Merge branch 'ah/log-decorate-default-to-auto'
[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->hash));
63                         break;
64                 case OBJ_BLOB:
65                         mark_blob_uninteresting(lookup_blob(entry.oid->hash));
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         unsigned char sha1[20];
181         struct object *obj;
182         if (get_sha1("HEAD", sha1))
183                 return;
184         obj = parse_object(sha1);
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 unsigned char *sha1,
192                                     unsigned int flags)
193 {
194         struct object *object;
195
196         object = parse_object(sha1);
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_sha1(struct rev_info *revs, const char *name,
207                       const unsigned char *sha1, unsigned int flags)
208 {
209         struct object *object = get_reference(revs, name, sha1, 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.hash);
232                 if (!object) {
233                         if (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 unsigned char *sha1,
405                     int sha1_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 unsigned char *old_sha1,
418                  const unsigned char *new_sha1,
419                  int old_sha1_valid, int new_sha1_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_sha1(t1->object.oid.hash, t2->object.oid.hash, "",
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_sha1(NULL, t1->object.oid.hash, "", &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, NULL))
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->hash, cb->all_flags);
1161         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1162         add_pending_sha1(cb->all_revs, path, oid->hash, 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->hash);
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->sha1);
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.hash);
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         unsigned char sha1[20];
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, sha1))
1307                 return 0;
1308         while (1) {
1309                 it = get_reference(revs, arg, sha1, 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                 hashcpy(sha1, ((struct tag*)it)->tagged->oid.hash);
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         revs->grep_filter.regflags = REG_NEWLINE;
1366
1367         diff_setup(&revs->diffopt);
1368         if (prefix && !revs->diffopt.prefix) {
1369                 revs->diffopt.prefix = prefix;
1370                 revs->diffopt.prefix_length = strlen(prefix);
1371         }
1372
1373         revs->notes_opt.use_default_notes = -1;
1374 }
1375
1376 static void add_pending_commit_list(struct rev_info *revs,
1377                                     struct commit_list *commit_list,
1378                                     unsigned int flags)
1379 {
1380         while (commit_list) {
1381                 struct object *object = &commit_list->item->object;
1382                 object->flags |= flags;
1383                 add_pending_object(revs, object, oid_to_hex(&object->oid));
1384                 commit_list = commit_list->next;
1385         }
1386 }
1387
1388 static void prepare_show_merge(struct rev_info *revs)
1389 {
1390         struct commit_list *bases;
1391         struct commit *head, *other;
1392         unsigned char sha1[20];
1393         const char **prune = NULL;
1394         int i, prune_num = 1; /* counting terminating NULL */
1395
1396         if (get_sha1("HEAD", sha1))
1397                 die("--merge without HEAD?");
1398         head = lookup_commit_or_die(sha1, "HEAD");
1399         if (get_sha1("MERGE_HEAD", sha1))
1400                 die("--merge without MERGE_HEAD?");
1401         other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1402         add_pending_object(revs, &head->object, "HEAD");
1403         add_pending_object(revs, &other->object, "MERGE_HEAD");
1404         bases = get_merge_bases(head, other);
1405         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1406         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1407         free_commit_list(bases);
1408         head->object.flags |= SYMMETRIC_LEFT;
1409
1410         if (!active_nr)
1411                 read_cache();
1412         for (i = 0; i < active_nr; i++) {
1413                 const struct cache_entry *ce = active_cache[i];
1414                 if (!ce_stage(ce))
1415                         continue;
1416                 if (ce_path_match(ce, &revs->prune_data, NULL)) {
1417                         prune_num++;
1418                         REALLOC_ARRAY(prune, prune_num);
1419                         prune[prune_num-2] = ce->name;
1420                         prune[prune_num-1] = NULL;
1421                 }
1422                 while ((i+1 < active_nr) &&
1423                        ce_same_name(ce, active_cache[i+1]))
1424                         i++;
1425         }
1426         clear_pathspec(&revs->prune_data);
1427         parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1428                        PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1429         revs->limited = 1;
1430 }
1431
1432 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1433 {
1434         struct object_context oc;
1435         char *dotdot;
1436         struct object *object;
1437         unsigned char sha1[20];
1438         int local_flags;
1439         const char *arg = arg_;
1440         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1441         unsigned get_sha1_flags = 0;
1442
1443         flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1444
1445         dotdot = strstr(arg, "..");
1446         if (dotdot) {
1447                 unsigned char from_sha1[20];
1448                 const char *next = dotdot + 2;
1449                 const char *this = arg;
1450                 int symmetric = *next == '.';
1451                 unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1452                 static const char head_by_default[] = "HEAD";
1453                 unsigned int a_flags;
1454
1455                 *dotdot = 0;
1456                 next += symmetric;
1457
1458                 if (!*next)
1459                         next = head_by_default;
1460                 if (dotdot == arg)
1461                         this = head_by_default;
1462                 if (this == head_by_default && next == head_by_default &&
1463                     !symmetric) {
1464                         /*
1465                          * Just ".."?  That is not a range but the
1466                          * pathspec for the parent directory.
1467                          */
1468                         if (!cant_be_filename) {
1469                                 *dotdot = '.';
1470                                 return -1;
1471                         }
1472                 }
1473                 if (!get_sha1_committish(this, from_sha1) &&
1474                     !get_sha1_committish(next, sha1)) {
1475                         struct object *a_obj, *b_obj;
1476
1477                         if (!cant_be_filename) {
1478                                 *dotdot = '.';
1479                                 verify_non_filename(revs->prefix, arg);
1480                         }
1481
1482                         a_obj = parse_object(from_sha1);
1483                         b_obj = parse_object(sha1);
1484                         if (!a_obj || !b_obj) {
1485                         missing:
1486                                 if (revs->ignore_missing)
1487                                         return 0;
1488                                 die(symmetric
1489                                     ? "Invalid symmetric difference expression %s"
1490                                     : "Invalid revision range %s", arg);
1491                         }
1492
1493                         if (!symmetric) {
1494                                 /* just A..B */
1495                                 a_flags = flags_exclude;
1496                         } else {
1497                                 /* A...B -- find merge bases between the two */
1498                                 struct commit *a, *b;
1499                                 struct commit_list *exclude;
1500
1501                                 a = (a_obj->type == OBJ_COMMIT
1502                                      ? (struct commit *)a_obj
1503                                      : lookup_commit_reference(a_obj->oid.hash));
1504                                 b = (b_obj->type == OBJ_COMMIT
1505                                      ? (struct commit *)b_obj
1506                                      : lookup_commit_reference(b_obj->oid.hash));
1507                                 if (!a || !b)
1508                                         goto missing;
1509                                 exclude = get_merge_bases(a, b);
1510                                 add_rev_cmdline_list(revs, exclude,
1511                                                      REV_CMD_MERGE_BASE,
1512                                                      flags_exclude);
1513                                 add_pending_commit_list(revs, exclude,
1514                                                         flags_exclude);
1515                                 free_commit_list(exclude);
1516
1517                                 a_flags = flags | SYMMETRIC_LEFT;
1518                         }
1519
1520                         a_obj->flags |= a_flags;
1521                         b_obj->flags |= flags;
1522                         add_rev_cmdline(revs, a_obj, this,
1523                                         REV_CMD_LEFT, a_flags);
1524                         add_rev_cmdline(revs, b_obj, next,
1525                                         REV_CMD_RIGHT, flags);
1526                         add_pending_object(revs, a_obj, this);
1527                         add_pending_object(revs, b_obj, next);
1528                         return 0;
1529                 }
1530                 *dotdot = '.';
1531         }
1532
1533         dotdot = strstr(arg, "^@");
1534         if (dotdot && !dotdot[2]) {
1535                 *dotdot = 0;
1536                 if (add_parents_only(revs, arg, flags, 0))
1537                         return 0;
1538                 *dotdot = '^';
1539         }
1540         dotdot = strstr(arg, "^!");
1541         if (dotdot && !dotdot[2]) {
1542                 *dotdot = 0;
1543                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
1544                         *dotdot = '^';
1545         }
1546         dotdot = strstr(arg, "^-");
1547         if (dotdot) {
1548                 int exclude_parent = 1;
1549
1550                 if (dotdot[2]) {
1551                         char *end;
1552                         exclude_parent = strtoul(dotdot + 2, &end, 10);
1553                         if (*end != '\0' || !exclude_parent)
1554                                 return -1;
1555                 }
1556
1557                 *dotdot = 0;
1558                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
1559                         *dotdot = '^';
1560         }
1561
1562         local_flags = 0;
1563         if (*arg == '^') {
1564                 local_flags = UNINTERESTING | BOTTOM;
1565                 arg++;
1566         }
1567
1568         if (revarg_opt & REVARG_COMMITTISH)
1569                 get_sha1_flags = GET_SHA1_COMMITTISH;
1570
1571         if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1572                 return revs->ignore_missing ? 0 : -1;
1573         if (!cant_be_filename)
1574                 verify_non_filename(revs->prefix, arg);
1575         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1576         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1577         add_pending_object_with_mode(revs, object, arg, oc.mode);
1578         return 0;
1579 }
1580
1581 struct cmdline_pathspec {
1582         int alloc;
1583         int nr;
1584         const char **path;
1585 };
1586
1587 static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1588 {
1589         while (*av) {
1590                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1591                 prune->path[prune->nr++] = *(av++);
1592         }
1593 }
1594
1595 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1596                                      struct cmdline_pathspec *prune)
1597 {
1598         while (strbuf_getline(sb, stdin) != EOF) {
1599                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1600                 prune->path[prune->nr++] = xstrdup(sb->buf);
1601         }
1602 }
1603
1604 static void read_revisions_from_stdin(struct rev_info *revs,
1605                                       struct cmdline_pathspec *prune)
1606 {
1607         struct strbuf sb;
1608         int seen_dashdash = 0;
1609         int save_warning;
1610
1611         save_warning = warn_on_object_refname_ambiguity;
1612         warn_on_object_refname_ambiguity = 0;
1613
1614         strbuf_init(&sb, 1000);
1615         while (strbuf_getline(&sb, stdin) != EOF) {
1616                 int len = sb.len;
1617                 if (!len)
1618                         break;
1619                 if (sb.buf[0] == '-') {
1620                         if (len == 2 && sb.buf[1] == '-') {
1621                                 seen_dashdash = 1;
1622                                 break;
1623                         }
1624                         die("options not supported in --stdin mode");
1625                 }
1626                 if (handle_revision_arg(sb.buf, revs, 0,
1627                                         REVARG_CANNOT_BE_FILENAME))
1628                         die("bad revision '%s'", sb.buf);
1629         }
1630         if (seen_dashdash)
1631                 read_pathspec_from_stdin(revs, &sb, prune);
1632
1633         strbuf_release(&sb);
1634         warn_on_object_refname_ambiguity = save_warning;
1635 }
1636
1637 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1638 {
1639         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1640 }
1641
1642 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1643 {
1644         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1645 }
1646
1647 static void add_message_grep(struct rev_info *revs, const char *pattern)
1648 {
1649         add_grep(revs, pattern, GREP_PATTERN_BODY);
1650 }
1651
1652 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1653                                int *unkc, const char **unkv)
1654 {
1655         const char *arg = argv[0];
1656         const char *optarg;
1657         int argcount;
1658
1659         /* pseudo revision arguments */
1660         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1661             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1662             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1663             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1664             !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
1665             !strcmp(arg, "--indexed-objects") ||
1666             starts_with(arg, "--exclude=") ||
1667             starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
1668             starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
1669         {
1670                 unkv[(*unkc)++] = arg;
1671                 return 1;
1672         }
1673
1674         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1675                 revs->max_count = atoi(optarg);
1676                 revs->no_walk = 0;
1677                 return argcount;
1678         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1679                 revs->skip_count = atoi(optarg);
1680                 return argcount;
1681         } else if ((*arg == '-') && isdigit(arg[1])) {
1682                 /* accept -<digit>, like traditional "head" */
1683                 if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
1684                     revs->max_count < 0)
1685                         die("'%s': not a non-negative integer", arg + 1);
1686                 revs->no_walk = 0;
1687         } else if (!strcmp(arg, "-n")) {
1688                 if (argc <= 1)
1689                         return error("-n requires an argument");
1690                 revs->max_count = atoi(argv[1]);
1691                 revs->no_walk = 0;
1692                 return 2;
1693         } else if (starts_with(arg, "-n")) {
1694                 revs->max_count = atoi(arg + 2);
1695                 revs->no_walk = 0;
1696         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1697                 revs->max_age = atoi(optarg);
1698                 return argcount;
1699         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1700                 revs->max_age = approxidate(optarg);
1701                 return argcount;
1702         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1703                 revs->max_age = approxidate(optarg);
1704                 return argcount;
1705         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1706                 revs->min_age = atoi(optarg);
1707                 return argcount;
1708         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1709                 revs->min_age = approxidate(optarg);
1710                 return argcount;
1711         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1712                 revs->min_age = approxidate(optarg);
1713                 return argcount;
1714         } else if (!strcmp(arg, "--first-parent")) {
1715                 revs->first_parent_only = 1;
1716         } else if (!strcmp(arg, "--ancestry-path")) {
1717                 revs->ancestry_path = 1;
1718                 revs->simplify_history = 0;
1719                 revs->limited = 1;
1720         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1721                 init_reflog_walk(&revs->reflog_info);
1722         } else if (!strcmp(arg, "--default")) {
1723                 if (argc <= 1)
1724                         return error("bad --default argument");
1725                 revs->def = argv[1];
1726                 return 2;
1727         } else if (!strcmp(arg, "--merge")) {
1728                 revs->show_merge = 1;
1729         } else if (!strcmp(arg, "--topo-order")) {
1730                 revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1731                 revs->topo_order = 1;
1732         } else if (!strcmp(arg, "--simplify-merges")) {
1733                 revs->simplify_merges = 1;
1734                 revs->topo_order = 1;
1735                 revs->rewrite_parents = 1;
1736                 revs->simplify_history = 0;
1737                 revs->limited = 1;
1738         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1739                 revs->simplify_merges = 1;
1740                 revs->topo_order = 1;
1741                 revs->rewrite_parents = 1;
1742                 revs->simplify_history = 0;
1743                 revs->simplify_by_decoration = 1;
1744                 revs->limited = 1;
1745                 revs->prune = 1;
1746                 load_ref_decorations(DECORATE_SHORT_REFS);
1747         } else if (!strcmp(arg, "--date-order")) {
1748                 revs->sort_order = REV_SORT_BY_COMMIT_DATE;
1749                 revs->topo_order = 1;
1750         } else if (!strcmp(arg, "--author-date-order")) {
1751                 revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
1752                 revs->topo_order = 1;
1753         } else if (starts_with(arg, "--early-output")) {
1754                 int count = 100;
1755                 switch (arg[14]) {
1756                 case '=':
1757                         count = atoi(arg+15);
1758                         /* Fallthrough */
1759                 case 0:
1760                         revs->topo_order = 1;
1761                        revs->early_output = count;
1762                 }
1763         } else if (!strcmp(arg, "--parents")) {
1764                 revs->rewrite_parents = 1;
1765                 revs->print_parents = 1;
1766         } else if (!strcmp(arg, "--dense")) {
1767                 revs->dense = 1;
1768         } else if (!strcmp(arg, "--sparse")) {
1769                 revs->dense = 0;
1770         } else if (!strcmp(arg, "--show-all")) {
1771                 revs->show_all = 1;
1772         } else if (!strcmp(arg, "--remove-empty")) {
1773                 revs->remove_empty_trees = 1;
1774         } else if (!strcmp(arg, "--merges")) {
1775                 revs->min_parents = 2;
1776         } else if (!strcmp(arg, "--no-merges")) {
1777                 revs->max_parents = 1;
1778         } else if (starts_with(arg, "--min-parents=")) {
1779                 revs->min_parents = atoi(arg+14);
1780         } else if (starts_with(arg, "--no-min-parents")) {
1781                 revs->min_parents = 0;
1782         } else if (starts_with(arg, "--max-parents=")) {
1783                 revs->max_parents = atoi(arg+14);
1784         } else if (starts_with(arg, "--no-max-parents")) {
1785                 revs->max_parents = -1;
1786         } else if (!strcmp(arg, "--boundary")) {
1787                 revs->boundary = 1;
1788         } else if (!strcmp(arg, "--left-right")) {
1789                 revs->left_right = 1;
1790         } else if (!strcmp(arg, "--left-only")) {
1791                 if (revs->right_only)
1792                         die("--left-only is incompatible with --right-only"
1793                             " or --cherry");
1794                 revs->left_only = 1;
1795         } else if (!strcmp(arg, "--right-only")) {
1796                 if (revs->left_only)
1797                         die("--right-only is incompatible with --left-only");
1798                 revs->right_only = 1;
1799         } else if (!strcmp(arg, "--cherry")) {
1800                 if (revs->left_only)
1801                         die("--cherry is incompatible with --left-only");
1802                 revs->cherry_mark = 1;
1803                 revs->right_only = 1;
1804                 revs->max_parents = 1;
1805                 revs->limited = 1;
1806         } else if (!strcmp(arg, "--count")) {
1807                 revs->count = 1;
1808         } else if (!strcmp(arg, "--cherry-mark")) {
1809                 if (revs->cherry_pick)
1810                         die("--cherry-mark is incompatible with --cherry-pick");
1811                 revs->cherry_mark = 1;
1812                 revs->limited = 1; /* needs limit_list() */
1813         } else if (!strcmp(arg, "--cherry-pick")) {
1814                 if (revs->cherry_mark)
1815                         die("--cherry-pick is incompatible with --cherry-mark");
1816                 revs->cherry_pick = 1;
1817                 revs->limited = 1;
1818         } else if (!strcmp(arg, "--objects")) {
1819                 revs->tag_objects = 1;
1820                 revs->tree_objects = 1;
1821                 revs->blob_objects = 1;
1822         } else if (!strcmp(arg, "--objects-edge")) {
1823                 revs->tag_objects = 1;
1824                 revs->tree_objects = 1;
1825                 revs->blob_objects = 1;
1826                 revs->edge_hint = 1;
1827         } else if (!strcmp(arg, "--objects-edge-aggressive")) {
1828                 revs->tag_objects = 1;
1829                 revs->tree_objects = 1;
1830                 revs->blob_objects = 1;
1831                 revs->edge_hint = 1;
1832                 revs->edge_hint_aggressive = 1;
1833         } else if (!strcmp(arg, "--verify-objects")) {
1834                 revs->tag_objects = 1;
1835                 revs->tree_objects = 1;
1836                 revs->blob_objects = 1;
1837                 revs->verify_objects = 1;
1838         } else if (!strcmp(arg, "--unpacked")) {
1839                 revs->unpacked = 1;
1840         } else if (starts_with(arg, "--unpacked=")) {
1841                 die("--unpacked=<packfile> no longer supported.");
1842         } else if (!strcmp(arg, "-r")) {
1843                 revs->diff = 1;
1844                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1845         } else if (!strcmp(arg, "-t")) {
1846                 revs->diff = 1;
1847                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1848                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1849         } else if (!strcmp(arg, "-m")) {
1850                 revs->ignore_merges = 0;
1851         } else if (!strcmp(arg, "-c")) {
1852                 revs->diff = 1;
1853                 revs->dense_combined_merges = 0;
1854                 revs->combine_merges = 1;
1855         } else if (!strcmp(arg, "--cc")) {
1856                 revs->diff = 1;
1857                 revs->dense_combined_merges = 1;
1858                 revs->combine_merges = 1;
1859         } else if (!strcmp(arg, "-v")) {
1860                 revs->verbose_header = 1;
1861         } else if (!strcmp(arg, "--pretty")) {
1862                 revs->verbose_header = 1;
1863                 revs->pretty_given = 1;
1864                 get_commit_format(NULL, revs);
1865         } else if (starts_with(arg, "--pretty=") || starts_with(arg, "--format=")) {
1866                 /*
1867                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1868                  * not allowed, since the argument is optional.
1869                  */
1870                 revs->verbose_header = 1;
1871                 revs->pretty_given = 1;
1872                 get_commit_format(arg+9, revs);
1873         } else if (!strcmp(arg, "--expand-tabs")) {
1874                 revs->expand_tabs_in_log = 8;
1875         } else if (!strcmp(arg, "--no-expand-tabs")) {
1876                 revs->expand_tabs_in_log = 0;
1877         } else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
1878                 int val;
1879                 if (strtol_i(arg, 10, &val) < 0 || val < 0)
1880                         die("'%s': not a non-negative integer", arg);
1881                 revs->expand_tabs_in_log = val;
1882         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1883                 revs->show_notes = 1;
1884                 revs->show_notes_given = 1;
1885                 revs->notes_opt.use_default_notes = 1;
1886         } else if (!strcmp(arg, "--show-signature")) {
1887                 revs->show_signature = 1;
1888         } else if (!strcmp(arg, "--no-show-signature")) {
1889                 revs->show_signature = 0;
1890         } else if (!strcmp(arg, "--show-linear-break") ||
1891                    starts_with(arg, "--show-linear-break=")) {
1892                 if (starts_with(arg, "--show-linear-break="))
1893                         revs->break_bar = xstrdup(arg + 20);
1894                 else
1895                         revs->break_bar = "                    ..........";
1896                 revs->track_linear = 1;
1897                 revs->track_first_time = 1;
1898         } else if (starts_with(arg, "--show-notes=") ||
1899                    starts_with(arg, "--notes=")) {
1900                 struct strbuf buf = STRBUF_INIT;
1901                 revs->show_notes = 1;
1902                 revs->show_notes_given = 1;
1903                 if (starts_with(arg, "--show-notes")) {
1904                         if (revs->notes_opt.use_default_notes < 0)
1905                                 revs->notes_opt.use_default_notes = 1;
1906                         strbuf_addstr(&buf, arg+13);
1907                 }
1908                 else
1909                         strbuf_addstr(&buf, arg+8);
1910                 expand_notes_ref(&buf);
1911                 string_list_append(&revs->notes_opt.extra_notes_refs,
1912                                    strbuf_detach(&buf, NULL));
1913         } else if (!strcmp(arg, "--no-notes")) {
1914                 revs->show_notes = 0;
1915                 revs->show_notes_given = 1;
1916                 revs->notes_opt.use_default_notes = -1;
1917                 /* we have been strdup'ing ourselves, so trick
1918                  * string_list into free()ing strings */
1919                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1920                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1921                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1922         } else if (!strcmp(arg, "--standard-notes")) {
1923                 revs->show_notes_given = 1;
1924                 revs->notes_opt.use_default_notes = 1;
1925         } else if (!strcmp(arg, "--no-standard-notes")) {
1926                 revs->notes_opt.use_default_notes = 0;
1927         } else if (!strcmp(arg, "--oneline")) {
1928                 revs->verbose_header = 1;
1929                 get_commit_format("oneline", revs);
1930                 revs->pretty_given = 1;
1931                 revs->abbrev_commit = 1;
1932         } else if (!strcmp(arg, "--graph")) {
1933                 revs->topo_order = 1;
1934                 revs->rewrite_parents = 1;
1935                 revs->graph = graph_init(revs);
1936         } else if (!strcmp(arg, "--root")) {
1937                 revs->show_root_diff = 1;
1938         } else if (!strcmp(arg, "--no-commit-id")) {
1939                 revs->no_commit_id = 1;
1940         } else if (!strcmp(arg, "--always")) {
1941                 revs->always_show_header = 1;
1942         } else if (!strcmp(arg, "--no-abbrev")) {
1943                 revs->abbrev = 0;
1944         } else if (!strcmp(arg, "--abbrev")) {
1945                 revs->abbrev = DEFAULT_ABBREV;
1946         } else if (starts_with(arg, "--abbrev=")) {
1947                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1948                 if (revs->abbrev < MINIMUM_ABBREV)
1949                         revs->abbrev = MINIMUM_ABBREV;
1950                 else if (revs->abbrev > 40)
1951                         revs->abbrev = 40;
1952         } else if (!strcmp(arg, "--abbrev-commit")) {
1953                 revs->abbrev_commit = 1;
1954                 revs->abbrev_commit_given = 1;
1955         } else if (!strcmp(arg, "--no-abbrev-commit")) {
1956                 revs->abbrev_commit = 0;
1957         } else if (!strcmp(arg, "--full-diff")) {
1958                 revs->diff = 1;
1959                 revs->full_diff = 1;
1960         } else if (!strcmp(arg, "--full-history")) {
1961                 revs->simplify_history = 0;
1962         } else if (!strcmp(arg, "--relative-date")) {
1963                 revs->date_mode.type = DATE_RELATIVE;
1964                 revs->date_mode_explicit = 1;
1965         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1966                 parse_date_format(optarg, &revs->date_mode);
1967                 revs->date_mode_explicit = 1;
1968                 return argcount;
1969         } else if (!strcmp(arg, "--log-size")) {
1970                 revs->show_log_size = 1;
1971         }
1972         /*
1973          * Grepping the commit log
1974          */
1975         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1976                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1977                 return argcount;
1978         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1979                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1980                 return argcount;
1981         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
1982                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
1983                 return argcount;
1984         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1985                 add_message_grep(revs, optarg);
1986                 return argcount;
1987         } else if (!strcmp(arg, "--grep-debug")) {
1988                 revs->grep_filter.debug = 1;
1989         } else if (!strcmp(arg, "--basic-regexp")) {
1990                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_BRE;
1991         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1992                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
1993         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1994                 revs->grep_filter.regflags |= REG_ICASE;
1995                 DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
1996         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1997                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
1998         } else if (!strcmp(arg, "--perl-regexp")) {
1999                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_PCRE;
2000         } else if (!strcmp(arg, "--all-match")) {
2001                 revs->grep_filter.all_match = 1;
2002         } else if (!strcmp(arg, "--invert-grep")) {
2003                 revs->invert_grep = 1;
2004         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2005                 if (strcmp(optarg, "none"))
2006                         git_log_output_encoding = xstrdup(optarg);
2007                 else
2008                         git_log_output_encoding = "";
2009                 return argcount;
2010         } else if (!strcmp(arg, "--reverse")) {
2011                 revs->reverse ^= 1;
2012         } else if (!strcmp(arg, "--children")) {
2013                 revs->children.name = "children";
2014                 revs->limited = 1;
2015         } else if (!strcmp(arg, "--ignore-missing")) {
2016                 revs->ignore_missing = 1;
2017         } else {
2018                 int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
2019                 if (!opts)
2020                         unkv[(*unkc)++] = arg;
2021                 return opts;
2022         }
2023         if (revs->graph && revs->track_linear)
2024                 die("--show-linear-break and --graph are incompatible");
2025
2026         return 1;
2027 }
2028
2029 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2030                         const struct option *options,
2031                         const char * const usagestr[])
2032 {
2033         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2034                                     &ctx->cpidx, ctx->out);
2035         if (n <= 0) {
2036                 error("unknown option `%s'", ctx->argv[0]);
2037                 usage_with_options(usagestr, options);
2038         }
2039         ctx->argv += n;
2040         ctx->argc -= n;
2041 }
2042
2043 static int for_each_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data, const char *term) {
2044         struct strbuf bisect_refs = STRBUF_INIT;
2045         int status;
2046         strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2047         status = for_each_ref_in_submodule(submodule, bisect_refs.buf, fn, cb_data);
2048         strbuf_release(&bisect_refs);
2049         return status;
2050 }
2051
2052 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2053 {
2054         return for_each_bisect_ref(submodule, fn, cb_data, term_bad);
2055 }
2056
2057 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2058 {
2059         return for_each_bisect_ref(submodule, fn, cb_data, term_good);
2060 }
2061
2062 static int handle_revision_pseudo_opt(const char *submodule,
2063                                 struct rev_info *revs,
2064                                 int argc, const char **argv, int *flags)
2065 {
2066         const char *arg = argv[0];
2067         const char *optarg;
2068         int argcount;
2069
2070         /*
2071          * NOTE!
2072          *
2073          * Commands like "git shortlog" will not accept the options below
2074          * unless parse_revision_opt queues them (as opposed to erroring
2075          * out).
2076          *
2077          * When implementing your new pseudo-option, remember to
2078          * register it in the list at the top of handle_revision_opt.
2079          */
2080         if (!strcmp(arg, "--all")) {
2081                 handle_refs(submodule, revs, *flags, for_each_ref_submodule);
2082                 handle_refs(submodule, revs, *flags, head_ref_submodule);
2083                 clear_ref_exclusion(&revs->ref_excludes);
2084         } else if (!strcmp(arg, "--branches")) {
2085                 handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
2086                 clear_ref_exclusion(&revs->ref_excludes);
2087         } else if (!strcmp(arg, "--bisect")) {
2088                 read_bisect_terms(&term_bad, &term_good);
2089                 handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
2090                 handle_refs(submodule, revs, *flags ^ (UNINTERESTING | BOTTOM), for_each_good_bisect_ref);
2091                 revs->bisect = 1;
2092         } else if (!strcmp(arg, "--tags")) {
2093                 handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
2094                 clear_ref_exclusion(&revs->ref_excludes);
2095         } else if (!strcmp(arg, "--remotes")) {
2096                 handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
2097                 clear_ref_exclusion(&revs->ref_excludes);
2098         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2099                 struct all_refs_cb cb;
2100                 init_all_refs_cb(&cb, revs, *flags);
2101                 for_each_glob_ref(handle_one_ref, optarg, &cb);
2102                 clear_ref_exclusion(&revs->ref_excludes);
2103                 return argcount;
2104         } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2105                 add_ref_exclusion(&revs->ref_excludes, optarg);
2106                 return argcount;
2107         } else if (starts_with(arg, "--branches=")) {
2108                 struct all_refs_cb cb;
2109                 init_all_refs_cb(&cb, revs, *flags);
2110                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
2111                 clear_ref_exclusion(&revs->ref_excludes);
2112         } else if (starts_with(arg, "--tags=")) {
2113                 struct all_refs_cb cb;
2114                 init_all_refs_cb(&cb, revs, *flags);
2115                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
2116                 clear_ref_exclusion(&revs->ref_excludes);
2117         } else if (starts_with(arg, "--remotes=")) {
2118                 struct all_refs_cb cb;
2119                 init_all_refs_cb(&cb, revs, *flags);
2120                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
2121                 clear_ref_exclusion(&revs->ref_excludes);
2122         } else if (!strcmp(arg, "--reflog")) {
2123                 add_reflogs_to_pending(revs, *flags);
2124         } else if (!strcmp(arg, "--indexed-objects")) {
2125                 add_index_objects_to_pending(revs, *flags);
2126         } else if (!strcmp(arg, "--not")) {
2127                 *flags ^= UNINTERESTING | BOTTOM;
2128         } else if (!strcmp(arg, "--no-walk")) {
2129                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2130         } else if (starts_with(arg, "--no-walk=")) {
2131                 /*
2132                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2133                  * not allowed, since the argument is optional.
2134                  */
2135                 if (!strcmp(arg + 10, "sorted"))
2136                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2137                 else if (!strcmp(arg + 10, "unsorted"))
2138                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2139                 else
2140                         return error("invalid argument to --no-walk");
2141         } else if (!strcmp(arg, "--do-walk")) {
2142                 revs->no_walk = 0;
2143         } else {
2144                 return 0;
2145         }
2146
2147         return 1;
2148 }
2149
2150 static void NORETURN diagnose_missing_default(const char *def)
2151 {
2152         unsigned char sha1[20];
2153         int flags;
2154         const char *refname;
2155
2156         refname = resolve_ref_unsafe(def, 0, sha1, &flags);
2157         if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2158                 die(_("your current branch appears to be broken"));
2159
2160         skip_prefix(refname, "refs/heads/", &refname);
2161         die(_("your current branch '%s' does not have any commits yet"),
2162             refname);
2163 }
2164
2165 /*
2166  * Parse revision information, filling in the "rev_info" structure,
2167  * and removing the used arguments from the argument list.
2168  *
2169  * Returns the number of arguments left that weren't recognized
2170  * (which are also moved to the head of the argument list)
2171  */
2172 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2173 {
2174         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
2175         struct cmdline_pathspec prune_data;
2176         const char *submodule = NULL;
2177
2178         memset(&prune_data, 0, sizeof(prune_data));
2179         if (opt)
2180                 submodule = opt->submodule;
2181
2182         /* First, search for "--" */
2183         if (opt && opt->assume_dashdash) {
2184                 seen_dashdash = 1;
2185         } else {
2186                 seen_dashdash = 0;
2187                 for (i = 1; i < argc; i++) {
2188                         const char *arg = argv[i];
2189                         if (strcmp(arg, "--"))
2190                                 continue;
2191                         argv[i] = NULL;
2192                         argc = i;
2193                         if (argv[i + 1])
2194                                 append_prune_data(&prune_data, argv + i + 1);
2195                         seen_dashdash = 1;
2196                         break;
2197                 }
2198         }
2199
2200         /* Second, deal with arguments and options */
2201         flags = 0;
2202         revarg_opt = opt ? opt->revarg_opt : 0;
2203         if (seen_dashdash)
2204                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2205         read_from_stdin = 0;
2206         for (left = i = 1; i < argc; i++) {
2207                 const char *arg = argv[i];
2208                 if (*arg == '-') {
2209                         int opts;
2210
2211                         opts = handle_revision_pseudo_opt(submodule,
2212                                                 revs, argc - i, argv + i,
2213                                                 &flags);
2214                         if (opts > 0) {
2215                                 i += opts - 1;
2216                                 continue;
2217                         }
2218
2219                         if (!strcmp(arg, "--stdin")) {
2220                                 if (revs->disable_stdin) {
2221                                         argv[left++] = arg;
2222                                         continue;
2223                                 }
2224                                 if (read_from_stdin++)
2225                                         die("--stdin given twice?");
2226                                 read_revisions_from_stdin(revs, &prune_data);
2227                                 continue;
2228                         }
2229
2230                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
2231                         if (opts > 0) {
2232                                 i += opts - 1;
2233                                 continue;
2234                         }
2235                         if (opts < 0)
2236                                 exit(128);
2237                         continue;
2238                 }
2239
2240
2241                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2242                         int j;
2243                         if (seen_dashdash || *arg == '^')
2244                                 die("bad revision '%s'", arg);
2245
2246                         /* If we didn't have a "--":
2247                          * (1) all filenames must exist;
2248                          * (2) all rev-args must not be interpretable
2249                          *     as a valid filename.
2250                          * but the latter we have checked in the main loop.
2251                          */
2252                         for (j = i; j < argc; j++)
2253                                 verify_filename(revs->prefix, argv[j], j == i);
2254
2255                         append_prune_data(&prune_data, argv + i);
2256                         break;
2257                 }
2258                 else
2259                         got_rev_arg = 1;
2260         }
2261
2262         if (prune_data.nr) {
2263                 /*
2264                  * If we need to introduce the magic "a lone ':' means no
2265                  * pathspec whatsoever", here is the place to do so.
2266                  *
2267                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2268                  *      prune_data.nr = 0;
2269                  *      prune_data.alloc = 0;
2270                  *      free(prune_data.path);
2271                  *      prune_data.path = NULL;
2272                  * } else {
2273                  *      terminate prune_data.alloc with NULL and
2274                  *      call init_pathspec() to set revs->prune_data here.
2275                  * }
2276                  */
2277                 ALLOC_GROW(prune_data.path, prune_data.nr + 1, prune_data.alloc);
2278                 prune_data.path[prune_data.nr++] = NULL;
2279                 parse_pathspec(&revs->prune_data, 0, 0,
2280                                revs->prefix, prune_data.path);
2281         }
2282
2283         if (revs->def == NULL)
2284                 revs->def = opt ? opt->def : NULL;
2285         if (opt && opt->tweak)
2286                 opt->tweak(revs, opt);
2287         if (revs->show_merge)
2288                 prepare_show_merge(revs);
2289         if (revs->def && !revs->pending.nr && !got_rev_arg) {
2290                 unsigned char sha1[20];
2291                 struct object *object;
2292                 struct object_context oc;
2293                 if (get_sha1_with_context(revs->def, 0, sha1, &oc))
2294                         diagnose_missing_default(revs->def);
2295                 object = get_reference(revs, revs->def, sha1, 0);
2296                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2297         }
2298
2299         /* Did the user ask for any diff output? Run the diff! */
2300         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2301                 revs->diff = 1;
2302
2303         /* Pickaxe, diff-filter and rename following need diffs */
2304         if (revs->diffopt.pickaxe ||
2305             revs->diffopt.filter ||
2306             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2307                 revs->diff = 1;
2308
2309         if (revs->topo_order)
2310                 revs->limited = 1;
2311
2312         if (revs->prune_data.nr) {
2313                 copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2314                 /* Can't prune commits with rename following: the paths change.. */
2315                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2316                         revs->prune = 1;
2317                 if (!revs->full_diff)
2318                         copy_pathspec(&revs->diffopt.pathspec,
2319                                       &revs->prune_data);
2320         }
2321         if (revs->combine_merges)
2322                 revs->ignore_merges = 0;
2323         revs->diffopt.abbrev = revs->abbrev;
2324
2325         if (revs->line_level_traverse) {
2326                 revs->limited = 1;
2327                 revs->topo_order = 1;
2328         }
2329
2330         diff_setup_done(&revs->diffopt);
2331
2332         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2333                                  &revs->grep_filter);
2334         compile_grep_patterns(&revs->grep_filter);
2335
2336         if (revs->reverse && revs->reflog_info)
2337                 die("cannot combine --reverse with --walk-reflogs");
2338         if (revs->rewrite_parents && revs->children.name)
2339                 die("cannot combine --parents and --children");
2340
2341         /*
2342          * Limitations on the graph functionality
2343          */
2344         if (revs->reverse && revs->graph)
2345                 die("cannot combine --reverse with --graph");
2346
2347         if (revs->reflog_info && revs->graph)
2348                 die("cannot combine --walk-reflogs with --graph");
2349         if (revs->no_walk && revs->graph)
2350                 die("cannot combine --no-walk with --graph");
2351         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2352                 die("cannot use --grep-reflog without --walk-reflogs");
2353
2354         if (revs->first_parent_only && revs->bisect)
2355                 die(_("--first-parent is incompatible with --bisect"));
2356
2357         if (revs->expand_tabs_in_log < 0)
2358                 revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
2359
2360         return left;
2361 }
2362
2363 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2364 {
2365         struct commit_list *l = xcalloc(1, sizeof(*l));
2366
2367         l->item = child;
2368         l->next = add_decoration(&revs->children, &parent->object, l);
2369 }
2370
2371 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2372 {
2373         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2374         struct commit_list **pp, *p;
2375         int surviving_parents;
2376
2377         /* Examine existing parents while marking ones we have seen... */
2378         pp = &commit->parents;
2379         surviving_parents = 0;
2380         while ((p = *pp) != NULL) {
2381                 struct commit *parent = p->item;
2382                 if (parent->object.flags & TMP_MARK) {
2383                         *pp = p->next;
2384                         if (ts)
2385                                 compact_treesame(revs, commit, surviving_parents);
2386                         continue;
2387                 }
2388                 parent->object.flags |= TMP_MARK;
2389                 surviving_parents++;
2390                 pp = &p->next;
2391         }
2392         /* clear the temporary mark */
2393         for (p = commit->parents; p; p = p->next) {
2394                 p->item->object.flags &= ~TMP_MARK;
2395         }
2396         /* no update_treesame() - removing duplicates can't affect TREESAME */
2397         return surviving_parents;
2398 }
2399
2400 struct merge_simplify_state {
2401         struct commit *simplified;
2402 };
2403
2404 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2405 {
2406         struct merge_simplify_state *st;
2407
2408         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2409         if (!st) {
2410                 st = xcalloc(1, sizeof(*st));
2411                 add_decoration(&revs->merge_simplification, &commit->object, st);
2412         }
2413         return st;
2414 }
2415
2416 static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2417 {
2418         struct commit_list *h = reduce_heads(commit->parents);
2419         int i = 0, marked = 0;
2420         struct commit_list *po, *pn;
2421
2422         /* Want these for sanity-checking only */
2423         int orig_cnt = commit_list_count(commit->parents);
2424         int cnt = commit_list_count(h);
2425
2426         /*
2427          * Not ready to remove items yet, just mark them for now, based
2428          * on the output of reduce_heads(). reduce_heads outputs the reduced
2429          * set in its original order, so this isn't too hard.
2430          */
2431         po = commit->parents;
2432         pn = h;
2433         while (po) {
2434                 if (pn && po->item == pn->item) {
2435                         pn = pn->next;
2436                         i++;
2437                 } else {
2438                         po->item->object.flags |= TMP_MARK;
2439                         marked++;
2440                 }
2441                 po=po->next;
2442         }
2443
2444         if (i != cnt || cnt+marked != orig_cnt)
2445                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2446
2447         free_commit_list(h);
2448
2449         return marked;
2450 }
2451
2452 static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2453 {
2454         struct commit_list *p;
2455         int marked = 0;
2456
2457         for (p = commit->parents; p; p = p->next) {
2458                 struct commit *parent = p->item;
2459                 if (!parent->parents && (parent->object.flags & TREESAME)) {
2460                         parent->object.flags |= TMP_MARK;
2461                         marked++;
2462                 }
2463         }
2464
2465         return marked;
2466 }
2467
2468 /*
2469  * Awkward naming - this means one parent we are TREESAME to.
2470  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2471  * empty tree). Better name suggestions?
2472  */
2473 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2474 {
2475         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2476         struct commit *unmarked = NULL, *marked = NULL;
2477         struct commit_list *p;
2478         unsigned n;
2479
2480         for (p = commit->parents, n = 0; p; p = p->next, n++) {
2481                 if (ts->treesame[n]) {
2482                         if (p->item->object.flags & TMP_MARK) {
2483                                 if (!marked)
2484                                         marked = p->item;
2485                         } else {
2486                                 if (!unmarked) {
2487                                         unmarked = p->item;
2488                                         break;
2489                                 }
2490                         }
2491                 }
2492         }
2493
2494         /*
2495          * If we are TREESAME to a marked-for-deletion parent, but not to any
2496          * unmarked parents, unmark the first TREESAME parent. This is the
2497          * parent that the default simplify_history==1 scan would have followed,
2498          * and it doesn't make sense to omit that path when asking for a
2499          * simplified full history. Retaining it improves the chances of
2500          * understanding odd missed merges that took an old version of a file.
2501          *
2502          * Example:
2503          *
2504          *   I--------*X       A modified the file, but mainline merge X used
2505          *    \       /        "-s ours", so took the version from I. X is
2506          *     `-*A--'         TREESAME to I and !TREESAME to A.
2507          *
2508          * Default log from X would produce "I". Without this check,
2509          * --full-history --simplify-merges would produce "I-A-X", showing
2510          * the merge commit X and that it changed A, but not making clear that
2511          * it had just taken the I version. With this check, the topology above
2512          * is retained.
2513          *
2514          * Note that it is possible that the simplification chooses a different
2515          * TREESAME parent from the default, in which case this test doesn't
2516          * activate, and we _do_ drop the default parent. Example:
2517          *
2518          *   I------X         A modified the file, but it was reverted in B,
2519          *    \    /          meaning mainline merge X is TREESAME to both
2520          *    *A-*B           parents.
2521          *
2522          * Default log would produce "I" by following the first parent;
2523          * --full-history --simplify-merges will produce "I-A-B". But this is a
2524          * reasonable result - it presents a logical full history leading from
2525          * I to X, and X is not an important merge.
2526          */
2527         if (!unmarked && marked) {
2528                 marked->object.flags &= ~TMP_MARK;
2529                 return 1;
2530         }
2531
2532         return 0;
2533 }
2534
2535 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2536 {
2537         struct commit_list **pp, *p;
2538         int nth_parent, removed = 0;
2539
2540         pp = &commit->parents;
2541         nth_parent = 0;
2542         while ((p = *pp) != NULL) {
2543                 struct commit *parent = p->item;
2544                 if (parent->object.flags & TMP_MARK) {
2545                         parent->object.flags &= ~TMP_MARK;
2546                         *pp = p->next;
2547                         free(p);
2548                         removed++;
2549                         compact_treesame(revs, commit, nth_parent);
2550                         continue;
2551                 }
2552                 pp = &p->next;
2553                 nth_parent++;
2554         }
2555
2556         /* Removing parents can only increase TREESAMEness */
2557         if (removed && !(commit->object.flags & TREESAME))
2558                 update_treesame(revs, commit);
2559
2560         return nth_parent;
2561 }
2562
2563 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2564 {
2565         struct commit_list *p;
2566         struct commit *parent;
2567         struct merge_simplify_state *st, *pst;
2568         int cnt;
2569
2570         st = locate_simplify_state(revs, commit);
2571
2572         /*
2573          * Have we handled this one?
2574          */
2575         if (st->simplified)
2576                 return tail;
2577
2578         /*
2579          * An UNINTERESTING commit simplifies to itself, so does a
2580          * root commit.  We do not rewrite parents of such commit
2581          * anyway.
2582          */
2583         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2584                 st->simplified = commit;
2585                 return tail;
2586         }
2587
2588         /*
2589          * Do we know what commit all of our parents that matter
2590          * should be rewritten to?  Otherwise we are not ready to
2591          * rewrite this one yet.
2592          */
2593         for (cnt = 0, p = commit->parents; p; p = p->next) {
2594                 pst = locate_simplify_state(revs, p->item);
2595                 if (!pst->simplified) {
2596                         tail = &commit_list_insert(p->item, tail)->next;
2597                         cnt++;
2598                 }
2599                 if (revs->first_parent_only)
2600                         break;
2601         }
2602         if (cnt) {
2603                 tail = &commit_list_insert(commit, tail)->next;
2604                 return tail;
2605         }
2606
2607         /*
2608          * Rewrite our list of parents. Note that this cannot
2609          * affect our TREESAME flags in any way - a commit is
2610          * always TREESAME to its simplification.
2611          */
2612         for (p = commit->parents; p; p = p->next) {
2613                 pst = locate_simplify_state(revs, p->item);
2614                 p->item = pst->simplified;
2615                 if (revs->first_parent_only)
2616                         break;
2617         }
2618
2619         if (revs->first_parent_only)
2620                 cnt = 1;
2621         else
2622                 cnt = remove_duplicate_parents(revs, commit);
2623
2624         /*
2625          * It is possible that we are a merge and one side branch
2626          * does not have any commit that touches the given paths;
2627          * in such a case, the immediate parent from that branch
2628          * will be rewritten to be the merge base.
2629          *
2630          *      o----X          X: the commit we are looking at;
2631          *     /    /           o: a commit that touches the paths;
2632          * ---o----'
2633          *
2634          * Further, a merge of an independent branch that doesn't
2635          * touch the path will reduce to a treesame root parent:
2636          *
2637          *  ----o----X          X: the commit we are looking at;
2638          *          /           o: a commit that touches the paths;
2639          *         r            r: a root commit not touching the paths
2640          *
2641          * Detect and simplify both cases.
2642          */
2643         if (1 < cnt) {
2644                 int marked = mark_redundant_parents(revs, commit);
2645                 marked += mark_treesame_root_parents(revs, commit);
2646                 if (marked)
2647                         marked -= leave_one_treesame_to_parent(revs, commit);
2648                 if (marked)
2649                         cnt = remove_marked_parents(revs, commit);
2650         }
2651
2652         /*
2653          * A commit simplifies to itself if it is a root, if it is
2654          * UNINTERESTING, if it touches the given paths, or if it is a
2655          * merge and its parents don't simplify to one relevant commit
2656          * (the first two cases are already handled at the beginning of
2657          * this function).
2658          *
2659          * Otherwise, it simplifies to what its sole relevant parent
2660          * simplifies to.
2661          */
2662         if (!cnt ||
2663             (commit->object.flags & UNINTERESTING) ||
2664             !(commit->object.flags & TREESAME) ||
2665             (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2666                 st->simplified = commit;
2667         else {
2668                 pst = locate_simplify_state(revs, parent);
2669                 st->simplified = pst->simplified;
2670         }
2671         return tail;
2672 }
2673
2674 static void simplify_merges(struct rev_info *revs)
2675 {
2676         struct commit_list *list, *next;
2677         struct commit_list *yet_to_do, **tail;
2678         struct commit *commit;
2679
2680         if (!revs->prune)
2681                 return;
2682
2683         /* feed the list reversed */
2684         yet_to_do = NULL;
2685         for (list = revs->commits; list; list = next) {
2686                 commit = list->item;
2687                 next = list->next;
2688                 /*
2689                  * Do not free(list) here yet; the original list
2690                  * is used later in this function.
2691                  */
2692                 commit_list_insert(commit, &yet_to_do);
2693         }
2694         while (yet_to_do) {
2695                 list = yet_to_do;
2696                 yet_to_do = NULL;
2697                 tail = &yet_to_do;
2698                 while (list) {
2699                         commit = pop_commit(&list);
2700                         tail = simplify_one(revs, commit, tail);
2701                 }
2702         }
2703
2704         /* clean up the result, removing the simplified ones */
2705         list = revs->commits;
2706         revs->commits = NULL;
2707         tail = &revs->commits;
2708         while (list) {
2709                 struct merge_simplify_state *st;
2710
2711                 commit = pop_commit(&list);
2712                 st = locate_simplify_state(revs, commit);
2713                 if (st->simplified == commit)
2714                         tail = &commit_list_insert(commit, tail)->next;
2715         }
2716 }
2717
2718 static void set_children(struct rev_info *revs)
2719 {
2720         struct commit_list *l;
2721         for (l = revs->commits; l; l = l->next) {
2722                 struct commit *commit = l->item;
2723                 struct commit_list *p;
2724
2725                 for (p = commit->parents; p; p = p->next)
2726                         add_child(revs, p->item, commit);
2727         }
2728 }
2729
2730 void reset_revision_walk(void)
2731 {
2732         clear_object_flags(SEEN | ADDED | SHOWN);
2733 }
2734
2735 int prepare_revision_walk(struct rev_info *revs)
2736 {
2737         int i;
2738         struct object_array old_pending;
2739         struct commit_list **next = &revs->commits;
2740
2741         memcpy(&old_pending, &revs->pending, sizeof(old_pending));
2742         revs->pending.nr = 0;
2743         revs->pending.alloc = 0;
2744         revs->pending.objects = NULL;
2745         for (i = 0; i < old_pending.nr; i++) {
2746                 struct object_array_entry *e = old_pending.objects + i;
2747                 struct commit *commit = handle_commit(revs, e);
2748                 if (commit) {
2749                         if (!(commit->object.flags & SEEN)) {
2750                                 commit->object.flags |= SEEN;
2751                                 next = commit_list_append(commit, next);
2752                         }
2753                 }
2754         }
2755         if (!revs->leak_pending)
2756                 object_array_clear(&old_pending);
2757
2758         /* Signal whether we need per-parent treesame decoration */
2759         if (revs->simplify_merges ||
2760             (revs->limited && limiting_can_increase_treesame(revs)))
2761                 revs->treesame.name = "treesame";
2762
2763         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2764                 commit_list_sort_by_date(&revs->commits);
2765         if (revs->no_walk)
2766                 return 0;
2767         if (revs->limited)
2768                 if (limit_list(revs) < 0)
2769                         return -1;
2770         if (revs->topo_order)
2771                 sort_in_topological_order(&revs->commits, revs->sort_order);
2772         if (revs->line_level_traverse)
2773                 line_log_filter(revs);
2774         if (revs->simplify_merges)
2775                 simplify_merges(revs);
2776         if (revs->children.name)
2777                 set_children(revs);
2778         return 0;
2779 }
2780
2781 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2782 {
2783         struct commit_list *cache = NULL;
2784
2785         for (;;) {
2786                 struct commit *p = *pp;
2787                 if (!revs->limited)
2788                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2789                                 return rewrite_one_error;
2790                 if (p->object.flags & UNINTERESTING)
2791                         return rewrite_one_ok;
2792                 if (!(p->object.flags & TREESAME))
2793                         return rewrite_one_ok;
2794                 if (!p->parents)
2795                         return rewrite_one_noparents;
2796                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2797                         return rewrite_one_ok;
2798                 *pp = p;
2799         }
2800 }
2801
2802 int rewrite_parents(struct rev_info *revs, struct commit *commit,
2803         rewrite_parent_fn_t rewrite_parent)
2804 {
2805         struct commit_list **pp = &commit->parents;
2806         while (*pp) {
2807                 struct commit_list *parent = *pp;
2808                 switch (rewrite_parent(revs, &parent->item)) {
2809                 case rewrite_one_ok:
2810                         break;
2811                 case rewrite_one_noparents:
2812                         *pp = parent->next;
2813                         continue;
2814                 case rewrite_one_error:
2815                         return -1;
2816                 }
2817                 pp = &parent->next;
2818         }
2819         remove_duplicate_parents(revs, commit);
2820         return 0;
2821 }
2822
2823 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2824 {
2825         char *person, *endp;
2826         size_t len, namelen, maillen;
2827         const char *name;
2828         const char *mail;
2829         struct ident_split ident;
2830
2831         person = strstr(buf->buf, what);
2832         if (!person)
2833                 return 0;
2834
2835         person += strlen(what);
2836         endp = strchr(person, '\n');
2837         if (!endp)
2838                 return 0;
2839
2840         len = endp - person;
2841
2842         if (split_ident_line(&ident, person, len))
2843                 return 0;
2844
2845         mail = ident.mail_begin;
2846         maillen = ident.mail_end - ident.mail_begin;
2847         name = ident.name_begin;
2848         namelen = ident.name_end - ident.name_begin;
2849
2850         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2851                 struct strbuf namemail = STRBUF_INIT;
2852
2853                 strbuf_addf(&namemail, "%.*s <%.*s>",
2854                             (int)namelen, name, (int)maillen, mail);
2855
2856                 strbuf_splice(buf, ident.name_begin - buf->buf,
2857                               ident.mail_end - ident.name_begin + 1,
2858                               namemail.buf, namemail.len);
2859
2860                 strbuf_release(&namemail);
2861
2862                 return 1;
2863         }
2864
2865         return 0;
2866 }
2867
2868 static int commit_match(struct commit *commit, struct rev_info *opt)
2869 {
2870         int retval;
2871         const char *encoding;
2872         const char *message;
2873         struct strbuf buf = STRBUF_INIT;
2874
2875         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2876                 return 1;
2877
2878         /* Prepend "fake" headers as needed */
2879         if (opt->grep_filter.use_reflog_filter) {
2880                 strbuf_addstr(&buf, "reflog ");
2881                 get_reflog_message(&buf, opt->reflog_info);
2882                 strbuf_addch(&buf, '\n');
2883         }
2884
2885         /*
2886          * We grep in the user's output encoding, under the assumption that it
2887          * is the encoding they are most likely to write their grep pattern
2888          * for. In addition, it means we will match the "notes" encoding below,
2889          * so we will not end up with a buffer that has two different encodings
2890          * in it.
2891          */
2892         encoding = get_log_output_encoding();
2893         message = logmsg_reencode(commit, NULL, encoding);
2894
2895         /* Copy the commit to temporary if we are using "fake" headers */
2896         if (buf.len)
2897                 strbuf_addstr(&buf, message);
2898
2899         if (opt->grep_filter.header_list && opt->mailmap) {
2900                 if (!buf.len)
2901                         strbuf_addstr(&buf, message);
2902
2903                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2904                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2905         }
2906
2907         /* Append "fake" message parts as needed */
2908         if (opt->show_notes) {
2909                 if (!buf.len)
2910                         strbuf_addstr(&buf, message);
2911                 format_display_notes(commit->object.oid.hash, &buf, encoding, 1);
2912         }
2913
2914         /*
2915          * Find either in the original commit message, or in the temporary.
2916          * Note that we cast away the constness of "message" here. It is
2917          * const because it may come from the cached commit buffer. That's OK,
2918          * because we know that it is modifiable heap memory, and that while
2919          * grep_buffer may modify it for speed, it will restore any
2920          * changes before returning.
2921          */
2922         if (buf.len)
2923                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2924         else
2925                 retval = grep_buffer(&opt->grep_filter,
2926                                      (char *)message, strlen(message));
2927         strbuf_release(&buf);
2928         unuse_commit_buffer(commit, message);
2929         return opt->invert_grep ? !retval : retval;
2930 }
2931
2932 static inline int want_ancestry(const struct rev_info *revs)
2933 {
2934         return (revs->rewrite_parents || revs->children.name);
2935 }
2936
2937 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2938 {
2939         if (commit->object.flags & SHOWN)
2940                 return commit_ignore;
2941         if (revs->unpacked && has_sha1_pack(commit->object.oid.hash))
2942                 return commit_ignore;
2943         if (revs->show_all)
2944                 return commit_show;
2945         if (commit->object.flags & UNINTERESTING)
2946                 return commit_ignore;
2947         if (revs->min_age != -1 && (commit->date > revs->min_age))
2948                 return commit_ignore;
2949         if (revs->min_parents || (revs->max_parents >= 0)) {
2950                 int n = commit_list_count(commit->parents);
2951                 if ((n < revs->min_parents) ||
2952                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2953                         return commit_ignore;
2954         }
2955         if (!commit_match(commit, revs))
2956                 return commit_ignore;
2957         if (revs->prune && revs->dense) {
2958                 /* Commit without changes? */
2959                 if (commit->object.flags & TREESAME) {
2960                         int n;
2961                         struct commit_list *p;
2962                         /* drop merges unless we want parenthood */
2963                         if (!want_ancestry(revs))
2964                                 return commit_ignore;
2965                         /*
2966                          * If we want ancestry, then need to keep any merges
2967                          * between relevant commits to tie together topology.
2968                          * For consistency with TREESAME and simplification
2969                          * use "relevant" here rather than just INTERESTING,
2970                          * to treat bottom commit(s) as part of the topology.
2971                          */
2972                         for (n = 0, p = commit->parents; p; p = p->next)
2973                                 if (relevant_commit(p->item))
2974                                         if (++n >= 2)
2975                                                 return commit_show;
2976                         return commit_ignore;
2977                 }
2978         }
2979         return commit_show;
2980 }
2981
2982 define_commit_slab(saved_parents, struct commit_list *);
2983
2984 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
2985
2986 /*
2987  * You may only call save_parents() once per commit (this is checked
2988  * for non-root commits).
2989  */
2990 static void save_parents(struct rev_info *revs, struct commit *commit)
2991 {
2992         struct commit_list **pp;
2993
2994         if (!revs->saved_parents_slab) {
2995                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
2996                 init_saved_parents(revs->saved_parents_slab);
2997         }
2998
2999         pp = saved_parents_at(revs->saved_parents_slab, commit);
3000
3001         /*
3002          * When walking with reflogs, we may visit the same commit
3003          * several times: once for each appearance in the reflog.
3004          *
3005          * In this case, save_parents() will be called multiple times.
3006          * We want to keep only the first set of parents.  We need to
3007          * store a sentinel value for an empty (i.e., NULL) parent
3008          * list to distinguish it from a not-yet-saved list, however.
3009          */
3010         if (*pp)
3011                 return;
3012         if (commit->parents)
3013                 *pp = copy_commit_list(commit->parents);
3014         else
3015                 *pp = EMPTY_PARENT_LIST;
3016 }
3017
3018 static void free_saved_parents(struct rev_info *revs)
3019 {
3020         if (revs->saved_parents_slab)
3021                 clear_saved_parents(revs->saved_parents_slab);
3022 }
3023
3024 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3025 {
3026         struct commit_list *parents;
3027
3028         if (!revs->saved_parents_slab)
3029                 return commit->parents;
3030
3031         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3032         if (parents == EMPTY_PARENT_LIST)
3033                 return NULL;
3034         return parents;
3035 }
3036
3037 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3038 {
3039         enum commit_action action = get_commit_action(revs, commit);
3040
3041         if (action == commit_show &&
3042             !revs->show_all &&
3043             revs->prune && revs->dense && want_ancestry(revs)) {
3044                 /*
3045                  * --full-diff on simplified parents is no good: it
3046                  * will show spurious changes from the commits that
3047                  * were elided.  So we save the parents on the side
3048                  * when --full-diff is in effect.
3049                  */
3050                 if (revs->full_diff)
3051                         save_parents(revs, commit);
3052                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
3053                         return commit_error;
3054         }
3055         return action;
3056 }
3057
3058 static void track_linear(struct rev_info *revs, struct commit *commit)
3059 {
3060         if (revs->track_first_time) {
3061                 revs->linear = 1;
3062                 revs->track_first_time = 0;
3063         } else {
3064                 struct commit_list *p;
3065                 for (p = revs->previous_parents; p; p = p->next)
3066                         if (p->item == NULL || /* first commit */
3067                             !oidcmp(&p->item->object.oid, &commit->object.oid))
3068                                 break;
3069                 revs->linear = p != NULL;
3070         }
3071         if (revs->reverse) {
3072                 if (revs->linear)
3073                         commit->object.flags |= TRACK_LINEAR;
3074         }
3075         free_commit_list(revs->previous_parents);
3076         revs->previous_parents = copy_commit_list(commit->parents);
3077 }
3078
3079 static struct commit *get_revision_1(struct rev_info *revs)
3080 {
3081         if (!revs->commits)
3082                 return NULL;
3083
3084         do {
3085                 struct commit *commit = pop_commit(&revs->commits);
3086
3087                 if (revs->reflog_info) {
3088                         save_parents(revs, commit);
3089                         fake_reflog_parent(revs->reflog_info, commit);
3090                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3091                 }
3092
3093                 /*
3094                  * If we haven't done the list limiting, we need to look at
3095                  * the parents here. We also need to do the date-based limiting
3096                  * that we'd otherwise have done in limit_list().
3097                  */
3098                 if (!revs->limited) {
3099                         if (revs->max_age != -1 &&
3100                             (commit->date < revs->max_age))
3101                                 continue;
3102                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
3103                                 if (!revs->ignore_missing_links)
3104                                         die("Failed to traverse parents of commit %s",
3105                                                 oid_to_hex(&commit->object.oid));
3106                         }
3107                 }
3108
3109                 switch (simplify_commit(revs, commit)) {
3110                 case commit_ignore:
3111                         continue;
3112                 case commit_error:
3113                         die("Failed to simplify parents of commit %s",
3114                             oid_to_hex(&commit->object.oid));
3115                 default:
3116                         if (revs->track_linear)
3117                                 track_linear(revs, commit);
3118                         return commit;
3119                 }
3120         } while (revs->commits);
3121         return NULL;
3122 }
3123
3124 /*
3125  * Return true for entries that have not yet been shown.  (This is an
3126  * object_array_each_func_t.)
3127  */
3128 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3129 {
3130         return !(entry->item->flags & SHOWN);
3131 }
3132
3133 /*
3134  * If array is on the verge of a realloc, garbage-collect any entries
3135  * that have already been shown to try to free up some space.
3136  */
3137 static void gc_boundary(struct object_array *array)
3138 {
3139         if (array->nr == array->alloc)
3140                 object_array_filter(array, entry_unshown, NULL);
3141 }
3142
3143 static void create_boundary_commit_list(struct rev_info *revs)
3144 {
3145         unsigned i;
3146         struct commit *c;
3147         struct object_array *array = &revs->boundary_commits;
3148         struct object_array_entry *objects = array->objects;
3149
3150         /*
3151          * If revs->commits is non-NULL at this point, an error occurred in
3152          * get_revision_1().  Ignore the error and continue printing the
3153          * boundary commits anyway.  (This is what the code has always
3154          * done.)
3155          */
3156         if (revs->commits) {
3157                 free_commit_list(revs->commits);
3158                 revs->commits = NULL;
3159         }
3160
3161         /*
3162          * Put all of the actual boundary commits from revs->boundary_commits
3163          * into revs->commits
3164          */
3165         for (i = 0; i < array->nr; i++) {
3166                 c = (struct commit *)(objects[i].item);
3167                 if (!c)
3168                         continue;
3169                 if (!(c->object.flags & CHILD_SHOWN))
3170                         continue;
3171                 if (c->object.flags & (SHOWN | BOUNDARY))
3172                         continue;
3173                 c->object.flags |= BOUNDARY;
3174                 commit_list_insert(c, &revs->commits);
3175         }
3176
3177         /*
3178          * If revs->topo_order is set, sort the boundary commits
3179          * in topological order
3180          */
3181         sort_in_topological_order(&revs->commits, revs->sort_order);
3182 }
3183
3184 static struct commit *get_revision_internal(struct rev_info *revs)
3185 {
3186         struct commit *c = NULL;
3187         struct commit_list *l;
3188
3189         if (revs->boundary == 2) {
3190                 /*
3191                  * All of the normal commits have already been returned,
3192                  * and we are now returning boundary commits.
3193                  * create_boundary_commit_list() has populated
3194                  * revs->commits with the remaining commits to return.
3195                  */
3196                 c = pop_commit(&revs->commits);
3197                 if (c)
3198                         c->object.flags |= SHOWN;
3199                 return c;
3200         }
3201
3202         /*
3203          * If our max_count counter has reached zero, then we are done. We
3204          * don't simply return NULL because we still might need to show
3205          * boundary commits. But we want to avoid calling get_revision_1, which
3206          * might do a considerable amount of work finding the next commit only
3207          * for us to throw it away.
3208          *
3209          * If it is non-zero, then either we don't have a max_count at all
3210          * (-1), or it is still counting, in which case we decrement.
3211          */
3212         if (revs->max_count) {
3213                 c = get_revision_1(revs);
3214                 if (c) {
3215                         while (revs->skip_count > 0) {
3216                                 revs->skip_count--;
3217                                 c = get_revision_1(revs);
3218                                 if (!c)
3219                                         break;
3220                         }
3221                 }
3222
3223                 if (revs->max_count > 0)
3224                         revs->max_count--;
3225         }
3226
3227         if (c)
3228                 c->object.flags |= SHOWN;
3229
3230         if (!revs->boundary)
3231                 return c;
3232
3233         if (!c) {
3234                 /*
3235                  * get_revision_1() runs out the commits, and
3236                  * we are done computing the boundaries.
3237                  * switch to boundary commits output mode.
3238                  */
3239                 revs->boundary = 2;
3240
3241                 /*
3242                  * Update revs->commits to contain the list of
3243                  * boundary commits.
3244                  */
3245                 create_boundary_commit_list(revs);
3246
3247                 return get_revision_internal(revs);
3248         }
3249
3250         /*
3251          * boundary commits are the commits that are parents of the
3252          * ones we got from get_revision_1() but they themselves are
3253          * not returned from get_revision_1().  Before returning
3254          * 'c', we need to mark its parents that they could be boundaries.
3255          */
3256
3257         for (l = c->parents; l; l = l->next) {
3258                 struct object *p;
3259                 p = &(l->item->object);
3260                 if (p->flags & (CHILD_SHOWN | SHOWN))
3261                         continue;
3262                 p->flags |= CHILD_SHOWN;
3263                 gc_boundary(&revs->boundary_commits);
3264                 add_object_array(p, NULL, &revs->boundary_commits);
3265         }
3266
3267         return c;
3268 }
3269
3270 struct commit *get_revision(struct rev_info *revs)
3271 {
3272         struct commit *c;
3273         struct commit_list *reversed;
3274
3275         if (revs->reverse) {
3276                 reversed = NULL;
3277                 while ((c = get_revision_internal(revs)))
3278                         commit_list_insert(c, &reversed);
3279                 revs->commits = reversed;
3280                 revs->reverse = 0;
3281                 revs->reverse_output_stage = 1;
3282         }
3283
3284         if (revs->reverse_output_stage) {
3285                 c = pop_commit(&revs->commits);
3286                 if (revs->track_linear)
3287                         revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
3288                 return c;
3289         }
3290
3291         c = get_revision_internal(revs);
3292         if (c && revs->graph)
3293                 graph_update(revs->graph, c);
3294         if (!c) {
3295                 free_saved_parents(revs);
3296                 if (revs->previous_parents) {
3297                         free_commit_list(revs->previous_parents);
3298                         revs->previous_parents = NULL;
3299                 }
3300         }
3301         return c;
3302 }
3303
3304 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3305 {
3306         if (commit->object.flags & BOUNDARY)
3307                 return "-";
3308         else if (commit->object.flags & UNINTERESTING)
3309                 return "^";
3310         else if (commit->object.flags & PATCHSAME)
3311                 return "=";
3312         else if (!revs || revs->left_right) {
3313                 if (commit->object.flags & SYMMETRIC_LEFT)
3314                         return "<";
3315                 else
3316                         return ">";
3317         } else if (revs->graph)
3318                 return "*";
3319         else if (revs->cherry_mark)
3320                 return "+";
3321         return "";
3322 }
3323
3324 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3325 {
3326         char *mark = get_revision_mark(revs, commit);
3327         if (!strlen(mark))
3328                 return;
3329         fputs(mark, stdout);
3330         putchar(' ');
3331 }