) {
2006                 revs->show_notes = 0;
2007                 revs->show_notes_given = 1;
2008                 revs->notes_opt.use_default_notes = -1;
2009                 /* we have been strdup'ing ourselves, so trick
2010                  * string_list into free()ing strings */
2011                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
2012                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
2013                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
2014         } else if (!strcmp(arg, "--standard-notes")) {
2015                 revs->show_notes_given = 1;
2016                 revs->notes_opt.use_default_notes = 1;
2017         } else if (!strcmp(arg, "--no-standard-notes")) {
2018                 revs->notes_opt.use_default_notes = 0;
2019         } else if (!strcmp(arg, "--oneline")) {
2020                 revs->verbose_header = 1;
2021                 get_commit_format("oneline", revs);
2022                 revs->pretty_given = 1;
2023                 revs->abbrev_commit = 1;
2024         } else if (!strcmp(arg, "--graph")) {
2025                 revs->topo_order = 1;
2026                 revs->rewrite_parents = 1;
2027                 revs->graph = graph_init(revs);
2028         } else if (!strcmp(arg, "--root")) {
2029                 revs->show_root_diff = 1;
2030         } else if (!strcmp(arg, "--no-commit-id")) {
2031                 revs->no_commit_id = 1;
2032         } else if (!strcmp(arg, "--always")) {
2033                 revs->always_show_header = 1;
2034         } else if (!strcmp(arg, "--no-abbrev")) {
2035                 revs->abbrev = 0;
2036         } else if (!strcmp(arg, "--abbrev")) {
2037                 revs->abbrev = DEFAULT_ABBREV;
2038         } else if (skip_prefix(arg, "--abbrev=", &optarg)) {
2039                 revs->abbrev = strtoul(optarg, NULL, 10);
2040                 if (revs->abbrev < MINIMUM_ABBREV)
2041                         revs->abbrev = MINIMUM_ABBREV;
2042                 else if (revs->abbrev > 40)
2043                         revs->abbrev = 40;
2044         } else if (!strcmp(arg, "--abbrev-commit")) {
2045                 revs->abbrev_commit = 1;
2046                 revs->abbrev_commit_given = 1;
2047         } else if (!strcmp(arg, "--no-abbrev-commit")) {
2048                 revs->abbrev_commit = 0;
2049         } else if (!strcmp(arg, "--full-diff")) {
2050                 revs->diff = 1;
2051                 revs->full_diff = 1;
2052         } else if (!strcmp(arg, "--full-history")) {
2053                 revs->simplify_history = 0;
2054         } else if (!strcmp(arg, "--relative-date")) {
2055                 revs->date_mode.type = DATE_RELATIVE;
2056                 revs->date_mode_explicit = 1;
2057         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
2058                 parse_date_format(optarg, &revs->date_mode);
2059                 revs->date_mode_explicit = 1;
2060                 return argcount;
2061         } else if (!strcmp(arg, "--log-size")) {
2062                 revs->show_log_size = 1;
2063         }
2064         /*
2065          * Grepping the commit log
2066          */
2067         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
2068                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
2069                 return argcount;
2070         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
2071                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
2072                 return argcount;
2073         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
2074                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
2075                 return argcount;
2076         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
2077                 add_message_grep(revs, optarg);
2078                 return argcount;
2079         } else if (!strcmp(arg, "--grep-debug")) {
2080                 revs->grep_filter.debug = 1;
2081         } else if (!strcmp(arg, "--basic-regexp")) {
2082                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_BRE;
2083         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
2084                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
2085         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
2086                 revs->grep_filter.ignore_case = 1;
2087                 revs->diffopt.pickaxe_opts |= DIFF_PICKAXE_IGNORE_CASE;
2088         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
2089                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
2090         } else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
2091                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_PCRE;
2092         } else if (!strcmp(arg, "--all-match")) {
2093                 revs->grep_filter.all_match = 1;
2094         } else if (!strcmp(arg, "--invert-grep")) {
2095                 revs->invert_grep = 1;
2096         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2097                 if (strcmp(optarg, "none"))
2098                         git_log_output_encoding = xstrdup(optarg);
2099                 else
2100                         git_log_output_encoding = "";
2101                 return argcount;
2102         } else if (!strcmp(arg, "--reverse")) {
2103                 revs->reverse ^= 1;
2104         } else if (!strcmp(arg, "--children")) {
2105                 revs->children.name = "children";
2106                 revs->limited = 1;
2107         } else if (!strcmp(arg, "--ignore-missing")) {
2108                 revs->ignore_missing = 1;
2109         } else if (!strcmp(arg, "--exclude-promisor-objects")) {
2110                 if (fetch_if_missing)
2111                         die("BUG: exclude_promisor_objects can only be used when fetch_if_missing is 0");
2112                 revs->exclude_promisor_objects = 1;
2113         } else {
2114                 int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
2115                 if (!opts)
2116                         unkv[(*unkc)++] = arg;
2117                 return opts;
2118         }
2119         if (revs->graph && revs->track_linear)
2120                 die("--show-linear-break and --graph are incompatible");
2121
2122         return 1;
2123 }
2124
2125 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2126                         const struct option *options,
2127                         const char * const usagestr[])
2128 {
2129         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2130                                     &ctx->cpidx, ctx->out);
2131         if (n <= 0) {
2132                 error("unknown option `%s'", ctx->argv[0]);
2133                 usage_with_options(usagestr, options);
2134         }
2135         ctx->argv += n;
2136         ctx->argc -= n;
2137 }
2138
2139 static int for_each_bisect_ref(struct ref_store *refs, each_ref_fn fn,
2140                                void *cb_data, const char *term)
2141 {
2142         struct strbuf bisect_refs = STRBUF_INIT;
2143         int status;
2144         strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2145         status = refs_for_each_fullref_in(refs, bisect_refs.buf, fn, cb_data, 0);
2146         strbuf_release(&bisect_refs);
2147         return status;
2148 }
2149
2150 static int for_each_bad_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2151 {
2152         return for_each_bisect_ref(refs, fn, cb_data, term_bad);
2153 }
2154
2155 static int for_each_good_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2156 {
2157         return for_each_bisect_ref(refs, fn, cb_data, term_good);
2158 }
2159
2160 static int handle_revision_pseudo_opt(const char *submodule,
2161                                 struct rev_info *revs,
2162                                 int argc, const char **argv, int *flags)
2163 {
2164         const char *arg = argv[0];
2165         const char *optarg;
2166         struct ref_store *refs;
2167         int argcount;
2168
2169         if (submodule) {
2170                 /*
2171                  * We need some something like get_submodule_worktrees()
2172                  * before we can go through all worktrees of a submodule,
2173                  * .e.g with adding all HEADs from --all, which is not
2174                  * supported right now, so stick to single worktree.
2175                  */
2176                 if (!revs->single_worktree)
2177                         die("BUG: --single-worktree cannot be used together with submodule");
2178                 refs = get_submodule_ref_store(submodule);
2179         } else
2180                 refs = get_main_ref_store(the_repository);
2181
2182         /*
2183          * NOTE!
2184          *
2185          * Commands like "git shortlog" will not accept the options below
2186          * unless parse_revision_opt queues them (as opposed to erroring
2187          * out).
2188          *
2189          * When implementing your new pseudo-option, remember to
2190          * register it in the list at the top of handle_revision_opt.
2191          */
2192         if (!strcmp(arg, "--all")) {
2193                 handle_refs(refs, revs, *flags, refs_for_each_ref);
2194                 handle_refs(refs, revs, *flags, refs_head_ref);
2195                 if (!revs->single_worktree) {
2196                         struct all_refs_cb cb;
2197
2198                         init_all_refs_cb(&cb, revs, *flags);
2199                         other_head_refs(handle_one_ref, &cb);
2200                 }
2201                 clear_ref_exclusion(&revs->ref_excludes);
2202         } else if (!strcmp(arg, "--branches")) {
2203                 handle_refs(refs, revs, *flags, refs_for_each_branch_ref);
2204                 clear_ref_exclusion(&revs->ref_excludes);
2205         } else if (!strcmp(arg, "--bisect")) {
2206                 read_bisect_terms(&term_bad, &term_good);
2207                 handle_refs(refs, revs, *flags, for_each_bad_bisect_ref);
2208                 handle_refs(refs, revs, *flags ^ (UNINTERESTING | BOTTOM),
2209                             for_each_good_bisect_ref);
2210                 revs->bisect = 1;
2211         } else if (!strcmp(arg, "--tags")) {
2212                 handle_refs(refs, revs, *flags, refs_for_each_tag_ref);
2213                 clear_ref_exclusion(&revs->ref_excludes);
2214         } else if (!strcmp(arg, "--remotes")) {
2215                 handle_refs(refs, revs, *flags, refs_for_each_remote_ref);
2216                 clear_ref_exclusion(&revs->ref_excludes);
2217         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2218                 struct all_refs_cb cb;
2219                 init_all_refs_cb(&cb, revs, *flags);
2220                 for_each_glob_ref(handle_one_ref, optarg, &cb);
2221                 clear_ref_exclusion(&revs->ref_excludes);
2222                 return argcount;
2223         } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2224                 add_ref_exclusion(&revs->ref_excludes, optarg);
2225                 return argcount;
2226         } else if (skip_prefix(arg, "--branches=", &optarg)) {
2227                 struct all_refs_cb cb;
2228                 init_all_refs_cb(&cb, revs, *flags);
2229                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/heads/", &cb);
2230                 clear_ref_exclusion(&revs->ref_excludes);
2231         } else if (skip_prefix(arg, "--tags=", &optarg)) {
2232                 struct all_refs_cb cb;
2233                 init_all_refs_cb(&cb, revs, *flags);
2234                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/tags/", &cb);
2235                 clear_ref_exclusion(&revs->ref_excludes);
2236         } else if (skip_prefix(arg, "--remotes=", &optarg)) {
2237                 struct all_refs_cb cb;
2238                 init_all_refs_cb(&cb, revs, *flags);
2239                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/remotes/", &cb);
2240                 clear_ref_exclusion(&revs->ref_excludes);
2241         } else if (!strcmp(arg, "--reflog")) {
2242                 add_reflogs_to_pending(revs, *flags);
2243         } else if (!strcmp(arg, "--indexed-objects")) {
2244                 add_index_objects_to_pending(revs, *flags);
2245         } else if (!strcmp(arg, "--not")) {
2246                 *flags ^= UNINTERESTING | BOTTOM;
2247         } else if (!strcmp(arg, "--no-walk")) {
2248                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2249         } else if (skip_prefix(arg, "--no-walk=", &optarg)) {
2250                 /*
2251                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2252                  * not allowed, since the argument is optional.
2253                  */
2254                 if (!strcmp(optarg, "sorted"))
2255                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2256                 else if (!strcmp(optarg, "unsorted"))
2257                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2258                 else
2259                         return error("invalid argument to --no-walk");
2260         } else if (!strcmp(arg, "--do-walk")) {
2261                 revs->no_walk = 0;
2262         } else if (!strcmp(arg, "--single-worktree")) {
2263                 revs->single_worktree = 1;
2264         } else {
2265                 return 0;
2266         }
2267
2268         return 1;
2269 }
2270
2271 static void NORETURN diagnose_missing_default(const char *def)
2272 {
2273         int flags;
2274         const char *refname;
2275
2276         refname = resolve_ref_unsafe(def, 0, NULL, &flags);
2277         if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2278                 die(_("your current branch appears to be broken"));
2279
2280         skip_prefix(refname, "refs/heads/", &refname);
2281         die(_("your current branch '%s' does not have any commits yet"),
2282             refname);
2283 }
2284
2285 /*
2286  * Parse revision information, filling in the "rev_info" structure,
2287  * and removing the used arguments from the argument list.
2288  *
2289  * Returns the number of arguments left that weren't recognized
2290  * (which are also moved to the head of the argument list)
2291  */
2292 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2293 {
2294         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
2295         struct argv_array prune_data = ARGV_ARRAY_INIT;
2296         const char *submodule = NULL;
2297
2298         if (opt)
2299                 submodule = opt->submodule;
2300
2301         /* First, search for "--" */
2302         if (opt && opt->assume_dashdash) {
2303                 seen_dashdash = 1;
2304         } else {
2305                 seen_dashdash = 0;
2306                 for (i = 1; i < argc; i++) {
2307                         const char *arg = argv[i];
2308                         if (strcmp(arg, "--"))
2309                                 continue;
2310                         argv[i] = NULL;
2311                         argc = i;
2312                         if (argv[i + 1])
2313                                 argv_array_pushv(&prune_data, argv + i + 1);
2314                         seen_dashdash = 1;
2315                         break;
2316                 }
2317         }
2318
2319         /* Second, deal with arguments and options */
2320         flags = 0;
2321         revarg_opt = opt ? opt->revarg_opt : 0;
2322         if (seen_dashdash)
2323                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2324         read_from_stdin = 0;
2325         for (left = i = 1; i < argc; i++) {
2326                 const char *arg = argv[i];
2327                 if (*arg == '-') {
2328                         int opts;
2329
2330                         opts = handle_revision_pseudo_opt(submodule,
2331                                                 revs, argc - i, argv + i,
2332                                                 &flags);
2333                         if (opts > 0) {
2334                                 i += opts - 1;
2335                                 continue;
2336                         }
2337
2338                         if (!strcmp(arg, "--stdin")) {
2339                                 if (revs->disable_stdin) {
2340                                         argv[left++] = arg;
2341                                         continue;
2342                                 }
2343                                 if (read_from_stdin++)
2344                                         die("--stdin given twice?");
2345                                 read_revisions_from_stdin(revs, &prune_data);
2346                                 continue;
2347                         }
2348
2349                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
2350                         if (opts > 0) {
2351                                 i += opts - 1;
2352                                 continue;
2353                         }
2354                         if (opts < 0)
2355                                 exit(128);
2356                         continue;
2357                 }
2358
2359
2360                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2361                         int j;
2362                         if (seen_dashdash || *arg == '^')
2363                                 die("bad revision '%s'", arg);
2364
2365                         /* If we didn't have a "--":
2366                          * (1) all filenames must exist;
2367                          * (2) all rev-args must not be interpretable
2368                          *     as a valid filename.
2369                          * but the latter we have checked in the main loop.
2370                          */
2371                         for (j = i; j < argc; j++)
2372                                 verify_filename(revs->prefix, argv[j], j == i);
2373
2374                         argv_array_pushv(&prune_data, argv + i);
2375                         break;
2376                 }
2377                 else
2378                         got_rev_arg = 1;
2379         }
2380
2381         if (prune_data.argc) {
2382                 /*
2383                  * If we need to introduce the magic "a lone ':' means no
2384                  * pathspec whatsoever", here is the place to do so.
2385                  *
2386                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2387                  *      prune_data.nr = 0;
2388                  *      prune_data.alloc = 0;
2389                  *      free(prune_data.path);
2390                  *      prune_data.path = NULL;
2391                  * } else {
2392                  *      terminate prune_data.alloc with NULL and
2393                  *      call init_pathspec() to set revs->prune_data here.
2394                  * }
2395                  */
2396                 parse_pathspec(&revs->prune_data, 0, 0,
2397                                revs->prefix, prune_data.argv);
2398         }
2399         argv_array_clear(&prune_data);
2400
2401         if (revs->def == NULL)
2402                 revs->def = opt ? opt->def : NULL;
2403         if (opt && opt->tweak)
2404                 opt->tweak(revs, opt);
2405         if (revs->show_merge)
2406                 prepare_show_merge(revs);
2407         if (revs->def && !revs->pending.nr && !revs->rev_input_given && !got_rev_arg) {
2408                 struct object_id oid;
2409                 struct object *object;
2410                 struct object_context oc;
2411                 if (get_oid_with_context(revs->def, 0, &oid, &oc))
2412                         diagnose_missing_default(revs->def);
2413                 object = get_reference(revs, revs->def, &oid, 0);
2414                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2415         }
2416
2417         /* Did the user ask for any diff output? Run the diff! */
2418         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2419                 revs->diff = 1;
2420
2421         /* Pickaxe, diff-filter and rename following need diffs */
2422         if ((revs->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
2423             revs->diffopt.filter ||
2424             revs->diffopt.flags.follow_renames)
2425                 revs->diff = 1;
2426
2427         if (revs->diffopt.objfind)
2428                 revs->simplify_history = 0;
2429
2430         if (revs->topo_order)
2431                 revs->limited = 1;
2432
2433         if (revs->prune_data.nr) {
2434                 copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2435                 /* Can't prune commits with rename following: the paths change.. */
2436                 if (!revs->diffopt.flags.follow_renames)
2437                         revs->prune = 1;
2438                 if (!revs->full_diff)
2439                         copy_pathspec(&revs->diffopt.pathspec,
2440                                       &revs->prune_data);
2441         }
2442         if (revs->combine_merges)
2443                 revs->ignore_merges = 0;
2444         revs->diffopt.abbrev = revs->abbrev;
2445
2446         if (revs->line_level_traverse) {
2447                 revs->limited = 1;
2448                 revs->topo_order = 1;
2449         }
2450
2451         diff_setup_done(&revs->diffopt);
2452
2453         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2454                                  &revs->grep_filter);
2455         compile_grep_patterns(&revs->grep_filter);
2456
2457         if (revs->reverse && revs->reflog_info)
2458                 die("cannot combine --reverse with --walk-reflogs");
2459         if (revs->reflog_info && revs->limited)
2460                 die("cannot combine --walk-reflogs with history-limiting options");
2461         if (revs->rewrite_parents && revs->children.name)
2462                 die("cannot combine --parents and --children");
2463
2464         /*
2465          * Limitations on the graph functionality
2466          */
2467         if (revs->reverse && revs->graph)
2468                 die("cannot combine --reverse with --graph");
2469
2470         if (revs->reflog_info && revs->graph)
2471                 die("cannot combine --walk-reflogs with --graph");
2472         if (revs->no_walk && revs->graph)
2473                 die("cannot combine --no-walk with --graph");
2474         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2475                 die("cannot use --grep-reflog without --walk-reflogs");
2476
2477         if (revs->first_parent_only && revs->bisect)
2478                 die(_("--first-parent is incompatible with --bisect"));
2479
2480         if (revs->expand_tabs_in_log < 0)
2481                 revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
2482
2483         return left;
2484 }
2485
2486 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2487 {
2488         struct commit_list *l = xcalloc(1, sizeof(*l));
2489
2490         l->item = child;
2491         l->next = add_decoration(&revs->children, &parent->object, l);
2492 }
2493
2494 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2495 {
2496         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2497         struct commit_list **pp, *p;
2498         int surviving_parents;
2499
2500         /* Examine existing parents while marking ones we have seen... */
2501         pp = &commit->parents;
2502         surviving_parents = 0;
2503         while ((p = *pp) != NULL) {
2504                 struct commit *parent = p->item;
2505                 if (parent->object.flags & TMP_MARK) {
2506                         *pp = p->next;
2507                         if (ts)
2508                                 compact_treesame(revs, commit, surviving_parents);
2509                         continue;
2510                 }
2511                 parent->object.flags |= TMP_MARK;
2512                 surviving_parents++;
2513                 pp = &p->next;
2514         }
2515         /* clear the temporary mark */
2516         for (p = commit->parents; p; p = p->next) {
2517                 p->item->object.flags &= ~TMP_MARK;
2518         }
2519         /* no update_treesame() - removing duplicates can't affect TREESAME */
2520         return surviving_parents;
2521 }
2522
2523 struct merge_simplify_state {
2524         struct commit *simplified;
2525 };
2526
2527 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2528 {
2529         struct merge_simplify_state *st;
2530
2531         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2532         if (!st) {
2533                 st = xcalloc(1, sizeof(*st));
2534                 add_decoration(&revs->merge_simplification, &commit->object, st);
2535         }
2536         return st;
2537 }
2538
2539 static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2540 {
2541         struct commit_list *h = reduce_heads(commit->parents);
2542         int i = 0, marked = 0;
2543         struct commit_list *po, *pn;
2544
2545         /* Want these for sanity-checking only */
2546         int orig_cnt = commit_list_count(commit->parents);
2547         int cnt = commit_list_count(h);
2548
2549         /*
2550          * Not ready to remove items yet, just mark them for now, based
2551          * on the output of reduce_heads(). reduce_heads outputs the reduced
2552          * set in its original order, so this isn't too hard.
2553          */
2554         po = commit->parents;
2555         pn = h;
2556         while (po) {
2557                 if (pn && po->item == pn->item) {
2558                         pn = pn->next;
2559                         i++;
2560                 } else {
2561                         po->item->object.flags |= TMP_MARK;
2562                         marked++;
2563                 }
2564                 po=po->next;
2565         }
2566
2567         if (i != cnt || cnt+marked != orig_cnt)
2568                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2569
2570         free_commit_list(h);
2571
2572         return marked;
2573 }
2574
2575 static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2576 {
2577         struct commit_list *p;
2578         int marked = 0;
2579
2580         for (p = commit->parents; p; p = p->next) {
2581                 struct commit *parent = p->item;
2582                 if (!parent->parents && (parent->object.flags & TREESAME)) {
2583                         parent->object.flags |= TMP_MARK;
2584                         marked++;
2585                 }
2586         }
2587
2588         return marked;
2589 }
2590
2591 /*
2592  * Awkward naming - this means one parent we are TREESAME to.
2593  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2594  * empty tree). Better name suggestions?
2595  */
2596 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2597 {
2598         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2599         struct commit *unmarked = NULL, *marked = NULL;
2600         struct commit_list *p;
2601         unsigned n;
2602
2603         for (p = commit->parents, n = 0; p; p = p->next, n++) {
2604                 if (ts->treesame[n]) {
2605                         if (p->item->object.flags & TMP_MARK) {
2606                                 if (!marked)
2607                                         marked = p->item;
2608                         } else {
2609                                 if (!unmarked) {
2610                                         unmarked = p->item;
2611                                         break;
2612                                 }
2613                         }
2614                 }
2615         }
2616
2617         /*
2618          * If we are TREESAME to a marked-for-deletion parent, but not to any
2619          * unmarked parents, unmark the first TREESAME parent. This is the
2620          * parent that the default simplify_history==1 scan would have followed,
2621          * and it doesn't make sense to omit that path when asking for a
2622          * simplified full history. Retaining it improves the chances of
2623          * understanding odd missed merges that took an old version of a file.
2624          *
2625          * Example:
2626          *
2627          *   I--------*X       A modified the file, but mainline merge X used
2628          *    \       /        "-s ours", so took the version from I. X is
2629          *     `-*A--'         TREESAME to I and !TREESAME to A.
2630          *
2631          * Default log from X would produce "I". Without this check,
2632          * --full-history --simplify-merges would produce "I-A-X", showing
2633          * the merge commit X and that it changed A, but not making clear that
2634          * it had just taken the I version. With this check, the topology above
2635          * is retained.
2636          *
2637          * Note that it is possible that the simplification chooses a different
2638          * TREESAME parent from the default, in which case this test doesn't
2639          * activate, and we _do_ drop the default parent. Example:
2640          *
2641          *   I------X         A modified the file, but it was reverted in B,
2642          *    \    /          meaning mainline merge X is TREESAME to both
2643          *    *A-*B           parents.
2644          *
2645          * Default log would produce "I" by following the first parent;
2646          * --full-history --simplify-merges will produce "I-A-B". But this is a
2647          * reasonable result - it presents a logical full history leading from
2648          * I to X, and X is not an important merge.
2649          */
2650         if (!unmarked && marked) {
2651                 marked->object.flags &= ~TMP_MARK;
2652                 return 1;
2653         }
2654
2655         return 0;
2656 }
2657
2658 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2659 {
2660         struct commit_list **pp, *p;
2661         int nth_parent, removed = 0;
2662
2663         pp = &commit->parents;
2664         nth_parent = 0;
2665         while ((p = *pp) != NULL) {
2666                 struct commit *parent = p->item;
2667                 if (parent->object.flags & TMP_MARK) {
2668                         parent->object.flags &= ~TMP_MARK;
2669                         *pp = p->next;
2670                         free(p);
2671                         removed++;
2672                         compact_treesame(revs, commit, nth_parent);
2673                         continue;
2674                 }
2675                 pp = &p->next;
2676                 nth_parent++;
2677         }
2678
2679         /* Removing parents can only increase TREESAMEness */
2680         if (removed && !(commit->object.flags & TREESAME))
2681                 update_treesame(revs, commit);
2682
2683         return nth_parent;
2684 }
2685
2686 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2687 {
2688         struct commit_list *p;
2689         struct commit *parent;
2690         struct merge_simplify_state *st, *pst;
2691         int cnt;
2692
2693         st = locate_simplify_state(revs, commit);
2694
2695         /*
2696          * Have we handled this one?
2697          */
2698         if (st->simplified)
2699                 return tail;
2700
2701         /*
2702          * An UNINTERESTING commit simplifies to itself, so does a
2703          * root commit.  We do not rewrite parents of such commit
2704          * anyway.
2705          */
2706         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2707                 st->simplified = commit;
2708                 return tail;
2709         }
2710
2711         /*
2712          * Do we know what commit all of our parents that matter
2713          * should be rewritten to?  Otherwise we are not ready to
2714          * rewrite this one yet.
2715          */
2716         for (cnt = 0, p = commit->parents; p; p = p->next) {
2717                 pst = locate_simplify_state(revs, p->item);
2718                 if (!pst->simplified) {
2719                         tail = &commit_list_insert(p->item, tail)->next;
2720                         cnt++;
2721                 }
2722                 if (revs->first_parent_only)
2723                         break;
2724         }
2725         if (cnt) {
2726                 tail = &commit_list_insert(commit, tail)->next;
2727                 return tail;
2728         }
2729
2730         /*
2731          * Rewrite our list of parents. Note that this cannot
2732          * affect our TREESAME flags in any way - a commit is
2733          * always TREESAME to its simplification.
2734          */
2735         for (p = commit->parents; p; p = p->next) {
2736                 pst = locate_simplify_state(revs, p->item);
2737                 p->item = pst->simplified;
2738                 if (revs->first_parent_only)
2739                         break;
2740         }
2741
2742         if (revs->first_parent_only)
2743                 cnt = 1;
2744         else
2745                 cnt = remove_duplicate_parents(revs, commit);
2746
2747         /*
2748          * It is possible that we are a merge and one side branch
2749          * does not have any commit that touches the given paths;
2750          * in such a case, the immediate parent from that branch
2751          * will be rewritten to be the merge base.
2752          *
2753          *      o----X          X: the commit we are looking at;
2754          *     /    /           o: a commit that touches the paths;
2755          * ---o----'
2756          *
2757          * Further, a merge of an independent branch that doesn't
2758          * touch the path will reduce to a treesame root parent:
2759          *
2760          *  ----o----X          X: the commit we are looking at;
2761          *          /           o: a commit that touches the paths;
2762          *         r            r: a root commit not touching the paths
2763          *
2764          * Detect and simplify both cases.
2765          */
2766         if (1 < cnt) {
2767                 int marked = mark_redundant_parents(revs, commit);
2768                 marked += mark_treesame_root_parents(revs, commit);
2769                 if (marked)
2770                         marked -= leave_one_treesame_to_parent(revs, commit);
2771                 if (marked)
2772                         cnt = remove_marked_parents(revs, commit);
2773         }
2774
2775         /*
2776          * A commit simplifies to itself if it is a root, if it is
2777          * UNINTERESTING, if it touches the given paths, or if it is a
2778          * merge and its parents don't simplify to one relevant commit
2779          * (the first two cases are already handled at the beginning of
2780          * this function).
2781          *
2782          * Otherwise, it simplifies to what its sole relevant parent
2783          * simplifies to.
2784          */
2785         if (!cnt ||
2786             (commit->object.flags & UNINTERESTING) ||
2787             !(commit->object.flags & TREESAME) ||
2788             (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2789                 st->simplified = commit;
2790         else {
2791                 pst = locate_simplify_state(revs, parent);
2792                 st->simplified = pst->simplified;
2793         }
2794         return tail;
2795 }
2796
2797 static void simplify_merges(struct rev_info *revs)
2798 {
2799         struct commit_list *list, *next;
2800         struct commit_list *yet_to_do, **tail;
2801         struct commit *commit;
2802
2803         if (!revs->prune)
2804                 return;
2805
2806         /* feed the list reversed */
2807         yet_to_do = NULL;
2808         for (list = revs->commits; list; list = next) {
2809                 commit = list->item;
2810                 next = list->next;
2811                 /*
2812                  * Do not free(list) here yet; the original list
2813                  * is used later in this function.
2814                  */
2815                 commit_list_insert(commit, &yet_to_do);
2816         }
2817         while (yet_to_do) {
2818                 list = yet_to_do;
2819                 yet_to_do = NULL;
2820                 tail = &yet_to_do;
2821                 while (list) {
2822                         commit = pop_commit(&list);
2823                         tail = simplify_one(revs, commit, tail);
2824                 }
2825         }
2826
2827         /* clean up the result, removing the simplified ones */
2828         list = revs->commits;
2829         revs->commits = NULL;
2830         tail = &revs->commits;
2831         while (list) {
2832                 struct merge_simplify_state *st;
2833
2834                 commit = pop_commit(&list);
2835                 st = locate_simplify_state(revs, commit);
2836                 if (st->simplified == commit)
2837                         tail = &commit_list_insert(commit, tail)->next;
2838         }
2839 }
2840
2841 static void set_children(struct rev_info *revs)
2842 {
2843         struct commit_list *l;
2844         for (l = revs->commits; l; l = l->next) {
2845                 struct commit *commit = l->item;
2846                 struct commit_list *p;
2847
2848                 for (p = commit->parents; p; p = p->next)
2849                         add_child(revs, p->item, commit);
2850         }
2851 }
2852
2853 void reset_revision_walk(void)
2854 {
2855         clear_object_flags(SEEN | ADDED | SHOWN);
2856 }
2857
2858 static int mark_uninteresting(const struct object_id *oid,
2859                               struct packed_git *pack,
2860                               uint32_t pos,
2861                               void *unused)
2862 {
2863         struct object *o = parse_object(oid);
2864         o->flags |= UNINTERESTING | SEEN;
2865         return 0;
2866 }
2867
2868 int prepare_revision_walk(struct rev_info *revs)
2869 {
2870         int i;
2871         struct object_array old_pending;
2872         struct commit_list **next = &revs->commits;
2873
2874         memcpy(&old_pending, &revs->pending, sizeof(old_pending));
2875         revs->pending.nr = 0;
2876         revs->pending.alloc = 0;
2877         revs->pending.objects = NULL;
2878         for (i = 0; i < old_pending.nr; i++) {
2879                 struct object_array_entry *e = old_pending.objects + i;
2880                 struct commit *commit = handle_commit(revs, e);
2881                 if (commit) {
2882                         if (!(commit->object.flags & SEEN)) {
2883                                 commit->object.flags |= SEEN;
2884                                 next = commit_list_append(commit, next);
2885                         }
2886                 }
2887         }
2888         object_array_clear(&old_pending);
2889
2890         /* Signal whether we need per-parent treesame decoration */
2891         if (revs->simplify_merges ||
2892             (revs->limited && limiting_can_increase_treesame(revs)))
2893                 revs->treesame.name = "treesame";
2894
2895         if (revs->exclude_promisor_objects) {
2896                 for_each_packed_object(mark_uninteresting, NULL,
2897                                        FOR_EACH_OBJECT_PROMISOR_ONLY);
2898         }
2899
2900         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2901                 commit_list_sort_by_date(&revs->commits);
2902         if (revs->no_walk)
2903                 return 0;
2904         if (revs->limited)
2905                 if (limit_list(revs) < 0)
2906                         return -1;
2907         if (revs->topo_order)
2908                 sort_in_topological_order(&revs->commits, revs->sort_order);
2909         if (revs->line_level_traverse)
2910                 line_log_filter(revs);
2911         if (revs->simplify_merges)
2912                 simplify_merges(revs);
2913         if (revs->children.name)
2914                 set_children(revs);
2915         return 0;
2916 }
2917
2918 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2919 {
2920         struct commit_list *cache = NULL;
2921
2922         for (;;) {
2923                 struct commit *p = *pp;
2924                 if (!revs->limited)
2925                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2926                                 return rewrite_one_error;
2927                 if (p->object.flags & UNINTERESTING)
2928                         return rewrite_one_ok;
2929                 if (!(p->object.flags & TREESAME))
2930                         return rewrite_one_ok;
2931                 if (!p->parents)
2932                         return rewrite_one_noparents;
2933                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2934                         return rewrite_one_ok;
2935                 *pp = p;
2936         }
2937 }
2938
2939 int rewrite_parents(struct rev_info *revs, struct commit *commit,
2940         rewrite_parent_fn_t rewrite_parent)
2941 {
2942         struct commit_list **pp = &commit->parents;
2943         while (*pp) {
2944                 struct commit_list *parent = *pp;
2945                 switch (rewrite_parent(revs, &parent->item)) {
2946                 case rewrite_one_ok:
2947                         break;
2948                 case rewrite_one_noparents:
2949                         *pp = parent->next;
2950                         continue;
2951                 case rewrite_one_error:
2952                         return -1;
2953                 }
2954                 pp = &parent->next;
2955         }
2956         remove_duplicate_parents(revs, commit);
2957         return 0;
2958 }
2959
2960 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2961 {
2962         char *person, *endp;
2963         size_t len, namelen, maillen;
2964         const char *name;
2965         const char *mail;
2966         struct ident_split ident;
2967
2968         person = strstr(buf->buf, what);
2969         if (!person)
2970                 return 0;
2971
2972         person += strlen(what);
2973         endp = strchr(person, '\n');
2974         if (!endp)
2975                 return 0;
2976
2977         len = endp - person;
2978
2979         if (split_ident_line(&ident, person, len))
2980                 return 0;
2981
2982         mail = ident.mail_begin;
2983         maillen = ident.mail_end - ident.mail_begin;
2984         name = ident.name_begin;
2985         namelen = ident.name_end - ident.name_begin;
2986
2987         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2988                 struct strbuf namemail = STRBUF_INIT;
2989
2990                 strbuf_addf(&namemail, "%.*s <%.*s>",
2991                             (int)namelen, name, (int)maillen, mail);
2992
2993                 strbuf_splice(buf, ident.name_begin - buf->buf,
2994                               ident.mail_end - ident.name_begin + 1,
2995                               namemail.buf, namemail.len);
2996
2997                 strbuf_release(&namemail);
2998
2999                 return 1;
3000         }
3001
3002         return 0;
3003 }
3004
3005 static int commit_match(struct commit *commit, struct rev_info *opt)
3006 {
3007         int retval;
3008         const char *encoding;
3009         const char *message;
3010         struct strbuf buf = STRBUF_INIT;
3011
3012         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
3013                 return 1;
3014
3015         /* Prepend "fake" headers as needed */
3016         if (opt->grep_filter.use_reflog_filter) {
3017                 strbuf_addstr(&buf, "reflog ");
3018                 get_reflog_message(&buf, opt->reflog_info);
3019                 strbuf_addch(&buf, '\n');
3020         }
3021
3022         /*
3023          * We grep in the user's output encoding, under the assumption that it
3024          * is the encoding they are most likely to write their grep pattern
3025          * for. In addition, it means we will match the "notes" encoding below,
3026          * so we will not end up with a buffer that has two different encodings
3027          * in it.
3028          */
3029         encoding = get_log_output_encoding();
3030         message = logmsg_reencode(commit, NULL, encoding);
3031
3032         /* Copy the commit to temporary if we are using "fake" headers */
3033         if (buf.len)
3034                 strbuf_addstr(&buf, message);
3035
3036         if (opt->grep_filter.header_list && opt->mailmap) {
3037                 if (!buf.len)
3038                         strbuf_addstr(&buf, message);
3039
3040                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
3041                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
3042         }
3043
3044         /* Append "fake" message parts as needed */
3045         if (opt->show_notes) {
3046                 if (!buf.len)
3047                         strbuf_addstr(&buf, message);
3048                 format_display_notes(&commit->object.oid, &buf, encoding, 1);
3049         }
3050
3051         /*
3052          * Find either in the original commit message, or in the temporary.
3053          * Note that we cast away the constness of "message" here. It is
3054          * const because it may come from the cached commit buffer. That's OK,
3055          * because we know that it is modifiable heap memory, and that while
3056          * grep_buffer may modify it for speed, it will restore any
3057          * changes before returning.
3058          */
3059         if (buf.len)
3060                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
3061         else
3062                 retval = grep_buffer(&opt->grep_filter,
3063                                      (char *)message, strlen(message));
3064         strbuf_release(&buf);
3065         unuse_commit_buffer(commit, message);
3066         return opt->invert_grep ? !retval : retval;
3067 }
3068
3069 static inline int want_ancestry(const struct rev_info *revs)
3070 {
3071         return (revs->rewrite_parents || revs->children.name);
3072 }
3073
3074 /*
3075  * Return a timestamp to be used for --since/--until comparisons for this
3076  * commit, based on the revision options.
3077  */
3078 static timestamp_t comparison_date(const struct rev_info *revs,
3079                                    struct commit *commit)
3080 {
3081         return revs->reflog_info ?
3082                 get_reflog_timestamp(revs->reflog_info) :
3083                 commit->date;
3084 }
3085
3086 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
3087 {
3088         if (commit->object.flags & SHOWN)
3089                 return commit_ignore;
3090         if (revs->unpacked && has_sha1_pack(commit->object.oid.hash))
3091                 return commit_ignore;
3092         if (commit->object.flags & UNINTERESTING)
3093                 return commit_ignore;
3094         if (revs->min_age != -1 &&
3095             comparison_date(revs, commit) > revs->min_age)
3096                         return commit_ignore;
3097         if (revs->min_parents || (revs->max_parents >= 0)) {
3098                 int n = commit_list_count(commit->parents);
3099                 if ((n < revs->min_parents) ||
3100                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
3101                         return commit_ignore;
3102         }
3103         if (!commit_match(commit, revs))
3104                 return commit_ignore;
3105         if (revs->prune && revs->dense) {
3106                 /* Commit without changes? */
3107                 if (commit->object.flags & TREESAME) {
3108                         int n;
3109                         struct commit_list *p;
3110                         /* drop merges unless we want parenthood */
3111                         if (!want_ancestry(revs))
3112                                 return commit_ignore;
3113                         /*
3114                          * If we want ancestry, then need to keep any merges
3115                          * between relevant commits to tie together topology.
3116                          * For consistency with TREESAME and simplification
3117                          * use "relevant" here rather than just INTERESTING,
3118                          * to treat bottom commit(s) as part of the topology.
3119                          */
3120                         for (n = 0, p = commit->parents; p; p = p->next)
3121                                 if (relevant_commit(p->item))
3122                                         if (++n >= 2)
3123                                                 return commit_show;
3124                         return commit_ignore;
3125                 }
3126         }
3127         return commit_show;
3128 }
3129
3130 define_commit_slab(saved_parents, struct commit_list *);
3131
3132 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3133
3134 /*
3135  * You may only call save_parents() once per commit (this is checked
3136  * for non-root commits).
3137  */
3138 static void save_parents(struct rev_info *revs, struct commit *commit)
3139 {
3140         struct commit_list **pp;
3141
3142         if (!revs->saved_parents_slab) {
3143                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3144                 init_saved_parents(revs->saved_parents_slab);
3145         }
3146
3147         pp = saved_parents_at(revs->saved_parents_slab, commit);
3148
3149         /*
3150          * When walking with reflogs, we may visit the same commit
3151          * several times: once for each appearance in the reflog.
3152          *
3153          * In this case, save_parents() will be called multiple times.
3154          * We want to keep only the first set of parents.  We need to
3155          * store a sentinel value for an empty (i.e., NULL) parent
3156          * list to distinguish it from a not-yet-saved list, however.
3157          */
3158         if (*pp)
3159                 return;
3160         if (commit->parents)
3161                 *pp = copy_commit_list(commit->parents);
3162         else
3163                 *pp = EMPTY_PARENT_LIST;
3164 }
3165
3166 static void free_saved_parents(struct rev_info *revs)
3167 {
3168         if (revs->saved_parents_slab)
3169                 clear_saved_parents(revs->saved_parents_slab);
3170 }
3171
3172 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3173 {
3174         struct commit_list *parents;
3175
3176         if (!revs->saved_parents_slab)
3177                 return commit->parents;
3178
3179         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3180         if (parents == EMPTY_PARENT_LIST)
3181                 return NULL;
3182         return parents;
3183 }
3184
3185 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3186 {
3187         enum commit_action action = get_commit_action(revs, commit);
3188
3189         if (action == commit_show &&
3190             revs->prune && revs->dense && want_ancestry(revs)) {
3191                 /*
3192                  * --full-diff on simplified parents is no good: it
3193                  * will show spurious changes from the commits that
3194                  * were elided.  So we save the parents on the side
3195                  * when --full-diff is in effect.
3196                  */
3197                 if (revs->full_diff)
3198                         save_parents(revs, commit);
3199                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
3200                         return commit_error;
3201         }
3202         return action;
3203 }
3204
3205 static void track_linear(struct rev_info *revs, struct commit *commit)
3206 {
3207         if (revs->track_first_time) {
3208                 revs->linear = 1;
3209                 revs->track_first_time = 0;
3210         } else {
3211                 struct commit_list *p;
3212                 for (p = revs->previous_parents; p; p = p->next)
3213                         if (p->item == NULL || /* first commit */
3214                             !oidcmp(&p->item->object.oid, &commit->object.oid))
3215                                 break;
3216                 revs->linear = p != NULL;
3217         }
3218         if (revs->reverse) {
3219                 if (revs->linear)
3220                         commit->object.flags |= TRACK_LINEAR;
3221         }
3222         free_commit_list(revs->previous_parents);
3223         revs->previous_parents = copy_commit_list(commit->parents);
3224 }
3225
3226 static struct commit *get_revision_1(struct rev_info *revs)
3227 {
3228         while (1) {
3229                 struct commit *commit;
3230
3231                 if (revs->reflog_info)
3232                         commit = next_reflog_entry(revs->reflog_info);
3233                 else
3234                         commit = pop_commit(&revs->commits);
3235
3236                 if (!commit)
3237                         return NULL;
3238
3239                 if (revs->reflog_info)
3240                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3241
3242                 /*
3243                  * If we haven't done the list limiting, we need to look at
3244                  * the parents here. We also need to do the date-based limiting
3245                  * that we'd otherwise have done in limit_list().
3246                  */
3247                 if (!revs->limited) {
3248                         if (revs->max_age != -1 &&
3249                             comparison_date(revs, commit) < revs->max_age)
3250                                 continue;
3251
3252                         if (revs->reflog_info)
3253                                 try_to_simplify_commit(revs, commit);
3254                         else if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
3255                                 if (!revs->ignore_missing_links)
3256                                         die("Failed to traverse parents of commit %s",
3257                                                 oid_to_hex(&commit->object.oid));
3258                         }
3259                 }
3260
3261                 switch (simplify_commit(revs, commit)) {
3262                 case commit_ignore:
3263                         continue;
3264                 case commit_error:
3265                         die("Failed to simplify parents of commit %s",
3266                             oid_to_hex(&commit->object.oid));
3267                 default:
3268                         if (revs->track_linear)
3269                                 track_linear(revs, commit);
3270                         return commit;
3271                 }
3272         }
3273 }
3274
3275 /*
3276  * Return true for entries that have not yet been shown.  (This is an
3277  * object_array_each_func_t.)
3278  */
3279 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3280 {
3281         return !(entry->item->flags & SHOWN);
3282 }
3283
3284 /*
3285  * If array is on the verge of a realloc, garbage-collect any entries
3286  * that have already been shown to try to free up some space.
3287  */
3288 static void gc_boundary(struct object_array *array)
3289 {
3290         if (array->nr == array->alloc)
3291                 object_array_filter(array, entry_unshown, NULL);
3292 }
3293
3294 static void create_boundary_commit_list(struct rev_info *revs)
3295 {
3296         unsigned i;
3297         struct commit *c;
3298         struct object_array *array = &revs->boundary_commits;
3299         struct object_array_entry *objects = array->objects;
3300
3301         /*
3302          * If revs->commits is non-NULL at this point, an error occurred in
3303          * get_revision_1().  Ignore the error and continue printing the
3304          * boundary commits anyway.  (This is what the code has always
3305          * done.)
3306          */
3307         if (revs->commits) {
3308                 free_commit_list(revs->commits);
3309                 revs->commits = NULL;
3310         }
3311
3312         /*
3313          * Put all of the actual boundary commits from revs->boundary_commits
3314          * into revs->commits
3315          */
3316         for (i = 0; i < array->nr; i++) {
3317                 c = (struct commit *)(objects[i].item);
3318                 if (!c)
3319                         continue;
3320                 if (!(c->object.flags & CHILD_SHOWN))
3321                         continue;
3322                 if (c->object.flags & (SHOWN | BOUNDARY))
3323                         continue;
3324                 c->object.flags |= BOUNDARY;
3325                 commit_list_insert(c, &revs->commits);
3326         }
3327
3328         /*
3329          * If revs->topo_order is set, sort the boundary commits
3330          * in topological order
3331          */
3332         sort_in_topological_order(&revs->commits, revs->sort_order);
3333 }
3334
3335 static struct commit *get_revision_internal(struct rev_info *revs)
3336 {
3337         struct commit *c = NULL;
3338         struct commit_list *l;
3339
3340         if (revs->boundary == 2) {
3341                 /*
3342                  * All of the normal commits have already been returned,
3343                  * and we are now returning boundary commits.
3344                  * create_boundary_commit_list() has populated
3345                  * revs->commits with the remaining commits to return.
3346                  */
3347                 c = pop_commit(&revs->commits);
3348                 if (c)
3349                         c->object.flags |= SHOWN;
3350                 return c;
3351         }
3352
3353         /*
3354          * If our max_count counter has reached zero, then we are done. We
3355          * don't simply return NULL because we still might need to show
3356          * boundary commits. But we want to avoid calling get_revision_1, which
3357          * might do a considerable amount of work finding the next commit only
3358          * for us to throw it away.
3359          *
3360          * If it is non-zero, then either we don't have a max_count at all
3361          * (-1), or it is still counting, in which case we decrement.
3362          */
3363         if (revs->max_count) {
3364                 c = get_revision_1(revs);
3365                 if (c) {
3366                         while (revs->skip_count > 0) {
3367                                 revs->skip_count--;
3368                                 c = get_revision_1(revs);
3369                                 if (!c)
3370                                         break;
3371                         }
3372                 }
3373
3374                 if (revs->max_count > 0)
3375                         revs->max_count--;
3376         }
3377
3378         if (c)
3379                 c->object.flags |= SHOWN;
3380
3381         if (!revs->boundary)
3382                 return c;
3383
3384         if (!c) {
3385                 /*
3386                  * get_revision_1() runs out the commits, and
3387                  * we are done computing the boundaries.
3388                  * switch to boundary commits output mode.
3389                  */
3390                 revs->boundary = 2;
3391
3392                 /*
3393                  * Update revs->commits to contain the list of
3394                  * boundary commits.
3395                  */
3396                 create_boundary_commit_list(revs);
3397
3398                 return get_revision_internal(revs);
3399         }
3400
3401         /*
3402          * boundary commits are the commits that are parents of the
3403          * ones we got from get_revision_1() but they themselves are
3404          * not returned from get_revision_1().  Before returning
3405          * 'c', we need to mark its parents that they could be boundaries.
3406          */
3407
3408         for (l = c->parents; l; l = l->next) {
3409                 struct object *p;
3410                 p = &(l->item->object);
3411                 if (p->flags & (CHILD_SHOWN | SHOWN))
3412                         continue;
3413                 p->flags |= CHILD_SHOWN;
3414                 gc_boundary(&revs->boundary_commits);
3415                 add_object_array(p, NULL, &revs->boundary_commits);
3416         }
3417
3418         return c;
3419 }
3420
3421 struct commit *get_revision(struct rev_info *revs)
3422 {
3423         struct commit *c;
3424         struct commit_list *reversed;
3425
3426         if (revs->reverse) {
3427                 reversed = NULL;
3428                 while ((c = get_revision_internal(revs)))
3429                         commit_list_insert(c, &reversed);
3430                 revs->commits = reversed;
3431                 revs->reverse = 0;
3432                 revs->reverse_output_stage = 1;
3433         }
3434
3435         if (revs->reverse_output_stage) {
3436                 c = pop_commit(&revs->commits);
3437                 if (revs->track_linear)
3438                         revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
3439                 return c;
3440         }
3441
3442         c = get_revision_internal(revs);
3443         if (c && revs->graph)
3444                 graph_update(revs->graph, c);
3445         if (!c) {
3446                 free_saved_parents(revs);
3447                 if (revs->previous_parents) {
3448                         free_commit_list(revs->previous_parents);
3449                         revs->previous_parents = NULL;
3450                 }
3451         }
3452         return c;
3453 }
3454
3455 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3456 {
3457         if (commit->object.flags & BOUNDARY)
3458                 return "-";
3459         else if (commit->object.flags & UNINTERESTING)
3460                 return "^";
3461         else if (commit->object.flags & PATCHSAME)
3462                 return "=";
3463         else if (!revs || revs->left_right) {
3464                 if (commit->object.flags & SYMMETRIC_LEFT)
3465                         return "<";
3466                 else
3467                         return ">";
3468         } else if (revs->graph)
3469                 return "*";
3470         else if (revs->cherry_mark)
3471                 return "+";
3472         return "";
3473 }
3474
3475 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3476 {
3477         char *mark = get_revision_mark(revs, commit);
3478         if (!strlen(mark))
3479                 return;
3480         fputs(mark, stdout);
3481         putchar(' ');
3482 }