commit: remove unused inline function single_parent()
[git] / revision.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "refs.h"
8 #include "revision.h"
9 #include "graph.h"
10 #include "grep.h"
11 #include "reflog-walk.h"
12 #include "patch-ids.h"
13 #include "decorate.h"
14 #include "log-tree.h"
15 #include "string-list.h"
16 #include "line-log.h"
17 #include "mailmap.h"
18 #include "commit-slab.h"
19 #include "dir.h"
20 #include "cache-tree.h"
21 #include "bisect.h"
22
23 volatile show_early_output_fn_t show_early_output;
24
25 static const char *term_bad;
26 static const char *term_good;
27
28 void show_object_with_name(FILE *out, struct object *obj, const char *name)
29 {
30         const char *p;
31
32         fprintf(out, "%s ", oid_to_hex(&obj->oid));
33         for (p = name; *p && *p != '\n'; p++)
34                 fputc(*p, out);
35         fputc('\n', out);
36 }
37
38 static void mark_blob_uninteresting(struct blob *blob)
39 {
40         if (!blob)
41                 return;
42         if (blob->object.flags & UNINTERESTING)
43                 return;
44         blob->object.flags |= UNINTERESTING;
45 }
46
47 static void mark_tree_contents_uninteresting(struct tree *tree)
48 {
49         struct tree_desc desc;
50         struct name_entry entry;
51         struct object *obj = &tree->object;
52
53         if (!has_object_file(&obj->oid))
54                 return;
55         if (parse_tree(tree) < 0)
56                 die("bad tree %s", oid_to_hex(&obj->oid));
57
58         init_tree_desc(&desc, tree->buffer, tree->size);
59         while (tree_entry(&desc, &entry)) {
60                 switch (object_type(entry.mode)) {
61                 case OBJ_TREE:
62                         mark_tree_uninteresting(lookup_tree(entry.oid));
63                         break;
64                 case OBJ_BLOB:
65                         mark_blob_uninteresting(lookup_blob(entry.oid));
66                         break;
67                 default:
68                         /* Subproject commit - not in this repository */
69                         break;
70                 }
71         }
72
73         /*
74          * We don't care about the tree any more
75          * after it has been marked uninteresting.
76          */
77         free_tree_buffer(tree);
78 }
79
80 void mark_tree_uninteresting(struct tree *tree)
81 {
82         struct object *obj;
83
84         if (!tree)
85                 return;
86
87         obj = &tree->object;
88         if (obj->flags & UNINTERESTING)
89                 return;
90         obj->flags |= UNINTERESTING;
91         mark_tree_contents_uninteresting(tree);
92 }
93
94 void mark_parents_uninteresting(struct commit *commit)
95 {
96         struct commit_list *parents = NULL, *l;
97
98         for (l = commit->parents; l; l = l->next)
99                 commit_list_insert(l->item, &parents);
100
101         while (parents) {
102                 struct commit *commit = pop_commit(&parents);
103
104                 while (commit) {
105                         /*
106                          * A missing commit is ok iff its parent is marked
107                          * uninteresting.
108                          *
109                          * We just mark such a thing parsed, so that when
110                          * it is popped next time around, we won't be trying
111                          * to parse it and get an error.
112                          */
113                         if (!has_object_file(&commit->object.oid))
114                                 commit->object.parsed = 1;
115
116                         if (commit->object.flags & UNINTERESTING)
117                                 break;
118
119                         commit->object.flags |= UNINTERESTING;
120
121                         /*
122                          * Normally we haven't parsed the parent
123                          * yet, so we won't have a parent of a parent
124                          * here. However, it may turn out that we've
125                          * reached this commit some other way (where it
126                          * wasn't uninteresting), in which case we need
127                          * to mark its parents recursively too..
128                          */
129                         if (!commit->parents)
130                                 break;
131
132                         for (l = commit->parents->next; l; l = l->next)
133                                 commit_list_insert(l->item, &parents);
134                         commit = commit->parents->item;
135                 }
136         }
137 }
138
139 static void add_pending_object_with_path(struct rev_info *revs,
140                                          struct object *obj,
141                                          const char *name, unsigned mode,
142                                          const char *path)
143 {
144         if (!obj)
145                 return;
146         if (revs->no_walk && (obj->flags & UNINTERESTING))
147                 revs->no_walk = 0;
148         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
149                 struct strbuf buf = STRBUF_INIT;
150                 int len = interpret_branch_name(name, 0, &buf, 0);
151                 int st;
152
153                 if (0 < len && name[len] && buf.len)
154                         strbuf_addstr(&buf, name + len);
155                 st = add_reflog_for_walk(revs->reflog_info,
156                                          (struct commit *)obj,
157                                          buf.buf[0] ? buf.buf: name);
158                 strbuf_release(&buf);
159                 if (st)
160                         return;
161         }
162         add_object_array_with_path(obj, name, &revs->pending, mode, path);
163 }
164
165 static void add_pending_object_with_mode(struct rev_info *revs,
166                                          struct object *obj,
167                                          const char *name, unsigned mode)
168 {
169         add_pending_object_with_path(revs, obj, name, mode, NULL);
170 }
171
172 void add_pending_object(struct rev_info *revs,
173                         struct object *obj, const char *name)
174 {
175         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
176 }
177
178 void add_head_to_pending(struct rev_info *revs)
179 {
180         struct object_id oid;
181         struct object *obj;
182         if (get_oid("HEAD", &oid))
183                 return;
184         obj = parse_object(&oid);
185         if (!obj)
186                 return;
187         add_pending_object(revs, obj, "HEAD");
188 }
189
190 static struct object *get_reference(struct rev_info *revs, const char *name,
191                                     const struct object_id *oid,
192                                     unsigned int flags)
193 {
194         struct object *object;
195
196         object = parse_object(oid);
197         if (!object) {
198                 if (revs->ignore_missing)
199                         return object;
200                 die("bad object %s", name);
201         }
202         object->flags |= flags;
203         return object;
204 }
205
206 void add_pending_oid(struct rev_info *revs, const char *name,
207                       const struct object_id *oid, unsigned int flags)
208 {
209         struct object *object = get_reference(revs, name, oid, flags);
210         add_pending_object(revs, object, name);
211 }
212
213 static struct commit *handle_commit(struct rev_info *revs,
214                                     struct object_array_entry *entry)
215 {
216         struct object *object = entry->item;
217         const char *name = entry->name;
218         const char *path = entry->path;
219         unsigned int mode = entry->mode;
220         unsigned long flags = object->flags;
221
222         /*
223          * Tag object? Look what it points to..
224          */
225         while (object->type == OBJ_TAG) {
226                 struct tag *tag = (struct tag *) object;
227                 if (revs->tag_objects && !(flags & UNINTERESTING))
228                         add_pending_object(revs, object, tag->tag);
229                 if (!tag->tagged)
230                         die("bad tag");
231                 object = parse_object(&tag->tagged->oid);
232                 if (!object) {
233                         if (revs->ignore_missing_links || (flags & UNINTERESTING))
234                                 return NULL;
235                         die("bad object %s", oid_to_hex(&tag->tagged->oid));
236                 }
237                 object->flags |= flags;
238                 /*
239                  * We'll handle the tagged object by looping or dropping
240                  * through to the non-tag handlers below. Do not
241                  * propagate path data from the tag's pending entry.
242                  */
243                 path = NULL;
244                 mode = 0;
245         }
246
247         /*
248          * Commit object? Just return it, we'll do all the complex
249          * reachability crud.
250          */
251         if (object->type == OBJ_COMMIT) {
252                 struct commit *commit = (struct commit *)object;
253                 if (parse_commit(commit) < 0)
254                         die("unable to parse commit %s", name);
255                 if (flags & UNINTERESTING) {
256                         mark_parents_uninteresting(commit);
257                         revs->limited = 1;
258                 }
259                 if (revs->show_source && !commit->util)
260                         commit->util = xstrdup(name);
261                 return commit;
262         }
263
264         /*
265          * Tree object? Either mark it uninteresting, or add it
266          * to the list of objects to look at later..
267          */
268         if (object->type == OBJ_TREE) {
269                 struct tree *tree = (struct tree *)object;
270                 if (!revs->tree_objects)
271                         return NULL;
272                 if (flags & UNINTERESTING) {
273                         mark_tree_contents_uninteresting(tree);
274                         return NULL;
275                 }
276                 add_pending_object_with_path(revs, object, name, mode, path);
277                 return NULL;
278         }
279
280         /*
281          * Blob object? You know the drill by now..
282          */
283         if (object->type == OBJ_BLOB) {
284                 if (!revs->blob_objects)
285                         return NULL;
286                 if (flags & UNINTERESTING)
287                         return NULL;
288                 add_pending_object_with_path(revs, object, name, mode, path);
289                 return NULL;
290         }
291         die("%s is unknown object", name);
292 }
293
294 static int everybody_uninteresting(struct commit_list *orig,
295                                    struct commit **interesting_cache)
296 {
297         struct commit_list *list = orig;
298
299         if (*interesting_cache) {
300                 struct commit *commit = *interesting_cache;
301                 if (!(commit->object.flags & UNINTERESTING))
302                         return 0;
303         }
304
305         while (list) {
306                 struct commit *commit = list->item;
307                 list = list->next;
308                 if (commit->object.flags & UNINTERESTING)
309                         continue;
310
311                 *interesting_cache = commit;
312                 return 0;
313         }
314         return 1;
315 }
316
317 /*
318  * A definition of "relevant" commit that we can use to simplify limited graphs
319  * by eliminating side branches.
320  *
321  * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
322  * in our list), or that is a specified BOTTOM commit. Then after computing
323  * a limited list, during processing we can generally ignore boundary merges
324  * coming from outside the graph, (ie from irrelevant parents), and treat
325  * those merges as if they were single-parent. TREESAME is defined to consider
326  * only relevant parents, if any. If we are TREESAME to our on-graph parents,
327  * we don't care if we were !TREESAME to non-graph parents.
328  *
329  * Treating bottom commits as relevant ensures that a limited graph's
330  * connection to the actual bottom commit is not viewed as a side branch, but
331  * treated as part of the graph. For example:
332  *
333  *   ....Z...A---X---o---o---B
334  *        .     /
335  *         W---Y
336  *
337  * When computing "A..B", the A-X connection is at least as important as
338  * Y-X, despite A being flagged UNINTERESTING.
339  *
340  * And when computing --ancestry-path "A..B", the A-X connection is more
341  * important than Y-X, despite both A and Y being flagged UNINTERESTING.
342  */
343 static inline int relevant_commit(struct commit *commit)
344 {
345         return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
346 }
347
348 /*
349  * Return a single relevant commit from a parent list. If we are a TREESAME
350  * commit, and this selects one of our parents, then we can safely simplify to
351  * that parent.
352  */
353 static struct commit *one_relevant_parent(const struct rev_info *revs,
354                                           struct commit_list *orig)
355 {
356         struct commit_list *list = orig;
357         struct commit *relevant = NULL;
358
359         if (!orig)
360                 return NULL;
361
362         /*
363          * For 1-parent commits, or if first-parent-only, then return that
364          * first parent (even if not "relevant" by the above definition).
365          * TREESAME will have been set purely on that parent.
366          */
367         if (revs->first_parent_only || !orig->next)
368                 return orig->item;
369
370         /*
371          * For multi-parent commits, identify a sole relevant parent, if any.
372          * If we have only one relevant parent, then TREESAME will be set purely
373          * with regard to that parent, and we can simplify accordingly.
374          *
375          * If we have more than one relevant parent, or no relevant parents
376          * (and multiple irrelevant ones), then we can't select a parent here
377          * and return NULL.
378          */
379         while (list) {
380                 struct commit *commit = list->item;
381                 list = list->next;
382                 if (relevant_commit(commit)) {
383                         if (relevant)
384                                 return NULL;
385                         relevant = commit;
386                 }
387         }
388         return relevant;
389 }
390
391 /*
392  * The goal is to get REV_TREE_NEW as the result only if the
393  * diff consists of all '+' (and no other changes), REV_TREE_OLD
394  * if the whole diff is removal of old data, and otherwise
395  * REV_TREE_DIFFERENT (of course if the trees are the same we
396  * want REV_TREE_SAME).
397  * That means that once we get to REV_TREE_DIFFERENT, we do not
398  * have to look any further.
399  */
400 static int tree_difference = REV_TREE_SAME;
401
402 static void file_add_remove(struct diff_options *options,
403                     int addremove, unsigned mode,
404                     const struct object_id *oid,
405                     int oid_valid,
406                     const char *fullpath, unsigned dirty_submodule)
407 {
408         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
409
410         tree_difference |= diff;
411         if (tree_difference == REV_TREE_DIFFERENT)
412                 DIFF_OPT_SET(options, HAS_CHANGES);
413 }
414
415 static void file_change(struct diff_options *options,
416                  unsigned old_mode, unsigned new_mode,
417                  const struct object_id *old_oid,
418                  const struct object_id *new_oid,
419                  int old_oid_valid, int new_oid_valid,
420                  const char *fullpath,
421                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
422 {
423         tree_difference = REV_TREE_DIFFERENT;
424         DIFF_OPT_SET(options, HAS_CHANGES);
425 }
426
427 static int rev_compare_tree(struct rev_info *revs,
428                             struct commit *parent, struct commit *commit)
429 {
430         struct tree *t1 = parent->tree;
431         struct tree *t2 = commit->tree;
432
433         if (!t1)
434                 return REV_TREE_NEW;
435         if (!t2)
436                 return REV_TREE_OLD;
437
438         if (revs->simplify_by_decoration) {
439                 /*
440                  * If we are simplifying by decoration, then the commit
441                  * is worth showing if it has a tag pointing at it.
442                  */
443                 if (get_name_decoration(&commit->object))
444                         return REV_TREE_DIFFERENT;
445                 /*
446                  * A commit that is not pointed by a tag is uninteresting
447                  * if we are not limited by path.  This means that you will
448                  * see the usual "commits that touch the paths" plus any
449                  * tagged commit by specifying both --simplify-by-decoration
450                  * and pathspec.
451                  */
452                 if (!revs->prune_data.nr)
453                         return REV_TREE_SAME;
454         }
455
456         tree_difference = REV_TREE_SAME;
457         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
458         if (diff_tree_oid(&t1->object.oid, &t2->object.oid, "",
459                            &revs->pruning) < 0)
460                 return REV_TREE_DIFFERENT;
461         return tree_difference;
462 }
463
464 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
465 {
466         int retval;
467         struct tree *t1 = commit->tree;
468
469         if (!t1)
470                 return 0;
471
472         tree_difference = REV_TREE_SAME;
473         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
474         retval = diff_tree_oid(NULL, &t1->object.oid, "", &revs->pruning);
475
476         return retval >= 0 && (tree_difference == REV_TREE_SAME);
477 }
478
479 struct treesame_state {
480         unsigned int nparents;
481         unsigned char treesame[FLEX_ARRAY];
482 };
483
484 static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
485 {
486         unsigned n = commit_list_count(commit->parents);
487         struct treesame_state *st = xcalloc(1, st_add(sizeof(*st), n));
488         st->nparents = n;
489         add_decoration(&revs->treesame, &commit->object, st);
490         return st;
491 }
492
493 /*
494  * Must be called immediately after removing the nth_parent from a commit's
495  * parent list, if we are maintaining the per-parent treesame[] decoration.
496  * This does not recalculate the master TREESAME flag - update_treesame()
497  * should be called to update it after a sequence of treesame[] modifications
498  * that may have affected it.
499  */
500 static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
501 {
502         struct treesame_state *st;
503         int old_same;
504
505         if (!commit->parents) {
506                 /*
507                  * Have just removed the only parent from a non-merge.
508                  * Different handling, as we lack decoration.
509                  */
510                 if (nth_parent != 0)
511                         die("compact_treesame %u", nth_parent);
512                 old_same = !!(commit->object.flags & TREESAME);
513                 if (rev_same_tree_as_empty(revs, commit))
514                         commit->object.flags |= TREESAME;
515                 else
516                         commit->object.flags &= ~TREESAME;
517                 return old_same;
518         }
519
520         st = lookup_decoration(&revs->treesame, &commit->object);
521         if (!st || nth_parent >= st->nparents)
522                 die("compact_treesame %u", nth_parent);
523
524         old_same = st->treesame[nth_parent];
525         memmove(st->treesame + nth_parent,
526                 st->treesame + nth_parent + 1,
527                 st->nparents - nth_parent - 1);
528
529         /*
530          * If we've just become a non-merge commit, update TREESAME
531          * immediately, and remove the no-longer-needed decoration.
532          * If still a merge, defer update until update_treesame().
533          */
534         if (--st->nparents == 1) {
535                 if (commit->parents->next)
536                         die("compact_treesame parents mismatch");
537                 if (st->treesame[0] && revs->dense)
538                         commit->object.flags |= TREESAME;
539                 else
540                         commit->object.flags &= ~TREESAME;
541                 free(add_decoration(&revs->treesame, &commit->object, NULL));
542         }
543
544         return old_same;
545 }
546
547 static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
548 {
549         if (commit->parents && commit->parents->next) {
550                 unsigned n;
551                 struct treesame_state *st;
552                 struct commit_list *p;
553                 unsigned relevant_parents;
554                 unsigned relevant_change, irrelevant_change;
555
556                 st = lookup_decoration(&revs->treesame, &commit->object);
557                 if (!st)
558                         die("update_treesame %s", oid_to_hex(&commit->object.oid));
559                 relevant_parents = 0;
560                 relevant_change = irrelevant_change = 0;
561                 for (p = commit->parents, n = 0; p; n++, p = p->next) {
562                         if (relevant_commit(p->item)) {
563                                 relevant_change |= !st->treesame[n];
564                                 relevant_parents++;
565                         } else
566                                 irrelevant_change |= !st->treesame[n];
567                 }
568                 if (relevant_parents ? relevant_change : irrelevant_change)
569                         commit->object.flags &= ~TREESAME;
570                 else
571                         commit->object.flags |= TREESAME;
572         }
573
574         return commit->object.flags & TREESAME;
575 }
576
577 static inline int limiting_can_increase_treesame(const struct rev_info *revs)
578 {
579         /*
580          * TREESAME is irrelevant unless prune && dense;
581          * if simplify_history is set, we can't have a mixture of TREESAME and
582          *    !TREESAME INTERESTING parents (and we don't have treesame[]
583          *    decoration anyway);
584          * if first_parent_only is set, then the TREESAME flag is locked
585          *    against the first parent (and again we lack treesame[] decoration).
586          */
587         return revs->prune && revs->dense &&
588                !revs->simplify_history &&
589                !revs->first_parent_only;
590 }
591
592 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
593 {
594         struct commit_list **pp, *parent;
595         struct treesame_state *ts = NULL;
596         int relevant_change = 0, irrelevant_change = 0;
597         int relevant_parents, nth_parent;
598
599         /*
600          * If we don't do pruning, everything is interesting
601          */
602         if (!revs->prune)
603                 return;
604
605         if (!commit->tree)
606                 return;
607
608         if (!commit->parents) {
609                 if (rev_same_tree_as_empty(revs, commit))
610                         commit->object.flags |= TREESAME;
611                 return;
612         }
613
614         /*
615          * Normal non-merge commit? If we don't want to make the
616          * history dense, we consider it always to be a change..
617          */
618         if (!revs->dense && !commit->parents->next)
619                 return;
620
621         for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
622              (parent = *pp) != NULL;
623              pp = &parent->next, nth_parent++) {
624                 struct commit *p = parent->item;
625                 if (relevant_commit(p))
626                         relevant_parents++;
627
628                 if (nth_parent == 1) {
629                         /*
630                          * This our second loop iteration - so we now know
631                          * we're dealing with a merge.
632                          *
633                          * Do not compare with later parents when we care only about
634                          * the first parent chain, in order to avoid derailing the
635                          * traversal to follow a side branch that brought everything
636                          * in the path we are limited to by the pathspec.
637                          */
638                         if (revs->first_parent_only)
639                                 break;
640                         /*
641                          * If this will remain a potentially-simplifiable
642                          * merge, remember per-parent treesame if needed.
643                          * Initialise the array with the comparison from our
644                          * first iteration.
645                          */
646                         if (revs->treesame.name &&
647                             !revs->simplify_history &&
648                             !(commit->object.flags & UNINTERESTING)) {
649                                 ts = initialise_treesame(revs, commit);
650                                 if (!(irrelevant_change || relevant_change))
651                                         ts->treesame[0] = 1;
652                         }
653                 }
654                 if (parse_commit(p) < 0)
655                         die("cannot simplify commit %s (because of %s)",
656                             oid_to_hex(&commit->object.oid),
657                             oid_to_hex(&p->object.oid));
658                 switch (rev_compare_tree(revs, p, commit)) {
659                 case REV_TREE_SAME:
660                         if (!revs->simplify_history || !relevant_commit(p)) {
661                                 /* Even if a merge with an uninteresting
662                                  * side branch brought the entire change
663                                  * we are interested in, we do not want
664                                  * to lose the other branches of this
665                                  * merge, so we just keep going.
666                                  */
667                                 if (ts)
668                                         ts->treesame[nth_parent] = 1;
669                                 continue;
670                         }
671                         parent->next = NULL;
672                         commit->parents = parent;
673                         commit->object.flags |= TREESAME;
674                         return;
675
676                 case REV_TREE_NEW:
677                         if (revs->remove_empty_trees &&
678                             rev_same_tree_as_empty(revs, p)) {
679                                 /* We are adding all the specified
680                                  * paths from this parent, so the
681                                  * history beyond this parent is not
682                                  * interesting.  Remove its parents
683                                  * (they are grandparents for us).
684                                  * IOW, we pretend this parent is a
685                                  * "root" commit.
686                                  */
687                                 if (parse_commit(p) < 0)
688                                         die("cannot simplify commit %s (invalid %s)",
689                                             oid_to_hex(&commit->object.oid),
690                                             oid_to_hex(&p->object.oid));
691                                 p->parents = NULL;
692                         }
693                 /* fallthrough */
694                 case REV_TREE_OLD:
695                 case REV_TREE_DIFFERENT:
696                         if (relevant_commit(p))
697                                 relevant_change = 1;
698                         else
699                                 irrelevant_change = 1;
700                         continue;
701                 }
702                 die("bad tree compare for commit %s", oid_to_hex(&commit->object.oid));
703         }
704
705         /*
706          * TREESAME is straightforward for single-parent commits. For merge
707          * commits, it is most useful to define it so that "irrelevant"
708          * parents cannot make us !TREESAME - if we have any relevant
709          * parents, then we only consider TREESAMEness with respect to them,
710          * allowing irrelevant merges from uninteresting branches to be
711          * simplified away. Only if we have only irrelevant parents do we
712          * base TREESAME on them. Note that this logic is replicated in
713          * update_treesame, which should be kept in sync.
714          */
715         if (relevant_parents ? !relevant_change : !irrelevant_change)
716                 commit->object.flags |= TREESAME;
717 }
718
719 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
720                     struct commit_list *cached_base, struct commit_list **cache)
721 {
722         struct commit_list *new_entry;
723
724         if (cached_base && p->date < cached_base->item->date)
725                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
726         else
727                 new_entry = commit_list_insert_by_date(p, head);
728
729         if (cache && (!*cache || p->date < (*cache)->item->date))
730                 *cache = new_entry;
731 }
732
733 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
734                     struct commit_list **list, struct commit_list **cache_ptr)
735 {
736         struct commit_list *parent = commit->parents;
737         unsigned left_flag;
738         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
739
740         if (commit->object.flags & ADDED)
741                 return 0;
742         commit->object.flags |= ADDED;
743
744         if (revs->include_check &&
745             !revs->include_check(commit, revs->include_check_data))
746                 return 0;
747
748         /*
749          * If the commit is uninteresting, don't try to
750          * prune parents - we want the maximal uninteresting
751          * set.
752          *
753          * Normally we haven't parsed the parent
754          * yet, so we won't have a parent of a parent
755          * here. However, it may turn out that we've
756          * reached this commit some other way (where it
757          * wasn't uninteresting), in which case we need
758          * to mark its parents recursively too..
759          */
760         if (commit->object.flags & UNINTERESTING) {
761                 while (parent) {
762                         struct commit *p = parent->item;
763                         parent = parent->next;
764                         if (p)
765                                 p->object.flags |= UNINTERESTING;
766                         if (parse_commit_gently(p, 1) < 0)
767                                 continue;
768                         if (p->parents)
769                                 mark_parents_uninteresting(p);
770                         if (p->object.flags & SEEN)
771                                 continue;
772                         p->object.flags |= SEEN;
773                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
774                 }
775                 return 0;
776         }
777
778         /*
779          * Ok, the commit wasn't uninteresting. Try to
780          * simplify the commit history and find the parent
781          * that has no differences in the path set if one exists.
782          */
783         try_to_simplify_commit(revs, commit);
784
785         if (revs->no_walk)
786                 return 0;
787
788         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
789
790         for (parent = commit->parents; parent; parent = parent->next) {
791                 struct commit *p = parent->item;
792
793                 if (parse_commit_gently(p, revs->ignore_missing_links) < 0)
794                         return -1;
795                 if (revs->show_source && !p->util)
796                         p->util = commit->util;
797                 p->object.flags |= left_flag;
798                 if (!(p->object.flags & SEEN)) {
799                         p->object.flags |= SEEN;
800                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
801                 }
802                 if (revs->first_parent_only)
803                         break;
804         }
805         return 0;
806 }
807
808 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
809 {
810         struct commit_list *p;
811         int left_count = 0, right_count = 0;
812         int left_first;
813         struct patch_ids ids;
814         unsigned cherry_flag;
815
816         /* First count the commits on the left and on the right */
817         for (p = list; p; p = p->next) {
818                 struct commit *commit = p->item;
819                 unsigned flags = commit->object.flags;
820                 if (flags & BOUNDARY)
821                         ;
822                 else if (flags & SYMMETRIC_LEFT)
823                         left_count++;
824                 else
825                         right_count++;
826         }
827
828         if (!left_count || !right_count)
829                 return;
830
831         left_first = left_count < right_count;
832         init_patch_ids(&ids);
833         ids.diffopts.pathspec = revs->diffopt.pathspec;
834
835         /* Compute patch-ids for one side */
836         for (p = list; p; p = p->next) {
837                 struct commit *commit = p->item;
838                 unsigned flags = commit->object.flags;
839
840                 if (flags & BOUNDARY)
841                         continue;
842                 /*
843                  * If we have fewer left, left_first is set and we omit
844                  * commits on the right branch in this loop.  If we have
845                  * fewer right, we skip the left ones.
846                  */
847                 if (left_first != !!(flags & SYMMETRIC_LEFT))
848                         continue;
849                 add_commit_patch_id(commit, &ids);
850         }
851
852         /* either cherry_mark or cherry_pick are true */
853         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
854
855         /* Check the other side */
856         for (p = list; p; p = p->next) {
857                 struct commit *commit = p->item;
858                 struct patch_id *id;
859                 unsigned flags = commit->object.flags;
860
861                 if (flags & BOUNDARY)
862                         continue;
863                 /*
864                  * If we have fewer left, left_first is set and we omit
865                  * commits on the left branch in this loop.
866                  */
867                 if (left_first == !!(flags & SYMMETRIC_LEFT))
868                         continue;
869
870                 /*
871                  * Have we seen the same patch id?
872                  */
873                 id = has_commit_patch_id(commit, &ids);
874                 if (!id)
875                         continue;
876
877                 commit->object.flags |= cherry_flag;
878                 id->commit->object.flags |= cherry_flag;
879         }
880
881         free_patch_ids(&ids);
882 }
883
884 /* How many extra uninteresting commits we want to see.. */
885 #define SLOP 5
886
887 static int still_interesting(struct commit_list *src, timestamp_t date, int slop,
888                              struct commit **interesting_cache)
889 {
890         /*
891          * No source list at all? We're definitely done..
892          */
893         if (!src)
894                 return 0;
895
896         /*
897          * Does the destination list contain entries with a date
898          * before the source list? Definitely _not_ done.
899          */
900         if (date <= src->item->date)
901                 return SLOP;
902
903         /*
904          * Does the source list still have interesting commits in
905          * it? Definitely not done..
906          */
907         if (!everybody_uninteresting(src, interesting_cache))
908                 return SLOP;
909
910         /* Ok, we're closing in.. */
911         return slop-1;
912 }
913
914 /*
915  * "rev-list --ancestry-path A..B" computes commits that are ancestors
916  * of B but not ancestors of A but further limits the result to those
917  * that are descendants of A.  This takes the list of bottom commits and
918  * the result of "A..B" without --ancestry-path, and limits the latter
919  * further to the ones that can reach one of the commits in "bottom".
920  */
921 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
922 {
923         struct commit_list *p;
924         struct commit_list *rlist = NULL;
925         int made_progress;
926
927         /*
928          * Reverse the list so that it will be likely that we would
929          * process parents before children.
930          */
931         for (p = list; p; p = p->next)
932                 commit_list_insert(p->item, &rlist);
933
934         for (p = bottom; p; p = p->next)
935                 p->item->object.flags |= TMP_MARK;
936
937         /*
938          * Mark the ones that can reach bottom commits in "list",
939          * in a bottom-up fashion.
940          */
941         do {
942                 made_progress = 0;
943                 for (p = rlist; p; p = p->next) {
944                         struct commit *c = p->item;
945                         struct commit_list *parents;
946                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
947                                 continue;
948                         for (parents = c->parents;
949                              parents;
950                              parents = parents->next) {
951                                 if (!(parents->item->object.flags & TMP_MARK))
952                                         continue;
953                                 c->object.flags |= TMP_MARK;
954                                 made_progress = 1;
955                                 break;
956                         }
957                 }
958         } while (made_progress);
959
960         /*
961          * NEEDSWORK: decide if we want to remove parents that are
962          * not marked with TMP_MARK from commit->parents for commits
963          * in the resulting list.  We may not want to do that, though.
964          */
965
966         /*
967          * The ones that are not marked with TMP_MARK are uninteresting
968          */
969         for (p = list; p; p = p->next) {
970                 struct commit *c = p->item;
971                 if (c->object.flags & TMP_MARK)
972                         continue;
973                 c->object.flags |= UNINTERESTING;
974         }
975
976         /* We are done with the TMP_MARK */
977         for (p = list; p; p = p->next)
978                 p->item->object.flags &= ~TMP_MARK;
979         for (p = bottom; p; p = p->next)
980                 p->item->object.flags &= ~TMP_MARK;
981         free_commit_list(rlist);
982 }
983
984 /*
985  * Before walking the history, keep the set of "negative" refs the
986  * caller has asked to exclude.
987  *
988  * This is used to compute "rev-list --ancestry-path A..B", as we need
989  * to filter the result of "A..B" further to the ones that can actually
990  * reach A.
991  */
992 static struct commit_list *collect_bottom_commits(struct commit_list *list)
993 {
994         struct commit_list *elem, *bottom = NULL;
995         for (elem = list; elem; elem = elem->next)
996                 if (elem->item->object.flags & BOTTOM)
997                         commit_list_insert(elem->item, &bottom);
998         return bottom;
999 }
1000
1001 /* Assumes either left_only or right_only is set */
1002 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1003 {
1004         struct commit_list *p;
1005
1006         for (p = list; p; p = p->next) {
1007                 struct commit *commit = p->item;
1008
1009                 if (revs->right_only) {
1010                         if (commit->object.flags & SYMMETRIC_LEFT)
1011                                 commit->object.flags |= SHOWN;
1012                 } else  /* revs->left_only is set */
1013                         if (!(commit->object.flags & SYMMETRIC_LEFT))
1014                                 commit->object.flags |= SHOWN;
1015         }
1016 }
1017
1018 static int limit_list(struct rev_info *revs)
1019 {
1020         int slop = SLOP;
1021         timestamp_t date = TIME_MAX;
1022         struct commit_list *list = revs->commits;
1023         struct commit_list *newlist = NULL;
1024         struct commit_list **p = &newlist;
1025         struct commit_list *bottom = NULL;
1026         struct commit *interesting_cache = NULL;
1027
1028         if (revs->ancestry_path) {
1029                 bottom = collect_bottom_commits(list);
1030                 if (!bottom)
1031                         die("--ancestry-path given but there are no bottom commits");
1032         }
1033
1034         while (list) {
1035                 struct commit *commit = pop_commit(&list);
1036                 struct object *obj = &commit->object;
1037                 show_early_output_fn_t show;
1038
1039                 if (commit == interesting_cache)
1040                         interesting_cache = NULL;
1041
1042                 if (revs->max_age != -1 && (commit->date < revs->max_age))
1043                         obj->flags |= UNINTERESTING;
1044                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
1045                         return -1;
1046                 if (obj->flags & UNINTERESTING) {
1047                         mark_parents_uninteresting(commit);
1048                         if (revs->show_all)
1049                                 p = &commit_list_insert(commit, p)->next;
1050                         slop = still_interesting(list, date, slop, &interesting_cache);
1051                         if (slop)
1052                                 continue;
1053                         /* If showing all, add the whole pending list to the end */
1054                         if (revs->show_all)
1055                                 *p = list;
1056                         break;
1057                 }
1058                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1059                         continue;
1060                 date = commit->date;
1061                 p = &commit_list_insert(commit, p)->next;
1062
1063                 show = show_early_output;
1064                 if (!show)
1065                         continue;
1066
1067                 show(revs, newlist);
1068                 show_early_output = NULL;
1069         }
1070         if (revs->cherry_pick || revs->cherry_mark)
1071                 cherry_pick_list(newlist, revs);
1072
1073         if (revs->left_only || revs->right_only)
1074                 limit_left_right(newlist, revs);
1075
1076         if (bottom) {
1077                 limit_to_ancestry(bottom, newlist);
1078                 free_commit_list(bottom);
1079         }
1080
1081         /*
1082          * Check if any commits have become TREESAME by some of their parents
1083          * becoming UNINTERESTING.
1084          */
1085         if (limiting_can_increase_treesame(revs))
1086                 for (list = newlist; list; list = list->next) {
1087                         struct commit *c = list->item;
1088                         if (c->object.flags & (UNINTERESTING | TREESAME))
1089                                 continue;
1090                         update_treesame(revs, c);
1091                 }
1092
1093         revs->commits = newlist;
1094         return 0;
1095 }
1096
1097 /*
1098  * Add an entry to refs->cmdline with the specified information.
1099  * *name is copied.
1100  */
1101 static void add_rev_cmdline(struct rev_info *revs,
1102                             struct object *item,
1103                             const char *name,
1104                             int whence,
1105                             unsigned flags)
1106 {
1107         struct rev_cmdline_info *info = &revs->cmdline;
1108         int nr = info->nr;
1109
1110         ALLOC_GROW(info->rev, nr + 1, info->alloc);
1111         info->rev[nr].item = item;
1112         info->rev[nr].name = xstrdup(name);
1113         info->rev[nr].whence = whence;
1114         info->rev[nr].flags = flags;
1115         info->nr++;
1116 }
1117
1118 static void add_rev_cmdline_list(struct rev_info *revs,
1119                                  struct commit_list *commit_list,
1120                                  int whence,
1121                                  unsigned flags)
1122 {
1123         while (commit_list) {
1124                 struct object *object = &commit_list->item->object;
1125                 add_rev_cmdline(revs, object, oid_to_hex(&object->oid),
1126                                 whence, flags);
1127                 commit_list = commit_list->next;
1128         }
1129 }
1130
1131 struct all_refs_cb {
1132         int all_flags;
1133         int warned_bad_reflog;
1134         struct rev_info *all_revs;
1135         const char *name_for_errormsg;
1136 };
1137
1138 int ref_excluded(struct string_list *ref_excludes, const char *path)
1139 {
1140         struct string_list_item *item;
1141
1142         if (!ref_excludes)
1143                 return 0;
1144         for_each_string_list_item(item, ref_excludes) {
1145                 if (!wildmatch(item->string, path, 0))
1146                         return 1;
1147         }
1148         return 0;
1149 }
1150
1151 static int handle_one_ref(const char *path, const struct object_id *oid,
1152                           int flag, void *cb_data)
1153 {
1154         struct all_refs_cb *cb = cb_data;
1155         struct object *object;
1156
1157         if (ref_excluded(cb->all_revs->ref_excludes, path))
1158             return 0;
1159
1160         object = get_reference(cb->all_revs, path, oid, cb->all_flags);
1161         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1162         add_pending_oid(cb->all_revs, path, oid, cb->all_flags);
1163         return 0;
1164 }
1165
1166 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1167         unsigned flags)
1168 {
1169         cb->all_revs = revs;
1170         cb->all_flags = flags;
1171 }
1172
1173 void clear_ref_exclusion(struct string_list **ref_excludes_p)
1174 {
1175         if (*ref_excludes_p) {
1176                 string_list_clear(*ref_excludes_p, 0);
1177                 free(*ref_excludes_p);
1178         }
1179         *ref_excludes_p = NULL;
1180 }
1181
1182 void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1183 {
1184         if (!*ref_excludes_p) {
1185                 *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1186                 (*ref_excludes_p)->strdup_strings = 1;
1187         }
1188         string_list_append(*ref_excludes_p, exclude);
1189 }
1190
1191 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
1192                 int (*for_each)(const char *, each_ref_fn, void *))
1193 {
1194         struct all_refs_cb cb;
1195         init_all_refs_cb(&cb, revs, flags);
1196         for_each(submodule, handle_one_ref, &cb);
1197 }
1198
1199 static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
1200 {
1201         struct all_refs_cb *cb = cb_data;
1202         if (!is_null_oid(oid)) {
1203                 struct object *o = parse_object(oid);
1204                 if (o) {
1205                         o->flags |= cb->all_flags;
1206                         /* ??? CMDLINEFLAGS ??? */
1207                         add_pending_object(cb->all_revs, o, "");
1208                 }
1209                 else if (!cb->warned_bad_reflog) {
1210                         warning("reflog of '%s' references pruned commits",
1211                                 cb->name_for_errormsg);
1212                         cb->warned_bad_reflog = 1;
1213                 }
1214         }
1215 }
1216
1217 static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
1218                 const char *email, timestamp_t timestamp, int tz,
1219                 const char *message, void *cb_data)
1220 {
1221         handle_one_reflog_commit(ooid, cb_data);
1222         handle_one_reflog_commit(noid, cb_data);
1223         return 0;
1224 }
1225
1226 static int handle_one_reflog(const char *path, const struct object_id *oid,
1227                              int flag, void *cb_data)
1228 {
1229         struct all_refs_cb *cb = cb_data;
1230         cb->warned_bad_reflog = 0;
1231         cb->name_for_errormsg = path;
1232         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
1233         return 0;
1234 }
1235
1236 void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1237 {
1238         struct all_refs_cb cb;
1239
1240         cb.all_revs = revs;
1241         cb.all_flags = flags;
1242         for_each_reflog(handle_one_reflog, &cb);
1243 }
1244
1245 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1246                            struct strbuf *path)
1247 {
1248         size_t baselen = path->len;
1249         int i;
1250
1251         if (it->entry_count >= 0) {
1252                 struct tree *tree = lookup_tree(&it->oid);
1253                 add_pending_object_with_path(revs, &tree->object, "",
1254                                              040000, path->buf);
1255         }
1256
1257         for (i = 0; i < it->subtree_nr; i++) {
1258                 struct cache_tree_sub *sub = it->down[i];
1259                 strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1260                 add_cache_tree(sub->cache_tree, revs, path);
1261                 strbuf_setlen(path, baselen);
1262         }
1263
1264 }
1265
1266 void add_index_objects_to_pending(struct rev_info *revs, unsigned flags)
1267 {
1268         int i;
1269
1270         read_cache();
1271         for (i = 0; i < active_nr; i++) {
1272                 struct cache_entry *ce = active_cache[i];
1273                 struct blob *blob;
1274
1275                 if (S_ISGITLINK(ce->ce_mode))
1276                         continue;
1277
1278                 blob = lookup_blob(&ce->oid);
1279                 if (!blob)
1280                         die("unable to add index blob to traversal");
1281                 add_pending_object_with_path(revs, &blob->object, "",
1282                                              ce->ce_mode, ce->name);
1283         }
1284
1285         if (active_cache_tree) {
1286                 struct strbuf path = STRBUF_INIT;
1287                 add_cache_tree(active_cache_tree, revs, &path);
1288                 strbuf_release(&path);
1289         }
1290 }
1291
1292 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
1293                             int exclude_parent)
1294 {
1295         struct object_id oid;
1296         struct object *it;
1297         struct commit *commit;
1298         struct commit_list *parents;
1299         int parent_number;
1300         const char *arg = arg_;
1301
1302         if (*arg == '^') {
1303                 flags ^= UNINTERESTING | BOTTOM;
1304                 arg++;
1305         }
1306         if (get_sha1_committish(arg, oid.hash))
1307                 return 0;
1308         while (1) {
1309                 it = get_reference(revs, arg, &oid, 0);
1310                 if (!it && revs->ignore_missing)
1311                         return 0;
1312                 if (it->type != OBJ_TAG)
1313                         break;
1314                 if (!((struct tag*)it)->tagged)
1315                         return 0;
1316                 oidcpy(&oid, &((struct tag*)it)->tagged->oid);
1317         }
1318         if (it->type != OBJ_COMMIT)
1319                 return 0;
1320         commit = (struct commit *)it;
1321         if (exclude_parent &&
1322             exclude_parent > commit_list_count(commit->parents))
1323                 return 0;
1324         for (parents = commit->parents, parent_number = 1;
1325              parents;
1326              parents = parents->next, parent_number++) {
1327                 if (exclude_parent && parent_number != exclude_parent)
1328                         continue;
1329
1330                 it = &parents->item->object;
1331                 it->flags |= flags;
1332                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1333                 add_pending_object(revs, it, arg);
1334         }
1335         return 1;
1336 }
1337
1338 void init_revisions(struct rev_info *revs, const char *prefix)
1339 {
1340         memset(revs, 0, sizeof(*revs));
1341
1342         revs->abbrev = DEFAULT_ABBREV;
1343         revs->ignore_merges = 1;
1344         revs->simplify_history = 1;
1345         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1346         DIFF_OPT_SET(&revs->pruning, QUICK);
1347         revs->pruning.add_remove = file_add_remove;
1348         revs->pruning.change = file_change;
1349         revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1350         revs->dense = 1;
1351         revs->prefix = prefix;
1352         revs->max_age = -1;
1353         revs->min_age = -1;
1354         revs->skip_count = -1;
1355         revs->max_count = -1;
1356         revs->max_parents = -1;
1357         revs->expand_tabs_in_log = -1;
1358
1359         revs->commit_format = CMIT_FMT_DEFAULT;
1360         revs->expand_tabs_in_log_default = 8;
1361
1362         init_grep_defaults();
1363         grep_init(&revs->grep_filter, prefix);
1364         revs->grep_filter.status_only = 1;
1365
1366         diff_setup(&revs->diffopt);
1367         if (prefix && !revs->diffopt.prefix) {
1368                 revs->diffopt.prefix = prefix;
1369                 revs->diffopt.prefix_length = strlen(prefix);
1370         }
1371
1372         revs->notes_opt.use_default_notes = -1;
1373 }
1374
1375 static void add_pending_commit_list(struct rev_info *revs,
1376                                     struct commit_list *commit_list,
1377                                     unsigned int flags)
1378 {
1379         while (commit_list) {
1380                 struct object *object = &commit_list->item->object;
1381                 object->flags |= flags;
1382                 add_pending_object(revs, object, oid_to_hex(&object->oid));
1383                 commit_list = commit_list->next;
1384         }
1385 }
1386
1387 static void prepare_show_merge(struct rev_info *revs)
1388 {
1389         struct commit_list *bases;
1390         struct commit *head, *other;
1391         struct object_id oid;
1392         const char **prune = NULL;
1393         int i, prune_num = 1; /* counting terminating NULL */
1394
1395         if (get_oid("HEAD", &oid))
1396                 die("--merge without HEAD?");
1397         head = lookup_commit_or_die(&oid, "HEAD");
1398         if (get_oid("MERGE_HEAD", &oid))
1399                 die("--merge without MERGE_HEAD?");
1400         other = lookup_commit_or_die(&oid, "MERGE_HEAD");
1401         add_pending_object(revs, &head->object, "HEAD");
1402         add_pending_object(revs, &other->object, "MERGE_HEAD");
1403         bases = get_merge_bases(head, other);
1404         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1405         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1406         free_commit_list(bases);
1407         head->object.flags |= SYMMETRIC_LEFT;
1408
1409         if (!active_nr)
1410                 read_cache();
1411         for (i = 0; i < active_nr; i++) {
1412                 const struct cache_entry *ce = active_cache[i];
1413                 if (!ce_stage(ce))
1414                         continue;
1415                 if (ce_path_match(ce, &revs->prune_data, NULL)) {
1416                         prune_num++;
1417                         REALLOC_ARRAY(prune, prune_num);
1418                         prune[prune_num-2] = ce->name;
1419                         prune[prune_num-1] = NULL;
1420                 }
1421                 while ((i+1 < active_nr) &&
1422                        ce_same_name(ce, active_cache[i+1]))
1423                         i++;
1424         }
1425         clear_pathspec(&revs->prune_data);
1426         parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1427                        PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1428         revs->limited = 1;
1429 }
1430
1431 static int dotdot_missing(const char *arg, char *dotdot,
1432                           struct rev_info *revs, int symmetric)
1433 {
1434         if (revs->ignore_missing)
1435                 return 0;
1436         /* de-munge so we report the full argument */
1437         *dotdot = '.';
1438         die(symmetric
1439             ? "Invalid symmetric difference expression %s"
1440             : "Invalid revision range %s", arg);
1441 }
1442
1443 static int handle_dotdot_1(const char *arg, char *dotdot,
1444                            struct rev_info *revs, int flags,
1445                            int cant_be_filename,
1446                            struct object_context *a_oc,
1447                            struct object_context *b_oc)
1448 {
1449         const char *a_name, *b_name;
1450         struct object_id a_oid, b_oid;
1451         struct object *a_obj, *b_obj;
1452         unsigned int a_flags, b_flags;
1453         int symmetric = 0;
1454         unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1455         unsigned int oc_flags = GET_SHA1_COMMITTISH | GET_SHA1_RECORD_PATH;
1456
1457         a_name = arg;
1458         if (!*a_name)
1459                 a_name = "HEAD";
1460
1461         b_name = dotdot + 2;
1462         if (*b_name == '.') {
1463                 symmetric = 1;
1464                 b_name++;
1465         }
1466         if (!*b_name)
1467                 b_name = "HEAD";
1468
1469         if (get_sha1_with_context(a_name, oc_flags, a_oid.hash, a_oc) ||
1470             get_sha1_with_context(b_name, oc_flags, b_oid.hash, b_oc))
1471                 return -1;
1472
1473         if (!cant_be_filename) {
1474                 *dotdot = '.';
1475                 verify_non_filename(revs->prefix, arg);
1476                 *dotdot = '\0';
1477         }
1478
1479         a_obj = parse_object(&a_oid);
1480         b_obj = parse_object(&b_oid);
1481         if (!a_obj || !b_obj)
1482                 return dotdot_missing(arg, dotdot, revs, symmetric);
1483
1484         if (!symmetric) {
1485                 /* just A..B */
1486                 b_flags = flags;
1487                 a_flags = flags_exclude;
1488         } else {
1489                 /* A...B -- find merge bases between the two */
1490                 struct commit *a, *b;
1491                 struct commit_list *exclude;
1492
1493                 a = lookup_commit_reference(&a_obj->oid);
1494                 b = lookup_commit_reference(&b_obj->oid);
1495                 if (!a || !b)
1496                         return dotdot_missing(arg, dotdot, revs, symmetric);
1497
1498                 exclude = get_merge_bases(a, b);
1499                 add_rev_cmdline_list(revs, exclude, REV_CMD_MERGE_BASE,
1500                                      flags_exclude);
1501                 add_pending_commit_list(revs, exclude, flags_exclude);
1502                 free_commit_list(exclude);
1503
1504                 b_flags = flags;
1505                 a_flags = flags | SYMMETRIC_LEFT;
1506         }
1507
1508         a_obj->flags |= a_flags;
1509         b_obj->flags |= b_flags;
1510         add_rev_cmdline(revs, a_obj, a_name, REV_CMD_LEFT, a_flags);
1511         add_rev_cmdline(revs, b_obj, b_name, REV_CMD_RIGHT, b_flags);
1512         add_pending_object_with_path(revs, a_obj, a_name, a_oc->mode, a_oc->path);
1513         add_pending_object_with_path(revs, b_obj, b_name, b_oc->mode, b_oc->path);
1514         return 0;
1515 }
1516
1517 static int handle_dotdot(const char *arg,
1518                          struct rev_info *revs, int flags,
1519                          int cant_be_filename)
1520 {
1521         struct object_context a_oc, b_oc;
1522         char *dotdot = strstr(arg, "..");
1523         int ret;
1524
1525         if (!dotdot)
1526                 return -1;
1527
1528         memset(&a_oc, 0, sizeof(a_oc));
1529         memset(&b_oc, 0, sizeof(b_oc));
1530
1531         *dotdot = '\0';
1532         ret = handle_dotdot_1(arg, dotdot, revs, flags, cant_be_filename,
1533                               &a_oc, &b_oc);
1534         *dotdot = '.';
1535
1536         free(a_oc.path);
1537         free(b_oc.path);
1538
1539         return ret;
1540 }
1541
1542 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1543 {
1544         struct object_context oc;
1545         char *mark;
1546         struct object *object;
1547         struct object_id oid;
1548         int local_flags;
1549         const char *arg = arg_;
1550         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1551         unsigned get_sha1_flags = GET_SHA1_RECORD_PATH;
1552
1553         flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1554
1555         if (!cant_be_filename && !strcmp(arg, "..")) {
1556                 /*
1557                  * Just ".."?  That is not a range but the
1558                  * pathspec for the parent directory.
1559                  */
1560                 return -1;
1561         }
1562
1563         if (!handle_dotdot(arg, revs, flags, revarg_opt))
1564                 return 0;
1565
1566         mark = strstr(arg, "^@");
1567         if (mark && !mark[2]) {
1568                 *mark = 0;
1569                 if (add_parents_only(revs, arg, flags, 0))
1570                         return 0;
1571                 *mark = '^';
1572         }
1573         mark = strstr(arg, "^!");
1574         if (mark && !mark[2]) {
1575                 *mark = 0;
1576                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
1577                         *mark = '^';
1578         }
1579         mark = strstr(arg, "^-");
1580         if (mark) {
1581                 int exclude_parent = 1;
1582
1583                 if (mark[2]) {
1584                         char *end;
1585                         exclude_parent = strtoul(mark + 2, &end, 10);
1586                         if (*end != '\0' || !exclude_parent)
1587                                 return -1;
1588                 }
1589
1590                 *mark = 0;
1591                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
1592                         *mark = '^';
1593         }
1594
1595         local_flags = 0;
1596         if (*arg == '^') {
1597                 local_flags = UNINTERESTING | BOTTOM;
1598                 arg++;
1599         }
1600
1601         if (revarg_opt & REVARG_COMMITTISH)
1602                 get_sha1_flags |= GET_SHA1_COMMITTISH;
1603
1604         if (get_sha1_with_context(arg, get_sha1_flags, oid.hash, &oc))
1605                 return revs->ignore_missing ? 0 : -1;
1606         if (!cant_be_filename)
1607                 verify_non_filename(revs->prefix, arg);
1608         object = get_reference(revs, arg, &oid, flags ^ local_flags);
1609         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1610         add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
1611         free(oc.path);
1612         return 0;
1613 }
1614
1615 struct cmdline_pathspec {
1616         int alloc;
1617         int nr;
1618         const char **path;
1619 };
1620
1621 static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1622 {
1623         while (*av) {
1624                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1625                 prune->path[prune->nr++] = *(av++);
1626         }
1627 }
1628
1629 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1630                                      struct cmdline_pathspec *prune)
1631 {
1632         while (strbuf_getline(sb, stdin) != EOF) {
1633                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1634                 prune->path[prune->nr++] = xstrdup(sb->buf);
1635         }
1636 }
1637
1638 static void read_revisions_from_stdin(struct rev_info *revs,
1639                                       struct cmdline_pathspec *prune)
1640 {
1641         struct strbuf sb;
1642         int seen_dashdash = 0;
1643         int save_warning;
1644
1645         save_warning = warn_on_object_refname_ambiguity;
1646         warn_on_object_refname_ambiguity = 0;
1647
1648         strbuf_init(&sb, 1000);
1649         while (strbuf_getline(&sb, stdin) != EOF) {
1650                 int len = sb.len;
1651                 if (!len)
1652                         break;
1653                 if (sb.buf[0] == '-') {
1654                         if (len == 2 && sb.buf[1] == '-') {
1655                                 seen_dashdash = 1;
1656                                 break;
1657                         }
1658                         die("options not supported in --stdin mode");
1659                 }
1660                 if (handle_revision_arg(sb.buf, revs, 0,
1661                                         REVARG_CANNOT_BE_FILENAME))
1662                         die("bad revision '%s'", sb.buf);
1663         }
1664         if (seen_dashdash)
1665                 read_pathspec_from_stdin(revs, &sb, prune);
1666
1667         strbuf_release(&sb);
1668         warn_on_object_refname_ambiguity = save_warning;
1669 }
1670
1671 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1672 {
1673         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1674 }
1675
1676 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1677 {
1678         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1679 }
1680
1681 static void add_message_grep(struct rev_info *revs, const char *pattern)
1682 {
1683         add_grep(revs, pattern, GREP_PATTERN_BODY);
1684 }
1685
1686 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1687                                int *unkc, const char **unkv)
1688 {
1689         const char *arg = argv[0];
1690         const char *optarg;
1691         int argcount;
1692
1693         /* pseudo revision arguments */
1694         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1695             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1696             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1697             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1698             !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
1699             !strcmp(arg, "--indexed-objects") ||
1700             starts_with(arg, "--exclude=") ||
1701             starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
1702             starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
1703         {
1704                 unkv[(*unkc)++] = arg;
1705                 return 1;
1706         }
1707
1708         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1709                 revs->max_count = atoi(optarg);
1710                 revs->no_walk = 0;
1711                 return argcount;
1712         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1713                 revs->skip_count = atoi(optarg);
1714                 return argcount;
1715         } else if ((*arg == '-') && isdigit(arg[1])) {
1716                 /* accept -<digit>, like traditional "head" */
1717                 if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
1718                     revs->max_count < 0)
1719                         die("'%s': not a non-negative integer", arg + 1);
1720                 revs->no_walk = 0;
1721         } else if (!strcmp(arg, "-n")) {
1722                 if (argc <= 1)
1723                         return error("-n requires an argument");
1724                 revs->max_count = atoi(argv[1]);
1725                 revs->no_walk = 0;
1726                 return 2;
1727         } else if (skip_prefix(arg, "-n", &optarg)) {
1728                 revs->max_count = atoi(optarg);
1729                 revs->no_walk = 0;
1730         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1731                 revs->max_age = atoi(optarg);
1732                 return argcount;
1733         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1734                 revs->max_age = approxidate(optarg);
1735                 return argcount;
1736         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1737                 revs->max_age = approxidate(optarg);
1738                 return argcount;
1739         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1740                 revs->min_age = atoi(optarg);
1741                 return argcount;
1742         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1743                 revs->min_age = approxidate(optarg);
1744                 return argcount;
1745         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1746                 revs->min_age = approxidate(optarg);
1747                 return argcount;
1748         } else if (!strcmp(arg, "--first-parent")) {
1749                 revs->first_parent_only = 1;
1750         } else if (!strcmp(arg, "--ancestry-path")) {
1751                 revs->ancestry_path = 1;
1752                 revs->simplify_history = 0;
1753                 revs->limited = 1;
1754         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1755                 init_reflog_walk(&revs->reflog_info);
1756         } else if (!strcmp(arg, "--default")) {
1757                 if (argc <= 1)
1758                         return error("bad --default argument");
1759                 revs->def = argv[1];
1760                 return 2;
1761         } else if (!strcmp(arg, "--merge")) {
1762                 revs->show_merge = 1;
1763         } else if (!strcmp(arg, "--topo-order")) {
1764                 revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1765                 revs->topo_order = 1;
1766         } else if (!strcmp(arg, "--simplify-merges")) {
1767                 revs->simplify_merges = 1;
1768                 revs->topo_order = 1;
1769                 revs->rewrite_parents = 1;
1770                 revs->simplify_history = 0;
1771                 revs->limited = 1;
1772         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1773                 revs->simplify_merges = 1;
1774                 revs->topo_order = 1;
1775                 revs->rewrite_parents = 1;
1776                 revs->simplify_history = 0;
1777                 revs->simplify_by_decoration = 1;
1778                 revs->limited = 1;
1779                 revs->prune = 1;
1780                 load_ref_decorations(DECORATE_SHORT_REFS);
1781         } else if (!strcmp(arg, "--date-order")) {
1782                 revs->sort_order = REV_SORT_BY_COMMIT_DATE;
1783                 revs->topo_order = 1;
1784         } else if (!strcmp(arg, "--author-date-order")) {
1785                 revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
1786                 revs->topo_order = 1;
1787         } else if (!strcmp(arg, "--early-output")) {
1788                 revs->early_output = 100;
1789                 revs->topo_order = 1;
1790         } else if (skip_prefix(arg, "--early-output=", &optarg)) {
1791                 if (strtoul_ui(optarg, 10, &revs->early_output) < 0)
1792                         die("'%s': not a non-negative integer", optarg);
1793                 revs->topo_order = 1;
1794         } else if (!strcmp(arg, "--parents")) {
1795                 revs->rewrite_parents = 1;
1796                 revs->print_parents = 1;
1797         } else if (!strcmp(arg, "--dense")) {
1798                 revs->dense = 1;
1799         } else if (!strcmp(arg, "--sparse")) {
1800                 revs->dense = 0;
1801         } else if (!strcmp(arg, "--show-all")) {
1802                 revs->show_all = 1;
1803         } else if (!strcmp(arg, "--remove-empty")) {
1804                 revs->remove_empty_trees = 1;
1805         } else if (!strcmp(arg, "--merges")) {
1806                 revs->min_parents = 2;
1807         } else if (!strcmp(arg, "--no-merges")) {
1808                 revs->max_parents = 1;
1809         } else if (skip_prefix(arg, "--min-parents=", &optarg)) {
1810                 revs->min_parents = atoi(optarg);
1811         } else if (!strcmp(arg, "--no-min-parents")) {
1812                 revs->min_parents = 0;
1813         } else if (skip_prefix(arg, "--max-parents=", &optarg)) {
1814                 revs->max_parents = atoi(optarg);
1815         } else if (!strcmp(arg, "--no-max-parents")) {
1816                 revs->max_parents = -1;
1817         } else if (!strcmp(arg, "--boundary")) {
1818                 revs->boundary = 1;
1819         } else if (!strcmp(arg, "--left-right")) {
1820                 revs->left_right = 1;
1821         } else if (!strcmp(arg, "--left-only")) {
1822                 if (revs->right_only)
1823                         die("--left-only is incompatible with --right-only"
1824                             " or --cherry");
1825                 revs->left_only = 1;
1826         } else if (!strcmp(arg, "--right-only")) {
1827                 if (revs->left_only)
1828                         die("--right-only is incompatible with --left-only");
1829                 revs->right_only = 1;
1830         } else if (!strcmp(arg, "--cherry")) {
1831                 if (revs->left_only)
1832                         die("--cherry is incompatible with --left-only");
1833                 revs->cherry_mark = 1;
1834                 revs->right_only = 1;
1835                 revs->max_parents = 1;
1836                 revs->limited = 1;
1837         } else if (!strcmp(arg, "--count")) {
1838                 revs->count = 1;
1839         } else if (!strcmp(arg, "--cherry-mark")) {
1840                 if (revs->cherry_pick)
1841                         die("--cherry-mark is incompatible with --cherry-pick");
1842                 revs->cherry_mark = 1;
1843                 revs->limited = 1; /* needs limit_list() */
1844         } else if (!strcmp(arg, "--cherry-pick")) {
1845                 if (revs->cherry_mark)
1846                         die("--cherry-pick is incompatible with --cherry-mark");
1847                 revs->cherry_pick = 1;
1848                 revs->limited = 1;
1849         } else if (!strcmp(arg, "--objects")) {
1850                 revs->tag_objects = 1;
1851                 revs->tree_objects = 1;
1852                 revs->blob_objects = 1;
1853         } else if (!strcmp(arg, "--objects-edge")) {
1854                 revs->tag_objects = 1;
1855                 revs->tree_objects = 1;
1856                 revs->blob_objects = 1;
1857                 revs->edge_hint = 1;
1858         } else if (!strcmp(arg, "--objects-edge-aggressive")) {
1859                 revs->tag_objects = 1;
1860                 revs->tree_objects = 1;
1861                 revs->blob_objects = 1;
1862                 revs->edge_hint = 1;
1863                 revs->edge_hint_aggressive = 1;
1864         } else if (!strcmp(arg, "--verify-objects")) {
1865                 revs->tag_objects = 1;
1866                 revs->tree_objects = 1;
1867                 revs->blob_objects = 1;
1868                 revs->verify_objects = 1;
1869         } else if (!strcmp(arg, "--unpacked")) {
1870                 revs->unpacked = 1;
1871         } else if (starts_with(arg, "--unpacked=")) {
1872                 die("--unpacked=<packfile> no longer supported.");
1873         } else if (!strcmp(arg, "-r")) {
1874                 revs->diff = 1;
1875                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1876         } else if (!strcmp(arg, "-t")) {
1877                 revs->diff = 1;
1878                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1879                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1880         } else if (!strcmp(arg, "-m")) {
1881                 revs->ignore_merges = 0;
1882         } else if (!strcmp(arg, "-c")) {
1883                 revs->diff = 1;
1884                 revs->dense_combined_merges = 0;
1885                 revs->combine_merges = 1;
1886         } else if (!strcmp(arg, "--cc")) {
1887                 revs->diff = 1;
1888                 revs->dense_combined_merges = 1;
1889                 revs->combine_merges = 1;
1890         } else if (!strcmp(arg, "-v")) {
1891                 revs->verbose_header = 1;
1892         } else if (!strcmp(arg, "--pretty")) {
1893                 revs->verbose_header = 1;
1894                 revs->pretty_given = 1;
1895                 get_commit_format(NULL, revs);
1896         } else if (skip_prefix(arg, "--pretty=", &optarg) ||
1897                    skip_prefix(arg, "--format=", &optarg)) {
1898                 /*
1899                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1900                  * not allowed, since the argument is optional.
1901                  */
1902                 revs->verbose_header = 1;
1903                 revs->pretty_given = 1;
1904                 get_commit_format(optarg, revs);
1905         } else if (!strcmp(arg, "--expand-tabs")) {
1906                 revs->expand_tabs_in_log = 8;
1907         } else if (!strcmp(arg, "--no-expand-tabs")) {
1908                 revs->expand_tabs_in_log = 0;
1909         } else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
1910                 int val;
1911                 if (strtol_i(arg, 10, &val) < 0 || val < 0)
1912                         die("'%s': not a non-negative integer", arg);
1913                 revs->expand_tabs_in_log = val;
1914         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1915                 revs->show_notes = 1;
1916                 revs->show_notes_given = 1;
1917                 revs->notes_opt.use_default_notes = 1;
1918         } else if (!strcmp(arg, "--show-signature")) {
1919                 revs->show_signature = 1;
1920         } else if (!strcmp(arg, "--no-show-signature")) {
1921                 revs->show_signature = 0;
1922         } else if (!strcmp(arg, "--show-linear-break")) {
1923                 revs->break_bar = "                    ..........";
1924                 revs->track_linear = 1;
1925                 revs->track_first_time = 1;
1926         } else if (skip_prefix(arg, "--show-linear-break=", &optarg)) {
1927                 revs->break_bar = xstrdup(optarg);
1928                 revs->track_linear = 1;
1929                 revs->track_first_time = 1;
1930         } else if (skip_prefix(arg, "--show-notes=", &optarg) ||
1931                    skip_prefix(arg, "--notes=", &optarg)) {
1932                 struct strbuf buf = STRBUF_INIT;
1933                 revs->show_notes = 1;
1934                 revs->show_notes_given = 1;
1935                 if (starts_with(arg, "--show-notes=") &&
1936                     revs->notes_opt.use_default_notes < 0)
1937                         revs->notes_opt.use_default_notes = 1;
1938                 strbuf_addstr(&buf, optarg);
1939                 expand_notes_ref(&buf);
1940                 string_list_append(&revs->notes_opt.extra_notes_refs,
1941                                    strbuf_detach(&buf, NULL));
1942         } else if (!strcmp(arg, "--no-notes")) {
1943                 revs->show_notes = 0;
1944                 revs->show_notes_given = 1;
1945                 revs->notes_opt.use_default_notes = -1;
1946                 /* we have been strdup'ing ourselves, so trick
1947                  * string_list into free()ing strings */
1948                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1949                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1950                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1951         } else if (!strcmp(arg, "--standard-notes")) {
1952                 revs->show_notes_given = 1;
1953                 revs->notes_opt.use_default_notes = 1;
1954         } else if (!strcmp(arg, "--no-standard-notes")) {
1955                 revs->notes_opt.use_default_notes = 0;
1956         } else if (!strcmp(arg, "--oneline")) {
1957                 revs->verbose_header = 1;
1958                 get_commit_format("oneline", revs);
1959                 revs->pretty_given = 1;
1960                 revs->abbrev_commit = 1;
1961         } else if (!strcmp(arg, "--graph")) {
1962                 revs->topo_order = 1;
1963                 revs->rewrite_parents = 1;
1964                 revs->graph = graph_init(revs);
1965         } else if (!strcmp(arg, "--root")) {
1966                 revs->show_root_diff = 1;
1967         } else if (!strcmp(arg, "--no-commit-id")) {
1968                 revs->no_commit_id = 1;
1969         } else if (!strcmp(arg, "--always")) {
1970                 revs->always_show_header = 1;
1971         } else if (!strcmp(arg, "--no-abbrev")) {
1972                 revs->abbrev = 0;
1973         } else if (!strcmp(arg, "--abbrev")) {
1974                 revs->abbrev = DEFAULT_ABBREV;
1975         } else if (skip_prefix(arg, "--abbrev=", &optarg)) {
1976                 revs->abbrev = strtoul(optarg, NULL, 10);
1977                 if (revs->abbrev < MINIMUM_ABBREV)
1978                         revs->abbrev = MINIMUM_ABBREV;
1979                 else if (revs->abbrev > 40)
1980                         revs->abbrev = 40;
1981         } else if (!strcmp(arg, "--abbrev-commit")) {
1982                 revs->abbrev_commit = 1;
1983                 revs->abbrev_commit_given = 1;
1984         } else if (!strcmp(arg, "--no-abbrev-commit")) {
1985                 revs->abbrev_commit = 0;
1986         } else if (!strcmp(arg, "--full-diff")) {
1987                 revs->diff = 1;
1988                 revs->full_diff = 1;
1989         } else if (!strcmp(arg, "--full-history")) {
1990                 revs->simplify_history = 0;
1991         } else if (!strcmp(arg, "--relative-date")) {
1992                 revs->date_mode.type = DATE_RELATIVE;
1993                 revs->date_mode_explicit = 1;
1994         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1995                 parse_date_format(optarg, &revs->date_mode);
1996                 revs->date_mode_explicit = 1;
1997                 return argcount;
1998         } else if (!strcmp(arg, "--log-size")) {
1999                 revs->show_log_size = 1;
2000         }
2001         /*
2002          * Grepping the commit log
2003          */
2004         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
2005                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
2006                 return argcount;
2007         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
2008                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
2009                 return argcount;
2010         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
2011                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
2012                 return argcount;
2013         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
2014                 add_message_grep(revs, optarg);
2015                 return argcount;
2016         } else if (!strcmp(arg, "--grep-debug")) {
2017                 revs->grep_filter.debug = 1;
2018         } else if (!strcmp(arg, "--basic-regexp")) {
2019                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_BRE;
2020         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
2021                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
2022         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
2023                 revs->grep_filter.ignore_case = 1;
2024                 DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
2025         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
2026                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
2027         } else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
2028                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_PCRE;
2029         } else if (!strcmp(arg, "--all-match")) {
2030                 revs->grep_filter.all_match = 1;
2031         } else if (!strcmp(arg, "--invert-grep")) {
2032                 revs->invert_grep = 1;
2033         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2034                 if (strcmp(optarg, "none"))
2035                         git_log_output_encoding = xstrdup(optarg);
2036                 else
2037                         git_log_output_encoding = "";
2038                 return argcount;
2039         } else if (!strcmp(arg, "--reverse")) {
2040                 revs->reverse ^= 1;
2041         } else if (!strcmp(arg, "--children")) {
2042                 revs->children.name = "children";
2043                 revs->limited = 1;
2044         } else if (!strcmp(arg, "--ignore-missing")) {
2045                 revs->ignore_missing = 1;
2046         } else {
2047                 int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
2048                 if (!opts)
2049                         unkv[(*unkc)++] = arg;
2050                 return opts;
2051         }
2052         if (revs->graph && revs->track_linear)
2053                 die("--show-linear-break and --graph are incompatible");
2054
2055         return 1;
2056 }
2057
2058 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2059                         const struct option *options,
2060                         const char * const usagestr[])
2061 {
2062         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2063                                     &ctx->cpidx, ctx->out);
2064         if (n <= 0) {
2065                 error("unknown option `%s'", ctx->argv[0]);
2066                 usage_with_options(usagestr, options);
2067         }
2068         ctx->argv += n;
2069         ctx->argc -= n;
2070 }
2071
2072 static int for_each_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data, const char *term) {
2073         struct strbuf bisect_refs = STRBUF_INIT;
2074         int status;
2075         strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2076         status = for_each_fullref_in_submodule(submodule, bisect_refs.buf, fn, cb_data, 0);
2077         strbuf_release(&bisect_refs);
2078         return status;
2079 }
2080
2081 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2082 {
2083         return for_each_bisect_ref(submodule, fn, cb_data, term_bad);
2084 }
2085
2086 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2087 {
2088         return for_each_bisect_ref(submodule, fn, cb_data, term_good);
2089 }
2090
2091 static int handle_revision_pseudo_opt(const char *submodule,
2092                                 struct rev_info *revs,
2093                                 int argc, const char **argv, int *flags)
2094 {
2095         const char *arg = argv[0];
2096         const char *optarg;
2097         int argcount;
2098
2099         /*
2100          * NOTE!
2101          *
2102          * Commands like "git shortlog" will not accept the options below
2103          * unless parse_revision_opt queues them (as opposed to erroring
2104          * out).
2105          *
2106          * When implementing your new pseudo-option, remember to
2107          * register it in the list at the top of handle_revision_opt.
2108          */
2109         if (!strcmp(arg, "--all")) {
2110                 handle_refs(submodule, revs, *flags, for_each_ref_submodule);
2111                 handle_refs(submodule, revs, *flags, head_ref_submodule);
2112                 clear_ref_exclusion(&revs->ref_excludes);
2113         } else if (!strcmp(arg, "--branches")) {
2114                 handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
2115                 clear_ref_exclusion(&revs->ref_excludes);
2116         } else if (!strcmp(arg, "--bisect")) {
2117                 read_bisect_terms(&term_bad, &term_good);
2118                 handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
2119                 handle_refs(submodule, revs, *flags ^ (UNINTERESTING | BOTTOM), for_each_good_bisect_ref);
2120                 revs->bisect = 1;
2121         } else if (!strcmp(arg, "--tags")) {
2122                 handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
2123                 clear_ref_exclusion(&revs->ref_excludes);
2124         } else if (!strcmp(arg, "--remotes")) {
2125                 handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
2126                 clear_ref_exclusion(&revs->ref_excludes);
2127         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2128                 struct all_refs_cb cb;
2129                 init_all_refs_cb(&cb, revs, *flags);
2130                 for_each_glob_ref(handle_one_ref, optarg, &cb);
2131                 clear_ref_exclusion(&revs->ref_excludes);
2132                 return argcount;
2133         } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2134                 add_ref_exclusion(&revs->ref_excludes, optarg);
2135                 return argcount;
2136         } else if (skip_prefix(arg, "--branches=", &optarg)) {
2137                 struct all_refs_cb cb;
2138                 init_all_refs_cb(&cb, revs, *flags);
2139                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/heads/", &cb);
2140                 clear_ref_exclusion(&revs->ref_excludes);
2141         } else if (skip_prefix(arg, "--tags=", &optarg)) {
2142                 struct all_refs_cb cb;
2143                 init_all_refs_cb(&cb, revs, *flags);
2144                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/tags/", &cb);
2145                 clear_ref_exclusion(&revs->ref_excludes);
2146         } else if (skip_prefix(arg, "--remotes=", &optarg)) {
2147                 struct all_refs_cb cb;
2148                 init_all_refs_cb(&cb, revs, *flags);
2149                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/remotes/", &cb);
2150                 clear_ref_exclusion(&revs->ref_excludes);
2151         } else if (!strcmp(arg, "--reflog")) {
2152                 add_reflogs_to_pending(revs, *flags);
2153         } else if (!strcmp(arg, "--indexed-objects")) {
2154                 add_index_objects_to_pending(revs, *flags);
2155         } else if (!strcmp(arg, "--not")) {
2156                 *flags ^= UNINTERESTING | BOTTOM;
2157         } else if (!strcmp(arg, "--no-walk")) {
2158                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2159         } else if (skip_prefix(arg, "--no-walk=", &optarg)) {
2160                 /*
2161                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2162                  * not allowed, since the argument is optional.
2163                  */
2164                 if (!strcmp(optarg, "sorted"))
2165                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2166                 else if (!strcmp(optarg, "unsorted"))
2167                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2168                 else
2169                         return error("invalid argument to --no-walk");
2170         } else if (!strcmp(arg, "--do-walk")) {
2171                 revs->no_walk = 0;
2172         } else {
2173                 return 0;
2174         }
2175
2176         return 1;
2177 }
2178
2179 static void NORETURN diagnose_missing_default(const char *def)
2180 {
2181         unsigned char sha1[20];
2182         int flags;
2183         const char *refname;
2184
2185         refname = resolve_ref_unsafe(def, 0, sha1, &flags);
2186         if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2187                 die(_("your current branch appears to be broken"));
2188
2189         skip_prefix(refname, "refs/heads/", &refname);
2190         die(_("your current branch '%s' does not have any commits yet"),
2191             refname);
2192 }
2193
2194 /*
2195  * Parse revision information, filling in the "rev_info" structure,
2196  * and removing the used arguments from the argument list.
2197  *
2198  * Returns the number of arguments left that weren't recognized
2199  * (which are also moved to the head of the argument list)
2200  */
2201 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2202 {
2203         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
2204         struct cmdline_pathspec prune_data;
2205         const char *submodule = NULL;
2206
2207         memset(&prune_data, 0, sizeof(prune_data));
2208         if (opt)
2209                 submodule = opt->submodule;
2210
2211         /* First, search for "--" */
2212         if (opt && opt->assume_dashdash) {
2213                 seen_dashdash = 1;
2214         } else {
2215                 seen_dashdash = 0;
2216                 for (i = 1; i < argc; i++) {
2217                         const char *arg = argv[i];
2218                         if (strcmp(arg, "--"))
2219                                 continue;
2220                         argv[i] = NULL;
2221                         argc = i;
2222                         if (argv[i + 1])
2223                                 append_prune_data(&prune_data, argv + i + 1);
2224                         seen_dashdash = 1;
2225                         break;
2226                 }
2227         }
2228
2229         /* Second, deal with arguments and options */
2230         flags = 0;
2231         revarg_opt = opt ? opt->revarg_opt : 0;
2232         if (seen_dashdash)
2233                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2234         read_from_stdin = 0;
2235         for (left = i = 1; i < argc; i++) {
2236                 const char *arg = argv[i];
2237                 if (*arg == '-') {
2238                         int opts;
2239
2240                         opts = handle_revision_pseudo_opt(submodule,
2241                                                 revs, argc - i, argv + i,
2242                                                 &flags);
2243                         if (opts > 0) {
2244                                 i += opts - 1;
2245                                 continue;
2246                         }
2247
2248                         if (!strcmp(arg, "--stdin")) {
2249                                 if (revs->disable_stdin) {
2250                                         argv[left++] = arg;
2251                                         continue;
2252                                 }
2253                                 if (read_from_stdin++)
2254                                         die("--stdin given twice?");
2255                                 read_revisions_from_stdin(revs, &prune_data);
2256                                 continue;
2257                         }
2258
2259                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
2260                         if (opts > 0) {
2261                                 i += opts - 1;
2262                                 continue;
2263                         }
2264                         if (opts < 0)
2265                                 exit(128);
2266                         continue;
2267                 }
2268
2269
2270                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2271                         int j;
2272                         if (seen_dashdash || *arg == '^')
2273                                 die("bad revision '%s'", arg);
2274
2275                         /* If we didn't have a "--":
2276                          * (1) all filenames must exist;
2277                          * (2) all rev-args must not be interpretable
2278                          *     as a valid filename.
2279                          * but the latter we have checked in the main loop.
2280                          */
2281                         for (j = i; j < argc; j++)
2282                                 verify_filename(revs->prefix, argv[j], j == i);
2283
2284                         append_prune_data(&prune_data, argv + i);
2285                         break;
2286                 }
2287                 else
2288                         got_rev_arg = 1;
2289         }
2290
2291         if (prune_data.nr) {
2292                 /*
2293                  * If we need to introduce the magic "a lone ':' means no
2294                  * pathspec whatsoever", here is the place to do so.
2295                  *
2296                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2297                  *      prune_data.nr = 0;
2298                  *      prune_data.alloc = 0;
2299                  *      free(prune_data.path);
2300                  *      prune_data.path = NULL;
2301                  * } else {
2302                  *      terminate prune_data.alloc with NULL and
2303                  *      call init_pathspec() to set revs->prune_data here.
2304                  * }
2305                  */
2306                 ALLOC_GROW(prune_data.path, prune_data.nr + 1, prune_data.alloc);
2307                 prune_data.path[prune_data.nr++] = NULL;
2308                 parse_pathspec(&revs->prune_data, 0, 0,
2309                                revs->prefix, prune_data.path);
2310         }
2311
2312         if (revs->def == NULL)
2313                 revs->def = opt ? opt->def : NULL;
2314         if (opt && opt->tweak)
2315                 opt->tweak(revs, opt);
2316         if (revs->show_merge)
2317                 prepare_show_merge(revs);
2318         if (revs->def && !revs->pending.nr && !got_rev_arg) {
2319                 struct object_id oid;
2320                 struct object *object;
2321                 struct object_context oc;
2322                 if (get_sha1_with_context(revs->def, 0, oid.hash, &oc))
2323                         diagnose_missing_default(revs->def);
2324                 object = get_reference(revs, revs->def, &oid, 0);
2325                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2326         }
2327
2328         /* Did the user ask for any diff output? Run the diff! */
2329         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2330                 revs->diff = 1;
2331
2332         /* Pickaxe, diff-filter and rename following need diffs */
2333         if (revs->diffopt.pickaxe ||
2334             revs->diffopt.filter ||
2335             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2336                 revs->diff = 1;
2337
2338         if (revs->topo_order)
2339                 revs->limited = 1;
2340
2341         if (revs->prune_data.nr) {
2342                 copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2343                 /* Can't prune commits with rename following: the paths change.. */
2344                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2345                         revs->prune = 1;
2346                 if (!revs->full_diff)
2347                         copy_pathspec(&revs->diffopt.pathspec,
2348                                       &revs->prune_data);
2349         }
2350         if (revs->combine_merges)
2351                 revs->ignore_merges = 0;
2352         revs->diffopt.abbrev = revs->abbrev;
2353
2354         if (revs->line_level_traverse) {
2355                 revs->limited = 1;
2356                 revs->topo_order = 1;
2357         }
2358
2359         diff_setup_done(&revs->diffopt);
2360
2361         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2362                                  &revs->grep_filter);
2363         compile_grep_patterns(&revs->grep_filter);
2364
2365         if (revs->reverse && revs->reflog_info)
2366                 die("cannot combine --reverse with --walk-reflogs");
2367         if (revs->rewrite_parents && revs->children.name)
2368                 die("cannot combine --parents and --children");
2369
2370         /*
2371          * Limitations on the graph functionality
2372          */
2373         if (revs->reverse && revs->graph)
2374                 die("cannot combine --reverse with --graph");
2375
2376         if (revs->reflog_info && revs->graph)
2377                 die("cannot combine --walk-reflogs with --graph");
2378         if (revs->no_walk && revs->graph)
2379                 die("cannot combine --no-walk with --graph");
2380         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2381                 die("cannot use --grep-reflog without --walk-reflogs");
2382
2383         if (revs->first_parent_only && revs->bisect)
2384                 die(_("--first-parent is incompatible with --bisect"));
2385
2386         if (revs->expand_tabs_in_log < 0)
2387                 revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
2388
2389         return left;
2390 }
2391
2392 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2393 {
2394         struct commit_list *l = xcalloc(1, sizeof(*l));
2395
2396         l->item = child;
2397         l->next = add_decoration(&revs->children, &parent->object, l);
2398 }
2399
2400 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2401 {
2402         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2403         struct commit_list **pp, *p;
2404         int surviving_parents;
2405
2406         /* Examine existing parents while marking ones we have seen... */
2407         pp = &commit->parents;
2408         surviving_parents = 0;
2409         while ((p = *pp) != NULL) {
2410                 struct commit *parent = p->item;
2411                 if (parent->object.flags & TMP_MARK) {
2412                         *pp = p->next;
2413                         if (ts)
2414                                 compact_treesame(revs, commit, surviving_parents);
2415                         continue;
2416                 }
2417                 parent->object.flags |= TMP_MARK;
2418                 surviving_parents++;
2419                 pp = &p->next;
2420         }
2421         /* clear the temporary mark */
2422         for (p = commit->parents; p; p = p->next) {
2423                 p->item->object.flags &= ~TMP_MARK;
2424         }
2425         /* no update_treesame() - removing duplicates can't affect TREESAME */
2426         return surviving_parents;
2427 }
2428
2429 struct merge_simplify_state {
2430         struct commit *simplified;
2431 };
2432
2433 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2434 {
2435         struct merge_simplify_state *st;
2436
2437         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2438         if (!st) {
2439                 st = xcalloc(1, sizeof(*st));
2440                 add_decoration(&revs->merge_simplification, &commit->object, st);
2441         }
2442         return st;
2443 }
2444
2445 static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2446 {
2447         struct commit_list *h = reduce_heads(commit->parents);
2448         int i = 0, marked = 0;
2449         struct commit_list *po, *pn;
2450
2451         /* Want these for sanity-checking only */
2452         int orig_cnt = commit_list_count(commit->parents);
2453         int cnt = commit_list_count(h);
2454
2455         /*
2456          * Not ready to remove items yet, just mark them for now, based
2457          * on the output of reduce_heads(). reduce_heads outputs the reduced
2458          * set in its original order, so this isn't too hard.
2459          */
2460         po = commit->parents;
2461         pn = h;
2462         while (po) {
2463                 if (pn && po->item == pn->item) {
2464                         pn = pn->next;
2465                         i++;
2466                 } else {
2467                         po->item->object.flags |= TMP_MARK;
2468                         marked++;
2469                 }
2470                 po=po->next;
2471         }
2472
2473         if (i != cnt || cnt+marked != orig_cnt)
2474                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2475
2476         free_commit_list(h);
2477
2478         return marked;
2479 }
2480
2481 static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2482 {
2483         struct commit_list *p;
2484         int marked = 0;
2485
2486         for (p = commit->parents; p; p = p->next) {
2487                 struct commit *parent = p->item;
2488                 if (!parent->parents && (parent->object.flags & TREESAME)) {
2489                         parent->object.flags |= TMP_MARK;
2490                         marked++;
2491                 }
2492         }
2493
2494         return marked;
2495 }
2496
2497 /*
2498  * Awkward naming - this means one parent we are TREESAME to.
2499  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2500  * empty tree). Better name suggestions?
2501  */
2502 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2503 {
2504         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2505         struct commit *unmarked = NULL, *marked = NULL;
2506         struct commit_list *p;
2507         unsigned n;
2508
2509         for (p = commit->parents, n = 0; p; p = p->next, n++) {
2510                 if (ts->treesame[n]) {
2511                         if (p->item->object.flags & TMP_MARK) {
2512                                 if (!marked)
2513                                         marked = p->item;
2514                         } else {
2515                                 if (!unmarked) {
2516                                         unmarked = p->item;
2517                                         break;
2518                                 }
2519                         }
2520                 }
2521         }
2522
2523         /*
2524          * If we are TREESAME to a marked-for-deletion parent, but not to any
2525          * unmarked parents, unmark the first TREESAME parent. This is the
2526          * parent that the default simplify_history==1 scan would have followed,
2527          * and it doesn't make sense to omit that path when asking for a
2528          * simplified full history. Retaining it improves the chances of
2529          * understanding odd missed merges that took an old version of a file.
2530          *
2531          * Example:
2532          *
2533          *   I--------*X       A modified the file, but mainline merge X used
2534          *    \       /        "-s ours", so took the version from I. X is
2535          *     `-*A--'         TREESAME to I and !TREESAME to A.
2536          *
2537          * Default log from X would produce "I". Without this check,
2538          * --full-history --simplify-merges would produce "I-A-X", showing
2539          * the merge commit X and that it changed A, but not making clear that
2540          * it had just taken the I version. With this check, the topology above
2541          * is retained.
2542          *
2543          * Note that it is possible that the simplification chooses a different
2544          * TREESAME parent from the default, in which case this test doesn't
2545          * activate, and we _do_ drop the default parent. Example:
2546          *
2547          *   I------X         A modified the file, but it was reverted in B,
2548          *    \    /          meaning mainline merge X is TREESAME to both
2549          *    *A-*B           parents.
2550          *
2551          * Default log would produce "I" by following the first parent;
2552          * --full-history --simplify-merges will produce "I-A-B". But this is a
2553          * reasonable result - it presents a logical full history leading from
2554          * I to X, and X is not an important merge.
2555          */
2556         if (!unmarked && marked) {
2557                 marked->object.flags &= ~TMP_MARK;
2558                 return 1;
2559         }
2560
2561         return 0;
2562 }
2563
2564 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2565 {
2566         struct commit_list **pp, *p;
2567         int nth_parent, removed = 0;
2568
2569         pp = &commit->parents;
2570         nth_parent = 0;
2571         while ((p = *pp) != NULL) {
2572                 struct commit *parent = p->item;
2573                 if (parent->object.flags & TMP_MARK) {
2574                         parent->object.flags &= ~TMP_MARK;
2575                         *pp = p->next;
2576                         free(p);
2577                         removed++;
2578                         compact_treesame(revs, commit, nth_parent);
2579                         continue;
2580                 }
2581                 pp = &p->next;
2582                 nth_parent++;
2583         }
2584
2585         /* Removing parents can only increase TREESAMEness */
2586         if (removed && !(commit->object.flags & TREESAME))
2587                 update_treesame(revs, commit);
2588
2589         return nth_parent;
2590 }
2591
2592 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2593 {
2594         struct commit_list *p;
2595         struct commit *parent;
2596         struct merge_simplify_state *st, *pst;
2597         int cnt;
2598
2599         st = locate_simplify_state(revs, commit);
2600
2601         /*
2602          * Have we handled this one?
2603          */
2604         if (st->simplified)
2605                 return tail;
2606
2607         /*
2608          * An UNINTERESTING commit simplifies to itself, so does a
2609          * root commit.  We do not rewrite parents of such commit
2610          * anyway.
2611          */
2612         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2613                 st->simplified = commit;
2614                 return tail;
2615         }
2616
2617         /*
2618          * Do we know what commit all of our parents that matter
2619          * should be rewritten to?  Otherwise we are not ready to
2620          * rewrite this one yet.
2621          */
2622         for (cnt = 0, p = commit->parents; p; p = p->next) {
2623                 pst = locate_simplify_state(revs, p->item);
2624                 if (!pst->simplified) {
2625                         tail = &commit_list_insert(p->item, tail)->next;
2626                         cnt++;
2627                 }
2628                 if (revs->first_parent_only)
2629                         break;
2630         }
2631         if (cnt) {
2632                 tail = &commit_list_insert(commit, tail)->next;
2633                 return tail;
2634         }
2635
2636         /*
2637          * Rewrite our list of parents. Note that this cannot
2638          * affect our TREESAME flags in any way - a commit is
2639          * always TREESAME to its simplification.
2640          */
2641         for (p = commit->parents; p; p = p->next) {
2642                 pst = locate_simplify_state(revs, p->item);
2643                 p->item = pst->simplified;
2644                 if (revs->first_parent_only)
2645                         break;
2646         }
2647
2648         if (revs->first_parent_only)
2649                 cnt = 1;
2650         else
2651                 cnt = remove_duplicate_parents(revs, commit);
2652
2653         /*
2654          * It is possible that we are a merge and one side branch
2655          * does not have any commit that touches the given paths;
2656          * in such a case, the immediate parent from that branch
2657          * will be rewritten to be the merge base.
2658          *
2659          *      o----X          X: the commit we are looking at;
2660          *     /    /           o: a commit that touches the paths;
2661          * ---o----'
2662          *
2663          * Further, a merge of an independent branch that doesn't
2664          * touch the path will reduce to a treesame root parent:
2665          *
2666          *  ----o----X          X: the commit we are looking at;
2667          *          /           o: a commit that touches the paths;
2668          *         r            r: a root commit not touching the paths
2669          *
2670          * Detect and simplify both cases.
2671          */
2672         if (1 < cnt) {
2673                 int marked = mark_redundant_parents(revs, commit);
2674                 marked += mark_treesame_root_parents(revs, commit);
2675                 if (marked)
2676                         marked -= leave_one_treesame_to_parent(revs, commit);
2677                 if (marked)
2678                         cnt = remove_marked_parents(revs, commit);
2679         }
2680
2681         /*
2682          * A commit simplifies to itself if it is a root, if it is
2683          * UNINTERESTING, if it touches the given paths, or if it is a
2684          * merge and its parents don't simplify to one relevant commit
2685          * (the first two cases are already handled at the beginning of
2686          * this function).
2687          *
2688          * Otherwise, it simplifies to what its sole relevant parent
2689          * simplifies to.
2690          */
2691         if (!cnt ||
2692             (commit->object.flags & UNINTERESTING) ||
2693             !(commit->object.flags & TREESAME) ||
2694             (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2695                 st->simplified = commit;
2696         else {
2697                 pst = locate_simplify_state(revs, parent);
2698                 st->simplified = pst->simplified;
2699         }
2700         return tail;
2701 }
2702
2703 static void simplify_merges(struct rev_info *revs)
2704 {
2705         struct commit_list *list, *next;
2706         struct commit_list *yet_to_do, **tail;
2707         struct commit *commit;
2708
2709         if (!revs->prune)
2710                 return;
2711
2712         /* feed the list reversed */
2713         yet_to_do = NULL;
2714         for (list = revs->commits; list; list = next) {
2715                 commit = list->item;
2716                 next = list->next;
2717                 /*
2718                  * Do not free(list) here yet; the original list
2719                  * is used later in this function.
2720                  */
2721                 commit_list_insert(commit, &yet_to_do);
2722         }
2723         while (yet_to_do) {
2724                 list = yet_to_do;
2725                 yet_to_do = NULL;
2726                 tail = &yet_to_do;
2727                 while (list) {
2728                         commit = pop_commit(&list);
2729                         tail = simplify_one(revs, commit, tail);
2730                 }
2731         }
2732
2733         /* clean up the result, removing the simplified ones */
2734         list = revs->commits;
2735         revs->commits = NULL;
2736         tail = &revs->commits;
2737         while (list) {
2738                 struct merge_simplify_state *st;
2739
2740                 commit = pop_commit(&list);
2741                 st = locate_simplify_state(revs, commit);
2742                 if (st->simplified == commit)
2743                         tail = &commit_list_insert(commit, tail)->next;
2744         }
2745 }
2746
2747 static void set_children(struct rev_info *revs)
2748 {
2749         struct commit_list *l;
2750         for (l = revs->commits; l; l = l->next) {
2751                 struct commit *commit = l->item;
2752                 struct commit_list *p;
2753
2754                 for (p = commit->parents; p; p = p->next)
2755                         add_child(revs, p->item, commit);
2756         }
2757 }
2758
2759 void reset_revision_walk(void)
2760 {
2761         clear_object_flags(SEEN | ADDED | SHOWN);
2762 }
2763
2764 int prepare_revision_walk(struct rev_info *revs)
2765 {
2766         int i;
2767         struct object_array old_pending;
2768         struct commit_list **next = &revs->commits;
2769
2770         memcpy(&old_pending, &revs->pending, sizeof(old_pending));
2771         revs->pending.nr = 0;
2772         revs->pending.alloc = 0;
2773         revs->pending.objects = NULL;
2774         for (i = 0; i < old_pending.nr; i++) {
2775                 struct object_array_entry *e = old_pending.objects + i;
2776                 struct commit *commit = handle_commit(revs, e);
2777                 if (commit) {
2778                         if (!(commit->object.flags & SEEN)) {
2779                                 commit->object.flags |= SEEN;
2780                                 next = commit_list_append(commit, next);
2781                         }
2782                 }
2783         }
2784         if (!revs->leak_pending)
2785                 object_array_clear(&old_pending);
2786
2787         /* Signal whether we need per-parent treesame decoration */
2788         if (revs->simplify_merges ||
2789             (revs->limited && limiting_can_increase_treesame(revs)))
2790                 revs->treesame.name = "treesame";
2791
2792         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2793                 commit_list_sort_by_date(&revs->commits);
2794         if (revs->no_walk)
2795                 return 0;
2796         if (revs->limited)
2797                 if (limit_list(revs) < 0)
2798                         return -1;
2799         if (revs->topo_order)
2800                 sort_in_topological_order(&revs->commits, revs->sort_order);
2801         if (revs->line_level_traverse)
2802                 line_log_filter(revs);
2803         if (revs->simplify_merges)
2804                 simplify_merges(revs);
2805         if (revs->children.name)
2806                 set_children(revs);
2807         return 0;
2808 }
2809
2810 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2811 {
2812         struct commit_list *cache = NULL;
2813
2814         for (;;) {
2815                 struct commit *p = *pp;
2816                 if (!revs->limited)
2817                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2818                                 return rewrite_one_error;
2819                 if (p->object.flags & UNINTERESTING)
2820                         return rewrite_one_ok;
2821                 if (!(p->object.flags & TREESAME))
2822                         return rewrite_one_ok;
2823                 if (!p->parents)
2824                         return rewrite_one_noparents;
2825                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2826                         return rewrite_one_ok;
2827                 *pp = p;
2828         }
2829 }
2830
2831 int rewrite_parents(struct rev_info *revs, struct commit *commit,
2832         rewrite_parent_fn_t rewrite_parent)
2833 {
2834         struct commit_list **pp = &commit->parents;
2835         while (*pp) {
2836                 struct commit_list *parent = *pp;
2837                 switch (rewrite_parent(revs, &parent->item)) {
2838                 case rewrite_one_ok:
2839                         break;
2840                 case rewrite_one_noparents:
2841                         *pp = parent->next;
2842                         continue;
2843                 case rewrite_one_error:
2844                         return -1;
2845                 }
2846                 pp = &parent->next;
2847         }
2848         remove_duplicate_parents(revs, commit);
2849         return 0;
2850 }
2851
2852 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2853 {
2854         char *person, *endp;
2855         size_t len, namelen, maillen;
2856         const char *name;
2857         const char *mail;
2858         struct ident_split ident;
2859
2860         person = strstr(buf->buf, what);
2861         if (!person)
2862                 return 0;
2863
2864         person += strlen(what);
2865         endp = strchr(person, '\n');
2866         if (!endp)
2867                 return 0;
2868
2869         len = endp - person;
2870
2871         if (split_ident_line(&ident, person, len))
2872                 return 0;
2873
2874         mail = ident.mail_begin;
2875         maillen = ident.mail_end - ident.mail_begin;
2876         name = ident.name_begin;
2877         namelen = ident.name_end - ident.name_begin;
2878
2879         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2880                 struct strbuf namemail = STRBUF_INIT;
2881
2882                 strbuf_addf(&namemail, "%.*s <%.*s>",
2883                             (int)namelen, name, (int)maillen, mail);
2884
2885                 strbuf_splice(buf, ident.name_begin - buf->buf,
2886                               ident.mail_end - ident.name_begin + 1,
2887                               namemail.buf, namemail.len);
2888
2889                 strbuf_release(&namemail);
2890
2891                 return 1;
2892         }
2893
2894         return 0;
2895 }
2896
2897 static int commit_match(struct commit *commit, struct rev_info *opt)
2898 {
2899         int retval;
2900         const char *encoding;
2901         const char *message;
2902         struct strbuf buf = STRBUF_INIT;
2903
2904         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2905                 return 1;
2906
2907         /* Prepend "fake" headers as needed */
2908         if (opt->grep_filter.use_reflog_filter) {
2909                 strbuf_addstr(&buf, "reflog ");
2910                 get_reflog_message(&buf, opt->reflog_info);
2911                 strbuf_addch(&buf, '\n');
2912         }
2913
2914         /*
2915          * We grep in the user's output encoding, under the assumption that it
2916          * is the encoding they are most likely to write their grep pattern
2917          * for. In addition, it means we will match the "notes" encoding below,
2918          * so we will not end up with a buffer that has two different encodings
2919          * in it.
2920          */
2921         encoding = get_log_output_encoding();
2922         message = logmsg_reencode(commit, NULL, encoding);
2923
2924         /* Copy the commit to temporary if we are using "fake" headers */
2925         if (buf.len)
2926                 strbuf_addstr(&buf, message);
2927
2928         if (opt->grep_filter.header_list && opt->mailmap) {
2929                 if (!buf.len)
2930                         strbuf_addstr(&buf, message);
2931
2932                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2933                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2934         }
2935
2936         /* Append "fake" message parts as needed */
2937         if (opt->show_notes) {
2938                 if (!buf.len)
2939                         strbuf_addstr(&buf, message);
2940                 format_display_notes(&commit->object.oid, &buf, encoding, 1);
2941         }
2942
2943         /*
2944          * Find either in the original commit message, or in the temporary.
2945          * Note that we cast away the constness of "message" here. It is
2946          * const because it may come from the cached commit buffer. That's OK,
2947          * because we know that it is modifiable heap memory, and that while
2948          * grep_buffer may modify it for speed, it will restore any
2949          * changes before returning.
2950          */
2951         if (buf.len)
2952                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2953         else
2954                 retval = grep_buffer(&opt->grep_filter,
2955                                      (char *)message, strlen(message));
2956         strbuf_release(&buf);
2957         unuse_commit_buffer(commit, message);
2958         return opt->invert_grep ? !retval : retval;
2959 }
2960
2961 static inline int want_ancestry(const struct rev_info *revs)
2962 {
2963         return (revs->rewrite_parents || revs->children.name);
2964 }
2965
2966 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2967 {
2968         if (commit->object.flags & SHOWN)
2969                 return commit_ignore;
2970         if (revs->unpacked && has_sha1_pack(commit->object.oid.hash))
2971                 return commit_ignore;
2972         if (revs->show_all)
2973                 return commit_show;
2974         if (commit->object.flags & UNINTERESTING)
2975                 return commit_ignore;
2976         if (revs->min_age != -1 && (commit->date > revs->min_age))
2977                 return commit_ignore;
2978         if (revs->min_parents || (revs->max_parents >= 0)) {
2979                 int n = commit_list_count(commit->parents);
2980                 if ((n < revs->min_parents) ||
2981                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2982                         return commit_ignore;
2983         }
2984         if (!commit_match(commit, revs))
2985                 return commit_ignore;
2986         if (revs->prune && revs->dense) {
2987                 /* Commit without changes? */
2988                 if (commit->object.flags & TREESAME) {
2989                         int n;
2990                         struct commit_list *p;
2991                         /* drop merges unless we want parenthood */
2992                         if (!want_ancestry(revs))
2993                                 return commit_ignore;
2994                         /*
2995                          * If we want ancestry, then need to keep any merges
2996                          * between relevant commits to tie together topology.
2997                          * For consistency with TREESAME and simplification
2998                          * use "relevant" here rather than just INTERESTING,
2999                          * to treat bottom commit(s) as part of the topology.
3000                          */
3001                         for (n = 0, p = commit->parents; p; p = p->next)
3002                                 if (relevant_commit(p->item))
3003                                         if (++n >= 2)
3004                                                 return commit_show;
3005                         return commit_ignore;
3006                 }
3007         }
3008         return commit_show;
3009 }
3010
3011 define_commit_slab(saved_parents, struct commit_list *);
3012
3013 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3014
3015 /*
3016  * You may only call save_parents() once per commit (this is checked
3017  * for non-root commits).
3018  */
3019 static void save_parents(struct rev_info *revs, struct commit *commit)
3020 {
3021         struct commit_list **pp;
3022
3023         if (!revs->saved_parents_slab) {
3024                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3025                 init_saved_parents(revs->saved_parents_slab);
3026         }
3027
3028         pp = saved_parents_at(revs->saved_parents_slab, commit);
3029
3030         /*
3031          * When walking with reflogs, we may visit the same commit
3032          * several times: once for each appearance in the reflog.
3033          *
3034          * In this case, save_parents() will be called multiple times.
3035          * We want to keep only the first set of parents.  We need to
3036          * store a sentinel value for an empty (i.e., NULL) parent
3037          * list to distinguish it from a not-yet-saved list, however.
3038          */
3039         if (*pp)
3040                 return;
3041         if (commit->parents)
3042                 *pp = copy_commit_list(commit->parents);
3043         else
3044                 *pp = EMPTY_PARENT_LIST;
3045 }
3046
3047 static void free_saved_parents(struct rev_info *revs)
3048 {
3049         if (revs->saved_parents_slab)
3050                 clear_saved_parents(revs->saved_parents_slab);
3051 }
3052
3053 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3054 {
3055         struct commit_list *parents;
3056
3057         if (!revs->saved_parents_slab)
3058                 return commit->parents;
3059
3060         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3061         if (parents == EMPTY_PARENT_LIST)
3062                 return NULL;
3063         return parents;
3064 }
3065
3066 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3067 {
3068         enum commit_action action = get_commit_action(revs, commit);
3069
3070         if (action == commit_show &&
3071             !revs->show_all &&
3072             revs->prune && revs->dense && want_ancestry(revs)) {
3073                 /*
3074                  * --full-diff on simplified parents is no good: it
3075                  * will show spurious changes from the commits that
3076                  * were elided.  So we save the parents on the side
3077                  * when --full-diff is in effect.
3078                  */
3079                 if (revs->full_diff)
3080                         save_parents(revs, commit);
3081                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
3082                         return commit_error;
3083         }
3084         return action;
3085 }
3086
3087 static void track_linear(struct rev_info *revs, struct commit *commit)
3088 {
3089         if (revs->track_first_time) {
3090                 revs->linear = 1;
3091                 revs->track_first_time = 0;
3092         } else {
3093                 struct commit_list *p;
3094                 for (p = revs->previous_parents; p; p = p->next)
3095                         if (p->item == NULL || /* first commit */
3096                             !oidcmp(&p->item->object.oid, &commit->object.oid))
3097                                 break;
3098                 revs->linear = p != NULL;
3099         }
3100         if (revs->reverse) {
3101                 if (revs->linear)
3102                         commit->object.flags |= TRACK_LINEAR;
3103         }
3104         free_commit_list(revs->previous_parents);
3105         revs->previous_parents = copy_commit_list(commit->parents);
3106 }
3107
3108 static struct commit *get_revision_1(struct rev_info *revs)
3109 {
3110         if (!revs->commits)
3111                 return NULL;
3112
3113         do {
3114                 struct commit *commit = pop_commit(&revs->commits);
3115
3116                 if (revs->reflog_info) {
3117                         save_parents(revs, commit);
3118                         fake_reflog_parent(revs->reflog_info, commit);
3119                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3120                 }
3121
3122                 /*
3123                  * If we haven't done the list limiting, we need to look at
3124                  * the parents here. We also need to do the date-based limiting
3125                  * that we'd otherwise have done in limit_list().
3126                  */
3127                 if (!revs->limited) {
3128                         if (revs->max_age != -1 &&
3129                             (commit->date < revs->max_age))
3130                                 continue;
3131                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
3132                                 if (!revs->ignore_missing_links)
3133                                         die("Failed to traverse parents of commit %s",
3134                                                 oid_to_hex(&commit->object.oid));
3135                         }
3136                 }
3137
3138                 switch (simplify_commit(revs, commit)) {
3139                 case commit_ignore:
3140                         continue;
3141                 case commit_error:
3142                         die("Failed to simplify parents of commit %s",
3143                             oid_to_hex(&commit->object.oid));
3144                 default:
3145                         if (revs->track_linear)
3146                                 track_linear(revs, commit);
3147                         return commit;
3148                 }
3149         } while (revs->commits);
3150         return NULL;
3151 }
3152
3153 /*
3154  * Return true for entries that have not yet been shown.  (This is an
3155  * object_array_each_func_t.)
3156  */
3157 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3158 {
3159         return !(entry->item->flags & SHOWN);
3160 }
3161
3162 /*
3163  * If array is on the verge of a realloc, garbage-collect any entries
3164  * that have already been shown to try to free up some space.
3165  */
3166 static void gc_boundary(struct object_array *array)
3167 {
3168         if (array->nr == array->alloc)
3169                 object_array_filter(array, entry_unshown, NULL);
3170 }
3171
3172 static void create_boundary_commit_list(struct rev_info *revs)
3173 {
3174         unsigned i;
3175         struct commit *c;
3176         struct object_array *array = &revs->boundary_commits;
3177         struct object_array_entry *objects = array->objects;
3178
3179         /*
3180          * If revs->commits is non-NULL at this point, an error occurred in
3181          * get_revision_1().  Ignore the error and continue printing the
3182          * boundary commits anyway.  (This is what the code has always
3183          * done.)
3184          */
3185         if (revs->commits) {
3186                 free_commit_list(revs->commits);
3187                 revs->commits = NULL;
3188         }
3189
3190         /*
3191          * Put all of the actual boundary commits from revs->boundary_commits
3192          * into revs->commits
3193          */
3194         for (i = 0; i < array->nr; i++) {
3195                 c = (struct commit *)(objects[i].item);
3196                 if (!c)
3197                         continue;
3198                 if (!(c->object.flags & CHILD_SHOWN))
3199                         continue;
3200                 if (c->object.flags & (SHOWN | BOUNDARY))
3201                         continue;
3202                 c->object.flags |= BOUNDARY;
3203                 commit_list_insert(c, &revs->commits);
3204         }
3205
3206         /*
3207          * If revs->topo_order is set, sort the boundary commits
3208          * in topological order
3209          */
3210         sort_in_topological_order(&revs->commits, revs->sort_order);
3211 }
3212
3213 static struct commit *get_revision_internal(struct rev_info *revs)
3214 {
3215         struct commit *c = NULL;
3216         struct commit_list *l;
3217
3218         if (revs->boundary == 2) {
3219                 /*
3220                  * All of the normal commits have already been returned,
3221                  * and we are now returning boundary commits.
3222                  * create_boundary_commit_list() has populated
3223                  * revs->commits with the remaining commits to return.
3224                  */
3225                 c = pop_commit(&revs->commits);
3226                 if (c)
3227                         c->object.flags |= SHOWN;
3228                 return c;
3229         }
3230
3231         /*
3232          * If our max_count counter has reached zero, then we are done. We
3233          * don't simply return NULL because we still might need to show
3234          * boundary commits. But we want to avoid calling get_revision_1, which
3235          * might do a considerable amount of work finding the next commit only
3236          * for us to throw it away.
3237          *
3238          * If it is non-zero, then either we don't have a max_count at all
3239          * (-1), or it is still counting, in which case we decrement.
3240          */
3241         if (revs->max_count) {
3242                 c = get_revision_1(revs);
3243                 if (c) {
3244                         while (revs->skip_count > 0) {
3245                                 revs->skip_count--;
3246                                 c = get_revision_1(revs);
3247                                 if (!c)
3248                                         break;
3249                         }
3250                 }
3251
3252                 if (revs->max_count > 0)
3253                         revs->max_count--;
3254         }
3255
3256         if (c)
3257                 c->object.flags |= SHOWN;
3258
3259         if (!revs->boundary)
3260                 return c;
3261
3262         if (!c) {
3263                 /*
3264                  * get_revision_1() runs out the commits, and
3265                  * we are done computing the boundaries.
3266                  * switch to boundary commits output mode.
3267                  */
3268                 revs->boundary = 2;
3269
3270                 /*
3271                  * Update revs->commits to contain the list of
3272                  * boundary commits.
3273                  */
3274                 create_boundary_commit_list(revs);
3275
3276                 return get_revision_internal(revs);
3277         }
3278
3279         /*
3280          * boundary commits are the commits that are parents of the
3281          * ones we got from get_revision_1() but they themselves are
3282          * not returned from get_revision_1().  Before returning
3283          * 'c', we need to mark its parents that they could be boundaries.
3284          */
3285
3286         for (l = c->parents; l; l = l->next) {
3287                 struct object *p;
3288                 p = &(l->item->object);
3289                 if (p->flags & (CHILD_SHOWN | SHOWN))
3290                         continue;
3291                 p->flags |= CHILD_SHOWN;
3292                 gc_boundary(&revs->boundary_commits);
3293                 add_object_array(p, NULL, &revs->boundary_commits);
3294         }
3295
3296         return c;
3297 }
3298
3299 struct commit *get_revision(struct rev_info *revs)
3300 {
3301         struct commit *c;
3302         struct commit_list *reversed;
3303
3304         if (revs->reverse) {
3305                 reversed = NULL;
3306                 while ((c = get_revision_internal(revs)))
3307                         commit_list_insert(c, &reversed);
3308                 revs->commits = reversed;
3309                 revs->reverse = 0;
3310                 revs->reverse_output_stage = 1;
3311         }
3312
3313         if (revs->reverse_output_stage) {
3314                 c = pop_commit(&revs->commits);
3315                 if (revs->track_linear)
3316                         revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
3317                 return c;
3318         }
3319
3320         c = get_revision_internal(revs);
3321         if (c && revs->graph)
3322                 graph_update(revs->graph, c);
3323         if (!c) {
3324                 free_saved_parents(revs);
3325                 if (revs->previous_parents) {
3326                         free_commit_list(revs->previous_parents);
3327                         revs->previous_parents = NULL;
3328                 }
3329         }
3330         return c;
3331 }
3332
3333 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3334 {
3335         if (commit->object.flags & BOUNDARY)
3336                 return "-";
3337         else if (commit->object.flags & UNINTERESTING)
3338                 return "^";
3339         else if (commit->object.flags & PATCHSAME)
3340                 return "=";
3341         else if (!revs || revs->left_right) {
3342                 if (commit->object.flags & SYMMETRIC_LEFT)
3343                         return "<";
3344                 else
3345                         return ">";
3346         } else if (revs->graph)
3347                 return "*";
3348         else if (revs->cherry_mark)
3349                 return "+";
3350         return "";
3351 }
3352
3353 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3354 {
3355         char *mark = get_revision_mark(revs, commit);
3356         if (!strlen(mark))
3357                 return;
3358         fputs(mark, stdout);
3359         putchar(' ');
3360 }