notes: refactor display notes extra refs field
[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
17 volatile show_early_output_fn_t show_early_output;
18
19 char *path_name(const struct name_path *path, const char *name)
20 {
21         const struct name_path *p;
22         char *n, *m;
23         int nlen = strlen(name);
24         int len = nlen + 1;
25
26         for (p = path; p; p = p->up) {
27                 if (p->elem_len)
28                         len += p->elem_len + 1;
29         }
30         n = xmalloc(len);
31         m = n + len - (nlen + 1);
32         strcpy(m, name);
33         for (p = path; p; p = p->up) {
34                 if (p->elem_len) {
35                         m -= p->elem_len + 1;
36                         memcpy(m, p->elem, p->elem_len);
37                         m[p->elem_len] = '/';
38                 }
39         }
40         return n;
41 }
42
43 void add_object(struct object *obj,
44                 struct object_array *p,
45                 struct name_path *path,
46                 const char *name)
47 {
48         add_object_array(obj, path_name(path, name), p);
49 }
50
51 static void mark_blob_uninteresting(struct blob *blob)
52 {
53         if (!blob)
54                 return;
55         if (blob->object.flags & UNINTERESTING)
56                 return;
57         blob->object.flags |= UNINTERESTING;
58 }
59
60 void mark_tree_uninteresting(struct tree *tree)
61 {
62         struct tree_desc desc;
63         struct name_entry entry;
64         struct object *obj = &tree->object;
65
66         if (!tree)
67                 return;
68         if (obj->flags & UNINTERESTING)
69                 return;
70         obj->flags |= UNINTERESTING;
71         if (!has_sha1_file(obj->sha1))
72                 return;
73         if (parse_tree(tree) < 0)
74                 die("bad tree %s", sha1_to_hex(obj->sha1));
75
76         init_tree_desc(&desc, tree->buffer, tree->size);
77         while (tree_entry(&desc, &entry)) {
78                 switch (object_type(entry.mode)) {
79                 case OBJ_TREE:
80                         mark_tree_uninteresting(lookup_tree(entry.sha1));
81                         break;
82                 case OBJ_BLOB:
83                         mark_blob_uninteresting(lookup_blob(entry.sha1));
84                         break;
85                 default:
86                         /* Subproject commit - not in this repository */
87                         break;
88                 }
89         }
90
91         /*
92          * We don't care about the tree any more
93          * after it has been marked uninteresting.
94          */
95         free(tree->buffer);
96         tree->buffer = NULL;
97 }
98
99 void mark_parents_uninteresting(struct commit *commit)
100 {
101         struct commit_list *parents = commit->parents;
102
103         while (parents) {
104                 struct commit *commit = parents->item;
105                 if (!(commit->object.flags & UNINTERESTING)) {
106                         commit->object.flags |= UNINTERESTING;
107
108                         /*
109                          * Normally we haven't parsed the parent
110                          * yet, so we won't have a parent of a parent
111                          * here. However, it may turn out that we've
112                          * reached this commit some other way (where it
113                          * wasn't uninteresting), in which case we need
114                          * to mark its parents recursively too..
115                          */
116                         if (commit->parents)
117                                 mark_parents_uninteresting(commit);
118                 }
119
120                 /*
121                  * A missing commit is ok iff its parent is marked
122                  * uninteresting.
123                  *
124                  * We just mark such a thing parsed, so that when
125                  * it is popped next time around, we won't be trying
126                  * to parse it and get an error.
127                  */
128                 if (!has_sha1_file(commit->object.sha1))
129                         commit->object.parsed = 1;
130                 parents = parents->next;
131         }
132 }
133
134 static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
135 {
136         if (revs->no_walk && (obj->flags & UNINTERESTING))
137                 revs->no_walk = 0;
138         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
139                 struct strbuf buf = STRBUF_INIT;
140                 int len = interpret_branch_name(name, &buf);
141                 int st;
142
143                 if (0 < len && name[len] && buf.len)
144                         strbuf_addstr(&buf, name + len);
145                 st = add_reflog_for_walk(revs->reflog_info,
146                                          (struct commit *)obj,
147                                          buf.buf[0] ? buf.buf: name);
148                 strbuf_release(&buf);
149                 if (st)
150                         return;
151         }
152         add_object_array_with_mode(obj, name, &revs->pending, mode);
153 }
154
155 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
156 {
157         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
158 }
159
160 void add_head_to_pending(struct rev_info *revs)
161 {
162         unsigned char sha1[20];
163         struct object *obj;
164         if (get_sha1("HEAD", sha1))
165                 return;
166         obj = parse_object(sha1);
167         if (!obj)
168                 return;
169         add_pending_object(revs, obj, "HEAD");
170 }
171
172 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
173 {
174         struct object *object;
175
176         object = parse_object(sha1);
177         if (!object)
178                 die("bad object %s", name);
179         object->flags |= flags;
180         return object;
181 }
182
183 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
184 {
185         unsigned long flags = object->flags;
186
187         /*
188          * Tag object? Look what it points to..
189          */
190         while (object->type == OBJ_TAG) {
191                 struct tag *tag = (struct tag *) object;
192                 if (revs->tag_objects && !(flags & UNINTERESTING))
193                         add_pending_object(revs, object, tag->tag);
194                 if (!tag->tagged)
195                         die("bad tag");
196                 object = parse_object(tag->tagged->sha1);
197                 if (!object) {
198                         if (flags & UNINTERESTING)
199                                 return NULL;
200                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
201                 }
202         }
203
204         /*
205          * Commit object? Just return it, we'll do all the complex
206          * reachability crud.
207          */
208         if (object->type == OBJ_COMMIT) {
209                 struct commit *commit = (struct commit *)object;
210                 if (parse_commit(commit) < 0)
211                         die("unable to parse commit %s", name);
212                 if (flags & UNINTERESTING) {
213                         commit->object.flags |= UNINTERESTING;
214                         mark_parents_uninteresting(commit);
215                         revs->limited = 1;
216                 }
217                 if (revs->show_source && !commit->util)
218                         commit->util = (void *) name;
219                 return commit;
220         }
221
222         /*
223          * Tree object? Either mark it uninteresting, or add it
224          * to the list of objects to look at later..
225          */
226         if (object->type == OBJ_TREE) {
227                 struct tree *tree = (struct tree *)object;
228                 if (!revs->tree_objects)
229                         return NULL;
230                 if (flags & UNINTERESTING) {
231                         mark_tree_uninteresting(tree);
232                         return NULL;
233                 }
234                 add_pending_object(revs, object, "");
235                 return NULL;
236         }
237
238         /*
239          * Blob object? You know the drill by now..
240          */
241         if (object->type == OBJ_BLOB) {
242                 struct blob *blob = (struct blob *)object;
243                 if (!revs->blob_objects)
244                         return NULL;
245                 if (flags & UNINTERESTING) {
246                         mark_blob_uninteresting(blob);
247                         return NULL;
248                 }
249                 add_pending_object(revs, object, "");
250                 return NULL;
251         }
252         die("%s is unknown object", name);
253 }
254
255 static int everybody_uninteresting(struct commit_list *orig)
256 {
257         struct commit_list *list = orig;
258         while (list) {
259                 struct commit *commit = list->item;
260                 list = list->next;
261                 if (commit->object.flags & UNINTERESTING)
262                         continue;
263                 return 0;
264         }
265         return 1;
266 }
267
268 /*
269  * The goal is to get REV_TREE_NEW as the result only if the
270  * diff consists of all '+' (and no other changes), REV_TREE_OLD
271  * if the whole diff is removal of old data, and otherwise
272  * REV_TREE_DIFFERENT (of course if the trees are the same we
273  * want REV_TREE_SAME).
274  * That means that once we get to REV_TREE_DIFFERENT, we do not
275  * have to look any further.
276  */
277 static int tree_difference = REV_TREE_SAME;
278
279 static void file_add_remove(struct diff_options *options,
280                     int addremove, unsigned mode,
281                     const unsigned char *sha1,
282                     const char *fullpath, unsigned dirty_submodule)
283 {
284         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
285
286         tree_difference |= diff;
287         if (tree_difference == REV_TREE_DIFFERENT)
288                 DIFF_OPT_SET(options, HAS_CHANGES);
289 }
290
291 static void file_change(struct diff_options *options,
292                  unsigned old_mode, unsigned new_mode,
293                  const unsigned char *old_sha1,
294                  const unsigned char *new_sha1,
295                  const char *fullpath,
296                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
297 {
298         tree_difference = REV_TREE_DIFFERENT;
299         DIFF_OPT_SET(options, HAS_CHANGES);
300 }
301
302 static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
303 {
304         struct tree *t1 = parent->tree;
305         struct tree *t2 = commit->tree;
306
307         if (!t1)
308                 return REV_TREE_NEW;
309         if (!t2)
310                 return REV_TREE_OLD;
311
312         if (revs->simplify_by_decoration) {
313                 /*
314                  * If we are simplifying by decoration, then the commit
315                  * is worth showing if it has a tag pointing at it.
316                  */
317                 if (lookup_decoration(&name_decoration, &commit->object))
318                         return REV_TREE_DIFFERENT;
319                 /*
320                  * A commit that is not pointed by a tag is uninteresting
321                  * if we are not limited by path.  This means that you will
322                  * see the usual "commits that touch the paths" plus any
323                  * tagged commit by specifying both --simplify-by-decoration
324                  * and pathspec.
325                  */
326                 if (!revs->prune_data.nr)
327                         return REV_TREE_SAME;
328         }
329
330         tree_difference = REV_TREE_SAME;
331         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
332         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
333                            &revs->pruning) < 0)
334                 return REV_TREE_DIFFERENT;
335         return tree_difference;
336 }
337
338 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
339 {
340         int retval;
341         void *tree;
342         unsigned long size;
343         struct tree_desc empty, real;
344         struct tree *t1 = commit->tree;
345
346         if (!t1)
347                 return 0;
348
349         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
350         if (!tree)
351                 return 0;
352         init_tree_desc(&real, tree, size);
353         init_tree_desc(&empty, "", 0);
354
355         tree_difference = REV_TREE_SAME;
356         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
357         retval = diff_tree(&empty, &real, "", &revs->pruning);
358         free(tree);
359
360         return retval >= 0 && (tree_difference == REV_TREE_SAME);
361 }
362
363 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
364 {
365         struct commit_list **pp, *parent;
366         int tree_changed = 0, tree_same = 0;
367
368         /*
369          * If we don't do pruning, everything is interesting
370          */
371         if (!revs->prune)
372                 return;
373
374         if (!commit->tree)
375                 return;
376
377         if (!commit->parents) {
378                 if (rev_same_tree_as_empty(revs, commit))
379                         commit->object.flags |= TREESAME;
380                 return;
381         }
382
383         /*
384          * Normal non-merge commit? If we don't want to make the
385          * history dense, we consider it always to be a change..
386          */
387         if (!revs->dense && !commit->parents->next)
388                 return;
389
390         pp = &commit->parents;
391         while ((parent = *pp) != NULL) {
392                 struct commit *p = parent->item;
393
394                 if (parse_commit(p) < 0)
395                         die("cannot simplify commit %s (because of %s)",
396                             sha1_to_hex(commit->object.sha1),
397                             sha1_to_hex(p->object.sha1));
398                 switch (rev_compare_tree(revs, p, commit)) {
399                 case REV_TREE_SAME:
400                         tree_same = 1;
401                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
402                                 /* Even if a merge with an uninteresting
403                                  * side branch brought the entire change
404                                  * we are interested in, we do not want
405                                  * to lose the other branches of this
406                                  * merge, so we just keep going.
407                                  */
408                                 pp = &parent->next;
409                                 continue;
410                         }
411                         parent->next = NULL;
412                         commit->parents = parent;
413                         commit->object.flags |= TREESAME;
414                         return;
415
416                 case REV_TREE_NEW:
417                         if (revs->remove_empty_trees &&
418                             rev_same_tree_as_empty(revs, p)) {
419                                 /* We are adding all the specified
420                                  * paths from this parent, so the
421                                  * history beyond this parent is not
422                                  * interesting.  Remove its parents
423                                  * (they are grandparents for us).
424                                  * IOW, we pretend this parent is a
425                                  * "root" commit.
426                                  */
427                                 if (parse_commit(p) < 0)
428                                         die("cannot simplify commit %s (invalid %s)",
429                                             sha1_to_hex(commit->object.sha1),
430                                             sha1_to_hex(p->object.sha1));
431                                 p->parents = NULL;
432                         }
433                 /* fallthrough */
434                 case REV_TREE_OLD:
435                 case REV_TREE_DIFFERENT:
436                         tree_changed = 1;
437                         pp = &parent->next;
438                         continue;
439                 }
440                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
441         }
442         if (tree_changed && !tree_same)
443                 return;
444         commit->object.flags |= TREESAME;
445 }
446
447 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
448                     struct commit_list *cached_base, struct commit_list **cache)
449 {
450         struct commit_list *new_entry;
451
452         if (cached_base && p->date < cached_base->item->date)
453                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
454         else
455                 new_entry = commit_list_insert_by_date(p, head);
456
457         if (cache && (!*cache || p->date < (*cache)->item->date))
458                 *cache = new_entry;
459 }
460
461 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
462                     struct commit_list **list, struct commit_list **cache_ptr)
463 {
464         struct commit_list *parent = commit->parents;
465         unsigned left_flag;
466         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
467
468         if (commit->object.flags & ADDED)
469                 return 0;
470         commit->object.flags |= ADDED;
471
472         /*
473          * If the commit is uninteresting, don't try to
474          * prune parents - we want the maximal uninteresting
475          * set.
476          *
477          * Normally we haven't parsed the parent
478          * yet, so we won't have a parent of a parent
479          * here. However, it may turn out that we've
480          * reached this commit some other way (where it
481          * wasn't uninteresting), in which case we need
482          * to mark its parents recursively too..
483          */
484         if (commit->object.flags & UNINTERESTING) {
485                 while (parent) {
486                         struct commit *p = parent->item;
487                         parent = parent->next;
488                         if (p)
489                                 p->object.flags |= UNINTERESTING;
490                         if (parse_commit(p) < 0)
491                                 continue;
492                         if (p->parents)
493                                 mark_parents_uninteresting(p);
494                         if (p->object.flags & SEEN)
495                                 continue;
496                         p->object.flags |= SEEN;
497                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
498                 }
499                 return 0;
500         }
501
502         /*
503          * Ok, the commit wasn't uninteresting. Try to
504          * simplify the commit history and find the parent
505          * that has no differences in the path set if one exists.
506          */
507         try_to_simplify_commit(revs, commit);
508
509         if (revs->no_walk)
510                 return 0;
511
512         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
513
514         for (parent = commit->parents; parent; parent = parent->next) {
515                 struct commit *p = parent->item;
516
517                 if (parse_commit(p) < 0)
518                         return -1;
519                 if (revs->show_source && !p->util)
520                         p->util = commit->util;
521                 p->object.flags |= left_flag;
522                 if (!(p->object.flags & SEEN)) {
523                         p->object.flags |= SEEN;
524                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
525                 }
526                 if (revs->first_parent_only)
527                         break;
528         }
529         return 0;
530 }
531
532 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
533 {
534         struct commit_list *p;
535         int left_count = 0, right_count = 0;
536         int left_first;
537         struct patch_ids ids;
538         unsigned cherry_flag;
539
540         /* First count the commits on the left and on the right */
541         for (p = list; p; p = p->next) {
542                 struct commit *commit = p->item;
543                 unsigned flags = commit->object.flags;
544                 if (flags & BOUNDARY)
545                         ;
546                 else if (flags & SYMMETRIC_LEFT)
547                         left_count++;
548                 else
549                         right_count++;
550         }
551
552         if (!left_count || !right_count)
553                 return;
554
555         left_first = left_count < right_count;
556         init_patch_ids(&ids);
557         ids.diffopts.pathspec = revs->diffopt.pathspec;
558
559         /* Compute patch-ids for one side */
560         for (p = list; p; p = p->next) {
561                 struct commit *commit = p->item;
562                 unsigned flags = commit->object.flags;
563
564                 if (flags & BOUNDARY)
565                         continue;
566                 /*
567                  * If we have fewer left, left_first is set and we omit
568                  * commits on the right branch in this loop.  If we have
569                  * fewer right, we skip the left ones.
570                  */
571                 if (left_first != !!(flags & SYMMETRIC_LEFT))
572                         continue;
573                 commit->util = add_commit_patch_id(commit, &ids);
574         }
575
576         /* either cherry_mark or cherry_pick are true */
577         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
578
579         /* Check the other side */
580         for (p = list; p; p = p->next) {
581                 struct commit *commit = p->item;
582                 struct patch_id *id;
583                 unsigned flags = commit->object.flags;
584
585                 if (flags & BOUNDARY)
586                         continue;
587                 /*
588                  * If we have fewer left, left_first is set and we omit
589                  * commits on the left branch in this loop.
590                  */
591                 if (left_first == !!(flags & SYMMETRIC_LEFT))
592                         continue;
593
594                 /*
595                  * Have we seen the same patch id?
596                  */
597                 id = has_commit_patch_id(commit, &ids);
598                 if (!id)
599                         continue;
600                 id->seen = 1;
601                 commit->object.flags |= cherry_flag;
602         }
603
604         /* Now check the original side for seen ones */
605         for (p = list; p; p = p->next) {
606                 struct commit *commit = p->item;
607                 struct patch_id *ent;
608
609                 ent = commit->util;
610                 if (!ent)
611                         continue;
612                 if (ent->seen)
613                         commit->object.flags |= cherry_flag;
614                 commit->util = NULL;
615         }
616
617         free_patch_ids(&ids);
618 }
619
620 /* How many extra uninteresting commits we want to see.. */
621 #define SLOP 5
622
623 static int still_interesting(struct commit_list *src, unsigned long date, int slop)
624 {
625         /*
626          * No source list at all? We're definitely done..
627          */
628         if (!src)
629                 return 0;
630
631         /*
632          * Does the destination list contain entries with a date
633          * before the source list? Definitely _not_ done.
634          */
635         if (date < src->item->date)
636                 return SLOP;
637
638         /*
639          * Does the source list still have interesting commits in
640          * it? Definitely not done..
641          */
642         if (!everybody_uninteresting(src))
643                 return SLOP;
644
645         /* Ok, we're closing in.. */
646         return slop-1;
647 }
648
649 /*
650  * "rev-list --ancestry-path A..B" computes commits that are ancestors
651  * of B but not ancestors of A but further limits the result to those
652  * that are descendants of A.  This takes the list of bottom commits and
653  * the result of "A..B" without --ancestry-path, and limits the latter
654  * further to the ones that can reach one of the commits in "bottom".
655  */
656 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
657 {
658         struct commit_list *p;
659         struct commit_list *rlist = NULL;
660         int made_progress;
661
662         /*
663          * Reverse the list so that it will be likely that we would
664          * process parents before children.
665          */
666         for (p = list; p; p = p->next)
667                 commit_list_insert(p->item, &rlist);
668
669         for (p = bottom; p; p = p->next)
670                 p->item->object.flags |= TMP_MARK;
671
672         /*
673          * Mark the ones that can reach bottom commits in "list",
674          * in a bottom-up fashion.
675          */
676         do {
677                 made_progress = 0;
678                 for (p = rlist; p; p = p->next) {
679                         struct commit *c = p->item;
680                         struct commit_list *parents;
681                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
682                                 continue;
683                         for (parents = c->parents;
684                              parents;
685                              parents = parents->next) {
686                                 if (!(parents->item->object.flags & TMP_MARK))
687                                         continue;
688                                 c->object.flags |= TMP_MARK;
689                                 made_progress = 1;
690                                 break;
691                         }
692                 }
693         } while (made_progress);
694
695         /*
696          * NEEDSWORK: decide if we want to remove parents that are
697          * not marked with TMP_MARK from commit->parents for commits
698          * in the resulting list.  We may not want to do that, though.
699          */
700
701         /*
702          * The ones that are not marked with TMP_MARK are uninteresting
703          */
704         for (p = list; p; p = p->next) {
705                 struct commit *c = p->item;
706                 if (c->object.flags & TMP_MARK)
707                         continue;
708                 c->object.flags |= UNINTERESTING;
709         }
710
711         /* We are done with the TMP_MARK */
712         for (p = list; p; p = p->next)
713                 p->item->object.flags &= ~TMP_MARK;
714         for (p = bottom; p; p = p->next)
715                 p->item->object.flags &= ~TMP_MARK;
716         free_commit_list(rlist);
717 }
718
719 /*
720  * Before walking the history, keep the set of "negative" refs the
721  * caller has asked to exclude.
722  *
723  * This is used to compute "rev-list --ancestry-path A..B", as we need
724  * to filter the result of "A..B" further to the ones that can actually
725  * reach A.
726  */
727 static struct commit_list *collect_bottom_commits(struct commit_list *list)
728 {
729         struct commit_list *elem, *bottom = NULL;
730         for (elem = list; elem; elem = elem->next)
731                 if (elem->item->object.flags & UNINTERESTING)
732                         commit_list_insert(elem->item, &bottom);
733         return bottom;
734 }
735
736 /* Assumes either left_only or right_only is set */
737 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
738 {
739         struct commit_list *p;
740
741         for (p = list; p; p = p->next) {
742                 struct commit *commit = p->item;
743
744                 if (revs->right_only) {
745                         if (commit->object.flags & SYMMETRIC_LEFT)
746                                 commit->object.flags |= SHOWN;
747                 } else  /* revs->left_only is set */
748                         if (!(commit->object.flags & SYMMETRIC_LEFT))
749                                 commit->object.flags |= SHOWN;
750         }
751 }
752
753 static int limit_list(struct rev_info *revs)
754 {
755         int slop = SLOP;
756         unsigned long date = ~0ul;
757         struct commit_list *list = revs->commits;
758         struct commit_list *newlist = NULL;
759         struct commit_list **p = &newlist;
760         struct commit_list *bottom = NULL;
761
762         if (revs->ancestry_path) {
763                 bottom = collect_bottom_commits(list);
764                 if (!bottom)
765                         die("--ancestry-path given but there are no bottom commits");
766         }
767
768         while (list) {
769                 struct commit_list *entry = list;
770                 struct commit *commit = list->item;
771                 struct object *obj = &commit->object;
772                 show_early_output_fn_t show;
773
774                 list = list->next;
775                 free(entry);
776
777                 if (revs->max_age != -1 && (commit->date < revs->max_age))
778                         obj->flags |= UNINTERESTING;
779                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
780                         return -1;
781                 if (obj->flags & UNINTERESTING) {
782                         mark_parents_uninteresting(commit);
783                         if (revs->show_all)
784                                 p = &commit_list_insert(commit, p)->next;
785                         slop = still_interesting(list, date, slop);
786                         if (slop)
787                                 continue;
788                         /* If showing all, add the whole pending list to the end */
789                         if (revs->show_all)
790                                 *p = list;
791                         break;
792                 }
793                 if (revs->min_age != -1 && (commit->date > revs->min_age))
794                         continue;
795                 date = commit->date;
796                 p = &commit_list_insert(commit, p)->next;
797
798                 show = show_early_output;
799                 if (!show)
800                         continue;
801
802                 show(revs, newlist);
803                 show_early_output = NULL;
804         }
805         if (revs->cherry_pick || revs->cherry_mark)
806                 cherry_pick_list(newlist, revs);
807
808         if (revs->left_only || revs->right_only)
809                 limit_left_right(newlist, revs);
810
811         if (bottom) {
812                 limit_to_ancestry(bottom, newlist);
813                 free_commit_list(bottom);
814         }
815
816         revs->commits = newlist;
817         return 0;
818 }
819
820 struct all_refs_cb {
821         int all_flags;
822         int warned_bad_reflog;
823         struct rev_info *all_revs;
824         const char *name_for_errormsg;
825 };
826
827 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
828 {
829         struct all_refs_cb *cb = cb_data;
830         struct object *object = get_reference(cb->all_revs, path, sha1,
831                                               cb->all_flags);
832         add_pending_object(cb->all_revs, object, path);
833         return 0;
834 }
835
836 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
837         unsigned flags)
838 {
839         cb->all_revs = revs;
840         cb->all_flags = flags;
841 }
842
843 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
844                 int (*for_each)(const char *, each_ref_fn, void *))
845 {
846         struct all_refs_cb cb;
847         init_all_refs_cb(&cb, revs, flags);
848         for_each(submodule, handle_one_ref, &cb);
849 }
850
851 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
852 {
853         struct all_refs_cb *cb = cb_data;
854         if (!is_null_sha1(sha1)) {
855                 struct object *o = parse_object(sha1);
856                 if (o) {
857                         o->flags |= cb->all_flags;
858                         add_pending_object(cb->all_revs, o, "");
859                 }
860                 else if (!cb->warned_bad_reflog) {
861                         warning("reflog of '%s' references pruned commits",
862                                 cb->name_for_errormsg);
863                         cb->warned_bad_reflog = 1;
864                 }
865         }
866 }
867
868 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
869                 const char *email, unsigned long timestamp, int tz,
870                 const char *message, void *cb_data)
871 {
872         handle_one_reflog_commit(osha1, cb_data);
873         handle_one_reflog_commit(nsha1, cb_data);
874         return 0;
875 }
876
877 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
878 {
879         struct all_refs_cb *cb = cb_data;
880         cb->warned_bad_reflog = 0;
881         cb->name_for_errormsg = path;
882         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
883         return 0;
884 }
885
886 static void handle_reflog(struct rev_info *revs, unsigned flags)
887 {
888         struct all_refs_cb cb;
889         cb.all_revs = revs;
890         cb.all_flags = flags;
891         for_each_reflog(handle_one_reflog, &cb);
892 }
893
894 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
895 {
896         unsigned char sha1[20];
897         struct object *it;
898         struct commit *commit;
899         struct commit_list *parents;
900
901         if (*arg == '^') {
902                 flags ^= UNINTERESTING;
903                 arg++;
904         }
905         if (get_sha1(arg, sha1))
906                 return 0;
907         while (1) {
908                 it = get_reference(revs, arg, sha1, 0);
909                 if (it->type != OBJ_TAG)
910                         break;
911                 if (!((struct tag*)it)->tagged)
912                         return 0;
913                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
914         }
915         if (it->type != OBJ_COMMIT)
916                 return 0;
917         commit = (struct commit *)it;
918         for (parents = commit->parents; parents; parents = parents->next) {
919                 it = &parents->item->object;
920                 it->flags |= flags;
921                 add_pending_object(revs, it, arg);
922         }
923         return 1;
924 }
925
926 void init_revisions(struct rev_info *revs, const char *prefix)
927 {
928         memset(revs, 0, sizeof(*revs));
929
930         revs->abbrev = DEFAULT_ABBREV;
931         revs->ignore_merges = 1;
932         revs->simplify_history = 1;
933         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
934         DIFF_OPT_SET(&revs->pruning, QUICK);
935         revs->pruning.add_remove = file_add_remove;
936         revs->pruning.change = file_change;
937         revs->lifo = 1;
938         revs->dense = 1;
939         revs->prefix = prefix;
940         revs->max_age = -1;
941         revs->min_age = -1;
942         revs->skip_count = -1;
943         revs->max_count = -1;
944         revs->max_parents = -1;
945
946         revs->commit_format = CMIT_FMT_DEFAULT;
947
948         revs->grep_filter.status_only = 1;
949         revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
950         revs->grep_filter.header_tail = &(revs->grep_filter.header_list);
951         revs->grep_filter.regflags = REG_NEWLINE;
952
953         diff_setup(&revs->diffopt);
954         if (prefix && !revs->diffopt.prefix) {
955                 revs->diffopt.prefix = prefix;
956                 revs->diffopt.prefix_length = strlen(prefix);
957         }
958 }
959
960 static void add_pending_commit_list(struct rev_info *revs,
961                                     struct commit_list *commit_list,
962                                     unsigned int flags)
963 {
964         while (commit_list) {
965                 struct object *object = &commit_list->item->object;
966                 object->flags |= flags;
967                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
968                 commit_list = commit_list->next;
969         }
970 }
971
972 static void prepare_show_merge(struct rev_info *revs)
973 {
974         struct commit_list *bases;
975         struct commit *head, *other;
976         unsigned char sha1[20];
977         const char **prune = NULL;
978         int i, prune_num = 1; /* counting terminating NULL */
979
980         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
981                 die("--merge without HEAD?");
982         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
983                 die("--merge without MERGE_HEAD?");
984         add_pending_object(revs, &head->object, "HEAD");
985         add_pending_object(revs, &other->object, "MERGE_HEAD");
986         bases = get_merge_bases(head, other, 1);
987         add_pending_commit_list(revs, bases, UNINTERESTING);
988         free_commit_list(bases);
989         head->object.flags |= SYMMETRIC_LEFT;
990
991         if (!active_nr)
992                 read_cache();
993         for (i = 0; i < active_nr; i++) {
994                 struct cache_entry *ce = active_cache[i];
995                 if (!ce_stage(ce))
996                         continue;
997                 if (ce_path_match(ce, &revs->prune_data)) {
998                         prune_num++;
999                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
1000                         prune[prune_num-2] = ce->name;
1001                         prune[prune_num-1] = NULL;
1002                 }
1003                 while ((i+1 < active_nr) &&
1004                        ce_same_name(ce, active_cache[i+1]))
1005                         i++;
1006         }
1007         free_pathspec(&revs->prune_data);
1008         init_pathspec(&revs->prune_data, prune);
1009         revs->limited = 1;
1010 }
1011
1012 int handle_revision_arg(const char *arg, struct rev_info *revs,
1013                         int flags,
1014                         int cant_be_filename)
1015 {
1016         unsigned mode;
1017         char *dotdot;
1018         struct object *object;
1019         unsigned char sha1[20];
1020         int local_flags;
1021
1022         dotdot = strstr(arg, "..");
1023         if (dotdot) {
1024                 unsigned char from_sha1[20];
1025                 const char *next = dotdot + 2;
1026                 const char *this = arg;
1027                 int symmetric = *next == '.';
1028                 unsigned int flags_exclude = flags ^ UNINTERESTING;
1029
1030                 *dotdot = 0;
1031                 next += symmetric;
1032
1033                 if (!*next)
1034                         next = "HEAD";
1035                 if (dotdot == arg)
1036                         this = "HEAD";
1037                 if (!get_sha1(this, from_sha1) &&
1038                     !get_sha1(next, sha1)) {
1039                         struct commit *a, *b;
1040                         struct commit_list *exclude;
1041
1042                         a = lookup_commit_reference(from_sha1);
1043                         b = lookup_commit_reference(sha1);
1044                         if (!a || !b) {
1045                                 die(symmetric ?
1046                                     "Invalid symmetric difference expression %s...%s" :
1047                                     "Invalid revision range %s..%s",
1048                                     arg, next);
1049                         }
1050
1051                         if (!cant_be_filename) {
1052                                 *dotdot = '.';
1053                                 verify_non_filename(revs->prefix, arg);
1054                         }
1055
1056                         if (symmetric) {
1057                                 exclude = get_merge_bases(a, b, 1);
1058                                 add_pending_commit_list(revs, exclude,
1059                                                         flags_exclude);
1060                                 free_commit_list(exclude);
1061                                 a->object.flags |= flags | SYMMETRIC_LEFT;
1062                         } else
1063                                 a->object.flags |= flags_exclude;
1064                         b->object.flags |= flags;
1065                         add_pending_object(revs, &a->object, this);
1066                         add_pending_object(revs, &b->object, next);
1067                         return 0;
1068                 }
1069                 *dotdot = '.';
1070         }
1071         dotdot = strstr(arg, "^@");
1072         if (dotdot && !dotdot[2]) {
1073                 *dotdot = 0;
1074                 if (add_parents_only(revs, arg, flags))
1075                         return 0;
1076                 *dotdot = '^';
1077         }
1078         dotdot = strstr(arg, "^!");
1079         if (dotdot && !dotdot[2]) {
1080                 *dotdot = 0;
1081                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
1082                         *dotdot = '^';
1083         }
1084
1085         local_flags = 0;
1086         if (*arg == '^') {
1087                 local_flags = UNINTERESTING;
1088                 arg++;
1089         }
1090         if (get_sha1_with_mode(arg, sha1, &mode))
1091                 return -1;
1092         if (!cant_be_filename)
1093                 verify_non_filename(revs->prefix, arg);
1094         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1095         add_pending_object_with_mode(revs, object, arg, mode);
1096         return 0;
1097 }
1098
1099 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb, const char ***prune_data)
1100 {
1101         const char **prune = *prune_data;
1102         int prune_nr;
1103         int prune_alloc;
1104
1105         /* count existing ones */
1106         if (!prune)
1107                 prune_nr = 0;
1108         else
1109                 for (prune_nr = 0; prune[prune_nr]; prune_nr++)
1110                         ;
1111         prune_alloc = prune_nr; /* not really, but we do not know */
1112
1113         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1114                 int len = sb->len;
1115                 if (len && sb->buf[len - 1] == '\n')
1116                         sb->buf[--len] = '\0';
1117                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1118                 prune[prune_nr++] = xstrdup(sb->buf);
1119         }
1120         if (prune) {
1121                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1122                 prune[prune_nr] = NULL;
1123         }
1124         *prune_data = prune;
1125 }
1126
1127 static void read_revisions_from_stdin(struct rev_info *revs, const char ***prune)
1128 {
1129         struct strbuf sb;
1130         int seen_dashdash = 0;
1131
1132         strbuf_init(&sb, 1000);
1133         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1134                 int len = sb.len;
1135                 if (len && sb.buf[len - 1] == '\n')
1136                         sb.buf[--len] = '\0';
1137                 if (!len)
1138                         break;
1139                 if (sb.buf[0] == '-') {
1140                         if (len == 2 && sb.buf[1] == '-') {
1141                                 seen_dashdash = 1;
1142                                 break;
1143                         }
1144                         die("options not supported in --stdin mode");
1145                 }
1146                 if (handle_revision_arg(sb.buf, revs, 0, 1))
1147                         die("bad revision '%s'", sb.buf);
1148         }
1149         if (seen_dashdash)
1150                 read_pathspec_from_stdin(revs, &sb, prune);
1151         strbuf_release(&sb);
1152 }
1153
1154 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1155 {
1156         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1157 }
1158
1159 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1160 {
1161         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1162 }
1163
1164 static void add_message_grep(struct rev_info *revs, const char *pattern)
1165 {
1166         add_grep(revs, pattern, GREP_PATTERN_BODY);
1167 }
1168
1169 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1170                                int *unkc, const char **unkv)
1171 {
1172         const char *arg = argv[0];
1173         const char *optarg;
1174         int argcount;
1175
1176         /* pseudo revision arguments */
1177         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1178             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1179             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1180             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1181             !strcmp(arg, "--bisect"))
1182         {
1183                 unkv[(*unkc)++] = arg;
1184                 return 1;
1185         }
1186
1187         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1188                 revs->max_count = atoi(optarg);
1189                 revs->no_walk = 0;
1190                 return argcount;
1191         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1192                 revs->skip_count = atoi(optarg);
1193                 return argcount;
1194         } else if ((*arg == '-') && isdigit(arg[1])) {
1195         /* accept -<digit>, like traditional "head" */
1196                 revs->max_count = atoi(arg + 1);
1197                 revs->no_walk = 0;
1198         } else if (!strcmp(arg, "-n")) {
1199                 if (argc <= 1)
1200                         return error("-n requires an argument");
1201                 revs->max_count = atoi(argv[1]);
1202                 revs->no_walk = 0;
1203                 return 2;
1204         } else if (!prefixcmp(arg, "-n")) {
1205                 revs->max_count = atoi(arg + 2);
1206                 revs->no_walk = 0;
1207         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1208                 revs->max_age = atoi(optarg);
1209                 return argcount;
1210         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1211                 revs->max_age = approxidate(optarg);
1212                 return argcount;
1213         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1214                 revs->max_age = approxidate(optarg);
1215                 return argcount;
1216         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1217                 revs->min_age = atoi(optarg);
1218                 return argcount;
1219         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1220                 revs->min_age = approxidate(optarg);
1221                 return argcount;
1222         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1223                 revs->min_age = approxidate(optarg);
1224                 return argcount;
1225         } else if (!strcmp(arg, "--first-parent")) {
1226                 revs->first_parent_only = 1;
1227         } else if (!strcmp(arg, "--ancestry-path")) {
1228                 revs->ancestry_path = 1;
1229                 revs->simplify_history = 0;
1230                 revs->limited = 1;
1231         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1232                 init_reflog_walk(&revs->reflog_info);
1233         } else if (!strcmp(arg, "--default")) {
1234                 if (argc <= 1)
1235                         return error("bad --default argument");
1236                 revs->def = argv[1];
1237                 return 2;
1238         } else if (!strcmp(arg, "--merge")) {
1239                 revs->show_merge = 1;
1240         } else if (!strcmp(arg, "--topo-order")) {
1241                 revs->lifo = 1;
1242                 revs->topo_order = 1;
1243         } else if (!strcmp(arg, "--simplify-merges")) {
1244                 revs->simplify_merges = 1;
1245                 revs->rewrite_parents = 1;
1246                 revs->simplify_history = 0;
1247                 revs->limited = 1;
1248         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1249                 revs->simplify_merges = 1;
1250                 revs->rewrite_parents = 1;
1251                 revs->simplify_history = 0;
1252                 revs->simplify_by_decoration = 1;
1253                 revs->limited = 1;
1254                 revs->prune = 1;
1255                 load_ref_decorations(DECORATE_SHORT_REFS);
1256         } else if (!strcmp(arg, "--date-order")) {
1257                 revs->lifo = 0;
1258                 revs->topo_order = 1;
1259         } else if (!prefixcmp(arg, "--early-output")) {
1260                 int count = 100;
1261                 switch (arg[14]) {
1262                 case '=':
1263                         count = atoi(arg+15);
1264                         /* Fallthrough */
1265                 case 0:
1266                         revs->topo_order = 1;
1267                        revs->early_output = count;
1268                 }
1269         } else if (!strcmp(arg, "--parents")) {
1270                 revs->rewrite_parents = 1;
1271                 revs->print_parents = 1;
1272         } else if (!strcmp(arg, "--dense")) {
1273                 revs->dense = 1;
1274         } else if (!strcmp(arg, "--sparse")) {
1275                 revs->dense = 0;
1276         } else if (!strcmp(arg, "--show-all")) {
1277                 revs->show_all = 1;
1278         } else if (!strcmp(arg, "--remove-empty")) {
1279                 revs->remove_empty_trees = 1;
1280         } else if (!strcmp(arg, "--merges")) {
1281                 revs->min_parents = 2;
1282         } else if (!strcmp(arg, "--no-merges")) {
1283                 revs->max_parents = 1;
1284         } else if (!prefixcmp(arg, "--min-parents=")) {
1285                 revs->min_parents = atoi(arg+14);
1286         } else if (!prefixcmp(arg, "--no-min-parents")) {
1287                 revs->min_parents = 0;
1288         } else if (!prefixcmp(arg, "--max-parents=")) {
1289                 revs->max_parents = atoi(arg+14);
1290         } else if (!prefixcmp(arg, "--no-max-parents")) {
1291                 revs->max_parents = -1;
1292         } else if (!strcmp(arg, "--boundary")) {
1293                 revs->boundary = 1;
1294         } else if (!strcmp(arg, "--left-right")) {
1295                 revs->left_right = 1;
1296         } else if (!strcmp(arg, "--left-only")) {
1297                 if (revs->right_only)
1298                         die("--left-only is incompatible with --right-only"
1299                             " or --cherry");
1300                 revs->left_only = 1;
1301         } else if (!strcmp(arg, "--right-only")) {
1302                 if (revs->left_only)
1303                         die("--right-only is incompatible with --left-only");
1304                 revs->right_only = 1;
1305         } else if (!strcmp(arg, "--cherry")) {
1306                 if (revs->left_only)
1307                         die("--cherry is incompatible with --left-only");
1308                 revs->cherry_mark = 1;
1309                 revs->right_only = 1;
1310                 revs->max_parents = 1;
1311                 revs->limited = 1;
1312         } else if (!strcmp(arg, "--count")) {
1313                 revs->count = 1;
1314         } else if (!strcmp(arg, "--cherry-mark")) {
1315                 if (revs->cherry_pick)
1316                         die("--cherry-mark is incompatible with --cherry-pick");
1317                 revs->cherry_mark = 1;
1318                 revs->limited = 1; /* needs limit_list() */
1319         } else if (!strcmp(arg, "--cherry-pick")) {
1320                 if (revs->cherry_mark)
1321                         die("--cherry-pick is incompatible with --cherry-mark");
1322                 revs->cherry_pick = 1;
1323                 revs->limited = 1;
1324         } else if (!strcmp(arg, "--objects")) {
1325                 revs->tag_objects = 1;
1326                 revs->tree_objects = 1;
1327                 revs->blob_objects = 1;
1328         } else if (!strcmp(arg, "--objects-edge")) {
1329                 revs->tag_objects = 1;
1330                 revs->tree_objects = 1;
1331                 revs->blob_objects = 1;
1332                 revs->edge_hint = 1;
1333         } else if (!strcmp(arg, "--unpacked")) {
1334                 revs->unpacked = 1;
1335         } else if (!prefixcmp(arg, "--unpacked=")) {
1336                 die("--unpacked=<packfile> no longer supported.");
1337         } else if (!strcmp(arg, "-r")) {
1338                 revs->diff = 1;
1339                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1340         } else if (!strcmp(arg, "-t")) {
1341                 revs->diff = 1;
1342                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1343                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1344         } else if (!strcmp(arg, "-m")) {
1345                 revs->ignore_merges = 0;
1346         } else if (!strcmp(arg, "-c")) {
1347                 revs->diff = 1;
1348                 revs->dense_combined_merges = 0;
1349                 revs->combine_merges = 1;
1350         } else if (!strcmp(arg, "--cc")) {
1351                 revs->diff = 1;
1352                 revs->dense_combined_merges = 1;
1353                 revs->combine_merges = 1;
1354         } else if (!strcmp(arg, "-v")) {
1355                 revs->verbose_header = 1;
1356         } else if (!strcmp(arg, "--pretty")) {
1357                 revs->verbose_header = 1;
1358                 revs->pretty_given = 1;
1359                 get_commit_format(arg+8, revs);
1360         } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1361                 /*
1362                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1363                  * not allowed, since the argument is optional.
1364                  */
1365                 revs->verbose_header = 1;
1366                 revs->pretty_given = 1;
1367                 get_commit_format(arg+9, revs);
1368         } else if (!strcmp(arg, "--show-notes")) {
1369                 revs->show_notes = 1;
1370                 revs->show_notes_given = 1;
1371         } else if (!prefixcmp(arg, "--show-notes=")) {
1372                 struct strbuf buf = STRBUF_INIT;
1373                 revs->show_notes = 1;
1374                 revs->show_notes_given = 1;
1375                 strbuf_addstr(&buf, arg+13);
1376                 expand_notes_ref(&buf);
1377                 string_list_append(&revs->notes_opt.extra_notes_refs,
1378                                    strbuf_detach(&buf, NULL));
1379         } else if (!strcmp(arg, "--no-notes")) {
1380                 revs->show_notes = 0;
1381                 revs->show_notes_given = 1;
1382         } else if (!strcmp(arg, "--standard-notes")) {
1383                 revs->show_notes_given = 1;
1384                 revs->notes_opt.suppress_default_notes = 0;
1385         } else if (!strcmp(arg, "--no-standard-notes")) {
1386                 revs->notes_opt.suppress_default_notes = 1;
1387         } else if (!strcmp(arg, "--oneline")) {
1388                 revs->verbose_header = 1;
1389                 get_commit_format("oneline", revs);
1390                 revs->pretty_given = 1;
1391                 revs->abbrev_commit = 1;
1392         } else if (!strcmp(arg, "--graph")) {
1393                 revs->topo_order = 1;
1394                 revs->rewrite_parents = 1;
1395                 revs->graph = graph_init(revs);
1396         } else if (!strcmp(arg, "--root")) {
1397                 revs->show_root_diff = 1;
1398         } else if (!strcmp(arg, "--no-commit-id")) {
1399                 revs->no_commit_id = 1;
1400         } else if (!strcmp(arg, "--always")) {
1401                 revs->always_show_header = 1;
1402         } else if (!strcmp(arg, "--no-abbrev")) {
1403                 revs->abbrev = 0;
1404         } else if (!strcmp(arg, "--abbrev")) {
1405                 revs->abbrev = DEFAULT_ABBREV;
1406         } else if (!prefixcmp(arg, "--abbrev=")) {
1407                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1408                 if (revs->abbrev < MINIMUM_ABBREV)
1409                         revs->abbrev = MINIMUM_ABBREV;
1410                 else if (revs->abbrev > 40)
1411                         revs->abbrev = 40;
1412         } else if (!strcmp(arg, "--abbrev-commit")) {
1413                 revs->abbrev_commit = 1;
1414         } else if (!strcmp(arg, "--full-diff")) {
1415                 revs->diff = 1;
1416                 revs->full_diff = 1;
1417         } else if (!strcmp(arg, "--full-history")) {
1418                 revs->simplify_history = 0;
1419         } else if (!strcmp(arg, "--relative-date")) {
1420                 revs->date_mode = DATE_RELATIVE;
1421                 revs->date_mode_explicit = 1;
1422         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1423                 revs->date_mode = parse_date_format(optarg);
1424                 revs->date_mode_explicit = 1;
1425                 return argcount;
1426         } else if (!strcmp(arg, "--log-size")) {
1427                 revs->show_log_size = 1;
1428         }
1429         /*
1430          * Grepping the commit log
1431          */
1432         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1433                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1434                 return argcount;
1435         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1436                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1437                 return argcount;
1438         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1439                 add_message_grep(revs, optarg);
1440                 return argcount;
1441         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1442                 revs->grep_filter.regflags |= REG_EXTENDED;
1443         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1444                 revs->grep_filter.regflags |= REG_ICASE;
1445         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1446                 revs->grep_filter.fixed = 1;
1447         } else if (!strcmp(arg, "--all-match")) {
1448                 revs->grep_filter.all_match = 1;
1449         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1450                 if (strcmp(optarg, "none"))
1451                         git_log_output_encoding = xstrdup(optarg);
1452                 else
1453                         git_log_output_encoding = "";
1454                 return argcount;
1455         } else if (!strcmp(arg, "--reverse")) {
1456                 revs->reverse ^= 1;
1457         } else if (!strcmp(arg, "--children")) {
1458                 revs->children.name = "children";
1459                 revs->limited = 1;
1460         } else {
1461                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1462                 if (!opts)
1463                         unkv[(*unkc)++] = arg;
1464                 return opts;
1465         }
1466
1467         return 1;
1468 }
1469
1470 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1471                         const struct option *options,
1472                         const char * const usagestr[])
1473 {
1474         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1475                                     &ctx->cpidx, ctx->out);
1476         if (n <= 0) {
1477                 error("unknown option `%s'", ctx->argv[0]);
1478                 usage_with_options(usagestr, options);
1479         }
1480         ctx->argv += n;
1481         ctx->argc -= n;
1482 }
1483
1484 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1485 {
1486         return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1487 }
1488
1489 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1490 {
1491         return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1492 }
1493
1494 static void append_prune_data(const char ***prune_data, const char **av)
1495 {
1496         const char **prune = *prune_data;
1497         int prune_nr;
1498         int prune_alloc;
1499
1500         if (!prune) {
1501                 *prune_data = av;
1502                 return;
1503         }
1504
1505         /* count existing ones */
1506         for (prune_nr = 0; prune[prune_nr]; prune_nr++)
1507                 ;
1508         prune_alloc = prune_nr; /* not really, but we do not know */
1509
1510         while (*av) {
1511                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1512                 prune[prune_nr++] = *av;
1513                 av++;
1514         }
1515         if (prune) {
1516                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1517                 prune[prune_nr] = NULL;
1518         }
1519         *prune_data = prune;
1520 }
1521
1522 /*
1523  * Parse revision information, filling in the "rev_info" structure,
1524  * and removing the used arguments from the argument list.
1525  *
1526  * Returns the number of arguments left that weren't recognized
1527  * (which are also moved to the head of the argument list)
1528  */
1529 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1530 {
1531         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0;
1532         const char **prune_data = NULL;
1533         const char *submodule = NULL;
1534         const char *optarg;
1535         int argcount;
1536
1537         if (opt)
1538                 submodule = opt->submodule;
1539
1540         /* First, search for "--" */
1541         seen_dashdash = 0;
1542         for (i = 1; i < argc; i++) {
1543                 const char *arg = argv[i];
1544                 if (strcmp(arg, "--"))
1545                         continue;
1546                 argv[i] = NULL;
1547                 argc = i;
1548                 if (argv[i + 1])
1549                         prune_data = argv + i + 1;
1550                 seen_dashdash = 1;
1551                 break;
1552         }
1553
1554         /* Second, deal with arguments and options */
1555         flags = 0;
1556         read_from_stdin = 0;
1557         for (left = i = 1; i < argc; i++) {
1558                 const char *arg = argv[i];
1559                 if (*arg == '-') {
1560                         int opts;
1561
1562                         if (!strcmp(arg, "--all")) {
1563                                 handle_refs(submodule, revs, flags, for_each_ref_submodule);
1564                                 handle_refs(submodule, revs, flags, head_ref_submodule);
1565                                 continue;
1566                         }
1567                         if (!strcmp(arg, "--branches")) {
1568                                 handle_refs(submodule, revs, flags, for_each_branch_ref_submodule);
1569                                 continue;
1570                         }
1571                         if (!strcmp(arg, "--bisect")) {
1572                                 handle_refs(submodule, revs, flags, for_each_bad_bisect_ref);
1573                                 handle_refs(submodule, revs, flags ^ UNINTERESTING, for_each_good_bisect_ref);
1574                                 revs->bisect = 1;
1575                                 continue;
1576                         }
1577                         if (!strcmp(arg, "--tags")) {
1578                                 handle_refs(submodule, revs, flags, for_each_tag_ref_submodule);
1579                                 continue;
1580                         }
1581                         if (!strcmp(arg, "--remotes")) {
1582                                 handle_refs(submodule, revs, flags, for_each_remote_ref_submodule);
1583                                 continue;
1584                         }
1585                         if ((argcount = parse_long_opt("glob", argv + i, &optarg))) {
1586                                 struct all_refs_cb cb;
1587                                 i += argcount - 1;
1588                                 init_all_refs_cb(&cb, revs, flags);
1589                                 for_each_glob_ref(handle_one_ref, optarg, &cb);
1590                                 continue;
1591                         }
1592                         if (!prefixcmp(arg, "--branches=")) {
1593                                 struct all_refs_cb cb;
1594                                 init_all_refs_cb(&cb, revs, flags);
1595                                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1596                                 continue;
1597                         }
1598                         if (!prefixcmp(arg, "--tags=")) {
1599                                 struct all_refs_cb cb;
1600                                 init_all_refs_cb(&cb, revs, flags);
1601                                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1602                                 continue;
1603                         }
1604                         if (!prefixcmp(arg, "--remotes=")) {
1605                                 struct all_refs_cb cb;
1606                                 init_all_refs_cb(&cb, revs, flags);
1607                                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1608                                 continue;
1609                         }
1610                         if (!strcmp(arg, "--reflog")) {
1611                                 handle_reflog(revs, flags);
1612                                 continue;
1613                         }
1614                         if (!strcmp(arg, "--not")) {
1615                                 flags ^= UNINTERESTING;
1616                                 continue;
1617                         }
1618                         if (!strcmp(arg, "--no-walk")) {
1619                                 revs->no_walk = 1;
1620                                 continue;
1621                         }
1622                         if (!strcmp(arg, "--do-walk")) {
1623                                 revs->no_walk = 0;
1624                                 continue;
1625                         }
1626                         if (!strcmp(arg, "--stdin")) {
1627                                 if (revs->disable_stdin) {
1628                                         argv[left++] = arg;
1629                                         continue;
1630                                 }
1631                                 if (read_from_stdin++)
1632                                         die("--stdin given twice?");
1633                                 read_revisions_from_stdin(revs, &prune_data);
1634                                 continue;
1635                         }
1636
1637                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1638                         if (opts > 0) {
1639                                 i += opts - 1;
1640                                 continue;
1641                         }
1642                         if (opts < 0)
1643                                 exit(128);
1644                         continue;
1645                 }
1646
1647                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1648                         int j;
1649                         if (seen_dashdash || *arg == '^')
1650                                 die("bad revision '%s'", arg);
1651
1652                         /* If we didn't have a "--":
1653                          * (1) all filenames must exist;
1654                          * (2) all rev-args must not be interpretable
1655                          *     as a valid filename.
1656                          * but the latter we have checked in the main loop.
1657                          */
1658                         for (j = i; j < argc; j++)
1659                                 verify_filename(revs->prefix, argv[j]);
1660
1661                         append_prune_data(&prune_data, argv + i);
1662                         break;
1663                 }
1664                 else
1665                         got_rev_arg = 1;
1666         }
1667
1668         if (prune_data)
1669                 init_pathspec(&revs->prune_data, get_pathspec(revs->prefix, prune_data));
1670
1671         if (revs->def == NULL)
1672                 revs->def = opt ? opt->def : NULL;
1673         if (opt && opt->tweak)
1674                 opt->tweak(revs, opt);
1675         if (revs->show_merge)
1676                 prepare_show_merge(revs);
1677         if (revs->def && !revs->pending.nr && !got_rev_arg) {
1678                 unsigned char sha1[20];
1679                 struct object *object;
1680                 unsigned mode;
1681                 if (get_sha1_with_mode(revs->def, sha1, &mode))
1682                         die("bad default revision '%s'", revs->def);
1683                 object = get_reference(revs, revs->def, sha1, 0);
1684                 add_pending_object_with_mode(revs, object, revs->def, mode);
1685         }
1686
1687         /* Did the user ask for any diff output? Run the diff! */
1688         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1689                 revs->diff = 1;
1690
1691         /* Pickaxe, diff-filter and rename following need diffs */
1692         if (revs->diffopt.pickaxe ||
1693             revs->diffopt.filter ||
1694             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1695                 revs->diff = 1;
1696
1697         if (revs->topo_order)
1698                 revs->limited = 1;
1699
1700         if (revs->prune_data.nr) {
1701                 diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
1702                 /* Can't prune commits with rename following: the paths change.. */
1703                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1704                         revs->prune = 1;
1705                 if (!revs->full_diff)
1706                         diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
1707         }
1708         if (revs->combine_merges)
1709                 revs->ignore_merges = 0;
1710         revs->diffopt.abbrev = revs->abbrev;
1711         if (diff_setup_done(&revs->diffopt) < 0)
1712                 die("diff_setup_done failed");
1713
1714         compile_grep_patterns(&revs->grep_filter);
1715
1716         if (revs->reverse && revs->reflog_info)
1717                 die("cannot combine --reverse with --walk-reflogs");
1718         if (revs->rewrite_parents && revs->children.name)
1719                 die("cannot combine --parents and --children");
1720
1721         /*
1722          * Limitations on the graph functionality
1723          */
1724         if (revs->reverse && revs->graph)
1725                 die("cannot combine --reverse with --graph");
1726
1727         if (revs->reflog_info && revs->graph)
1728                 die("cannot combine --walk-reflogs with --graph");
1729
1730         return left;
1731 }
1732
1733 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1734 {
1735         struct commit_list *l = xcalloc(1, sizeof(*l));
1736
1737         l->item = child;
1738         l->next = add_decoration(&revs->children, &parent->object, l);
1739 }
1740
1741 static int remove_duplicate_parents(struct commit *commit)
1742 {
1743         struct commit_list **pp, *p;
1744         int surviving_parents;
1745
1746         /* Examine existing parents while marking ones we have seen... */
1747         pp = &commit->parents;
1748         while ((p = *pp) != NULL) {
1749                 struct commit *parent = p->item;
1750                 if (parent->object.flags & TMP_MARK) {
1751                         *pp = p->next;
1752                         continue;
1753                 }
1754                 parent->object.flags |= TMP_MARK;
1755                 pp = &p->next;
1756         }
1757         /* count them while clearing the temporary mark */
1758         surviving_parents = 0;
1759         for (p = commit->parents; p; p = p->next) {
1760                 p->item->object.flags &= ~TMP_MARK;
1761                 surviving_parents++;
1762         }
1763         return surviving_parents;
1764 }
1765
1766 struct merge_simplify_state {
1767         struct commit *simplified;
1768 };
1769
1770 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1771 {
1772         struct merge_simplify_state *st;
1773
1774         st = lookup_decoration(&revs->merge_simplification, &commit->object);
1775         if (!st) {
1776                 st = xcalloc(1, sizeof(*st));
1777                 add_decoration(&revs->merge_simplification, &commit->object, st);
1778         }
1779         return st;
1780 }
1781
1782 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1783 {
1784         struct commit_list *p;
1785         struct merge_simplify_state *st, *pst;
1786         int cnt;
1787
1788         st = locate_simplify_state(revs, commit);
1789
1790         /*
1791          * Have we handled this one?
1792          */
1793         if (st->simplified)
1794                 return tail;
1795
1796         /*
1797          * An UNINTERESTING commit simplifies to itself, so does a
1798          * root commit.  We do not rewrite parents of such commit
1799          * anyway.
1800          */
1801         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1802                 st->simplified = commit;
1803                 return tail;
1804         }
1805
1806         /*
1807          * Do we know what commit all of our parents should be rewritten to?
1808          * Otherwise we are not ready to rewrite this one yet.
1809          */
1810         for (cnt = 0, p = commit->parents; p; p = p->next) {
1811                 pst = locate_simplify_state(revs, p->item);
1812                 if (!pst->simplified) {
1813                         tail = &commit_list_insert(p->item, tail)->next;
1814                         cnt++;
1815                 }
1816         }
1817         if (cnt) {
1818                 tail = &commit_list_insert(commit, tail)->next;
1819                 return tail;
1820         }
1821
1822         /*
1823          * Rewrite our list of parents.
1824          */
1825         for (p = commit->parents; p; p = p->next) {
1826                 pst = locate_simplify_state(revs, p->item);
1827                 p->item = pst->simplified;
1828         }
1829         cnt = remove_duplicate_parents(commit);
1830
1831         /*
1832          * It is possible that we are a merge and one side branch
1833          * does not have any commit that touches the given paths;
1834          * in such a case, the immediate parents will be rewritten
1835          * to different commits.
1836          *
1837          *      o----X          X: the commit we are looking at;
1838          *     /    /           o: a commit that touches the paths;
1839          * ---o----'
1840          *
1841          * Further reduce the parents by removing redundant parents.
1842          */
1843         if (1 < cnt) {
1844                 struct commit_list *h = reduce_heads(commit->parents);
1845                 cnt = commit_list_count(h);
1846                 free_commit_list(commit->parents);
1847                 commit->parents = h;
1848         }
1849
1850         /*
1851          * A commit simplifies to itself if it is a root, if it is
1852          * UNINTERESTING, if it touches the given paths, or if it is a
1853          * merge and its parents simplifies to more than one commits
1854          * (the first two cases are already handled at the beginning of
1855          * this function).
1856          *
1857          * Otherwise, it simplifies to what its sole parent simplifies to.
1858          */
1859         if (!cnt ||
1860             (commit->object.flags & UNINTERESTING) ||
1861             !(commit->object.flags & TREESAME) ||
1862             (1 < cnt))
1863                 st->simplified = commit;
1864         else {
1865                 pst = locate_simplify_state(revs, commit->parents->item);
1866                 st->simplified = pst->simplified;
1867         }
1868         return tail;
1869 }
1870
1871 static void simplify_merges(struct rev_info *revs)
1872 {
1873         struct commit_list *list;
1874         struct commit_list *yet_to_do, **tail;
1875
1876         if (!revs->topo_order)
1877                 sort_in_topological_order(&revs->commits, revs->lifo);
1878         if (!revs->prune)
1879                 return;
1880
1881         /* feed the list reversed */
1882         yet_to_do = NULL;
1883         for (list = revs->commits; list; list = list->next)
1884                 commit_list_insert(list->item, &yet_to_do);
1885         while (yet_to_do) {
1886                 list = yet_to_do;
1887                 yet_to_do = NULL;
1888                 tail = &yet_to_do;
1889                 while (list) {
1890                         struct commit *commit = list->item;
1891                         struct commit_list *next = list->next;
1892                         free(list);
1893                         list = next;
1894                         tail = simplify_one(revs, commit, tail);
1895                 }
1896         }
1897
1898         /* clean up the result, removing the simplified ones */
1899         list = revs->commits;
1900         revs->commits = NULL;
1901         tail = &revs->commits;
1902         while (list) {
1903                 struct commit *commit = list->item;
1904                 struct commit_list *next = list->next;
1905                 struct merge_simplify_state *st;
1906                 free(list);
1907                 list = next;
1908                 st = locate_simplify_state(revs, commit);
1909                 if (st->simplified == commit)
1910                         tail = &commit_list_insert(commit, tail)->next;
1911         }
1912 }
1913
1914 static void set_children(struct rev_info *revs)
1915 {
1916         struct commit_list *l;
1917         for (l = revs->commits; l; l = l->next) {
1918                 struct commit *commit = l->item;
1919                 struct commit_list *p;
1920
1921                 for (p = commit->parents; p; p = p->next)
1922                         add_child(revs, p->item, commit);
1923         }
1924 }
1925
1926 int prepare_revision_walk(struct rev_info *revs)
1927 {
1928         int nr = revs->pending.nr;
1929         struct object_array_entry *e, *list;
1930
1931         e = list = revs->pending.objects;
1932         revs->pending.nr = 0;
1933         revs->pending.alloc = 0;
1934         revs->pending.objects = NULL;
1935         while (--nr >= 0) {
1936                 struct commit *commit = handle_commit(revs, e->item, e->name);
1937                 if (commit) {
1938                         if (!(commit->object.flags & SEEN)) {
1939                                 commit->object.flags |= SEEN;
1940                                 commit_list_insert_by_date(commit, &revs->commits);
1941                         }
1942                 }
1943                 e++;
1944         }
1945         free(list);
1946
1947         if (revs->no_walk)
1948                 return 0;
1949         if (revs->limited)
1950                 if (limit_list(revs) < 0)
1951                         return -1;
1952         if (revs->topo_order)
1953                 sort_in_topological_order(&revs->commits, revs->lifo);
1954         if (revs->simplify_merges)
1955                 simplify_merges(revs);
1956         if (revs->children.name)
1957                 set_children(revs);
1958         return 0;
1959 }
1960
1961 enum rewrite_result {
1962         rewrite_one_ok,
1963         rewrite_one_noparents,
1964         rewrite_one_error
1965 };
1966
1967 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1968 {
1969         struct commit_list *cache = NULL;
1970
1971         for (;;) {
1972                 struct commit *p = *pp;
1973                 if (!revs->limited)
1974                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
1975                                 return rewrite_one_error;
1976                 if (p->parents && p->parents->next)
1977                         return rewrite_one_ok;
1978                 if (p->object.flags & UNINTERESTING)
1979                         return rewrite_one_ok;
1980                 if (!(p->object.flags & TREESAME))
1981                         return rewrite_one_ok;
1982                 if (!p->parents)
1983                         return rewrite_one_noparents;
1984                 *pp = p->parents->item;
1985         }
1986 }
1987
1988 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1989 {
1990         struct commit_list **pp = &commit->parents;
1991         while (*pp) {
1992                 struct commit_list *parent = *pp;
1993                 switch (rewrite_one(revs, &parent->item)) {
1994                 case rewrite_one_ok:
1995                         break;
1996                 case rewrite_one_noparents:
1997                         *pp = parent->next;
1998                         continue;
1999                 case rewrite_one_error:
2000                         return -1;
2001                 }
2002                 pp = &parent->next;
2003         }
2004         remove_duplicate_parents(commit);
2005         return 0;
2006 }
2007
2008 static int commit_match(struct commit *commit, struct rev_info *opt)
2009 {
2010         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2011                 return 1;
2012         return grep_buffer(&opt->grep_filter,
2013                            NULL, /* we say nothing, not even filename */
2014                            commit->buffer, strlen(commit->buffer));
2015 }
2016
2017 static inline int want_ancestry(struct rev_info *revs)
2018 {
2019         return (revs->rewrite_parents || revs->children.name);
2020 }
2021
2022 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2023 {
2024         if (commit->object.flags & SHOWN)
2025                 return commit_ignore;
2026         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2027                 return commit_ignore;
2028         if (revs->show_all)
2029                 return commit_show;
2030         if (commit->object.flags & UNINTERESTING)
2031                 return commit_ignore;
2032         if (revs->min_age != -1 && (commit->date > revs->min_age))
2033                 return commit_ignore;
2034         if (revs->min_parents || (revs->max_parents >= 0)) {
2035                 int n = 0;
2036                 struct commit_list *p;
2037                 for (p = commit->parents; p; p = p->next)
2038                         n++;
2039                 if ((n < revs->min_parents) ||
2040                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2041                         return commit_ignore;
2042         }
2043         if (!commit_match(commit, revs))
2044                 return commit_ignore;
2045         if (revs->prune && revs->dense) {
2046                 /* Commit without changes? */
2047                 if (commit->object.flags & TREESAME) {
2048                         /* drop merges unless we want parenthood */
2049                         if (!want_ancestry(revs))
2050                                 return commit_ignore;
2051                         /* non-merge - always ignore it */
2052                         if (!commit->parents || !commit->parents->next)
2053                                 return commit_ignore;
2054                 }
2055         }
2056         return commit_show;
2057 }
2058
2059 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2060 {
2061         enum commit_action action = get_commit_action(revs, commit);
2062
2063         if (action == commit_show &&
2064             !revs->show_all &&
2065             revs->prune && revs->dense && want_ancestry(revs)) {
2066                 if (rewrite_parents(revs, commit) < 0)
2067                         return commit_error;
2068         }
2069         return action;
2070 }
2071
2072 static struct commit *get_revision_1(struct rev_info *revs)
2073 {
2074         if (!revs->commits)
2075                 return NULL;
2076
2077         do {
2078                 struct commit_list *entry = revs->commits;
2079                 struct commit *commit = entry->item;
2080
2081                 revs->commits = entry->next;
2082                 free(entry);
2083
2084                 if (revs->reflog_info) {
2085                         fake_reflog_parent(revs->reflog_info, commit);
2086                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2087                 }
2088
2089                 /*
2090                  * If we haven't done the list limiting, we need to look at
2091                  * the parents here. We also need to do the date-based limiting
2092                  * that we'd otherwise have done in limit_list().
2093                  */
2094                 if (!revs->limited) {
2095                         if (revs->max_age != -1 &&
2096                             (commit->date < revs->max_age))
2097                                 continue;
2098                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2099                                 die("Failed to traverse parents of commit %s",
2100                                     sha1_to_hex(commit->object.sha1));
2101                 }
2102
2103                 switch (simplify_commit(revs, commit)) {
2104                 case commit_ignore:
2105                         continue;
2106                 case commit_error:
2107                         die("Failed to simplify parents of commit %s",
2108                             sha1_to_hex(commit->object.sha1));
2109                 default:
2110                         return commit;
2111                 }
2112         } while (revs->commits);
2113         return NULL;
2114 }
2115
2116 static void gc_boundary(struct object_array *array)
2117 {
2118         unsigned nr = array->nr;
2119         unsigned alloc = array->alloc;
2120         struct object_array_entry *objects = array->objects;
2121
2122         if (alloc <= nr) {
2123                 unsigned i, j;
2124                 for (i = j = 0; i < nr; i++) {
2125                         if (objects[i].item->flags & SHOWN)
2126                                 continue;
2127                         if (i != j)
2128                                 objects[j] = objects[i];
2129                         j++;
2130                 }
2131                 for (i = j; i < nr; i++)
2132                         objects[i].item = NULL;
2133                 array->nr = j;
2134         }
2135 }
2136
2137 static void create_boundary_commit_list(struct rev_info *revs)
2138 {
2139         unsigned i;
2140         struct commit *c;
2141         struct object_array *array = &revs->boundary_commits;
2142         struct object_array_entry *objects = array->objects;
2143
2144         /*
2145          * If revs->commits is non-NULL at this point, an error occurred in
2146          * get_revision_1().  Ignore the error and continue printing the
2147          * boundary commits anyway.  (This is what the code has always
2148          * done.)
2149          */
2150         if (revs->commits) {
2151                 free_commit_list(revs->commits);
2152                 revs->commits = NULL;
2153         }
2154
2155         /*
2156          * Put all of the actual boundary commits from revs->boundary_commits
2157          * into revs->commits
2158          */
2159         for (i = 0; i < array->nr; i++) {
2160                 c = (struct commit *)(objects[i].item);
2161                 if (!c)
2162                         continue;
2163                 if (!(c->object.flags & CHILD_SHOWN))
2164                         continue;
2165                 if (c->object.flags & (SHOWN | BOUNDARY))
2166                         continue;
2167                 c->object.flags |= BOUNDARY;
2168                 commit_list_insert(c, &revs->commits);
2169         }
2170
2171         /*
2172          * If revs->topo_order is set, sort the boundary commits
2173          * in topological order
2174          */
2175         sort_in_topological_order(&revs->commits, revs->lifo);
2176 }
2177
2178 static struct commit *get_revision_internal(struct rev_info *revs)
2179 {
2180         struct commit *c = NULL;
2181         struct commit_list *l;
2182
2183         if (revs->boundary == 2) {
2184                 /*
2185                  * All of the normal commits have already been returned,
2186                  * and we are now returning boundary commits.
2187                  * create_boundary_commit_list() has populated
2188                  * revs->commits with the remaining commits to return.
2189                  */
2190                 c = pop_commit(&revs->commits);
2191                 if (c)
2192                         c->object.flags |= SHOWN;
2193                 return c;
2194         }
2195
2196         /*
2197          * Now pick up what they want to give us
2198          */
2199         c = get_revision_1(revs);
2200         if (c) {
2201                 while (0 < revs->skip_count) {
2202                         revs->skip_count--;
2203                         c = get_revision_1(revs);
2204                         if (!c)
2205                                 break;
2206                 }
2207         }
2208
2209         /*
2210          * Check the max_count.
2211          */
2212         switch (revs->max_count) {
2213         case -1:
2214                 break;
2215         case 0:
2216                 c = NULL;
2217                 break;
2218         default:
2219                 revs->max_count--;
2220         }
2221
2222         if (c)
2223                 c->object.flags |= SHOWN;
2224
2225         if (!revs->boundary) {
2226                 return c;
2227         }
2228
2229         if (!c) {
2230                 /*
2231                  * get_revision_1() runs out the commits, and
2232                  * we are done computing the boundaries.
2233                  * switch to boundary commits output mode.
2234                  */
2235                 revs->boundary = 2;
2236
2237                 /*
2238                  * Update revs->commits to contain the list of
2239                  * boundary commits.
2240                  */
2241                 create_boundary_commit_list(revs);
2242
2243                 return get_revision_internal(revs);
2244         }
2245
2246         /*
2247          * boundary commits are the commits that are parents of the
2248          * ones we got from get_revision_1() but they themselves are
2249          * not returned from get_revision_1().  Before returning
2250          * 'c', we need to mark its parents that they could be boundaries.
2251          */
2252
2253         for (l = c->parents; l; l = l->next) {
2254                 struct object *p;
2255                 p = &(l->item->object);
2256                 if (p->flags & (CHILD_SHOWN | SHOWN))
2257                         continue;
2258                 p->flags |= CHILD_SHOWN;
2259                 gc_boundary(&revs->boundary_commits);
2260                 add_object_array(p, NULL, &revs->boundary_commits);
2261         }
2262
2263         return c;
2264 }
2265
2266 struct commit *get_revision(struct rev_info *revs)
2267 {
2268         struct commit *c;
2269         struct commit_list *reversed;
2270
2271         if (revs->reverse) {
2272                 reversed = NULL;
2273                 while ((c = get_revision_internal(revs))) {
2274                         commit_list_insert(c, &reversed);
2275                 }
2276                 revs->commits = reversed;
2277                 revs->reverse = 0;
2278                 revs->reverse_output_stage = 1;
2279         }
2280
2281         if (revs->reverse_output_stage)
2282                 return pop_commit(&revs->commits);
2283
2284         c = get_revision_internal(revs);
2285         if (c && revs->graph)
2286                 graph_update(revs->graph, c);
2287         return c;
2288 }
2289
2290 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2291 {
2292         if (commit->object.flags & BOUNDARY)
2293                 return "-";
2294         else if (commit->object.flags & UNINTERESTING)
2295                 return "^";
2296         else if (commit->object.flags & PATCHSAME)
2297                 return "=";
2298         else if (!revs || revs->left_right) {
2299                 if (commit->object.flags & SYMMETRIC_LEFT)
2300                         return "<";
2301                 else
2302                         return ">";
2303         } else if (revs->graph)
2304                 return "*";
2305         else if (revs->cherry_mark)
2306                 return "+";
2307         return "";
2308 }
2309
2310 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2311 {
2312         char *mark = get_revision_mark(revs, commit);
2313         if (!strlen(mark))
2314                 return;
2315         fputs(mark, stdout);
2316         putchar(' ');
2317 }