Merge branch 'maint-1.7.6' into maint
[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 (!obj)
137                 return;
138         if (revs->no_walk && (obj->flags & UNINTERESTING))
139                 revs->no_walk = 0;
140         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
141                 struct strbuf buf = STRBUF_INIT;
142                 int len = interpret_branch_name(name, &buf);
143                 int st;
144
145                 if (0 < len && name[len] && buf.len)
146                         strbuf_addstr(&buf, name + len);
147                 st = add_reflog_for_walk(revs->reflog_info,
148                                          (struct commit *)obj,
149                                          buf.buf[0] ? buf.buf: name);
150                 strbuf_release(&buf);
151                 if (st)
152                         return;
153         }
154         add_object_array_with_mode(obj, name, &revs->pending, mode);
155 }
156
157 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
158 {
159         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
160 }
161
162 void add_head_to_pending(struct rev_info *revs)
163 {
164         unsigned char sha1[20];
165         struct object *obj;
166         if (get_sha1("HEAD", sha1))
167                 return;
168         obj = parse_object(sha1);
169         if (!obj)
170                 return;
171         add_pending_object(revs, obj, "HEAD");
172 }
173
174 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
175 {
176         struct object *object;
177
178         object = parse_object(sha1);
179         if (!object) {
180                 if (revs->ignore_missing)
181                         return object;
182                 die("bad object %s", name);
183         }
184         object->flags |= flags;
185         return object;
186 }
187
188 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
189 {
190         unsigned long flags = object->flags;
191
192         /*
193          * Tag object? Look what it points to..
194          */
195         while (object->type == OBJ_TAG) {
196                 struct tag *tag = (struct tag *) object;
197                 if (revs->tag_objects && !(flags & UNINTERESTING))
198                         add_pending_object(revs, object, tag->tag);
199                 if (!tag->tagged)
200                         die("bad tag");
201                 object = parse_object(tag->tagged->sha1);
202                 if (!object) {
203                         if (flags & UNINTERESTING)
204                                 return NULL;
205                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
206                 }
207         }
208
209         /*
210          * Commit object? Just return it, we'll do all the complex
211          * reachability crud.
212          */
213         if (object->type == OBJ_COMMIT) {
214                 struct commit *commit = (struct commit *)object;
215                 if (parse_commit(commit) < 0)
216                         die("unable to parse commit %s", name);
217                 if (flags & UNINTERESTING) {
218                         commit->object.flags |= UNINTERESTING;
219                         mark_parents_uninteresting(commit);
220                         revs->limited = 1;
221                 }
222                 if (revs->show_source && !commit->util)
223                         commit->util = (void *) name;
224                 return commit;
225         }
226
227         /*
228          * Tree object? Either mark it uninteresting, or add it
229          * to the list of objects to look at later..
230          */
231         if (object->type == OBJ_TREE) {
232                 struct tree *tree = (struct tree *)object;
233                 if (!revs->tree_objects)
234                         return NULL;
235                 if (flags & UNINTERESTING) {
236                         mark_tree_uninteresting(tree);
237                         return NULL;
238                 }
239                 add_pending_object(revs, object, "");
240                 return NULL;
241         }
242
243         /*
244          * Blob object? You know the drill by now..
245          */
246         if (object->type == OBJ_BLOB) {
247                 struct blob *blob = (struct blob *)object;
248                 if (!revs->blob_objects)
249                         return NULL;
250                 if (flags & UNINTERESTING) {
251                         mark_blob_uninteresting(blob);
252                         return NULL;
253                 }
254                 add_pending_object(revs, object, "");
255                 return NULL;
256         }
257         die("%s is unknown object", name);
258 }
259
260 static int everybody_uninteresting(struct commit_list *orig)
261 {
262         struct commit_list *list = orig;
263         while (list) {
264                 struct commit *commit = list->item;
265                 list = list->next;
266                 if (commit->object.flags & UNINTERESTING)
267                         continue;
268                 return 0;
269         }
270         return 1;
271 }
272
273 /*
274  * The goal is to get REV_TREE_NEW as the result only if the
275  * diff consists of all '+' (and no other changes), REV_TREE_OLD
276  * if the whole diff is removal of old data, and otherwise
277  * REV_TREE_DIFFERENT (of course if the trees are the same we
278  * want REV_TREE_SAME).
279  * That means that once we get to REV_TREE_DIFFERENT, we do not
280  * have to look any further.
281  */
282 static int tree_difference = REV_TREE_SAME;
283
284 static void file_add_remove(struct diff_options *options,
285                     int addremove, unsigned mode,
286                     const unsigned char *sha1,
287                     const char *fullpath, unsigned dirty_submodule)
288 {
289         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
290
291         tree_difference |= diff;
292         if (tree_difference == REV_TREE_DIFFERENT)
293                 DIFF_OPT_SET(options, HAS_CHANGES);
294 }
295
296 static void file_change(struct diff_options *options,
297                  unsigned old_mode, unsigned new_mode,
298                  const unsigned char *old_sha1,
299                  const unsigned char *new_sha1,
300                  const char *fullpath,
301                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
302 {
303         tree_difference = REV_TREE_DIFFERENT;
304         DIFF_OPT_SET(options, HAS_CHANGES);
305 }
306
307 static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
308 {
309         struct tree *t1 = parent->tree;
310         struct tree *t2 = commit->tree;
311
312         if (!t1)
313                 return REV_TREE_NEW;
314         if (!t2)
315                 return REV_TREE_OLD;
316
317         if (revs->simplify_by_decoration) {
318                 /*
319                  * If we are simplifying by decoration, then the commit
320                  * is worth showing if it has a tag pointing at it.
321                  */
322                 if (lookup_decoration(&name_decoration, &commit->object))
323                         return REV_TREE_DIFFERENT;
324                 /*
325                  * A commit that is not pointed by a tag is uninteresting
326                  * if we are not limited by path.  This means that you will
327                  * see the usual "commits that touch the paths" plus any
328                  * tagged commit by specifying both --simplify-by-decoration
329                  * and pathspec.
330                  */
331                 if (!revs->prune_data.nr)
332                         return REV_TREE_SAME;
333         }
334
335         tree_difference = REV_TREE_SAME;
336         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
337         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
338                            &revs->pruning) < 0)
339                 return REV_TREE_DIFFERENT;
340         return tree_difference;
341 }
342
343 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
344 {
345         int retval;
346         void *tree;
347         unsigned long size;
348         struct tree_desc empty, real;
349         struct tree *t1 = commit->tree;
350
351         if (!t1)
352                 return 0;
353
354         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
355         if (!tree)
356                 return 0;
357         init_tree_desc(&real, tree, size);
358         init_tree_desc(&empty, "", 0);
359
360         tree_difference = REV_TREE_SAME;
361         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
362         retval = diff_tree(&empty, &real, "", &revs->pruning);
363         free(tree);
364
365         return retval >= 0 && (tree_difference == REV_TREE_SAME);
366 }
367
368 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
369 {
370         struct commit_list **pp, *parent;
371         int tree_changed = 0, tree_same = 0;
372
373         /*
374          * If we don't do pruning, everything is interesting
375          */
376         if (!revs->prune)
377                 return;
378
379         if (!commit->tree)
380                 return;
381
382         if (!commit->parents) {
383                 if (rev_same_tree_as_empty(revs, commit))
384                         commit->object.flags |= TREESAME;
385                 return;
386         }
387
388         /*
389          * Normal non-merge commit? If we don't want to make the
390          * history dense, we consider it always to be a change..
391          */
392         if (!revs->dense && !commit->parents->next)
393                 return;
394
395         pp = &commit->parents;
396         while ((parent = *pp) != NULL) {
397                 struct commit *p = parent->item;
398
399                 if (parse_commit(p) < 0)
400                         die("cannot simplify commit %s (because of %s)",
401                             sha1_to_hex(commit->object.sha1),
402                             sha1_to_hex(p->object.sha1));
403                 switch (rev_compare_tree(revs, p, commit)) {
404                 case REV_TREE_SAME:
405                         tree_same = 1;
406                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
407                                 /* Even if a merge with an uninteresting
408                                  * side branch brought the entire change
409                                  * we are interested in, we do not want
410                                  * to lose the other branches of this
411                                  * merge, so we just keep going.
412                                  */
413                                 pp = &parent->next;
414                                 continue;
415                         }
416                         parent->next = NULL;
417                         commit->parents = parent;
418                         commit->object.flags |= TREESAME;
419                         return;
420
421                 case REV_TREE_NEW:
422                         if (revs->remove_empty_trees &&
423                             rev_same_tree_as_empty(revs, p)) {
424                                 /* We are adding all the specified
425                                  * paths from this parent, so the
426                                  * history beyond this parent is not
427                                  * interesting.  Remove its parents
428                                  * (they are grandparents for us).
429                                  * IOW, we pretend this parent is a
430                                  * "root" commit.
431                                  */
432                                 if (parse_commit(p) < 0)
433                                         die("cannot simplify commit %s (invalid %s)",
434                                             sha1_to_hex(commit->object.sha1),
435                                             sha1_to_hex(p->object.sha1));
436                                 p->parents = NULL;
437                         }
438                 /* fallthrough */
439                 case REV_TREE_OLD:
440                 case REV_TREE_DIFFERENT:
441                         tree_changed = 1;
442                         pp = &parent->next;
443                         continue;
444                 }
445                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
446         }
447         if (tree_changed && !tree_same)
448                 return;
449         commit->object.flags |= TREESAME;
450 }
451
452 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
453                     struct commit_list *cached_base, struct commit_list **cache)
454 {
455         struct commit_list *new_entry;
456
457         if (cached_base && p->date < cached_base->item->date)
458                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
459         else
460                 new_entry = commit_list_insert_by_date(p, head);
461
462         if (cache && (!*cache || p->date < (*cache)->item->date))
463                 *cache = new_entry;
464 }
465
466 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
467                     struct commit_list **list, struct commit_list **cache_ptr)
468 {
469         struct commit_list *parent = commit->parents;
470         unsigned left_flag;
471         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
472
473         if (commit->object.flags & ADDED)
474                 return 0;
475         commit->object.flags |= ADDED;
476
477         /*
478          * If the commit is uninteresting, don't try to
479          * prune parents - we want the maximal uninteresting
480          * set.
481          *
482          * Normally we haven't parsed the parent
483          * yet, so we won't have a parent of a parent
484          * here. However, it may turn out that we've
485          * reached this commit some other way (where it
486          * wasn't uninteresting), in which case we need
487          * to mark its parents recursively too..
488          */
489         if (commit->object.flags & UNINTERESTING) {
490                 while (parent) {
491                         struct commit *p = parent->item;
492                         parent = parent->next;
493                         if (p)
494                                 p->object.flags |= UNINTERESTING;
495                         if (parse_commit(p) < 0)
496                                 continue;
497                         if (p->parents)
498                                 mark_parents_uninteresting(p);
499                         if (p->object.flags & SEEN)
500                                 continue;
501                         p->object.flags |= SEEN;
502                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
503                 }
504                 return 0;
505         }
506
507         /*
508          * Ok, the commit wasn't uninteresting. Try to
509          * simplify the commit history and find the parent
510          * that has no differences in the path set if one exists.
511          */
512         try_to_simplify_commit(revs, commit);
513
514         if (revs->no_walk)
515                 return 0;
516
517         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
518
519         for (parent = commit->parents; parent; parent = parent->next) {
520                 struct commit *p = parent->item;
521
522                 if (parse_commit(p) < 0)
523                         return -1;
524                 if (revs->show_source && !p->util)
525                         p->util = commit->util;
526                 p->object.flags |= left_flag;
527                 if (!(p->object.flags & SEEN)) {
528                         p->object.flags |= SEEN;
529                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
530                 }
531                 if (revs->first_parent_only)
532                         break;
533         }
534         return 0;
535 }
536
537 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
538 {
539         struct commit_list *p;
540         int left_count = 0, right_count = 0;
541         int left_first;
542         struct patch_ids ids;
543         unsigned cherry_flag;
544
545         /* First count the commits on the left and on the right */
546         for (p = list; p; p = p->next) {
547                 struct commit *commit = p->item;
548                 unsigned flags = commit->object.flags;
549                 if (flags & BOUNDARY)
550                         ;
551                 else if (flags & SYMMETRIC_LEFT)
552                         left_count++;
553                 else
554                         right_count++;
555         }
556
557         if (!left_count || !right_count)
558                 return;
559
560         left_first = left_count < right_count;
561         init_patch_ids(&ids);
562         ids.diffopts.pathspec = revs->diffopt.pathspec;
563
564         /* Compute patch-ids for one side */
565         for (p = list; p; p = p->next) {
566                 struct commit *commit = p->item;
567                 unsigned flags = commit->object.flags;
568
569                 if (flags & BOUNDARY)
570                         continue;
571                 /*
572                  * If we have fewer left, left_first is set and we omit
573                  * commits on the right branch in this loop.  If we have
574                  * fewer right, we skip the left ones.
575                  */
576                 if (left_first != !!(flags & SYMMETRIC_LEFT))
577                         continue;
578                 commit->util = add_commit_patch_id(commit, &ids);
579         }
580
581         /* either cherry_mark or cherry_pick are true */
582         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
583
584         /* Check the other side */
585         for (p = list; p; p = p->next) {
586                 struct commit *commit = p->item;
587                 struct patch_id *id;
588                 unsigned flags = commit->object.flags;
589
590                 if (flags & BOUNDARY)
591                         continue;
592                 /*
593                  * If we have fewer left, left_first is set and we omit
594                  * commits on the left branch in this loop.
595                  */
596                 if (left_first == !!(flags & SYMMETRIC_LEFT))
597                         continue;
598
599                 /*
600                  * Have we seen the same patch id?
601                  */
602                 id = has_commit_patch_id(commit, &ids);
603                 if (!id)
604                         continue;
605                 id->seen = 1;
606                 commit->object.flags |= cherry_flag;
607         }
608
609         /* Now check the original side for seen ones */
610         for (p = list; p; p = p->next) {
611                 struct commit *commit = p->item;
612                 struct patch_id *ent;
613
614                 ent = commit->util;
615                 if (!ent)
616                         continue;
617                 if (ent->seen)
618                         commit->object.flags |= cherry_flag;
619                 commit->util = NULL;
620         }
621
622         free_patch_ids(&ids);
623 }
624
625 /* How many extra uninteresting commits we want to see.. */
626 #define SLOP 5
627
628 static int still_interesting(struct commit_list *src, unsigned long date, int slop)
629 {
630         /*
631          * No source list at all? We're definitely done..
632          */
633         if (!src)
634                 return 0;
635
636         /*
637          * Does the destination list contain entries with a date
638          * before the source list? Definitely _not_ done.
639          */
640         if (date < src->item->date)
641                 return SLOP;
642
643         /*
644          * Does the source list still have interesting commits in
645          * it? Definitely not done..
646          */
647         if (!everybody_uninteresting(src))
648                 return SLOP;
649
650         /* Ok, we're closing in.. */
651         return slop-1;
652 }
653
654 /*
655  * "rev-list --ancestry-path A..B" computes commits that are ancestors
656  * of B but not ancestors of A but further limits the result to those
657  * that are descendants of A.  This takes the list of bottom commits and
658  * the result of "A..B" without --ancestry-path, and limits the latter
659  * further to the ones that can reach one of the commits in "bottom".
660  */
661 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
662 {
663         struct commit_list *p;
664         struct commit_list *rlist = NULL;
665         int made_progress;
666
667         /*
668          * Reverse the list so that it will be likely that we would
669          * process parents before children.
670          */
671         for (p = list; p; p = p->next)
672                 commit_list_insert(p->item, &rlist);
673
674         for (p = bottom; p; p = p->next)
675                 p->item->object.flags |= TMP_MARK;
676
677         /*
678          * Mark the ones that can reach bottom commits in "list",
679          * in a bottom-up fashion.
680          */
681         do {
682                 made_progress = 0;
683                 for (p = rlist; p; p = p->next) {
684                         struct commit *c = p->item;
685                         struct commit_list *parents;
686                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
687                                 continue;
688                         for (parents = c->parents;
689                              parents;
690                              parents = parents->next) {
691                                 if (!(parents->item->object.flags & TMP_MARK))
692                                         continue;
693                                 c->object.flags |= TMP_MARK;
694                                 made_progress = 1;
695                                 break;
696                         }
697                 }
698         } while (made_progress);
699
700         /*
701          * NEEDSWORK: decide if we want to remove parents that are
702          * not marked with TMP_MARK from commit->parents for commits
703          * in the resulting list.  We may not want to do that, though.
704          */
705
706         /*
707          * The ones that are not marked with TMP_MARK are uninteresting
708          */
709         for (p = list; p; p = p->next) {
710                 struct commit *c = p->item;
711                 if (c->object.flags & TMP_MARK)
712                         continue;
713                 c->object.flags |= UNINTERESTING;
714         }
715
716         /* We are done with the TMP_MARK */
717         for (p = list; p; p = p->next)
718                 p->item->object.flags &= ~TMP_MARK;
719         for (p = bottom; p; p = p->next)
720                 p->item->object.flags &= ~TMP_MARK;
721         free_commit_list(rlist);
722 }
723
724 /*
725  * Before walking the history, keep the set of "negative" refs the
726  * caller has asked to exclude.
727  *
728  * This is used to compute "rev-list --ancestry-path A..B", as we need
729  * to filter the result of "A..B" further to the ones that can actually
730  * reach A.
731  */
732 static struct commit_list *collect_bottom_commits(struct rev_info *revs)
733 {
734         struct commit_list *bottom = NULL;
735         int i;
736         for (i = 0; i < revs->cmdline.nr; i++) {
737                 struct rev_cmdline_entry *elem = &revs->cmdline.rev[i];
738                 if ((elem->flags & UNINTERESTING) &&
739                     elem->item->type == OBJ_COMMIT)
740                         commit_list_insert((struct commit *)elem->item, &bottom);
741         }
742         return bottom;
743 }
744
745 /* Assumes either left_only or right_only is set */
746 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
747 {
748         struct commit_list *p;
749
750         for (p = list; p; p = p->next) {
751                 struct commit *commit = p->item;
752
753                 if (revs->right_only) {
754                         if (commit->object.flags & SYMMETRIC_LEFT)
755                                 commit->object.flags |= SHOWN;
756                 } else  /* revs->left_only is set */
757                         if (!(commit->object.flags & SYMMETRIC_LEFT))
758                                 commit->object.flags |= SHOWN;
759         }
760 }
761
762 static int limit_list(struct rev_info *revs)
763 {
764         int slop = SLOP;
765         unsigned long date = ~0ul;
766         struct commit_list *list = revs->commits;
767         struct commit_list *newlist = NULL;
768         struct commit_list **p = &newlist;
769         struct commit_list *bottom = NULL;
770
771         if (revs->ancestry_path) {
772                 bottom = collect_bottom_commits(revs);
773                 if (!bottom)
774                         die("--ancestry-path given but there are no bottom commits");
775         }
776
777         while (list) {
778                 struct commit_list *entry = list;
779                 struct commit *commit = list->item;
780                 struct object *obj = &commit->object;
781                 show_early_output_fn_t show;
782
783                 list = list->next;
784                 free(entry);
785
786                 if (revs->max_age != -1 && (commit->date < revs->max_age))
787                         obj->flags |= UNINTERESTING;
788                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
789                         return -1;
790                 if (obj->flags & UNINTERESTING) {
791                         mark_parents_uninteresting(commit);
792                         if (revs->show_all)
793                                 p = &commit_list_insert(commit, p)->next;
794                         slop = still_interesting(list, date, slop);
795                         if (slop)
796                                 continue;
797                         /* If showing all, add the whole pending list to the end */
798                         if (revs->show_all)
799                                 *p = list;
800                         break;
801                 }
802                 if (revs->min_age != -1 && (commit->date > revs->min_age))
803                         continue;
804                 date = commit->date;
805                 p = &commit_list_insert(commit, p)->next;
806
807                 show = show_early_output;
808                 if (!show)
809                         continue;
810
811                 show(revs, newlist);
812                 show_early_output = NULL;
813         }
814         if (revs->cherry_pick || revs->cherry_mark)
815                 cherry_pick_list(newlist, revs);
816
817         if (revs->left_only || revs->right_only)
818                 limit_left_right(newlist, revs);
819
820         if (bottom) {
821                 limit_to_ancestry(bottom, newlist);
822                 free_commit_list(bottom);
823         }
824
825         revs->commits = newlist;
826         return 0;
827 }
828
829 static void add_rev_cmdline(struct rev_info *revs,
830                             struct object *item,
831                             const char *name,
832                             int whence,
833                             unsigned flags)
834 {
835         struct rev_cmdline_info *info = &revs->cmdline;
836         int nr = info->nr;
837
838         ALLOC_GROW(info->rev, nr + 1, info->alloc);
839         info->rev[nr].item = item;
840         info->rev[nr].name = name;
841         info->rev[nr].whence = whence;
842         info->rev[nr].flags = flags;
843         info->nr++;
844 }
845
846 struct all_refs_cb {
847         int all_flags;
848         int warned_bad_reflog;
849         struct rev_info *all_revs;
850         const char *name_for_errormsg;
851 };
852
853 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
854 {
855         struct all_refs_cb *cb = cb_data;
856         struct object *object = get_reference(cb->all_revs, path, sha1,
857                                               cb->all_flags);
858         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
859         add_pending_object(cb->all_revs, object, path);
860         return 0;
861 }
862
863 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
864         unsigned flags)
865 {
866         cb->all_revs = revs;
867         cb->all_flags = flags;
868 }
869
870 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
871                 int (*for_each)(const char *, each_ref_fn, void *))
872 {
873         struct all_refs_cb cb;
874         init_all_refs_cb(&cb, revs, flags);
875         for_each(submodule, handle_one_ref, &cb);
876 }
877
878 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
879 {
880         struct all_refs_cb *cb = cb_data;
881         if (!is_null_sha1(sha1)) {
882                 struct object *o = parse_object(sha1);
883                 if (o) {
884                         o->flags |= cb->all_flags;
885                         /* ??? CMDLINEFLAGS ??? */
886                         add_pending_object(cb->all_revs, o, "");
887                 }
888                 else if (!cb->warned_bad_reflog) {
889                         warning("reflog of '%s' references pruned commits",
890                                 cb->name_for_errormsg);
891                         cb->warned_bad_reflog = 1;
892                 }
893         }
894 }
895
896 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
897                 const char *email, unsigned long timestamp, int tz,
898                 const char *message, void *cb_data)
899 {
900         handle_one_reflog_commit(osha1, cb_data);
901         handle_one_reflog_commit(nsha1, cb_data);
902         return 0;
903 }
904
905 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
906 {
907         struct all_refs_cb *cb = cb_data;
908         cb->warned_bad_reflog = 0;
909         cb->name_for_errormsg = path;
910         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
911         return 0;
912 }
913
914 static void handle_reflog(struct rev_info *revs, unsigned flags)
915 {
916         struct all_refs_cb cb;
917         cb.all_revs = revs;
918         cb.all_flags = flags;
919         for_each_reflog(handle_one_reflog, &cb);
920 }
921
922 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
923 {
924         unsigned char sha1[20];
925         struct object *it;
926         struct commit *commit;
927         struct commit_list *parents;
928         const char *arg = arg_;
929
930         if (*arg == '^') {
931                 flags ^= UNINTERESTING;
932                 arg++;
933         }
934         if (get_sha1(arg, sha1))
935                 return 0;
936         while (1) {
937                 it = get_reference(revs, arg, sha1, 0);
938                 if (!it && revs->ignore_missing)
939                         return 0;
940                 if (it->type != OBJ_TAG)
941                         break;
942                 if (!((struct tag*)it)->tagged)
943                         return 0;
944                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
945         }
946         if (it->type != OBJ_COMMIT)
947                 return 0;
948         commit = (struct commit *)it;
949         for (parents = commit->parents; parents; parents = parents->next) {
950                 it = &parents->item->object;
951                 it->flags |= flags;
952                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
953                 add_pending_object(revs, it, arg);
954         }
955         return 1;
956 }
957
958 void init_revisions(struct rev_info *revs, const char *prefix)
959 {
960         memset(revs, 0, sizeof(*revs));
961
962         revs->abbrev = DEFAULT_ABBREV;
963         revs->ignore_merges = 1;
964         revs->simplify_history = 1;
965         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
966         DIFF_OPT_SET(&revs->pruning, QUICK);
967         revs->pruning.add_remove = file_add_remove;
968         revs->pruning.change = file_change;
969         revs->lifo = 1;
970         revs->dense = 1;
971         revs->prefix = prefix;
972         revs->max_age = -1;
973         revs->min_age = -1;
974         revs->skip_count = -1;
975         revs->max_count = -1;
976         revs->max_parents = -1;
977
978         revs->commit_format = CMIT_FMT_DEFAULT;
979
980         revs->grep_filter.status_only = 1;
981         revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
982         revs->grep_filter.header_tail = &(revs->grep_filter.header_list);
983         revs->grep_filter.regflags = REG_NEWLINE;
984
985         diff_setup(&revs->diffopt);
986         if (prefix && !revs->diffopt.prefix) {
987                 revs->diffopt.prefix = prefix;
988                 revs->diffopt.prefix_length = strlen(prefix);
989         }
990
991         revs->notes_opt.use_default_notes = -1;
992 }
993
994 static void add_pending_commit_list(struct rev_info *revs,
995                                     struct commit_list *commit_list,
996                                     unsigned int flags)
997 {
998         while (commit_list) {
999                 struct object *object = &commit_list->item->object;
1000                 object->flags |= flags;
1001                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
1002                 commit_list = commit_list->next;
1003         }
1004 }
1005
1006 static void prepare_show_merge(struct rev_info *revs)
1007 {
1008         struct commit_list *bases;
1009         struct commit *head, *other;
1010         unsigned char sha1[20];
1011         const char **prune = NULL;
1012         int i, prune_num = 1; /* counting terminating NULL */
1013
1014         if (get_sha1("HEAD", sha1))
1015                 die("--merge without HEAD?");
1016         head = lookup_commit_or_die(sha1, "HEAD");
1017         if (get_sha1("MERGE_HEAD", sha1))
1018                 die("--merge without MERGE_HEAD?");
1019         other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1020         add_pending_object(revs, &head->object, "HEAD");
1021         add_pending_object(revs, &other->object, "MERGE_HEAD");
1022         bases = get_merge_bases(head, other, 1);
1023         add_pending_commit_list(revs, bases, UNINTERESTING);
1024         free_commit_list(bases);
1025         head->object.flags |= SYMMETRIC_LEFT;
1026
1027         if (!active_nr)
1028                 read_cache();
1029         for (i = 0; i < active_nr; i++) {
1030                 struct cache_entry *ce = active_cache[i];
1031                 if (!ce_stage(ce))
1032                         continue;
1033                 if (ce_path_match(ce, &revs->prune_data)) {
1034                         prune_num++;
1035                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
1036                         prune[prune_num-2] = ce->name;
1037                         prune[prune_num-1] = NULL;
1038                 }
1039                 while ((i+1 < active_nr) &&
1040                        ce_same_name(ce, active_cache[i+1]))
1041                         i++;
1042         }
1043         free_pathspec(&revs->prune_data);
1044         init_pathspec(&revs->prune_data, prune);
1045         revs->limited = 1;
1046 }
1047
1048 int handle_revision_arg(const char *arg_, struct rev_info *revs,
1049                         int flags,
1050                         int cant_be_filename)
1051 {
1052         unsigned mode;
1053         char *dotdot;
1054         struct object *object;
1055         unsigned char sha1[20];
1056         int local_flags;
1057         const char *arg = arg_;
1058
1059         dotdot = strstr(arg, "..");
1060         if (dotdot) {
1061                 unsigned char from_sha1[20];
1062                 const char *next = dotdot + 2;
1063                 const char *this = arg;
1064                 int symmetric = *next == '.';
1065                 unsigned int flags_exclude = flags ^ UNINTERESTING;
1066                 unsigned int a_flags;
1067
1068                 *dotdot = 0;
1069                 next += symmetric;
1070
1071                 if (!*next)
1072                         next = "HEAD";
1073                 if (dotdot == arg)
1074                         this = "HEAD";
1075                 if (!get_sha1(this, from_sha1) &&
1076                     !get_sha1(next, sha1)) {
1077                         struct commit *a, *b;
1078                         struct commit_list *exclude;
1079
1080                         a = lookup_commit_reference(from_sha1);
1081                         b = lookup_commit_reference(sha1);
1082                         if (!a || !b) {
1083                                 if (revs->ignore_missing)
1084                                         return 0;
1085                                 die(symmetric ?
1086                                     "Invalid symmetric difference expression %s...%s" :
1087                                     "Invalid revision range %s..%s",
1088                                     arg, next);
1089                         }
1090
1091                         if (!cant_be_filename) {
1092                                 *dotdot = '.';
1093                                 verify_non_filename(revs->prefix, arg);
1094                         }
1095
1096                         if (symmetric) {
1097                                 exclude = get_merge_bases(a, b, 1);
1098                                 add_pending_commit_list(revs, exclude,
1099                                                         flags_exclude);
1100                                 free_commit_list(exclude);
1101                                 a_flags = flags | SYMMETRIC_LEFT;
1102                         } else
1103                                 a_flags = flags_exclude;
1104                         a->object.flags |= a_flags;
1105                         b->object.flags |= flags;
1106                         add_rev_cmdline(revs, &a->object, this,
1107                                         REV_CMD_LEFT, a_flags);
1108                         add_rev_cmdline(revs, &b->object, next,
1109                                         REV_CMD_RIGHT, flags);
1110                         add_pending_object(revs, &a->object, this);
1111                         add_pending_object(revs, &b->object, next);
1112                         return 0;
1113                 }
1114                 *dotdot = '.';
1115         }
1116         dotdot = strstr(arg, "^@");
1117         if (dotdot && !dotdot[2]) {
1118                 *dotdot = 0;
1119                 if (add_parents_only(revs, arg, flags))
1120                         return 0;
1121                 *dotdot = '^';
1122         }
1123         dotdot = strstr(arg, "^!");
1124         if (dotdot && !dotdot[2]) {
1125                 *dotdot = 0;
1126                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
1127                         *dotdot = '^';
1128         }
1129
1130         local_flags = 0;
1131         if (*arg == '^') {
1132                 local_flags = UNINTERESTING;
1133                 arg++;
1134         }
1135         if (get_sha1_with_mode(arg, sha1, &mode))
1136                 return revs->ignore_missing ? 0 : -1;
1137         if (!cant_be_filename)
1138                 verify_non_filename(revs->prefix, arg);
1139         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1140         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1141         add_pending_object_with_mode(revs, object, arg, mode);
1142         return 0;
1143 }
1144
1145 struct cmdline_pathspec {
1146         int alloc;
1147         int nr;
1148         const char **path;
1149 };
1150
1151 static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1152 {
1153         while (*av) {
1154                 ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1155                 prune->path[prune->nr++] = *(av++);
1156         }
1157 }
1158
1159 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1160                                      struct cmdline_pathspec *prune)
1161 {
1162         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1163                 int len = sb->len;
1164                 if (len && sb->buf[len - 1] == '\n')
1165                         sb->buf[--len] = '\0';
1166                 ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1167                 prune->path[prune->nr++] = xstrdup(sb->buf);
1168         }
1169 }
1170
1171 static void read_revisions_from_stdin(struct rev_info *revs,
1172                                       struct cmdline_pathspec *prune)
1173 {
1174         struct strbuf sb;
1175         int seen_dashdash = 0;
1176
1177         strbuf_init(&sb, 1000);
1178         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1179                 int len = sb.len;
1180                 if (len && sb.buf[len - 1] == '\n')
1181                         sb.buf[--len] = '\0';
1182                 if (!len)
1183                         break;
1184                 if (sb.buf[0] == '-') {
1185                         if (len == 2 && sb.buf[1] == '-') {
1186                                 seen_dashdash = 1;
1187                                 break;
1188                         }
1189                         die("options not supported in --stdin mode");
1190                 }
1191                 if (handle_revision_arg(sb.buf, revs, 0, 1))
1192                         die("bad revision '%s'", sb.buf);
1193         }
1194         if (seen_dashdash)
1195                 read_pathspec_from_stdin(revs, &sb, prune);
1196         strbuf_release(&sb);
1197 }
1198
1199 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1200 {
1201         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1202 }
1203
1204 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1205 {
1206         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1207 }
1208
1209 static void add_message_grep(struct rev_info *revs, const char *pattern)
1210 {
1211         add_grep(revs, pattern, GREP_PATTERN_BODY);
1212 }
1213
1214 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1215                                int *unkc, const char **unkv)
1216 {
1217         const char *arg = argv[0];
1218         const char *optarg;
1219         int argcount;
1220
1221         /* pseudo revision arguments */
1222         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1223             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1224             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1225             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1226             !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
1227             !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
1228             !prefixcmp(arg, "--remotes="))
1229         {
1230                 unkv[(*unkc)++] = arg;
1231                 return 1;
1232         }
1233
1234         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1235                 revs->max_count = atoi(optarg);
1236                 revs->no_walk = 0;
1237                 return argcount;
1238         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1239                 revs->skip_count = atoi(optarg);
1240                 return argcount;
1241         } else if ((*arg == '-') && isdigit(arg[1])) {
1242         /* accept -<digit>, like traditional "head" */
1243                 revs->max_count = atoi(arg + 1);
1244                 revs->no_walk = 0;
1245         } else if (!strcmp(arg, "-n")) {
1246                 if (argc <= 1)
1247                         return error("-n requires an argument");
1248                 revs->max_count = atoi(argv[1]);
1249                 revs->no_walk = 0;
1250                 return 2;
1251         } else if (!prefixcmp(arg, "-n")) {
1252                 revs->max_count = atoi(arg + 2);
1253                 revs->no_walk = 0;
1254         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1255                 revs->max_age = atoi(optarg);
1256                 return argcount;
1257         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1258                 revs->max_age = approxidate(optarg);
1259                 return argcount;
1260         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1261                 revs->max_age = approxidate(optarg);
1262                 return argcount;
1263         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1264                 revs->min_age = atoi(optarg);
1265                 return argcount;
1266         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1267                 revs->min_age = approxidate(optarg);
1268                 return argcount;
1269         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1270                 revs->min_age = approxidate(optarg);
1271                 return argcount;
1272         } else if (!strcmp(arg, "--first-parent")) {
1273                 revs->first_parent_only = 1;
1274         } else if (!strcmp(arg, "--ancestry-path")) {
1275                 revs->ancestry_path = 1;
1276                 revs->simplify_history = 0;
1277                 revs->limited = 1;
1278         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1279                 init_reflog_walk(&revs->reflog_info);
1280         } else if (!strcmp(arg, "--default")) {
1281                 if (argc <= 1)
1282                         return error("bad --default argument");
1283                 revs->def = argv[1];
1284                 return 2;
1285         } else if (!strcmp(arg, "--merge")) {
1286                 revs->show_merge = 1;
1287         } else if (!strcmp(arg, "--topo-order")) {
1288                 revs->lifo = 1;
1289                 revs->topo_order = 1;
1290         } else if (!strcmp(arg, "--simplify-merges")) {
1291                 revs->simplify_merges = 1;
1292                 revs->rewrite_parents = 1;
1293                 revs->simplify_history = 0;
1294                 revs->limited = 1;
1295         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1296                 revs->simplify_merges = 1;
1297                 revs->rewrite_parents = 1;
1298                 revs->simplify_history = 0;
1299                 revs->simplify_by_decoration = 1;
1300                 revs->limited = 1;
1301                 revs->prune = 1;
1302                 load_ref_decorations(DECORATE_SHORT_REFS);
1303         } else if (!strcmp(arg, "--date-order")) {
1304                 revs->lifo = 0;
1305                 revs->topo_order = 1;
1306         } else if (!prefixcmp(arg, "--early-output")) {
1307                 int count = 100;
1308                 switch (arg[14]) {
1309                 case '=':
1310                         count = atoi(arg+15);
1311                         /* Fallthrough */
1312                 case 0:
1313                         revs->topo_order = 1;
1314                        revs->early_output = count;
1315                 }
1316         } else if (!strcmp(arg, "--parents")) {
1317                 revs->rewrite_parents = 1;
1318                 revs->print_parents = 1;
1319         } else if (!strcmp(arg, "--dense")) {
1320                 revs->dense = 1;
1321         } else if (!strcmp(arg, "--sparse")) {
1322                 revs->dense = 0;
1323         } else if (!strcmp(arg, "--show-all")) {
1324                 revs->show_all = 1;
1325         } else if (!strcmp(arg, "--remove-empty")) {
1326                 revs->remove_empty_trees = 1;
1327         } else if (!strcmp(arg, "--merges")) {
1328                 revs->min_parents = 2;
1329         } else if (!strcmp(arg, "--no-merges")) {
1330                 revs->max_parents = 1;
1331         } else if (!prefixcmp(arg, "--min-parents=")) {
1332                 revs->min_parents = atoi(arg+14);
1333         } else if (!prefixcmp(arg, "--no-min-parents")) {
1334                 revs->min_parents = 0;
1335         } else if (!prefixcmp(arg, "--max-parents=")) {
1336                 revs->max_parents = atoi(arg+14);
1337         } else if (!prefixcmp(arg, "--no-max-parents")) {
1338                 revs->max_parents = -1;
1339         } else if (!strcmp(arg, "--boundary")) {
1340                 revs->boundary = 1;
1341         } else if (!strcmp(arg, "--left-right")) {
1342                 revs->left_right = 1;
1343         } else if (!strcmp(arg, "--left-only")) {
1344                 if (revs->right_only)
1345                         die("--left-only is incompatible with --right-only"
1346                             " or --cherry");
1347                 revs->left_only = 1;
1348         } else if (!strcmp(arg, "--right-only")) {
1349                 if (revs->left_only)
1350                         die("--right-only is incompatible with --left-only");
1351                 revs->right_only = 1;
1352         } else if (!strcmp(arg, "--cherry")) {
1353                 if (revs->left_only)
1354                         die("--cherry is incompatible with --left-only");
1355                 revs->cherry_mark = 1;
1356                 revs->right_only = 1;
1357                 revs->max_parents = 1;
1358                 revs->limited = 1;
1359         } else if (!strcmp(arg, "--count")) {
1360                 revs->count = 1;
1361         } else if (!strcmp(arg, "--cherry-mark")) {
1362                 if (revs->cherry_pick)
1363                         die("--cherry-mark is incompatible with --cherry-pick");
1364                 revs->cherry_mark = 1;
1365                 revs->limited = 1; /* needs limit_list() */
1366         } else if (!strcmp(arg, "--cherry-pick")) {
1367                 if (revs->cherry_mark)
1368                         die("--cherry-pick is incompatible with --cherry-mark");
1369                 revs->cherry_pick = 1;
1370                 revs->limited = 1;
1371         } else if (!strcmp(arg, "--objects")) {
1372                 revs->tag_objects = 1;
1373                 revs->tree_objects = 1;
1374                 revs->blob_objects = 1;
1375         } else if (!strcmp(arg, "--objects-edge")) {
1376                 revs->tag_objects = 1;
1377                 revs->tree_objects = 1;
1378                 revs->blob_objects = 1;
1379                 revs->edge_hint = 1;
1380         } else if (!strcmp(arg, "--unpacked")) {
1381                 revs->unpacked = 1;
1382         } else if (!prefixcmp(arg, "--unpacked=")) {
1383                 die("--unpacked=<packfile> no longer supported.");
1384         } else if (!strcmp(arg, "-r")) {
1385                 revs->diff = 1;
1386                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1387         } else if (!strcmp(arg, "-t")) {
1388                 revs->diff = 1;
1389                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1390                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1391         } else if (!strcmp(arg, "-m")) {
1392                 revs->ignore_merges = 0;
1393         } else if (!strcmp(arg, "-c")) {
1394                 revs->diff = 1;
1395                 revs->dense_combined_merges = 0;
1396                 revs->combine_merges = 1;
1397         } else if (!strcmp(arg, "--cc")) {
1398                 revs->diff = 1;
1399                 revs->dense_combined_merges = 1;
1400                 revs->combine_merges = 1;
1401         } else if (!strcmp(arg, "-v")) {
1402                 revs->verbose_header = 1;
1403         } else if (!strcmp(arg, "--pretty")) {
1404                 revs->verbose_header = 1;
1405                 revs->pretty_given = 1;
1406                 get_commit_format(arg+8, revs);
1407         } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1408                 /*
1409                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1410                  * not allowed, since the argument is optional.
1411                  */
1412                 revs->verbose_header = 1;
1413                 revs->pretty_given = 1;
1414                 get_commit_format(arg+9, revs);
1415         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1416                 revs->show_notes = 1;
1417                 revs->show_notes_given = 1;
1418                 revs->notes_opt.use_default_notes = 1;
1419         } else if (!prefixcmp(arg, "--show-notes=") ||
1420                    !prefixcmp(arg, "--notes=")) {
1421                 struct strbuf buf = STRBUF_INIT;
1422                 revs->show_notes = 1;
1423                 revs->show_notes_given = 1;
1424                 if (!prefixcmp(arg, "--show-notes")) {
1425                         if (revs->notes_opt.use_default_notes < 0)
1426                                 revs->notes_opt.use_default_notes = 1;
1427                         strbuf_addstr(&buf, arg+13);
1428                 }
1429                 else
1430                         strbuf_addstr(&buf, arg+8);
1431                 expand_notes_ref(&buf);
1432                 string_list_append(&revs->notes_opt.extra_notes_refs,
1433                                    strbuf_detach(&buf, NULL));
1434         } else if (!strcmp(arg, "--no-notes")) {
1435                 revs->show_notes = 0;
1436                 revs->show_notes_given = 1;
1437                 revs->notes_opt.use_default_notes = -1;
1438                 /* we have been strdup'ing ourselves, so trick
1439                  * string_list into free()ing strings */
1440                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1441                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1442                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1443         } else if (!strcmp(arg, "--standard-notes")) {
1444                 revs->show_notes_given = 1;
1445                 revs->notes_opt.use_default_notes = 1;
1446         } else if (!strcmp(arg, "--no-standard-notes")) {
1447                 revs->notes_opt.use_default_notes = 0;
1448         } else if (!strcmp(arg, "--oneline")) {
1449                 revs->verbose_header = 1;
1450                 get_commit_format("oneline", revs);
1451                 revs->pretty_given = 1;
1452                 revs->abbrev_commit = 1;
1453         } else if (!strcmp(arg, "--graph")) {
1454                 revs->topo_order = 1;
1455                 revs->rewrite_parents = 1;
1456                 revs->graph = graph_init(revs);
1457         } else if (!strcmp(arg, "--root")) {
1458                 revs->show_root_diff = 1;
1459         } else if (!strcmp(arg, "--no-commit-id")) {
1460                 revs->no_commit_id = 1;
1461         } else if (!strcmp(arg, "--always")) {
1462                 revs->always_show_header = 1;
1463         } else if (!strcmp(arg, "--no-abbrev")) {
1464                 revs->abbrev = 0;
1465         } else if (!strcmp(arg, "--abbrev")) {
1466                 revs->abbrev = DEFAULT_ABBREV;
1467         } else if (!prefixcmp(arg, "--abbrev=")) {
1468                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1469                 if (revs->abbrev < MINIMUM_ABBREV)
1470                         revs->abbrev = MINIMUM_ABBREV;
1471                 else if (revs->abbrev > 40)
1472                         revs->abbrev = 40;
1473         } else if (!strcmp(arg, "--abbrev-commit")) {
1474                 revs->abbrev_commit = 1;
1475                 revs->abbrev_commit_given = 1;
1476         } else if (!strcmp(arg, "--no-abbrev-commit")) {
1477                 revs->abbrev_commit = 0;
1478         } else if (!strcmp(arg, "--full-diff")) {
1479                 revs->diff = 1;
1480                 revs->full_diff = 1;
1481         } else if (!strcmp(arg, "--full-history")) {
1482                 revs->simplify_history = 0;
1483         } else if (!strcmp(arg, "--relative-date")) {
1484                 revs->date_mode = DATE_RELATIVE;
1485                 revs->date_mode_explicit = 1;
1486         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1487                 revs->date_mode = parse_date_format(optarg);
1488                 revs->date_mode_explicit = 1;
1489                 return argcount;
1490         } else if (!strcmp(arg, "--log-size")) {
1491                 revs->show_log_size = 1;
1492         }
1493         /*
1494          * Grepping the commit log
1495          */
1496         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1497                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1498                 return argcount;
1499         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1500                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1501                 return argcount;
1502         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1503                 add_message_grep(revs, optarg);
1504                 return argcount;
1505         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1506                 revs->grep_filter.regflags |= REG_EXTENDED;
1507         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1508                 revs->grep_filter.regflags |= REG_ICASE;
1509         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1510                 revs->grep_filter.fixed = 1;
1511         } else if (!strcmp(arg, "--all-match")) {
1512                 revs->grep_filter.all_match = 1;
1513         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1514                 if (strcmp(optarg, "none"))
1515                         git_log_output_encoding = xstrdup(optarg);
1516                 else
1517                         git_log_output_encoding = "";
1518                 return argcount;
1519         } else if (!strcmp(arg, "--reverse")) {
1520                 revs->reverse ^= 1;
1521         } else if (!strcmp(arg, "--children")) {
1522                 revs->children.name = "children";
1523                 revs->limited = 1;
1524         } else if (!strcmp(arg, "--ignore-missing")) {
1525                 revs->ignore_missing = 1;
1526         } else {
1527                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1528                 if (!opts)
1529                         unkv[(*unkc)++] = arg;
1530                 return opts;
1531         }
1532
1533         return 1;
1534 }
1535
1536 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1537                         const struct option *options,
1538                         const char * const usagestr[])
1539 {
1540         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1541                                     &ctx->cpidx, ctx->out);
1542         if (n <= 0) {
1543                 error("unknown option `%s'", ctx->argv[0]);
1544                 usage_with_options(usagestr, options);
1545         }
1546         ctx->argv += n;
1547         ctx->argc -= n;
1548 }
1549
1550 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1551 {
1552         return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1553 }
1554
1555 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1556 {
1557         return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1558 }
1559
1560 static int handle_revision_pseudo_opt(const char *submodule,
1561                                 struct rev_info *revs,
1562                                 int argc, const char **argv, int *flags)
1563 {
1564         const char *arg = argv[0];
1565         const char *optarg;
1566         int argcount;
1567
1568         /*
1569          * NOTE!
1570          *
1571          * Commands like "git shortlog" will not accept the options below
1572          * unless parse_revision_opt queues them (as opposed to erroring
1573          * out).
1574          *
1575          * When implementing your new pseudo-option, remember to
1576          * register it in the list at the top of handle_revision_opt.
1577          */
1578         if (!strcmp(arg, "--all")) {
1579                 handle_refs(submodule, revs, *flags, for_each_ref_submodule);
1580                 handle_refs(submodule, revs, *flags, head_ref_submodule);
1581         } else if (!strcmp(arg, "--branches")) {
1582                 handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
1583         } else if (!strcmp(arg, "--bisect")) {
1584                 handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
1585                 handle_refs(submodule, revs, *flags ^ UNINTERESTING, for_each_good_bisect_ref);
1586                 revs->bisect = 1;
1587         } else if (!strcmp(arg, "--tags")) {
1588                 handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
1589         } else if (!strcmp(arg, "--remotes")) {
1590                 handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
1591         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
1592                 struct all_refs_cb cb;
1593                 init_all_refs_cb(&cb, revs, *flags);
1594                 for_each_glob_ref(handle_one_ref, optarg, &cb);
1595                 return argcount;
1596         } else if (!prefixcmp(arg, "--branches=")) {
1597                 struct all_refs_cb cb;
1598                 init_all_refs_cb(&cb, revs, *flags);
1599                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1600         } else if (!prefixcmp(arg, "--tags=")) {
1601                 struct all_refs_cb cb;
1602                 init_all_refs_cb(&cb, revs, *flags);
1603                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1604         } else if (!prefixcmp(arg, "--remotes=")) {
1605                 struct all_refs_cb cb;
1606                 init_all_refs_cb(&cb, revs, *flags);
1607                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1608         } else if (!strcmp(arg, "--reflog")) {
1609                 handle_reflog(revs, *flags);
1610         } else if (!strcmp(arg, "--not")) {
1611                 *flags ^= UNINTERESTING;
1612         } else if (!strcmp(arg, "--no-walk")) {
1613                 revs->no_walk = 1;
1614         } else if (!strcmp(arg, "--do-walk")) {
1615                 revs->no_walk = 0;
1616         } else {
1617                 return 0;
1618         }
1619
1620         return 1;
1621 }
1622
1623 /*
1624  * Parse revision information, filling in the "rev_info" structure,
1625  * and removing the used arguments from the argument list.
1626  *
1627  * Returns the number of arguments left that weren't recognized
1628  * (which are also moved to the head of the argument list)
1629  */
1630 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1631 {
1632         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0;
1633         struct cmdline_pathspec prune_data;
1634         const char *submodule = NULL;
1635
1636         memset(&prune_data, 0, sizeof(prune_data));
1637         if (opt)
1638                 submodule = opt->submodule;
1639
1640         /* First, search for "--" */
1641         seen_dashdash = 0;
1642         for (i = 1; i < argc; i++) {
1643                 const char *arg = argv[i];
1644                 if (strcmp(arg, "--"))
1645                         continue;
1646                 argv[i] = NULL;
1647                 argc = i;
1648                 if (argv[i + 1])
1649                         append_prune_data(&prune_data, argv + i + 1);
1650                 seen_dashdash = 1;
1651                 break;
1652         }
1653
1654         /* Second, deal with arguments and options */
1655         flags = 0;
1656         read_from_stdin = 0;
1657         for (left = i = 1; i < argc; i++) {
1658                 const char *arg = argv[i];
1659                 if (*arg == '-') {
1660                         int opts;
1661
1662                         opts = handle_revision_pseudo_opt(submodule,
1663                                                 revs, argc - i, argv + i,
1664                                                 &flags);
1665                         if (opts > 0) {
1666                                 i += opts - 1;
1667                                 continue;
1668                         }
1669
1670                         if (!strcmp(arg, "--stdin")) {
1671                                 if (revs->disable_stdin) {
1672                                         argv[left++] = arg;
1673                                         continue;
1674                                 }
1675                                 if (read_from_stdin++)
1676                                         die("--stdin given twice?");
1677                                 read_revisions_from_stdin(revs, &prune_data);
1678                                 continue;
1679                         }
1680
1681                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1682                         if (opts > 0) {
1683                                 i += opts - 1;
1684                                 continue;
1685                         }
1686                         if (opts < 0)
1687                                 exit(128);
1688                         continue;
1689                 }
1690
1691                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1692                         int j;
1693                         if (seen_dashdash || *arg == '^')
1694                                 die("bad revision '%s'", arg);
1695
1696                         /* If we didn't have a "--":
1697                          * (1) all filenames must exist;
1698                          * (2) all rev-args must not be interpretable
1699                          *     as a valid filename.
1700                          * but the latter we have checked in the main loop.
1701                          */
1702                         for (j = i; j < argc; j++)
1703                                 verify_filename(revs->prefix, argv[j]);
1704
1705                         append_prune_data(&prune_data, argv + i);
1706                         break;
1707                 }
1708                 else
1709                         got_rev_arg = 1;
1710         }
1711
1712         if (prune_data.nr) {
1713                 /*
1714                  * If we need to introduce the magic "a lone ':' means no
1715                  * pathspec whatsoever", here is the place to do so.
1716                  *
1717                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
1718                  *      prune_data.nr = 0;
1719                  *      prune_data.alloc = 0;
1720                  *      free(prune_data.path);
1721                  *      prune_data.path = NULL;
1722                  * } else {
1723                  *      terminate prune_data.alloc with NULL and
1724                  *      call init_pathspec() to set revs->prune_data here.
1725                  * }
1726                  */
1727                 ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
1728                 prune_data.path[prune_data.nr++] = NULL;
1729                 init_pathspec(&revs->prune_data,
1730                               get_pathspec(revs->prefix, prune_data.path));
1731         }
1732
1733         if (revs->def == NULL)
1734                 revs->def = opt ? opt->def : NULL;
1735         if (opt && opt->tweak)
1736                 opt->tweak(revs, opt);
1737         if (revs->show_merge)
1738                 prepare_show_merge(revs);
1739         if (revs->def && !revs->pending.nr && !got_rev_arg) {
1740                 unsigned char sha1[20];
1741                 struct object *object;
1742                 unsigned mode;
1743                 if (get_sha1_with_mode(revs->def, sha1, &mode))
1744                         die("bad default revision '%s'", revs->def);
1745                 object = get_reference(revs, revs->def, sha1, 0);
1746                 add_pending_object_with_mode(revs, object, revs->def, mode);
1747         }
1748
1749         /* Did the user ask for any diff output? Run the diff! */
1750         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1751                 revs->diff = 1;
1752
1753         /* Pickaxe, diff-filter and rename following need diffs */
1754         if (revs->diffopt.pickaxe ||
1755             revs->diffopt.filter ||
1756             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1757                 revs->diff = 1;
1758
1759         if (revs->topo_order)
1760                 revs->limited = 1;
1761
1762         if (revs->prune_data.nr) {
1763                 diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
1764                 /* Can't prune commits with rename following: the paths change.. */
1765                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1766                         revs->prune = 1;
1767                 if (!revs->full_diff)
1768                         diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
1769         }
1770         if (revs->combine_merges)
1771                 revs->ignore_merges = 0;
1772         revs->diffopt.abbrev = revs->abbrev;
1773         if (diff_setup_done(&revs->diffopt) < 0)
1774                 die("diff_setup_done failed");
1775
1776         compile_grep_patterns(&revs->grep_filter);
1777
1778         if (revs->reverse && revs->reflog_info)
1779                 die("cannot combine --reverse with --walk-reflogs");
1780         if (revs->rewrite_parents && revs->children.name)
1781                 die("cannot combine --parents and --children");
1782
1783         /*
1784          * Limitations on the graph functionality
1785          */
1786         if (revs->reverse && revs->graph)
1787                 die("cannot combine --reverse with --graph");
1788
1789         if (revs->reflog_info && revs->graph)
1790                 die("cannot combine --walk-reflogs with --graph");
1791
1792         return left;
1793 }
1794
1795 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1796 {
1797         struct commit_list *l = xcalloc(1, sizeof(*l));
1798
1799         l->item = child;
1800         l->next = add_decoration(&revs->children, &parent->object, l);
1801 }
1802
1803 static int remove_duplicate_parents(struct commit *commit)
1804 {
1805         struct commit_list **pp, *p;
1806         int surviving_parents;
1807
1808         /* Examine existing parents while marking ones we have seen... */
1809         pp = &commit->parents;
1810         while ((p = *pp) != NULL) {
1811                 struct commit *parent = p->item;
1812                 if (parent->object.flags & TMP_MARK) {
1813                         *pp = p->next;
1814                         continue;
1815                 }
1816                 parent->object.flags |= TMP_MARK;
1817                 pp = &p->next;
1818         }
1819         /* count them while clearing the temporary mark */
1820         surviving_parents = 0;
1821         for (p = commit->parents; p; p = p->next) {
1822                 p->item->object.flags &= ~TMP_MARK;
1823                 surviving_parents++;
1824         }
1825         return surviving_parents;
1826 }
1827
1828 struct merge_simplify_state {
1829         struct commit *simplified;
1830 };
1831
1832 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1833 {
1834         struct merge_simplify_state *st;
1835
1836         st = lookup_decoration(&revs->merge_simplification, &commit->object);
1837         if (!st) {
1838                 st = xcalloc(1, sizeof(*st));
1839                 add_decoration(&revs->merge_simplification, &commit->object, st);
1840         }
1841         return st;
1842 }
1843
1844 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1845 {
1846         struct commit_list *p;
1847         struct merge_simplify_state *st, *pst;
1848         int cnt;
1849
1850         st = locate_simplify_state(revs, commit);
1851
1852         /*
1853          * Have we handled this one?
1854          */
1855         if (st->simplified)
1856                 return tail;
1857
1858         /*
1859          * An UNINTERESTING commit simplifies to itself, so does a
1860          * root commit.  We do not rewrite parents of such commit
1861          * anyway.
1862          */
1863         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1864                 st->simplified = commit;
1865                 return tail;
1866         }
1867
1868         /*
1869          * Do we know what commit all of our parents should be rewritten to?
1870          * Otherwise we are not ready to rewrite this one yet.
1871          */
1872         for (cnt = 0, p = commit->parents; p; p = p->next) {
1873                 pst = locate_simplify_state(revs, p->item);
1874                 if (!pst->simplified) {
1875                         tail = &commit_list_insert(p->item, tail)->next;
1876                         cnt++;
1877                 }
1878         }
1879         if (cnt) {
1880                 tail = &commit_list_insert(commit, tail)->next;
1881                 return tail;
1882         }
1883
1884         /*
1885          * Rewrite our list of parents.
1886          */
1887         for (p = commit->parents; p; p = p->next) {
1888                 pst = locate_simplify_state(revs, p->item);
1889                 p->item = pst->simplified;
1890         }
1891         cnt = remove_duplicate_parents(commit);
1892
1893         /*
1894          * It is possible that we are a merge and one side branch
1895          * does not have any commit that touches the given paths;
1896          * in such a case, the immediate parents will be rewritten
1897          * to different commits.
1898          *
1899          *      o----X          X: the commit we are looking at;
1900          *     /    /           o: a commit that touches the paths;
1901          * ---o----'
1902          *
1903          * Further reduce the parents by removing redundant parents.
1904          */
1905         if (1 < cnt) {
1906                 struct commit_list *h = reduce_heads(commit->parents);
1907                 cnt = commit_list_count(h);
1908                 free_commit_list(commit->parents);
1909                 commit->parents = h;
1910         }
1911
1912         /*
1913          * A commit simplifies to itself if it is a root, if it is
1914          * UNINTERESTING, if it touches the given paths, or if it is a
1915          * merge and its parents simplifies to more than one commits
1916          * (the first two cases are already handled at the beginning of
1917          * this function).
1918          *
1919          * Otherwise, it simplifies to what its sole parent simplifies to.
1920          */
1921         if (!cnt ||
1922             (commit->object.flags & UNINTERESTING) ||
1923             !(commit->object.flags & TREESAME) ||
1924             (1 < cnt))
1925                 st->simplified = commit;
1926         else {
1927                 pst = locate_simplify_state(revs, commit->parents->item);
1928                 st->simplified = pst->simplified;
1929         }
1930         return tail;
1931 }
1932
1933 static void simplify_merges(struct rev_info *revs)
1934 {
1935         struct commit_list *list;
1936         struct commit_list *yet_to_do, **tail;
1937
1938         if (!revs->topo_order)
1939                 sort_in_topological_order(&revs->commits, revs->lifo);
1940         if (!revs->prune)
1941                 return;
1942
1943         /* feed the list reversed */
1944         yet_to_do = NULL;
1945         for (list = revs->commits; list; list = list->next)
1946                 commit_list_insert(list->item, &yet_to_do);
1947         while (yet_to_do) {
1948                 list = yet_to_do;
1949                 yet_to_do = NULL;
1950                 tail = &yet_to_do;
1951                 while (list) {
1952                         struct commit *commit = list->item;
1953                         struct commit_list *next = list->next;
1954                         free(list);
1955                         list = next;
1956                         tail = simplify_one(revs, commit, tail);
1957                 }
1958         }
1959
1960         /* clean up the result, removing the simplified ones */
1961         list = revs->commits;
1962         revs->commits = NULL;
1963         tail = &revs->commits;
1964         while (list) {
1965                 struct commit *commit = list->item;
1966                 struct commit_list *next = list->next;
1967                 struct merge_simplify_state *st;
1968                 free(list);
1969                 list = next;
1970                 st = locate_simplify_state(revs, commit);
1971                 if (st->simplified == commit)
1972                         tail = &commit_list_insert(commit, tail)->next;
1973         }
1974 }
1975
1976 static void set_children(struct rev_info *revs)
1977 {
1978         struct commit_list *l;
1979         for (l = revs->commits; l; l = l->next) {
1980                 struct commit *commit = l->item;
1981                 struct commit_list *p;
1982
1983                 for (p = commit->parents; p; p = p->next)
1984                         add_child(revs, p->item, commit);
1985         }
1986 }
1987
1988 int prepare_revision_walk(struct rev_info *revs)
1989 {
1990         int nr = revs->pending.nr;
1991         struct object_array_entry *e, *list;
1992
1993         e = list = revs->pending.objects;
1994         revs->pending.nr = 0;
1995         revs->pending.alloc = 0;
1996         revs->pending.objects = NULL;
1997         while (--nr >= 0) {
1998                 struct commit *commit = handle_commit(revs, e->item, e->name);
1999                 if (commit) {
2000                         if (!(commit->object.flags & SEEN)) {
2001                                 commit->object.flags |= SEEN;
2002                                 commit_list_insert_by_date(commit, &revs->commits);
2003                         }
2004                 }
2005                 e++;
2006         }
2007         free(list);
2008
2009         if (revs->no_walk)
2010                 return 0;
2011         if (revs->limited)
2012                 if (limit_list(revs) < 0)
2013                         return -1;
2014         if (revs->topo_order)
2015                 sort_in_topological_order(&revs->commits, revs->lifo);
2016         if (revs->simplify_merges)
2017                 simplify_merges(revs);
2018         if (revs->children.name)
2019                 set_children(revs);
2020         return 0;
2021 }
2022
2023 enum rewrite_result {
2024         rewrite_one_ok,
2025         rewrite_one_noparents,
2026         rewrite_one_error
2027 };
2028
2029 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2030 {
2031         struct commit_list *cache = NULL;
2032
2033         for (;;) {
2034                 struct commit *p = *pp;
2035                 if (!revs->limited)
2036                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2037                                 return rewrite_one_error;
2038                 if (p->parents && p->parents->next)
2039                         return rewrite_one_ok;
2040                 if (p->object.flags & UNINTERESTING)
2041                         return rewrite_one_ok;
2042                 if (!(p->object.flags & TREESAME))
2043                         return rewrite_one_ok;
2044                 if (!p->parents)
2045                         return rewrite_one_noparents;
2046                 *pp = p->parents->item;
2047         }
2048 }
2049
2050 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
2051 {
2052         struct commit_list **pp = &commit->parents;
2053         while (*pp) {
2054                 struct commit_list *parent = *pp;
2055                 switch (rewrite_one(revs, &parent->item)) {
2056                 case rewrite_one_ok:
2057                         break;
2058                 case rewrite_one_noparents:
2059                         *pp = parent->next;
2060                         continue;
2061                 case rewrite_one_error:
2062                         return -1;
2063                 }
2064                 pp = &parent->next;
2065         }
2066         remove_duplicate_parents(commit);
2067         return 0;
2068 }
2069
2070 static int commit_match(struct commit *commit, struct rev_info *opt)
2071 {
2072         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2073                 return 1;
2074         return grep_buffer(&opt->grep_filter,
2075                            NULL, /* we say nothing, not even filename */
2076                            commit->buffer, strlen(commit->buffer));
2077 }
2078
2079 static inline int want_ancestry(struct rev_info *revs)
2080 {
2081         return (revs->rewrite_parents || revs->children.name);
2082 }
2083
2084 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2085 {
2086         if (commit->object.flags & SHOWN)
2087                 return commit_ignore;
2088         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2089                 return commit_ignore;
2090         if (revs->show_all)
2091                 return commit_show;
2092         if (commit->object.flags & UNINTERESTING)
2093                 return commit_ignore;
2094         if (revs->min_age != -1 && (commit->date > revs->min_age))
2095                 return commit_ignore;
2096         if (revs->min_parents || (revs->max_parents >= 0)) {
2097                 int n = 0;
2098                 struct commit_list *p;
2099                 for (p = commit->parents; p; p = p->next)
2100                         n++;
2101                 if ((n < revs->min_parents) ||
2102                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2103                         return commit_ignore;
2104         }
2105         if (!commit_match(commit, revs))
2106                 return commit_ignore;
2107         if (revs->prune && revs->dense) {
2108                 /* Commit without changes? */
2109                 if (commit->object.flags & TREESAME) {
2110                         /* drop merges unless we want parenthood */
2111                         if (!want_ancestry(revs))
2112                                 return commit_ignore;
2113                         /* non-merge - always ignore it */
2114                         if (!commit->parents || !commit->parents->next)
2115                                 return commit_ignore;
2116                 }
2117         }
2118         return commit_show;
2119 }
2120
2121 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2122 {
2123         enum commit_action action = get_commit_action(revs, commit);
2124
2125         if (action == commit_show &&
2126             !revs->show_all &&
2127             revs->prune && revs->dense && want_ancestry(revs)) {
2128                 if (rewrite_parents(revs, commit) < 0)
2129                         return commit_error;
2130         }
2131         return action;
2132 }
2133
2134 static struct commit *get_revision_1(struct rev_info *revs)
2135 {
2136         if (!revs->commits)
2137                 return NULL;
2138
2139         do {
2140                 struct commit_list *entry = revs->commits;
2141                 struct commit *commit = entry->item;
2142
2143                 revs->commits = entry->next;
2144                 free(entry);
2145
2146                 if (revs->reflog_info) {
2147                         fake_reflog_parent(revs->reflog_info, commit);
2148                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2149                 }
2150
2151                 /*
2152                  * If we haven't done the list limiting, we need to look at
2153                  * the parents here. We also need to do the date-based limiting
2154                  * that we'd otherwise have done in limit_list().
2155                  */
2156                 if (!revs->limited) {
2157                         if (revs->max_age != -1 &&
2158                             (commit->date < revs->max_age))
2159                                 continue;
2160                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2161                                 die("Failed to traverse parents of commit %s",
2162                                     sha1_to_hex(commit->object.sha1));
2163                 }
2164
2165                 switch (simplify_commit(revs, commit)) {
2166                 case commit_ignore:
2167                         continue;
2168                 case commit_error:
2169                         die("Failed to simplify parents of commit %s",
2170                             sha1_to_hex(commit->object.sha1));
2171                 default:
2172                         return commit;
2173                 }
2174         } while (revs->commits);
2175         return NULL;
2176 }
2177
2178 static void gc_boundary(struct object_array *array)
2179 {
2180         unsigned nr = array->nr;
2181         unsigned alloc = array->alloc;
2182         struct object_array_entry *objects = array->objects;
2183
2184         if (alloc <= nr) {
2185                 unsigned i, j;
2186                 for (i = j = 0; i < nr; i++) {
2187                         if (objects[i].item->flags & SHOWN)
2188                                 continue;
2189                         if (i != j)
2190                                 objects[j] = objects[i];
2191                         j++;
2192                 }
2193                 for (i = j; i < nr; i++)
2194                         objects[i].item = NULL;
2195                 array->nr = j;
2196         }
2197 }
2198
2199 static void create_boundary_commit_list(struct rev_info *revs)
2200 {
2201         unsigned i;
2202         struct commit *c;
2203         struct object_array *array = &revs->boundary_commits;
2204         struct object_array_entry *objects = array->objects;
2205
2206         /*
2207          * If revs->commits is non-NULL at this point, an error occurred in
2208          * get_revision_1().  Ignore the error and continue printing the
2209          * boundary commits anyway.  (This is what the code has always
2210          * done.)
2211          */
2212         if (revs->commits) {
2213                 free_commit_list(revs->commits);
2214                 revs->commits = NULL;
2215         }
2216
2217         /*
2218          * Put all of the actual boundary commits from revs->boundary_commits
2219          * into revs->commits
2220          */
2221         for (i = 0; i < array->nr; i++) {
2222                 c = (struct commit *)(objects[i].item);
2223                 if (!c)
2224                         continue;
2225                 if (!(c->object.flags & CHILD_SHOWN))
2226                         continue;
2227                 if (c->object.flags & (SHOWN | BOUNDARY))
2228                         continue;
2229                 c->object.flags |= BOUNDARY;
2230                 commit_list_insert(c, &revs->commits);
2231         }
2232
2233         /*
2234          * If revs->topo_order is set, sort the boundary commits
2235          * in topological order
2236          */
2237         sort_in_topological_order(&revs->commits, revs->lifo);
2238 }
2239
2240 static struct commit *get_revision_internal(struct rev_info *revs)
2241 {
2242         struct commit *c = NULL;
2243         struct commit_list *l;
2244
2245         if (revs->boundary == 2) {
2246                 /*
2247                  * All of the normal commits have already been returned,
2248                  * and we are now returning boundary commits.
2249                  * create_boundary_commit_list() has populated
2250                  * revs->commits with the remaining commits to return.
2251                  */
2252                 c = pop_commit(&revs->commits);
2253                 if (c)
2254                         c->object.flags |= SHOWN;
2255                 return c;
2256         }
2257
2258         /*
2259          * Now pick up what they want to give us
2260          */
2261         c = get_revision_1(revs);
2262         if (c) {
2263                 while (0 < revs->skip_count) {
2264                         revs->skip_count--;
2265                         c = get_revision_1(revs);
2266                         if (!c)
2267                                 break;
2268                 }
2269         }
2270
2271         /*
2272          * Check the max_count.
2273          */
2274         switch (revs->max_count) {
2275         case -1:
2276                 break;
2277         case 0:
2278                 c = NULL;
2279                 break;
2280         default:
2281                 revs->max_count--;
2282         }
2283
2284         if (c)
2285                 c->object.flags |= SHOWN;
2286
2287         if (!revs->boundary) {
2288                 return c;
2289         }
2290
2291         if (!c) {
2292                 /*
2293                  * get_revision_1() runs out the commits, and
2294                  * we are done computing the boundaries.
2295                  * switch to boundary commits output mode.
2296                  */
2297                 revs->boundary = 2;
2298
2299                 /*
2300                  * Update revs->commits to contain the list of
2301                  * boundary commits.
2302                  */
2303                 create_boundary_commit_list(revs);
2304
2305                 return get_revision_internal(revs);
2306         }
2307
2308         /*
2309          * boundary commits are the commits that are parents of the
2310          * ones we got from get_revision_1() but they themselves are
2311          * not returned from get_revision_1().  Before returning
2312          * 'c', we need to mark its parents that they could be boundaries.
2313          */
2314
2315         for (l = c->parents; l; l = l->next) {
2316                 struct object *p;
2317                 p = &(l->item->object);
2318                 if (p->flags & (CHILD_SHOWN | SHOWN))
2319                         continue;
2320                 p->flags |= CHILD_SHOWN;
2321                 gc_boundary(&revs->boundary_commits);
2322                 add_object_array(p, NULL, &revs->boundary_commits);
2323         }
2324
2325         return c;
2326 }
2327
2328 struct commit *get_revision(struct rev_info *revs)
2329 {
2330         struct commit *c;
2331         struct commit_list *reversed;
2332
2333         if (revs->reverse) {
2334                 reversed = NULL;
2335                 while ((c = get_revision_internal(revs))) {
2336                         commit_list_insert(c, &reversed);
2337                 }
2338                 revs->commits = reversed;
2339                 revs->reverse = 0;
2340                 revs->reverse_output_stage = 1;
2341         }
2342
2343         if (revs->reverse_output_stage)
2344                 return pop_commit(&revs->commits);
2345
2346         c = get_revision_internal(revs);
2347         if (c && revs->graph)
2348                 graph_update(revs->graph, c);
2349         return c;
2350 }
2351
2352 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2353 {
2354         if (commit->object.flags & BOUNDARY)
2355                 return "-";
2356         else if (commit->object.flags & UNINTERESTING)
2357                 return "^";
2358         else if (commit->object.flags & PATCHSAME)
2359                 return "=";
2360         else if (!revs || revs->left_right) {
2361                 if (commit->object.flags & SYMMETRIC_LEFT)
2362                         return "<";
2363                 else
2364                         return ">";
2365         } else if (revs->graph)
2366                 return "*";
2367         else if (revs->cherry_mark)
2368                 return "+";
2369         return "";
2370 }
2371
2372 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2373 {
2374         char *mark = get_revision_mark(revs, commit);
2375         if (!strlen(mark))
2376                 return;
2377         fputs(mark, stdout);
2378         putchar(' ');
2379 }