Merge branch 'jn/maint-c99-format'
[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
945         revs->commit_format = CMIT_FMT_DEFAULT;
946
947         revs->grep_filter.status_only = 1;
948         revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
949         revs->grep_filter.header_tail = &(revs->grep_filter.header_list);
950         revs->grep_filter.regflags = REG_NEWLINE;
951
952         diff_setup(&revs->diffopt);
953         if (prefix && !revs->diffopt.prefix) {
954                 revs->diffopt.prefix = prefix;
955                 revs->diffopt.prefix_length = strlen(prefix);
956         }
957 }
958
959 static void add_pending_commit_list(struct rev_info *revs,
960                                     struct commit_list *commit_list,
961                                     unsigned int flags)
962 {
963         while (commit_list) {
964                 struct object *object = &commit_list->item->object;
965                 object->flags |= flags;
966                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
967                 commit_list = commit_list->next;
968         }
969 }
970
971 static void prepare_show_merge(struct rev_info *revs)
972 {
973         struct commit_list *bases;
974         struct commit *head, *other;
975         unsigned char sha1[20];
976         const char **prune = NULL;
977         int i, prune_num = 1; /* counting terminating NULL */
978
979         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
980                 die("--merge without HEAD?");
981         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
982                 die("--merge without MERGE_HEAD?");
983         add_pending_object(revs, &head->object, "HEAD");
984         add_pending_object(revs, &other->object, "MERGE_HEAD");
985         bases = get_merge_bases(head, other, 1);
986         add_pending_commit_list(revs, bases, UNINTERESTING);
987         free_commit_list(bases);
988         head->object.flags |= SYMMETRIC_LEFT;
989
990         if (!active_nr)
991                 read_cache();
992         for (i = 0; i < active_nr; i++) {
993                 struct cache_entry *ce = active_cache[i];
994                 if (!ce_stage(ce))
995                         continue;
996                 if (ce_path_match(ce, &revs->prune_data)) {
997                         prune_num++;
998                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
999                         prune[prune_num-2] = ce->name;
1000                         prune[prune_num-1] = NULL;
1001                 }
1002                 while ((i+1 < active_nr) &&
1003                        ce_same_name(ce, active_cache[i+1]))
1004                         i++;
1005         }
1006         free_pathspec(&revs->prune_data);
1007         init_pathspec(&revs->prune_data, prune);
1008         revs->limited = 1;
1009 }
1010
1011 int handle_revision_arg(const char *arg, struct rev_info *revs,
1012                         int flags,
1013                         int cant_be_filename)
1014 {
1015         unsigned mode;
1016         char *dotdot;
1017         struct object *object;
1018         unsigned char sha1[20];
1019         int local_flags;
1020
1021         dotdot = strstr(arg, "..");
1022         if (dotdot) {
1023                 unsigned char from_sha1[20];
1024                 const char *next = dotdot + 2;
1025                 const char *this = arg;
1026                 int symmetric = *next == '.';
1027                 unsigned int flags_exclude = flags ^ UNINTERESTING;
1028
1029                 *dotdot = 0;
1030                 next += symmetric;
1031
1032                 if (!*next)
1033                         next = "HEAD";
1034                 if (dotdot == arg)
1035                         this = "HEAD";
1036                 if (!get_sha1(this, from_sha1) &&
1037                     !get_sha1(next, sha1)) {
1038                         struct commit *a, *b;
1039                         struct commit_list *exclude;
1040
1041                         a = lookup_commit_reference(from_sha1);
1042                         b = lookup_commit_reference(sha1);
1043                         if (!a || !b) {
1044                                 die(symmetric ?
1045                                     "Invalid symmetric difference expression %s...%s" :
1046                                     "Invalid revision range %s..%s",
1047                                     arg, next);
1048                         }
1049
1050                         if (!cant_be_filename) {
1051                                 *dotdot = '.';
1052                                 verify_non_filename(revs->prefix, arg);
1053                         }
1054
1055                         if (symmetric) {
1056                                 exclude = get_merge_bases(a, b, 1);
1057                                 add_pending_commit_list(revs, exclude,
1058                                                         flags_exclude);
1059                                 free_commit_list(exclude);
1060                                 a->object.flags |= flags | SYMMETRIC_LEFT;
1061                         } else
1062                                 a->object.flags |= flags_exclude;
1063                         b->object.flags |= flags;
1064                         add_pending_object(revs, &a->object, this);
1065                         add_pending_object(revs, &b->object, next);
1066                         return 0;
1067                 }
1068                 *dotdot = '.';
1069         }
1070         dotdot = strstr(arg, "^@");
1071         if (dotdot && !dotdot[2]) {
1072                 *dotdot = 0;
1073                 if (add_parents_only(revs, arg, flags))
1074                         return 0;
1075                 *dotdot = '^';
1076         }
1077         dotdot = strstr(arg, "^!");
1078         if (dotdot && !dotdot[2]) {
1079                 *dotdot = 0;
1080                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
1081                         *dotdot = '^';
1082         }
1083
1084         local_flags = 0;
1085         if (*arg == '^') {
1086                 local_flags = UNINTERESTING;
1087                 arg++;
1088         }
1089         if (get_sha1_with_mode(arg, sha1, &mode))
1090                 return -1;
1091         if (!cant_be_filename)
1092                 verify_non_filename(revs->prefix, arg);
1093         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1094         add_pending_object_with_mode(revs, object, arg, mode);
1095         return 0;
1096 }
1097
1098 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb, const char ***prune_data)
1099 {
1100         const char **prune = *prune_data;
1101         int prune_nr;
1102         int prune_alloc;
1103
1104         /* count existing ones */
1105         if (!prune)
1106                 prune_nr = 0;
1107         else
1108                 for (prune_nr = 0; prune[prune_nr]; prune_nr++)
1109                         ;
1110         prune_alloc = prune_nr; /* not really, but we do not know */
1111
1112         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1113                 int len = sb->len;
1114                 if (len && sb->buf[len - 1] == '\n')
1115                         sb->buf[--len] = '\0';
1116                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1117                 prune[prune_nr++] = xstrdup(sb->buf);
1118         }
1119         if (prune) {
1120                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1121                 prune[prune_nr] = NULL;
1122         }
1123         *prune_data = prune;
1124 }
1125
1126 static void read_revisions_from_stdin(struct rev_info *revs, const char ***prune)
1127 {
1128         struct strbuf sb;
1129         int seen_dashdash = 0;
1130
1131         strbuf_init(&sb, 1000);
1132         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1133                 int len = sb.len;
1134                 if (len && sb.buf[len - 1] == '\n')
1135                         sb.buf[--len] = '\0';
1136                 if (!len)
1137                         break;
1138                 if (sb.buf[0] == '-') {
1139                         if (len == 2 && sb.buf[1] == '-') {
1140                                 seen_dashdash = 1;
1141                                 break;
1142                         }
1143                         die("options not supported in --stdin mode");
1144                 }
1145                 if (handle_revision_arg(sb.buf, revs, 0, 1))
1146                         die("bad revision '%s'", sb.buf);
1147         }
1148         if (seen_dashdash)
1149                 read_pathspec_from_stdin(revs, &sb, prune);
1150         strbuf_release(&sb);
1151 }
1152
1153 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1154 {
1155         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1156 }
1157
1158 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1159 {
1160         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1161 }
1162
1163 static void add_message_grep(struct rev_info *revs, const char *pattern)
1164 {
1165         add_grep(revs, pattern, GREP_PATTERN_BODY);
1166 }
1167
1168 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1169                                int *unkc, const char **unkv)
1170 {
1171         const char *arg = argv[0];
1172         const char *optarg;
1173         int argcount;
1174
1175         /* pseudo revision arguments */
1176         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1177             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1178             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1179             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1180             !strcmp(arg, "--bisect"))
1181         {
1182                 unkv[(*unkc)++] = arg;
1183                 return 1;
1184         }
1185
1186         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1187                 revs->max_count = atoi(optarg);
1188                 revs->no_walk = 0;
1189                 return argcount;
1190         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1191                 revs->skip_count = atoi(optarg);
1192                 return argcount;
1193         } else if ((*arg == '-') && isdigit(arg[1])) {
1194         /* accept -<digit>, like traditional "head" */
1195                 revs->max_count = atoi(arg + 1);
1196                 revs->no_walk = 0;
1197         } else if (!strcmp(arg, "-n")) {
1198                 if (argc <= 1)
1199                         return error("-n requires an argument");
1200                 revs->max_count = atoi(argv[1]);
1201                 revs->no_walk = 0;
1202                 return 2;
1203         } else if (!prefixcmp(arg, "-n")) {
1204                 revs->max_count = atoi(arg + 2);
1205                 revs->no_walk = 0;
1206         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1207                 revs->max_age = atoi(optarg);
1208                 return argcount;
1209         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1210                 revs->max_age = approxidate(optarg);
1211                 return argcount;
1212         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1213                 revs->max_age = approxidate(optarg);
1214                 return argcount;
1215         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1216                 revs->min_age = atoi(optarg);
1217                 return argcount;
1218         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1219                 revs->min_age = approxidate(optarg);
1220                 return argcount;
1221         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1222                 revs->min_age = approxidate(optarg);
1223                 return argcount;
1224         } else if (!strcmp(arg, "--first-parent")) {
1225                 revs->first_parent_only = 1;
1226         } else if (!strcmp(arg, "--ancestry-path")) {
1227                 revs->ancestry_path = 1;
1228                 revs->simplify_history = 0;
1229                 revs->limited = 1;
1230         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1231                 init_reflog_walk(&revs->reflog_info);
1232         } else if (!strcmp(arg, "--default")) {
1233                 if (argc <= 1)
1234                         return error("bad --default argument");
1235                 revs->def = argv[1];
1236                 return 2;
1237         } else if (!strcmp(arg, "--merge")) {
1238                 revs->show_merge = 1;
1239         } else if (!strcmp(arg, "--topo-order")) {
1240                 revs->lifo = 1;
1241                 revs->topo_order = 1;
1242         } else if (!strcmp(arg, "--simplify-merges")) {
1243                 revs->simplify_merges = 1;
1244                 revs->rewrite_parents = 1;
1245                 revs->simplify_history = 0;
1246                 revs->limited = 1;
1247         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1248                 revs->simplify_merges = 1;
1249                 revs->rewrite_parents = 1;
1250                 revs->simplify_history = 0;
1251                 revs->simplify_by_decoration = 1;
1252                 revs->limited = 1;
1253                 revs->prune = 1;
1254                 load_ref_decorations(DECORATE_SHORT_REFS);
1255         } else if (!strcmp(arg, "--date-order")) {
1256                 revs->lifo = 0;
1257                 revs->topo_order = 1;
1258         } else if (!prefixcmp(arg, "--early-output")) {
1259                 int count = 100;
1260                 switch (arg[14]) {
1261                 case '=':
1262                         count = atoi(arg+15);
1263                         /* Fallthrough */
1264                 case 0:
1265                         revs->topo_order = 1;
1266                        revs->early_output = count;
1267                 }
1268         } else if (!strcmp(arg, "--parents")) {
1269                 revs->rewrite_parents = 1;
1270                 revs->print_parents = 1;
1271         } else if (!strcmp(arg, "--dense")) {
1272                 revs->dense = 1;
1273         } else if (!strcmp(arg, "--sparse")) {
1274                 revs->dense = 0;
1275         } else if (!strcmp(arg, "--show-all")) {
1276                 revs->show_all = 1;
1277         } else if (!strcmp(arg, "--remove-empty")) {
1278                 revs->remove_empty_trees = 1;
1279         } else if (!strcmp(arg, "--merges")) {
1280                 revs->merges_only = 1;
1281         } else if (!strcmp(arg, "--no-merges")) {
1282                 revs->no_merges = 1;
1283         } else if (!strcmp(arg, "--boundary")) {
1284                 revs->boundary = 1;
1285         } else if (!strcmp(arg, "--left-right")) {
1286                 revs->left_right = 1;
1287         } else if (!strcmp(arg, "--left-only")) {
1288                 if (revs->right_only)
1289                         die("--left-only is incompatible with --right-only"
1290                             " or --cherry");
1291                 revs->left_only = 1;
1292         } else if (!strcmp(arg, "--right-only")) {
1293                 if (revs->left_only)
1294                         die("--right-only is incompatible with --left-only");
1295                 revs->right_only = 1;
1296         } else if (!strcmp(arg, "--cherry")) {
1297                 if (revs->left_only)
1298                         die("--cherry is incompatible with --left-only");
1299                 revs->cherry_mark = 1;
1300                 revs->right_only = 1;
1301                 revs->no_merges = 1;
1302                 revs->limited = 1;
1303         } else if (!strcmp(arg, "--count")) {
1304                 revs->count = 1;
1305         } else if (!strcmp(arg, "--cherry-mark")) {
1306                 if (revs->cherry_pick)
1307                         die("--cherry-mark is incompatible with --cherry-pick");
1308                 revs->cherry_mark = 1;
1309                 revs->limited = 1; /* needs limit_list() */
1310         } else if (!strcmp(arg, "--cherry-pick")) {
1311                 if (revs->cherry_mark)
1312                         die("--cherry-pick is incompatible with --cherry-mark");
1313                 revs->cherry_pick = 1;
1314                 revs->limited = 1;
1315         } else if (!strcmp(arg, "--objects")) {
1316                 revs->tag_objects = 1;
1317                 revs->tree_objects = 1;
1318                 revs->blob_objects = 1;
1319         } else if (!strcmp(arg, "--objects-edge")) {
1320                 revs->tag_objects = 1;
1321                 revs->tree_objects = 1;
1322                 revs->blob_objects = 1;
1323                 revs->edge_hint = 1;
1324         } else if (!strcmp(arg, "--unpacked")) {
1325                 revs->unpacked = 1;
1326         } else if (!prefixcmp(arg, "--unpacked=")) {
1327                 die("--unpacked=<packfile> no longer supported.");
1328         } else if (!strcmp(arg, "-r")) {
1329                 revs->diff = 1;
1330                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1331         } else if (!strcmp(arg, "-t")) {
1332                 revs->diff = 1;
1333                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1334                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1335         } else if (!strcmp(arg, "-m")) {
1336                 revs->ignore_merges = 0;
1337         } else if (!strcmp(arg, "-c")) {
1338                 revs->diff = 1;
1339                 revs->dense_combined_merges = 0;
1340                 revs->combine_merges = 1;
1341         } else if (!strcmp(arg, "--cc")) {
1342                 revs->diff = 1;
1343                 revs->dense_combined_merges = 1;
1344                 revs->combine_merges = 1;
1345         } else if (!strcmp(arg, "-v")) {
1346                 revs->verbose_header = 1;
1347         } else if (!strcmp(arg, "--pretty")) {
1348                 revs->verbose_header = 1;
1349                 revs->pretty_given = 1;
1350                 get_commit_format(arg+8, revs);
1351         } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1352                 /*
1353                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1354                  * not allowed, since the argument is optional.
1355                  */
1356                 revs->verbose_header = 1;
1357                 revs->pretty_given = 1;
1358                 get_commit_format(arg+9, revs);
1359         } else if (!strcmp(arg, "--show-notes")) {
1360                 revs->show_notes = 1;
1361                 revs->show_notes_given = 1;
1362         } else if (!prefixcmp(arg, "--show-notes=")) {
1363                 struct strbuf buf = STRBUF_INIT;
1364                 revs->show_notes = 1;
1365                 revs->show_notes_given = 1;
1366                 if (!revs->notes_opt.extra_notes_refs)
1367                         revs->notes_opt.extra_notes_refs = xcalloc(1, sizeof(struct string_list));
1368                 if (!prefixcmp(arg+13, "refs/"))
1369                         /* happy */;
1370                 else if (!prefixcmp(arg+13, "notes/"))
1371                         strbuf_addstr(&buf, "refs/");
1372                 else
1373                         strbuf_addstr(&buf, "refs/notes/");
1374                 strbuf_addstr(&buf, arg+13);
1375                 string_list_append(revs->notes_opt.extra_notes_refs,
1376                                    strbuf_detach(&buf, NULL));
1377         } else if (!strcmp(arg, "--no-notes")) {
1378                 revs->show_notes = 0;
1379                 revs->show_notes_given = 1;
1380         } else if (!strcmp(arg, "--standard-notes")) {
1381                 revs->show_notes_given = 1;
1382                 revs->notes_opt.suppress_default_notes = 0;
1383         } else if (!strcmp(arg, "--no-standard-notes")) {
1384                 revs->notes_opt.suppress_default_notes = 1;
1385         } else if (!strcmp(arg, "--oneline")) {
1386                 revs->verbose_header = 1;
1387                 get_commit_format("oneline", revs);
1388                 revs->pretty_given = 1;
1389                 revs->abbrev_commit = 1;
1390         } else if (!strcmp(arg, "--graph")) {
1391                 revs->topo_order = 1;
1392                 revs->rewrite_parents = 1;
1393                 revs->graph = graph_init(revs);
1394         } else if (!strcmp(arg, "--root")) {
1395                 revs->show_root_diff = 1;
1396         } else if (!strcmp(arg, "--no-commit-id")) {
1397                 revs->no_commit_id = 1;
1398         } else if (!strcmp(arg, "--always")) {
1399                 revs->always_show_header = 1;
1400         } else if (!strcmp(arg, "--no-abbrev")) {
1401                 revs->abbrev = 0;
1402         } else if (!strcmp(arg, "--abbrev")) {
1403                 revs->abbrev = DEFAULT_ABBREV;
1404         } else if (!prefixcmp(arg, "--abbrev=")) {
1405                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1406                 if (revs->abbrev < MINIMUM_ABBREV)
1407                         revs->abbrev = MINIMUM_ABBREV;
1408                 else if (revs->abbrev > 40)
1409                         revs->abbrev = 40;
1410         } else if (!strcmp(arg, "--abbrev-commit")) {
1411                 revs->abbrev_commit = 1;
1412         } else if (!strcmp(arg, "--full-diff")) {
1413                 revs->diff = 1;
1414                 revs->full_diff = 1;
1415         } else if (!strcmp(arg, "--full-history")) {
1416                 revs->simplify_history = 0;
1417         } else if (!strcmp(arg, "--relative-date")) {
1418                 revs->date_mode = DATE_RELATIVE;
1419                 revs->date_mode_explicit = 1;
1420         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1421                 revs->date_mode = parse_date_format(optarg);
1422                 revs->date_mode_explicit = 1;
1423                 return argcount;
1424         } else if (!strcmp(arg, "--log-size")) {
1425                 revs->show_log_size = 1;
1426         }
1427         /*
1428          * Grepping the commit log
1429          */
1430         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1431                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1432                 return argcount;
1433         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1434                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1435                 return argcount;
1436         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1437                 add_message_grep(revs, optarg);
1438                 return argcount;
1439         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1440                 revs->grep_filter.regflags |= REG_EXTENDED;
1441         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1442                 revs->grep_filter.regflags |= REG_ICASE;
1443         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1444                 revs->grep_filter.fixed = 1;
1445         } else if (!strcmp(arg, "--all-match")) {
1446                 revs->grep_filter.all_match = 1;
1447         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1448                 if (strcmp(optarg, "none"))
1449                         git_log_output_encoding = xstrdup(optarg);
1450                 else
1451                         git_log_output_encoding = "";
1452                 return argcount;
1453         } else if (!strcmp(arg, "--reverse")) {
1454                 revs->reverse ^= 1;
1455         } else if (!strcmp(arg, "--children")) {
1456                 revs->children.name = "children";
1457                 revs->limited = 1;
1458         } else {
1459                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1460                 if (!opts)
1461                         unkv[(*unkc)++] = arg;
1462                 return opts;
1463         }
1464
1465         return 1;
1466 }
1467
1468 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1469                         const struct option *options,
1470                         const char * const usagestr[])
1471 {
1472         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1473                                     &ctx->cpidx, ctx->out);
1474         if (n <= 0) {
1475                 error("unknown option `%s'", ctx->argv[0]);
1476                 usage_with_options(usagestr, options);
1477         }
1478         ctx->argv += n;
1479         ctx->argc -= n;
1480 }
1481
1482 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1483 {
1484         return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1485 }
1486
1487 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1488 {
1489         return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1490 }
1491
1492 static void append_prune_data(const char ***prune_data, const char **av)
1493 {
1494         const char **prune = *prune_data;
1495         int prune_nr;
1496         int prune_alloc;
1497
1498         if (!prune) {
1499                 *prune_data = av;
1500                 return;
1501         }
1502
1503         /* count existing ones */
1504         for (prune_nr = 0; prune[prune_nr]; prune_nr++)
1505                 ;
1506         prune_alloc = prune_nr; /* not really, but we do not know */
1507
1508         while (*av) {
1509                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1510                 prune[prune_nr++] = *av;
1511                 av++;
1512         }
1513         if (prune) {
1514                 ALLOC_GROW(prune, prune_nr+1, prune_alloc);
1515                 prune[prune_nr] = NULL;
1516         }
1517         *prune_data = prune;
1518 }
1519
1520 /*
1521  * Parse revision information, filling in the "rev_info" structure,
1522  * and removing the used arguments from the argument list.
1523  *
1524  * Returns the number of arguments left that weren't recognized
1525  * (which are also moved to the head of the argument list)
1526  */
1527 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1528 {
1529         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0;
1530         const char **prune_data = NULL;
1531         const char *submodule = NULL;
1532         const char *optarg;
1533         int argcount;
1534
1535         if (opt)
1536                 submodule = opt->submodule;
1537
1538         /* First, search for "--" */
1539         seen_dashdash = 0;
1540         for (i = 1; i < argc; i++) {
1541                 const char *arg = argv[i];
1542                 if (strcmp(arg, "--"))
1543                         continue;
1544                 argv[i] = NULL;
1545                 argc = i;
1546                 if (argv[i + 1])
1547                         prune_data = argv + i + 1;
1548                 seen_dashdash = 1;
1549                 break;
1550         }
1551
1552         /* Second, deal with arguments and options */
1553         flags = 0;
1554         read_from_stdin = 0;
1555         for (left = i = 1; i < argc; i++) {
1556                 const char *arg = argv[i];
1557                 if (*arg == '-') {
1558                         int opts;
1559
1560                         if (!strcmp(arg, "--all")) {
1561                                 handle_refs(submodule, revs, flags, for_each_ref_submodule);
1562                                 handle_refs(submodule, revs, flags, head_ref_submodule);
1563                                 continue;
1564                         }
1565                         if (!strcmp(arg, "--branches")) {
1566                                 handle_refs(submodule, revs, flags, for_each_branch_ref_submodule);
1567                                 continue;
1568                         }
1569                         if (!strcmp(arg, "--bisect")) {
1570                                 handle_refs(submodule, revs, flags, for_each_bad_bisect_ref);
1571                                 handle_refs(submodule, revs, flags ^ UNINTERESTING, for_each_good_bisect_ref);
1572                                 revs->bisect = 1;
1573                                 continue;
1574                         }
1575                         if (!strcmp(arg, "--tags")) {
1576                                 handle_refs(submodule, revs, flags, for_each_tag_ref_submodule);
1577                                 continue;
1578                         }
1579                         if (!strcmp(arg, "--remotes")) {
1580                                 handle_refs(submodule, revs, flags, for_each_remote_ref_submodule);
1581                                 continue;
1582                         }
1583                         if ((argcount = parse_long_opt("glob", argv + i, &optarg))) {
1584                                 struct all_refs_cb cb;
1585                                 i += argcount - 1;
1586                                 init_all_refs_cb(&cb, revs, flags);
1587                                 for_each_glob_ref(handle_one_ref, optarg, &cb);
1588                                 continue;
1589                         }
1590                         if (!prefixcmp(arg, "--branches=")) {
1591                                 struct all_refs_cb cb;
1592                                 init_all_refs_cb(&cb, revs, flags);
1593                                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1594                                 continue;
1595                         }
1596                         if (!prefixcmp(arg, "--tags=")) {
1597                                 struct all_refs_cb cb;
1598                                 init_all_refs_cb(&cb, revs, flags);
1599                                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1600                                 continue;
1601                         }
1602                         if (!prefixcmp(arg, "--remotes=")) {
1603                                 struct all_refs_cb cb;
1604                                 init_all_refs_cb(&cb, revs, flags);
1605                                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1606                                 continue;
1607                         }
1608                         if (!strcmp(arg, "--reflog")) {
1609                                 handle_reflog(revs, flags);
1610                                 continue;
1611                         }
1612                         if (!strcmp(arg, "--not")) {
1613                                 flags ^= UNINTERESTING;
1614                                 continue;
1615                         }
1616                         if (!strcmp(arg, "--no-walk")) {
1617                                 revs->no_walk = 1;
1618                                 continue;
1619                         }
1620                         if (!strcmp(arg, "--do-walk")) {
1621                                 revs->no_walk = 0;
1622                                 continue;
1623                         }
1624                         if (!strcmp(arg, "--stdin")) {
1625                                 if (revs->disable_stdin) {
1626                                         argv[left++] = arg;
1627                                         continue;
1628                                 }
1629                                 if (read_from_stdin++)
1630                                         die("--stdin given twice?");
1631                                 read_revisions_from_stdin(revs, &prune_data);
1632                                 continue;
1633                         }
1634
1635                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1636                         if (opts > 0) {
1637                                 i += opts - 1;
1638                                 continue;
1639                         }
1640                         if (opts < 0)
1641                                 exit(128);
1642                         continue;
1643                 }
1644
1645                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1646                         int j;
1647                         if (seen_dashdash || *arg == '^')
1648                                 die("bad revision '%s'", arg);
1649
1650                         /* If we didn't have a "--":
1651                          * (1) all filenames must exist;
1652                          * (2) all rev-args must not be interpretable
1653                          *     as a valid filename.
1654                          * but the latter we have checked in the main loop.
1655                          */
1656                         for (j = i; j < argc; j++)
1657                                 verify_filename(revs->prefix, argv[j]);
1658
1659                         append_prune_data(&prune_data, argv + i);
1660                         break;
1661                 }
1662                 else
1663                         got_rev_arg = 1;
1664         }
1665
1666         if (prune_data)
1667                 init_pathspec(&revs->prune_data, get_pathspec(revs->prefix, prune_data));
1668
1669         if (revs->def == NULL)
1670                 revs->def = opt ? opt->def : NULL;
1671         if (opt && opt->tweak)
1672                 opt->tweak(revs, opt);
1673         if (revs->show_merge)
1674                 prepare_show_merge(revs);
1675         if (revs->def && !revs->pending.nr && !got_rev_arg) {
1676                 unsigned char sha1[20];
1677                 struct object *object;
1678                 unsigned mode;
1679                 if (get_sha1_with_mode(revs->def, sha1, &mode))
1680                         die("bad default revision '%s'", revs->def);
1681                 object = get_reference(revs, revs->def, sha1, 0);
1682                 add_pending_object_with_mode(revs, object, revs->def, mode);
1683         }
1684
1685         /* Did the user ask for any diff output? Run the diff! */
1686         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1687                 revs->diff = 1;
1688
1689         /* Pickaxe, diff-filter and rename following need diffs */
1690         if (revs->diffopt.pickaxe ||
1691             revs->diffopt.filter ||
1692             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1693                 revs->diff = 1;
1694
1695         if (revs->topo_order)
1696                 revs->limited = 1;
1697
1698         if (revs->prune_data.nr) {
1699                 diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
1700                 /* Can't prune commits with rename following: the paths change.. */
1701                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1702                         revs->prune = 1;
1703                 if (!revs->full_diff)
1704                         diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
1705         }
1706         if (revs->combine_merges)
1707                 revs->ignore_merges = 0;
1708         revs->diffopt.abbrev = revs->abbrev;
1709         if (diff_setup_done(&revs->diffopt) < 0)
1710                 die("diff_setup_done failed");
1711
1712         compile_grep_patterns(&revs->grep_filter);
1713
1714         if (revs->reverse && revs->reflog_info)
1715                 die("cannot combine --reverse with --walk-reflogs");
1716         if (revs->rewrite_parents && revs->children.name)
1717                 die("cannot combine --parents and --children");
1718
1719         /*
1720          * Limitations on the graph functionality
1721          */
1722         if (revs->reverse && revs->graph)
1723                 die("cannot combine --reverse with --graph");
1724
1725         if (revs->reflog_info && revs->graph)
1726                 die("cannot combine --walk-reflogs with --graph");
1727
1728         return left;
1729 }
1730
1731 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1732 {
1733         struct commit_list *l = xcalloc(1, sizeof(*l));
1734
1735         l->item = child;
1736         l->next = add_decoration(&revs->children, &parent->object, l);
1737 }
1738
1739 static int remove_duplicate_parents(struct commit *commit)
1740 {
1741         struct commit_list **pp, *p;
1742         int surviving_parents;
1743
1744         /* Examine existing parents while marking ones we have seen... */
1745         pp = &commit->parents;
1746         while ((p = *pp) != NULL) {
1747                 struct commit *parent = p->item;
1748                 if (parent->object.flags & TMP_MARK) {
1749                         *pp = p->next;
1750                         continue;
1751                 }
1752                 parent->object.flags |= TMP_MARK;
1753                 pp = &p->next;
1754         }
1755         /* count them while clearing the temporary mark */
1756         surviving_parents = 0;
1757         for (p = commit->parents; p; p = p->next) {
1758                 p->item->object.flags &= ~TMP_MARK;
1759                 surviving_parents++;
1760         }
1761         return surviving_parents;
1762 }
1763
1764 struct merge_simplify_state {
1765         struct commit *simplified;
1766 };
1767
1768 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1769 {
1770         struct merge_simplify_state *st;
1771
1772         st = lookup_decoration(&revs->merge_simplification, &commit->object);
1773         if (!st) {
1774                 st = xcalloc(1, sizeof(*st));
1775                 add_decoration(&revs->merge_simplification, &commit->object, st);
1776         }
1777         return st;
1778 }
1779
1780 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1781 {
1782         struct commit_list *p;
1783         struct merge_simplify_state *st, *pst;
1784         int cnt;
1785
1786         st = locate_simplify_state(revs, commit);
1787
1788         /*
1789          * Have we handled this one?
1790          */
1791         if (st->simplified)
1792                 return tail;
1793
1794         /*
1795          * An UNINTERESTING commit simplifies to itself, so does a
1796          * root commit.  We do not rewrite parents of such commit
1797          * anyway.
1798          */
1799         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1800                 st->simplified = commit;
1801                 return tail;
1802         }
1803
1804         /*
1805          * Do we know what commit all of our parents should be rewritten to?
1806          * Otherwise we are not ready to rewrite this one yet.
1807          */
1808         for (cnt = 0, p = commit->parents; p; p = p->next) {
1809                 pst = locate_simplify_state(revs, p->item);
1810                 if (!pst->simplified) {
1811                         tail = &commit_list_insert(p->item, tail)->next;
1812                         cnt++;
1813                 }
1814         }
1815         if (cnt) {
1816                 tail = &commit_list_insert(commit, tail)->next;
1817                 return tail;
1818         }
1819
1820         /*
1821          * Rewrite our list of parents.
1822          */
1823         for (p = commit->parents; p; p = p->next) {
1824                 pst = locate_simplify_state(revs, p->item);
1825                 p->item = pst->simplified;
1826         }
1827         cnt = remove_duplicate_parents(commit);
1828
1829         /*
1830          * It is possible that we are a merge and one side branch
1831          * does not have any commit that touches the given paths;
1832          * in such a case, the immediate parents will be rewritten
1833          * to different commits.
1834          *
1835          *      o----X          X: the commit we are looking at;
1836          *     /    /           o: a commit that touches the paths;
1837          * ---o----'
1838          *
1839          * Further reduce the parents by removing redundant parents.
1840          */
1841         if (1 < cnt) {
1842                 struct commit_list *h = reduce_heads(commit->parents);
1843                 cnt = commit_list_count(h);
1844                 free_commit_list(commit->parents);
1845                 commit->parents = h;
1846         }
1847
1848         /*
1849          * A commit simplifies to itself if it is a root, if it is
1850          * UNINTERESTING, if it touches the given paths, or if it is a
1851          * merge and its parents simplifies to more than one commits
1852          * (the first two cases are already handled at the beginning of
1853          * this function).
1854          *
1855          * Otherwise, it simplifies to what its sole parent simplifies to.
1856          */
1857         if (!cnt ||
1858             (commit->object.flags & UNINTERESTING) ||
1859             !(commit->object.flags & TREESAME) ||
1860             (1 < cnt))
1861                 st->simplified = commit;
1862         else {
1863                 pst = locate_simplify_state(revs, commit->parents->item);
1864                 st->simplified = pst->simplified;
1865         }
1866         return tail;
1867 }
1868
1869 static void simplify_merges(struct rev_info *revs)
1870 {
1871         struct commit_list *list;
1872         struct commit_list *yet_to_do, **tail;
1873
1874         if (!revs->topo_order)
1875                 sort_in_topological_order(&revs->commits, revs->lifo);
1876         if (!revs->prune)
1877                 return;
1878
1879         /* feed the list reversed */
1880         yet_to_do = NULL;
1881         for (list = revs->commits; list; list = list->next)
1882                 commit_list_insert(list->item, &yet_to_do);
1883         while (yet_to_do) {
1884                 list = yet_to_do;
1885                 yet_to_do = NULL;
1886                 tail = &yet_to_do;
1887                 while (list) {
1888                         struct commit *commit = list->item;
1889                         struct commit_list *next = list->next;
1890                         free(list);
1891                         list = next;
1892                         tail = simplify_one(revs, commit, tail);
1893                 }
1894         }
1895
1896         /* clean up the result, removing the simplified ones */
1897         list = revs->commits;
1898         revs->commits = NULL;
1899         tail = &revs->commits;
1900         while (list) {
1901                 struct commit *commit = list->item;
1902                 struct commit_list *next = list->next;
1903                 struct merge_simplify_state *st;
1904                 free(list);
1905                 list = next;
1906                 st = locate_simplify_state(revs, commit);
1907                 if (st->simplified == commit)
1908                         tail = &commit_list_insert(commit, tail)->next;
1909         }
1910 }
1911
1912 static void set_children(struct rev_info *revs)
1913 {
1914         struct commit_list *l;
1915         for (l = revs->commits; l; l = l->next) {
1916                 struct commit *commit = l->item;
1917                 struct commit_list *p;
1918
1919                 for (p = commit->parents; p; p = p->next)
1920                         add_child(revs, p->item, commit);
1921         }
1922 }
1923
1924 int prepare_revision_walk(struct rev_info *revs)
1925 {
1926         int nr = revs->pending.nr;
1927         struct object_array_entry *e, *list;
1928
1929         e = list = revs->pending.objects;
1930         revs->pending.nr = 0;
1931         revs->pending.alloc = 0;
1932         revs->pending.objects = NULL;
1933         while (--nr >= 0) {
1934                 struct commit *commit = handle_commit(revs, e->item, e->name);
1935                 if (commit) {
1936                         if (!(commit->object.flags & SEEN)) {
1937                                 commit->object.flags |= SEEN;
1938                                 commit_list_insert_by_date(commit, &revs->commits);
1939                         }
1940                 }
1941                 e++;
1942         }
1943         free(list);
1944
1945         if (revs->no_walk)
1946                 return 0;
1947         if (revs->limited)
1948                 if (limit_list(revs) < 0)
1949                         return -1;
1950         if (revs->topo_order)
1951                 sort_in_topological_order(&revs->commits, revs->lifo);
1952         if (revs->simplify_merges)
1953                 simplify_merges(revs);
1954         if (revs->children.name)
1955                 set_children(revs);
1956         return 0;
1957 }
1958
1959 enum rewrite_result {
1960         rewrite_one_ok,
1961         rewrite_one_noparents,
1962         rewrite_one_error
1963 };
1964
1965 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1966 {
1967         struct commit_list *cache = NULL;
1968
1969         for (;;) {
1970                 struct commit *p = *pp;
1971                 if (!revs->limited)
1972                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
1973                                 return rewrite_one_error;
1974                 if (p->parents && p->parents->next)
1975                         return rewrite_one_ok;
1976                 if (p->object.flags & UNINTERESTING)
1977                         return rewrite_one_ok;
1978                 if (!(p->object.flags & TREESAME))
1979                         return rewrite_one_ok;
1980                 if (!p->parents)
1981                         return rewrite_one_noparents;
1982                 *pp = p->parents->item;
1983         }
1984 }
1985
1986 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1987 {
1988         struct commit_list **pp = &commit->parents;
1989         while (*pp) {
1990                 struct commit_list *parent = *pp;
1991                 switch (rewrite_one(revs, &parent->item)) {
1992                 case rewrite_one_ok:
1993                         break;
1994                 case rewrite_one_noparents:
1995                         *pp = parent->next;
1996                         continue;
1997                 case rewrite_one_error:
1998                         return -1;
1999                 }
2000                 pp = &parent->next;
2001         }
2002         remove_duplicate_parents(commit);
2003         return 0;
2004 }
2005
2006 static int commit_match(struct commit *commit, struct rev_info *opt)
2007 {
2008         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2009                 return 1;
2010         return grep_buffer(&opt->grep_filter,
2011                            NULL, /* we say nothing, not even filename */
2012                            commit->buffer, strlen(commit->buffer));
2013 }
2014
2015 static inline int want_ancestry(struct rev_info *revs)
2016 {
2017         return (revs->rewrite_parents || revs->children.name);
2018 }
2019
2020 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2021 {
2022         if (commit->object.flags & SHOWN)
2023                 return commit_ignore;
2024         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2025                 return commit_ignore;
2026         if (revs->show_all)
2027                 return commit_show;
2028         if (commit->object.flags & UNINTERESTING)
2029                 return commit_ignore;
2030         if (revs->min_age != -1 && (commit->date > revs->min_age))
2031                 return commit_ignore;
2032         if (revs->no_merges && commit->parents && commit->parents->next)
2033                 return commit_ignore;
2034         if (revs->merges_only && !(commit->parents && commit->parents->next))
2035                 return commit_ignore;
2036         if (!commit_match(commit, revs))
2037                 return commit_ignore;
2038         if (revs->prune && revs->dense) {
2039                 /* Commit without changes? */
2040                 if (commit->object.flags & TREESAME) {
2041                         /* drop merges unless we want parenthood */
2042                         if (!want_ancestry(revs))
2043                                 return commit_ignore;
2044                         /* non-merge - always ignore it */
2045                         if (!commit->parents || !commit->parents->next)
2046                                 return commit_ignore;
2047                 }
2048         }
2049         return commit_show;
2050 }
2051
2052 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2053 {
2054         enum commit_action action = get_commit_action(revs, commit);
2055
2056         if (action == commit_show &&
2057             !revs->show_all &&
2058             revs->prune && revs->dense && want_ancestry(revs)) {
2059                 if (rewrite_parents(revs, commit) < 0)
2060                         return commit_error;
2061         }
2062         return action;
2063 }
2064
2065 static struct commit *get_revision_1(struct rev_info *revs)
2066 {
2067         if (!revs->commits)
2068                 return NULL;
2069
2070         do {
2071                 struct commit_list *entry = revs->commits;
2072                 struct commit *commit = entry->item;
2073
2074                 revs->commits = entry->next;
2075                 free(entry);
2076
2077                 if (revs->reflog_info) {
2078                         fake_reflog_parent(revs->reflog_info, commit);
2079                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2080                 }
2081
2082                 /*
2083                  * If we haven't done the list limiting, we need to look at
2084                  * the parents here. We also need to do the date-based limiting
2085                  * that we'd otherwise have done in limit_list().
2086                  */
2087                 if (!revs->limited) {
2088                         if (revs->max_age != -1 &&
2089                             (commit->date < revs->max_age))
2090                                 continue;
2091                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2092                                 die("Failed to traverse parents of commit %s",
2093                                     sha1_to_hex(commit->object.sha1));
2094                 }
2095
2096                 switch (simplify_commit(revs, commit)) {
2097                 case commit_ignore:
2098                         continue;
2099                 case commit_error:
2100                         die("Failed to simplify parents of commit %s",
2101                             sha1_to_hex(commit->object.sha1));
2102                 default:
2103                         return commit;
2104                 }
2105         } while (revs->commits);
2106         return NULL;
2107 }
2108
2109 static void gc_boundary(struct object_array *array)
2110 {
2111         unsigned nr = array->nr;
2112         unsigned alloc = array->alloc;
2113         struct object_array_entry *objects = array->objects;
2114
2115         if (alloc <= nr) {
2116                 unsigned i, j;
2117                 for (i = j = 0; i < nr; i++) {
2118                         if (objects[i].item->flags & SHOWN)
2119                                 continue;
2120                         if (i != j)
2121                                 objects[j] = objects[i];
2122                         j++;
2123                 }
2124                 for (i = j; i < nr; i++)
2125                         objects[i].item = NULL;
2126                 array->nr = j;
2127         }
2128 }
2129
2130 static void create_boundary_commit_list(struct rev_info *revs)
2131 {
2132         unsigned i;
2133         struct commit *c;
2134         struct object_array *array = &revs->boundary_commits;
2135         struct object_array_entry *objects = array->objects;
2136
2137         /*
2138          * If revs->commits is non-NULL at this point, an error occurred in
2139          * get_revision_1().  Ignore the error and continue printing the
2140          * boundary commits anyway.  (This is what the code has always
2141          * done.)
2142          */
2143         if (revs->commits) {
2144                 free_commit_list(revs->commits);
2145                 revs->commits = NULL;
2146         }
2147
2148         /*
2149          * Put all of the actual boundary commits from revs->boundary_commits
2150          * into revs->commits
2151          */
2152         for (i = 0; i < array->nr; i++) {
2153                 c = (struct commit *)(objects[i].item);
2154                 if (!c)
2155                         continue;
2156                 if (!(c->object.flags & CHILD_SHOWN))
2157                         continue;
2158                 if (c->object.flags & (SHOWN | BOUNDARY))
2159                         continue;
2160                 c->object.flags |= BOUNDARY;
2161                 commit_list_insert(c, &revs->commits);
2162         }
2163
2164         /*
2165          * If revs->topo_order is set, sort the boundary commits
2166          * in topological order
2167          */
2168         sort_in_topological_order(&revs->commits, revs->lifo);
2169 }
2170
2171 static struct commit *get_revision_internal(struct rev_info *revs)
2172 {
2173         struct commit *c = NULL;
2174         struct commit_list *l;
2175
2176         if (revs->boundary == 2) {
2177                 /*
2178                  * All of the normal commits have already been returned,
2179                  * and we are now returning boundary commits.
2180                  * create_boundary_commit_list() has populated
2181                  * revs->commits with the remaining commits to return.
2182                  */
2183                 c = pop_commit(&revs->commits);
2184                 if (c)
2185                         c->object.flags |= SHOWN;
2186                 return c;
2187         }
2188
2189         /*
2190          * Now pick up what they want to give us
2191          */
2192         c = get_revision_1(revs);
2193         if (c) {
2194                 while (0 < revs->skip_count) {
2195                         revs->skip_count--;
2196                         c = get_revision_1(revs);
2197                         if (!c)
2198                                 break;
2199                 }
2200         }
2201
2202         /*
2203          * Check the max_count.
2204          */
2205         switch (revs->max_count) {
2206         case -1:
2207                 break;
2208         case 0:
2209                 c = NULL;
2210                 break;
2211         default:
2212                 revs->max_count--;
2213         }
2214
2215         if (c)
2216                 c->object.flags |= SHOWN;
2217
2218         if (!revs->boundary) {
2219                 return c;
2220         }
2221
2222         if (!c) {
2223                 /*
2224                  * get_revision_1() runs out the commits, and
2225                  * we are done computing the boundaries.
2226                  * switch to boundary commits output mode.
2227                  */
2228                 revs->boundary = 2;
2229
2230                 /*
2231                  * Update revs->commits to contain the list of
2232                  * boundary commits.
2233                  */
2234                 create_boundary_commit_list(revs);
2235
2236                 return get_revision_internal(revs);
2237         }
2238
2239         /*
2240          * boundary commits are the commits that are parents of the
2241          * ones we got from get_revision_1() but they themselves are
2242          * not returned from get_revision_1().  Before returning
2243          * 'c', we need to mark its parents that they could be boundaries.
2244          */
2245
2246         for (l = c->parents; l; l = l->next) {
2247                 struct object *p;
2248                 p = &(l->item->object);
2249                 if (p->flags & (CHILD_SHOWN | SHOWN))
2250                         continue;
2251                 p->flags |= CHILD_SHOWN;
2252                 gc_boundary(&revs->boundary_commits);
2253                 add_object_array(p, NULL, &revs->boundary_commits);
2254         }
2255
2256         return c;
2257 }
2258
2259 struct commit *get_revision(struct rev_info *revs)
2260 {
2261         struct commit *c;
2262         struct commit_list *reversed;
2263
2264         if (revs->reverse) {
2265                 reversed = NULL;
2266                 while ((c = get_revision_internal(revs))) {
2267                         commit_list_insert(c, &reversed);
2268                 }
2269                 revs->commits = reversed;
2270                 revs->reverse = 0;
2271                 revs->reverse_output_stage = 1;
2272         }
2273
2274         if (revs->reverse_output_stage)
2275                 return pop_commit(&revs->commits);
2276
2277         c = get_revision_internal(revs);
2278         if (c && revs->graph)
2279                 graph_update(revs->graph, c);
2280         return c;
2281 }
2282
2283 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2284 {
2285         if (commit->object.flags & BOUNDARY)
2286                 return "-";
2287         else if (commit->object.flags & UNINTERESTING)
2288                 return "^";
2289         else if (commit->object.flags & PATCHSAME)
2290                 return "=";
2291         else if (!revs || revs->left_right) {
2292                 if (commit->object.flags & SYMMETRIC_LEFT)
2293                         return "<";
2294                 else
2295                         return ">";
2296         } else if (revs->graph)
2297                 return "*";
2298         else if (revs->cherry_mark)
2299                 return "+";
2300         return "";
2301 }
2302
2303 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2304 {
2305         char *mark = get_revision_mark(revs, commit);
2306         if (!strlen(mark))
2307                 return;
2308         fputs(mark, stdout);
2309         putchar(' ');
2310 }