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