builtin/apply: remove whitespace_option arg from set_default_whitespace_mode()
[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);
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                 commit->util = 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                 id->seen = 1;
877                 commit->object.flags |= cherry_flag;
878         }
879
880         /* Now check the original side for seen ones */
881         for (p = list; p; p = p->next) {
882                 struct commit *commit = p->item;
883                 struct patch_id *ent;
884
885                 ent = commit->util;
886                 if (!ent)
887                         continue;
888                 if (ent->seen)
889                         commit->object.flags |= cherry_flag;
890                 commit->util = NULL;
891         }
892
893         free_patch_ids(&ids);
894 }
895
896 /* How many extra uninteresting commits we want to see.. */
897 #define SLOP 5
898
899 static int still_interesting(struct commit_list *src, unsigned long date, int slop,
900                              struct commit **interesting_cache)
901 {
902         /*
903          * No source list at all? We're definitely done..
904          */
905         if (!src)
906                 return 0;
907
908         /*
909          * Does the destination list contain entries with a date
910          * before the source list? Definitely _not_ done.
911          */
912         if (date <= src->item->date)
913                 return SLOP;
914
915         /*
916          * Does the source list still have interesting commits in
917          * it? Definitely not done..
918          */
919         if (!everybody_uninteresting(src, interesting_cache))
920                 return SLOP;
921
922         /* Ok, we're closing in.. */
923         return slop-1;
924 }
925
926 /*
927  * "rev-list --ancestry-path A..B" computes commits that are ancestors
928  * of B but not ancestors of A but further limits the result to those
929  * that are descendants of A.  This takes the list of bottom commits and
930  * the result of "A..B" without --ancestry-path, and limits the latter
931  * further to the ones that can reach one of the commits in "bottom".
932  */
933 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
934 {
935         struct commit_list *p;
936         struct commit_list *rlist = NULL;
937         int made_progress;
938
939         /*
940          * Reverse the list so that it will be likely that we would
941          * process parents before children.
942          */
943         for (p = list; p; p = p->next)
944                 commit_list_insert(p->item, &rlist);
945
946         for (p = bottom; p; p = p->next)
947                 p->item->object.flags |= TMP_MARK;
948
949         /*
950          * Mark the ones that can reach bottom commits in "list",
951          * in a bottom-up fashion.
952          */
953         do {
954                 made_progress = 0;
955                 for (p = rlist; p; p = p->next) {
956                         struct commit *c = p->item;
957                         struct commit_list *parents;
958                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
959                                 continue;
960                         for (parents = c->parents;
961                              parents;
962                              parents = parents->next) {
963                                 if (!(parents->item->object.flags & TMP_MARK))
964                                         continue;
965                                 c->object.flags |= TMP_MARK;
966                                 made_progress = 1;
967                                 break;
968                         }
969                 }
970         } while (made_progress);
971
972         /*
973          * NEEDSWORK: decide if we want to remove parents that are
974          * not marked with TMP_MARK from commit->parents for commits
975          * in the resulting list.  We may not want to do that, though.
976          */
977
978         /*
979          * The ones that are not marked with TMP_MARK are uninteresting
980          */
981         for (p = list; p; p = p->next) {
982                 struct commit *c = p->item;
983                 if (c->object.flags & TMP_MARK)
984                         continue;
985                 c->object.flags |= UNINTERESTING;
986         }
987
988         /* We are done with the TMP_MARK */
989         for (p = list; p; p = p->next)
990                 p->item->object.flags &= ~TMP_MARK;
991         for (p = bottom; p; p = p->next)
992                 p->item->object.flags &= ~TMP_MARK;
993         free_commit_list(rlist);
994 }
995
996 /*
997  * Before walking the history, keep the set of "negative" refs the
998  * caller has asked to exclude.
999  *
1000  * This is used to compute "rev-list --ancestry-path A..B", as we need
1001  * to filter the result of "A..B" further to the ones that can actually
1002  * reach A.
1003  */
1004 static struct commit_list *collect_bottom_commits(struct commit_list *list)
1005 {
1006         struct commit_list *elem, *bottom = NULL;
1007         for (elem = list; elem; elem = elem->next)
1008                 if (elem->item->object.flags & BOTTOM)
1009                         commit_list_insert(elem->item, &bottom);
1010         return bottom;
1011 }
1012
1013 /* Assumes either left_only or right_only is set */
1014 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1015 {
1016         struct commit_list *p;
1017
1018         for (p = list; p; p = p->next) {
1019                 struct commit *commit = p->item;
1020
1021                 if (revs->right_only) {
1022                         if (commit->object.flags & SYMMETRIC_LEFT)
1023                                 commit->object.flags |= SHOWN;
1024                 } else  /* revs->left_only is set */
1025                         if (!(commit->object.flags & SYMMETRIC_LEFT))
1026                                 commit->object.flags |= SHOWN;
1027         }
1028 }
1029
1030 static int limit_list(struct rev_info *revs)
1031 {
1032         int slop = SLOP;
1033         unsigned long date = ~0ul;
1034         struct commit_list *list = revs->commits;
1035         struct commit_list *newlist = NULL;
1036         struct commit_list **p = &newlist;
1037         struct commit_list *bottom = NULL;
1038         struct commit *interesting_cache = NULL;
1039
1040         if (revs->ancestry_path) {
1041                 bottom = collect_bottom_commits(list);
1042                 if (!bottom)
1043                         die("--ancestry-path given but there are no bottom commits");
1044         }
1045
1046         while (list) {
1047                 struct commit *commit = pop_commit(&list);
1048                 struct object *obj = &commit->object;
1049                 show_early_output_fn_t show;
1050
1051                 if (commit == interesting_cache)
1052                         interesting_cache = NULL;
1053
1054                 if (revs->max_age != -1 && (commit->date < revs->max_age))
1055                         obj->flags |= UNINTERESTING;
1056                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
1057                         return -1;
1058                 if (obj->flags & UNINTERESTING) {
1059                         mark_parents_uninteresting(commit);
1060                         if (revs->show_all)
1061                                 p = &commit_list_insert(commit, p)->next;
1062                         slop = still_interesting(list, date, slop, &interesting_cache);
1063                         if (slop)
1064                                 continue;
1065                         /* If showing all, add the whole pending list to the end */
1066                         if (revs->show_all)
1067                                 *p = list;
1068                         break;
1069                 }
1070                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1071                         continue;
1072                 date = commit->date;
1073                 p = &commit_list_insert(commit, p)->next;
1074
1075                 show = show_early_output;
1076                 if (!show)
1077                         continue;
1078
1079                 show(revs, newlist);
1080                 show_early_output = NULL;
1081         }
1082         if (revs->cherry_pick || revs->cherry_mark)
1083                 cherry_pick_list(newlist, revs);
1084
1085         if (revs->left_only || revs->right_only)
1086                 limit_left_right(newlist, revs);
1087
1088         if (bottom) {
1089                 limit_to_ancestry(bottom, newlist);
1090                 free_commit_list(bottom);
1091         }
1092
1093         /*
1094          * Check if any commits have become TREESAME by some of their parents
1095          * becoming UNINTERESTING.
1096          */
1097         if (limiting_can_increase_treesame(revs))
1098                 for (list = newlist; list; list = list->next) {
1099                         struct commit *c = list->item;
1100                         if (c->object.flags & (UNINTERESTING | TREESAME))
1101                                 continue;
1102                         update_treesame(revs, c);
1103                 }
1104
1105         revs->commits = newlist;
1106         return 0;
1107 }
1108
1109 /*
1110  * Add an entry to refs->cmdline with the specified information.
1111  * *name is copied.
1112  */
1113 static void add_rev_cmdline(struct rev_info *revs,
1114                             struct object *item,
1115                             const char *name,
1116                             int whence,
1117                             unsigned flags)
1118 {
1119         struct rev_cmdline_info *info = &revs->cmdline;
1120         int nr = info->nr;
1121
1122         ALLOC_GROW(info->rev, nr + 1, info->alloc);
1123         info->rev[nr].item = item;
1124         info->rev[nr].name = xstrdup(name);
1125         info->rev[nr].whence = whence;
1126         info->rev[nr].flags = flags;
1127         info->nr++;
1128 }
1129
1130 static void add_rev_cmdline_list(struct rev_info *revs,
1131                                  struct commit_list *commit_list,
1132                                  int whence,
1133                                  unsigned flags)
1134 {
1135         while (commit_list) {
1136                 struct object *object = &commit_list->item->object;
1137                 add_rev_cmdline(revs, object, oid_to_hex(&object->oid),
1138                                 whence, flags);
1139                 commit_list = commit_list->next;
1140         }
1141 }
1142
1143 struct all_refs_cb {
1144         int all_flags;
1145         int warned_bad_reflog;
1146         struct rev_info *all_revs;
1147         const char *name_for_errormsg;
1148 };
1149
1150 int ref_excluded(struct string_list *ref_excludes, const char *path)
1151 {
1152         struct string_list_item *item;
1153
1154         if (!ref_excludes)
1155                 return 0;
1156         for_each_string_list_item(item, ref_excludes) {
1157                 if (!wildmatch(item->string, path, 0, NULL))
1158                         return 1;
1159         }
1160         return 0;
1161 }
1162
1163 static int handle_one_ref(const char *path, const struct object_id *oid,
1164                           int flag, void *cb_data)
1165 {
1166         struct all_refs_cb *cb = cb_data;
1167         struct object *object;
1168
1169         if (ref_excluded(cb->all_revs->ref_excludes, path))
1170             return 0;
1171
1172         object = get_reference(cb->all_revs, path, oid->hash, cb->all_flags);
1173         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1174         add_pending_sha1(cb->all_revs, path, oid->hash, cb->all_flags);
1175         return 0;
1176 }
1177
1178 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1179         unsigned flags)
1180 {
1181         cb->all_revs = revs;
1182         cb->all_flags = flags;
1183 }
1184
1185 void clear_ref_exclusion(struct string_list **ref_excludes_p)
1186 {
1187         if (*ref_excludes_p) {
1188                 string_list_clear(*ref_excludes_p, 0);
1189                 free(*ref_excludes_p);
1190         }
1191         *ref_excludes_p = NULL;
1192 }
1193
1194 void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1195 {
1196         if (!*ref_excludes_p) {
1197                 *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1198                 (*ref_excludes_p)->strdup_strings = 1;
1199         }
1200         string_list_append(*ref_excludes_p, exclude);
1201 }
1202
1203 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
1204                 int (*for_each)(const char *, each_ref_fn, void *))
1205 {
1206         struct all_refs_cb cb;
1207         init_all_refs_cb(&cb, revs, flags);
1208         for_each(submodule, handle_one_ref, &cb);
1209 }
1210
1211 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
1212 {
1213         struct all_refs_cb *cb = cb_data;
1214         if (!is_null_sha1(sha1)) {
1215                 struct object *o = parse_object(sha1);
1216                 if (o) {
1217                         o->flags |= cb->all_flags;
1218                         /* ??? CMDLINEFLAGS ??? */
1219                         add_pending_object(cb->all_revs, o, "");
1220                 }
1221                 else if (!cb->warned_bad_reflog) {
1222                         warning("reflog of '%s' references pruned commits",
1223                                 cb->name_for_errormsg);
1224                         cb->warned_bad_reflog = 1;
1225                 }
1226         }
1227 }
1228
1229 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
1230                 const char *email, unsigned long timestamp, int tz,
1231                 const char *message, void *cb_data)
1232 {
1233         handle_one_reflog_commit(osha1, cb_data);
1234         handle_one_reflog_commit(nsha1, cb_data);
1235         return 0;
1236 }
1237
1238 static int handle_one_reflog(const char *path, const struct object_id *oid,
1239                              int flag, void *cb_data)
1240 {
1241         struct all_refs_cb *cb = cb_data;
1242         cb->warned_bad_reflog = 0;
1243         cb->name_for_errormsg = path;
1244         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
1245         return 0;
1246 }
1247
1248 void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1249 {
1250         struct all_refs_cb cb;
1251
1252         cb.all_revs = revs;
1253         cb.all_flags = flags;
1254         for_each_reflog(handle_one_reflog, &cb);
1255 }
1256
1257 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1258                            struct strbuf *path)
1259 {
1260         size_t baselen = path->len;
1261         int i;
1262
1263         if (it->entry_count >= 0) {
1264                 struct tree *tree = lookup_tree(it->sha1);
1265                 add_pending_object_with_path(revs, &tree->object, "",
1266                                              040000, path->buf);
1267         }
1268
1269         for (i = 0; i < it->subtree_nr; i++) {
1270                 struct cache_tree_sub *sub = it->down[i];
1271                 strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1272                 add_cache_tree(sub->cache_tree, revs, path);
1273                 strbuf_setlen(path, baselen);
1274         }
1275
1276 }
1277
1278 void add_index_objects_to_pending(struct rev_info *revs, unsigned flags)
1279 {
1280         int i;
1281
1282         read_cache();
1283         for (i = 0; i < active_nr; i++) {
1284                 struct cache_entry *ce = active_cache[i];
1285                 struct blob *blob;
1286
1287                 if (S_ISGITLINK(ce->ce_mode))
1288                         continue;
1289
1290                 blob = lookup_blob(ce->sha1);
1291                 if (!blob)
1292                         die("unable to add index blob to traversal");
1293                 add_pending_object_with_path(revs, &blob->object, "",
1294                                              ce->ce_mode, ce->name);
1295         }
1296
1297         if (active_cache_tree) {
1298                 struct strbuf path = STRBUF_INIT;
1299                 add_cache_tree(active_cache_tree, revs, &path);
1300                 strbuf_release(&path);
1301         }
1302 }
1303
1304 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
1305 {
1306         unsigned char sha1[20];
1307         struct object *it;
1308         struct commit *commit;
1309         struct commit_list *parents;
1310         const char *arg = arg_;
1311
1312         if (*arg == '^') {
1313                 flags ^= UNINTERESTING | BOTTOM;
1314                 arg++;
1315         }
1316         if (get_sha1_committish(arg, sha1))
1317                 return 0;
1318         while (1) {
1319                 it = get_reference(revs, arg, sha1, 0);
1320                 if (!it && revs->ignore_missing)
1321                         return 0;
1322                 if (it->type != OBJ_TAG)
1323                         break;
1324                 if (!((struct tag*)it)->tagged)
1325                         return 0;
1326                 hashcpy(sha1, ((struct tag*)it)->tagged->oid.hash);
1327         }
1328         if (it->type != OBJ_COMMIT)
1329                 return 0;
1330         commit = (struct commit *)it;
1331         for (parents = commit->parents; parents; parents = parents->next) {
1332                 it = &parents->item->object;
1333                 it->flags |= flags;
1334                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1335                 add_pending_object(revs, it, arg);
1336         }
1337         return 1;
1338 }
1339
1340 void init_revisions(struct rev_info *revs, const char *prefix)
1341 {
1342         memset(revs, 0, sizeof(*revs));
1343
1344         revs->abbrev = DEFAULT_ABBREV;
1345         revs->ignore_merges = 1;
1346         revs->simplify_history = 1;
1347         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1348         DIFF_OPT_SET(&revs->pruning, QUICK);
1349         revs->pruning.add_remove = file_add_remove;
1350         revs->pruning.change = file_change;
1351         revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1352         revs->dense = 1;
1353         revs->prefix = prefix;
1354         revs->max_age = -1;
1355         revs->min_age = -1;
1356         revs->skip_count = -1;
1357         revs->max_count = -1;
1358         revs->max_parents = -1;
1359         revs->expand_tabs_in_log = -1;
1360
1361         revs->commit_format = CMIT_FMT_DEFAULT;
1362         revs->expand_tabs_in_log_default = 8;
1363
1364         init_grep_defaults();
1365         grep_init(&revs->grep_filter, prefix);
1366         revs->grep_filter.status_only = 1;
1367         revs->grep_filter.regflags = REG_NEWLINE;
1368
1369         diff_setup(&revs->diffopt);
1370         if (prefix && !revs->diffopt.prefix) {
1371                 revs->diffopt.prefix = prefix;
1372                 revs->diffopt.prefix_length = strlen(prefix);
1373         }
1374
1375         revs->notes_opt.use_default_notes = -1;
1376 }
1377
1378 static void add_pending_commit_list(struct rev_info *revs,
1379                                     struct commit_list *commit_list,
1380                                     unsigned int flags)
1381 {
1382         while (commit_list) {
1383                 struct object *object = &commit_list->item->object;
1384                 object->flags |= flags;
1385                 add_pending_object(revs, object, oid_to_hex(&object->oid));
1386                 commit_list = commit_list->next;
1387         }
1388 }
1389
1390 static void prepare_show_merge(struct rev_info *revs)
1391 {
1392         struct commit_list *bases;
1393         struct commit *head, *other;
1394         unsigned char sha1[20];
1395         const char **prune = NULL;
1396         int i, prune_num = 1; /* counting terminating NULL */
1397
1398         if (get_sha1("HEAD", sha1))
1399                 die("--merge without HEAD?");
1400         head = lookup_commit_or_die(sha1, "HEAD");
1401         if (get_sha1("MERGE_HEAD", sha1))
1402                 die("--merge without MERGE_HEAD?");
1403         other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1404         add_pending_object(revs, &head->object, "HEAD");
1405         add_pending_object(revs, &other->object, "MERGE_HEAD");
1406         bases = get_merge_bases(head, other);
1407         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1408         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1409         free_commit_list(bases);
1410         head->object.flags |= SYMMETRIC_LEFT;
1411
1412         if (!active_nr)
1413                 read_cache();
1414         for (i = 0; i < active_nr; i++) {
1415                 const struct cache_entry *ce = active_cache[i];
1416                 if (!ce_stage(ce))
1417                         continue;
1418                 if (ce_path_match(ce, &revs->prune_data, NULL)) {
1419                         prune_num++;
1420                         REALLOC_ARRAY(prune, prune_num);
1421                         prune[prune_num-2] = ce->name;
1422                         prune[prune_num-1] = NULL;
1423                 }
1424                 while ((i+1 < active_nr) &&
1425                        ce_same_name(ce, active_cache[i+1]))
1426                         i++;
1427         }
1428         free_pathspec(&revs->prune_data);
1429         parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1430                        PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1431         revs->limited = 1;
1432 }
1433
1434 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1435 {
1436         struct object_context oc;
1437         char *dotdot;
1438         struct object *object;
1439         unsigned char sha1[20];
1440         int local_flags;
1441         const char *arg = arg_;
1442         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1443         unsigned get_sha1_flags = 0;
1444
1445         flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1446
1447         dotdot = strstr(arg, "..");
1448         if (dotdot) {
1449                 unsigned char from_sha1[20];
1450                 const char *next = dotdot + 2;
1451                 const char *this = arg;
1452                 int symmetric = *next == '.';
1453                 unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1454                 static const char head_by_default[] = "HEAD";
1455                 unsigned int a_flags;
1456
1457                 *dotdot = 0;
1458                 next += symmetric;
1459
1460                 if (!*next)
1461                         next = head_by_default;
1462                 if (dotdot == arg)
1463                         this = head_by_default;
1464                 if (this == head_by_default && next == head_by_default &&
1465                     !symmetric) {
1466                         /*
1467                          * Just ".."?  That is not a range but the
1468                          * pathspec for the parent directory.
1469                          */
1470                         if (!cant_be_filename) {
1471                                 *dotdot = '.';
1472                                 return -1;
1473                         }
1474                 }
1475                 if (!get_sha1_committish(this, from_sha1) &&
1476                     !get_sha1_committish(next, sha1)) {
1477                         struct object *a_obj, *b_obj;
1478
1479                         if (!cant_be_filename) {
1480                                 *dotdot = '.';
1481                                 verify_non_filename(revs->prefix, arg);
1482                         }
1483
1484                         a_obj = parse_object(from_sha1);
1485                         b_obj = parse_object(sha1);
1486                         if (!a_obj || !b_obj) {
1487                         missing:
1488                                 if (revs->ignore_missing)
1489                                         return 0;
1490                                 die(symmetric
1491                                     ? "Invalid symmetric difference expression %s"
1492                                     : "Invalid revision range %s", arg);
1493                         }
1494
1495                         if (!symmetric) {
1496                                 /* just A..B */
1497                                 a_flags = flags_exclude;
1498                         } else {
1499                                 /* A...B -- find merge bases between the two */
1500                                 struct commit *a, *b;
1501                                 struct commit_list *exclude;
1502
1503                                 a = (a_obj->type == OBJ_COMMIT
1504                                      ? (struct commit *)a_obj
1505                                      : lookup_commit_reference(a_obj->oid.hash));
1506                                 b = (b_obj->type == OBJ_COMMIT
1507                                      ? (struct commit *)b_obj
1508                                      : lookup_commit_reference(b_obj->oid.hash));
1509                                 if (!a || !b)
1510                                         goto missing;
1511                                 exclude = get_merge_bases(a, b);
1512                                 add_rev_cmdline_list(revs, exclude,
1513                                                      REV_CMD_MERGE_BASE,
1514                                                      flags_exclude);
1515                                 add_pending_commit_list(revs, exclude,
1516                                                         flags_exclude);
1517                                 free_commit_list(exclude);
1518
1519                                 a_flags = flags | SYMMETRIC_LEFT;
1520                         }
1521
1522                         a_obj->flags |= a_flags;
1523                         b_obj->flags |= flags;
1524                         add_rev_cmdline(revs, a_obj, this,
1525                                         REV_CMD_LEFT, a_flags);
1526                         add_rev_cmdline(revs, b_obj, next,
1527                                         REV_CMD_RIGHT, flags);
1528                         add_pending_object(revs, a_obj, this);
1529                         add_pending_object(revs, b_obj, next);
1530                         return 0;
1531                 }
1532                 *dotdot = '.';
1533         }
1534         dotdot = strstr(arg, "^@");
1535         if (dotdot && !dotdot[2]) {
1536                 *dotdot = 0;
1537                 if (add_parents_only(revs, arg, flags))
1538                         return 0;
1539                 *dotdot = '^';
1540         }
1541         dotdot = strstr(arg, "^!");
1542         if (dotdot && !dotdot[2]) {
1543                 *dotdot = 0;
1544                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM)))
1545                         *dotdot = '^';
1546         }
1547
1548         local_flags = 0;
1549         if (*arg == '^') {
1550                 local_flags = UNINTERESTING | BOTTOM;
1551                 arg++;
1552         }
1553
1554         if (revarg_opt & REVARG_COMMITTISH)
1555                 get_sha1_flags = GET_SHA1_COMMITTISH;
1556
1557         if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1558                 return revs->ignore_missing ? 0 : -1;
1559         if (!cant_be_filename)
1560                 verify_non_filename(revs->prefix, arg);
1561         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1562         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1563         add_pending_object_with_mode(revs, object, arg, oc.mode);
1564         return 0;
1565 }
1566
1567 struct cmdline_pathspec {
1568         int alloc;
1569         int nr;
1570         const char **path;
1571 };
1572
1573 static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1574 {
1575         while (*av) {
1576                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1577                 prune->path[prune->nr++] = *(av++);
1578         }
1579 }
1580
1581 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1582                                      struct cmdline_pathspec *prune)
1583 {
1584         while (strbuf_getline(sb, stdin) != EOF) {
1585                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1586                 prune->path[prune->nr++] = xstrdup(sb->buf);
1587         }
1588 }
1589
1590 static void read_revisions_from_stdin(struct rev_info *revs,
1591                                       struct cmdline_pathspec *prune)
1592 {
1593         struct strbuf sb;
1594         int seen_dashdash = 0;
1595         int save_warning;
1596
1597         save_warning = warn_on_object_refname_ambiguity;
1598         warn_on_object_refname_ambiguity = 0;
1599
1600         strbuf_init(&sb, 1000);
1601         while (strbuf_getline(&sb, stdin) != EOF) {
1602                 int len = sb.len;
1603                 if (!len)
1604                         break;
1605                 if (sb.buf[0] == '-') {
1606                         if (len == 2 && sb.buf[1] == '-') {
1607                                 seen_dashdash = 1;
1608                                 break;
1609                         }
1610                         die("options not supported in --stdin mode");
1611                 }
1612                 if (handle_revision_arg(sb.buf, revs, 0,
1613                                         REVARG_CANNOT_BE_FILENAME))
1614                         die("bad revision '%s'", sb.buf);
1615         }
1616         if (seen_dashdash)
1617                 read_pathspec_from_stdin(revs, &sb, prune);
1618
1619         strbuf_release(&sb);
1620         warn_on_object_refname_ambiguity = save_warning;
1621 }
1622
1623 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1624 {
1625         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1626 }
1627
1628 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1629 {
1630         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1631 }
1632
1633 static void add_message_grep(struct rev_info *revs, const char *pattern)
1634 {
1635         add_grep(revs, pattern, GREP_PATTERN_BODY);
1636 }
1637
1638 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1639                                int *unkc, const char **unkv)
1640 {
1641         const char *arg = argv[0];
1642         const char *optarg;
1643         int argcount;
1644
1645         /* pseudo revision arguments */
1646         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1647             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1648             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1649             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1650             !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
1651             !strcmp(arg, "--indexed-objects") ||
1652             starts_with(arg, "--exclude=") ||
1653             starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
1654             starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
1655         {
1656                 unkv[(*unkc)++] = arg;
1657                 return 1;
1658         }
1659
1660         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1661                 revs->max_count = atoi(optarg);
1662                 revs->no_walk = 0;
1663                 return argcount;
1664         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1665                 revs->skip_count = atoi(optarg);
1666                 return argcount;
1667         } else if ((*arg == '-') && isdigit(arg[1])) {
1668                 /* accept -<digit>, like traditional "head" */
1669                 if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
1670                     revs->max_count < 0)
1671                         die("'%s': not a non-negative integer", arg + 1);
1672                 revs->no_walk = 0;
1673         } else if (!strcmp(arg, "-n")) {
1674                 if (argc <= 1)
1675                         return error("-n requires an argument");
1676                 revs->max_count = atoi(argv[1]);
1677                 revs->no_walk = 0;
1678                 return 2;
1679         } else if (starts_with(arg, "-n")) {
1680                 revs->max_count = atoi(arg + 2);
1681                 revs->no_walk = 0;
1682         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1683                 revs->max_age = atoi(optarg);
1684                 return argcount;
1685         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1686                 revs->max_age = approxidate(optarg);
1687                 return argcount;
1688         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1689                 revs->max_age = approxidate(optarg);
1690                 return argcount;
1691         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1692                 revs->min_age = atoi(optarg);
1693                 return argcount;
1694         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1695                 revs->min_age = approxidate(optarg);
1696                 return argcount;
1697         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1698                 revs->min_age = approxidate(optarg);
1699                 return argcount;
1700         } else if (!strcmp(arg, "--first-parent")) {
1701                 revs->first_parent_only = 1;
1702         } else if (!strcmp(arg, "--ancestry-path")) {
1703                 revs->ancestry_path = 1;
1704                 revs->simplify_history = 0;
1705                 revs->limited = 1;
1706         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1707                 init_reflog_walk(&revs->reflog_info);
1708         } else if (!strcmp(arg, "--default")) {
1709                 if (argc <= 1)
1710                         return error("bad --default argument");
1711                 revs->def = argv[1];
1712                 return 2;
1713         } else if (!strcmp(arg, "--merge")) {
1714                 revs->show_merge = 1;
1715         } else if (!strcmp(arg, "--topo-order")) {
1716                 revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1717                 revs->topo_order = 1;
1718         } else if (!strcmp(arg, "--simplify-merges")) {
1719                 revs->simplify_merges = 1;
1720                 revs->topo_order = 1;
1721                 revs->rewrite_parents = 1;
1722                 revs->simplify_history = 0;
1723                 revs->limited = 1;
1724         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1725                 revs->simplify_merges = 1;
1726                 revs->topo_order = 1;
1727                 revs->rewrite_parents = 1;
1728                 revs->simplify_history = 0;
1729                 revs->simplify_by_decoration = 1;
1730                 revs->limited = 1;
1731                 revs->prune = 1;
1732                 load_ref_decorations(DECORATE_SHORT_REFS);
1733         } else if (!strcmp(arg, "--date-order")) {
1734                 revs->sort_order = REV_SORT_BY_COMMIT_DATE;
1735                 revs->topo_order = 1;
1736         } else if (!strcmp(arg, "--author-date-order")) {
1737                 revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
1738                 revs->topo_order = 1;
1739         } else if (starts_with(arg, "--early-output")) {
1740                 int count = 100;
1741                 switch (arg[14]) {
1742                 case '=':
1743                         count = atoi(arg+15);
1744                         /* Fallthrough */
1745                 case 0:
1746                         revs->topo_order = 1;
1747                        revs->early_output = count;
1748                 }
1749         } else if (!strcmp(arg, "--parents")) {
1750                 revs->rewrite_parents = 1;
1751                 revs->print_parents = 1;
1752         } else if (!strcmp(arg, "--dense")) {
1753                 revs->dense = 1;
1754         } else if (!strcmp(arg, "--sparse")) {
1755                 revs->dense = 0;
1756         } else if (!strcmp(arg, "--show-all")) {
1757                 revs->show_all = 1;
1758         } else if (!strcmp(arg, "--remove-empty")) {
1759                 revs->remove_empty_trees = 1;
1760         } else if (!strcmp(arg, "--merges")) {
1761                 revs->min_parents = 2;
1762         } else if (!strcmp(arg, "--no-merges")) {
1763                 revs->max_parents = 1;
1764         } else if (starts_with(arg, "--min-parents=")) {
1765                 revs->min_parents = atoi(arg+14);
1766         } else if (starts_with(arg, "--no-min-parents")) {
1767                 revs->min_parents = 0;
1768         } else if (starts_with(arg, "--max-parents=")) {
1769                 revs->max_parents = atoi(arg+14);
1770         } else if (starts_with(arg, "--no-max-parents")) {
1771                 revs->max_parents = -1;
1772         } else if (!strcmp(arg, "--boundary")) {
1773                 revs->boundary = 1;
1774         } else if (!strcmp(arg, "--left-right")) {
1775                 revs->left_right = 1;
1776         } else if (!strcmp(arg, "--left-only")) {
1777                 if (revs->right_only)
1778                         die("--left-only is incompatible with --right-only"
1779                             " or --cherry");
1780                 revs->left_only = 1;
1781         } else if (!strcmp(arg, "--right-only")) {
1782                 if (revs->left_only)
1783                         die("--right-only is incompatible with --left-only");
1784                 revs->right_only = 1;
1785         } else if (!strcmp(arg, "--cherry")) {
1786                 if (revs->left_only)
1787                         die("--cherry is incompatible with --left-only");
1788                 revs->cherry_mark = 1;
1789                 revs->right_only = 1;
1790                 revs->max_parents = 1;
1791                 revs->limited = 1;
1792         } else if (!strcmp(arg, "--count")) {
1793                 revs->count = 1;
1794         } else if (!strcmp(arg, "--cherry-mark")) {
1795                 if (revs->cherry_pick)
1796                         die("--cherry-mark is incompatible with --cherry-pick");
1797                 revs->cherry_mark = 1;
1798                 revs->limited = 1; /* needs limit_list() */
1799         } else if (!strcmp(arg, "--cherry-pick")) {
1800                 if (revs->cherry_mark)
1801                         die("--cherry-pick is incompatible with --cherry-mark");
1802                 revs->cherry_pick = 1;
1803                 revs->limited = 1;
1804         } else if (!strcmp(arg, "--objects")) {
1805                 revs->tag_objects = 1;
1806                 revs->tree_objects = 1;
1807                 revs->blob_objects = 1;
1808         } else if (!strcmp(arg, "--objects-edge")) {
1809                 revs->tag_objects = 1;
1810                 revs->tree_objects = 1;
1811                 revs->blob_objects = 1;
1812                 revs->edge_hint = 1;
1813         } else if (!strcmp(arg, "--objects-edge-aggressive")) {
1814                 revs->tag_objects = 1;
1815                 revs->tree_objects = 1;
1816                 revs->blob_objects = 1;
1817                 revs->edge_hint = 1;
1818                 revs->edge_hint_aggressive = 1;
1819         } else if (!strcmp(arg, "--verify-objects")) {
1820                 revs->tag_objects = 1;
1821                 revs->tree_objects = 1;
1822                 revs->blob_objects = 1;
1823                 revs->verify_objects = 1;
1824         } else if (!strcmp(arg, "--unpacked")) {
1825                 revs->unpacked = 1;
1826         } else if (starts_with(arg, "--unpacked=")) {
1827                 die("--unpacked=<packfile> no longer supported.");
1828         } else if (!strcmp(arg, "-r")) {
1829                 revs->diff = 1;
1830                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1831         } else if (!strcmp(arg, "-t")) {
1832                 revs->diff = 1;
1833                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1834                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1835         } else if (!strcmp(arg, "-m")) {
1836                 revs->ignore_merges = 0;
1837         } else if (!strcmp(arg, "-c")) {
1838                 revs->diff = 1;
1839                 revs->dense_combined_merges = 0;
1840                 revs->combine_merges = 1;
1841         } else if (!strcmp(arg, "--cc")) {
1842                 revs->diff = 1;
1843                 revs->dense_combined_merges = 1;
1844                 revs->combine_merges = 1;
1845         } else if (!strcmp(arg, "-v")) {
1846                 revs->verbose_header = 1;
1847         } else if (!strcmp(arg, "--pretty")) {
1848                 revs->verbose_header = 1;
1849                 revs->pretty_given = 1;
1850                 get_commit_format(NULL, revs);
1851         } else if (starts_with(arg, "--pretty=") || starts_with(arg, "--format=")) {
1852                 /*
1853                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1854                  * not allowed, since the argument is optional.
1855                  */
1856                 revs->verbose_header = 1;
1857                 revs->pretty_given = 1;
1858                 get_commit_format(arg+9, revs);
1859         } else if (!strcmp(arg, "--expand-tabs")) {
1860                 revs->expand_tabs_in_log = 8;
1861         } else if (!strcmp(arg, "--no-expand-tabs")) {
1862                 revs->expand_tabs_in_log = 0;
1863         } else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
1864                 int val;
1865                 if (strtol_i(arg, 10, &val) < 0 || val < 0)
1866                         die("'%s': not a non-negative integer", arg);
1867                 revs->expand_tabs_in_log = val;
1868         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1869                 revs->show_notes = 1;
1870                 revs->show_notes_given = 1;
1871                 revs->notes_opt.use_default_notes = 1;
1872         } else if (!strcmp(arg, "--show-signature")) {
1873                 revs->show_signature = 1;
1874         } else if (!strcmp(arg, "--show-linear-break") ||
1875                    starts_with(arg, "--show-linear-break=")) {
1876                 if (starts_with(arg, "--show-linear-break="))
1877                         revs->break_bar = xstrdup(arg + 20);
1878                 else
1879                         revs->break_bar = "                    ..........";
1880                 revs->track_linear = 1;
1881                 revs->track_first_time = 1;
1882         } else if (starts_with(arg, "--show-notes=") ||
1883                    starts_with(arg, "--notes=")) {
1884                 struct strbuf buf = STRBUF_INIT;
1885                 revs->show_notes = 1;
1886                 revs->show_notes_given = 1;
1887                 if (starts_with(arg, "--show-notes")) {
1888                         if (revs->notes_opt.use_default_notes < 0)
1889                                 revs->notes_opt.use_default_notes = 1;
1890                         strbuf_addstr(&buf, arg+13);
1891                 }
1892                 else
1893                         strbuf_addstr(&buf, arg+8);
1894                 expand_notes_ref(&buf);
1895                 string_list_append(&revs->notes_opt.extra_notes_refs,
1896                                    strbuf_detach(&buf, NULL));
1897         } else if (!strcmp(arg, "--no-notes")) {
1898                 revs->show_notes = 0;
1899                 revs->show_notes_given = 1;
1900                 revs->notes_opt.use_default_notes = -1;
1901                 /* we have been strdup'ing ourselves, so trick
1902                  * string_list into free()ing strings */
1903                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1904                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1905                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1906         } else if (!strcmp(arg, "--standard-notes")) {
1907                 revs->show_notes_given = 1;
1908                 revs->notes_opt.use_default_notes = 1;
1909         } else if (!strcmp(arg, "--no-standard-notes")) {
1910                 revs->notes_opt.use_default_notes = 0;
1911         } else if (!strcmp(arg, "--oneline")) {
1912                 revs->verbose_header = 1;
1913                 get_commit_format("oneline", revs);
1914                 revs->pretty_given = 1;
1915                 revs->abbrev_commit = 1;
1916         } else if (!strcmp(arg, "--graph")) {
1917                 revs->topo_order = 1;
1918                 revs->rewrite_parents = 1;
1919                 revs->graph = graph_init(revs);
1920         } else if (!strcmp(arg, "--root")) {
1921                 revs->show_root_diff = 1;
1922         } else if (!strcmp(arg, "--no-commit-id")) {
1923                 revs->no_commit_id = 1;
1924         } else if (!strcmp(arg, "--always")) {
1925                 revs->always_show_header = 1;
1926         } else if (!strcmp(arg, "--no-abbrev")) {
1927                 revs->abbrev = 0;
1928         } else if (!strcmp(arg, "--abbrev")) {
1929                 revs->abbrev = DEFAULT_ABBREV;
1930         } else if (starts_with(arg, "--abbrev=")) {
1931                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1932                 if (revs->abbrev < MINIMUM_ABBREV)
1933                         revs->abbrev = MINIMUM_ABBREV;
1934                 else if (revs->abbrev > 40)
1935                         revs->abbrev = 40;
1936         } else if (!strcmp(arg, "--abbrev-commit")) {
1937                 revs->abbrev_commit = 1;
1938                 revs->abbrev_commit_given = 1;
1939         } else if (!strcmp(arg, "--no-abbrev-commit")) {
1940                 revs->abbrev_commit = 0;
1941         } else if (!strcmp(arg, "--full-diff")) {
1942                 revs->diff = 1;
1943                 revs->full_diff = 1;
1944         } else if (!strcmp(arg, "--full-history")) {
1945                 revs->simplify_history = 0;
1946         } else if (!strcmp(arg, "--relative-date")) {
1947                 revs->date_mode.type = DATE_RELATIVE;
1948                 revs->date_mode_explicit = 1;
1949         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1950                 parse_date_format(optarg, &revs->date_mode);
1951                 revs->date_mode_explicit = 1;
1952                 return argcount;
1953         } else if (!strcmp(arg, "--log-size")) {
1954                 revs->show_log_size = 1;
1955         }
1956         /*
1957          * Grepping the commit log
1958          */
1959         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1960                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1961                 return argcount;
1962         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1963                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1964                 return argcount;
1965         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
1966                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
1967                 return argcount;
1968         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1969                 add_message_grep(revs, optarg);
1970                 return argcount;
1971         } else if (!strcmp(arg, "--grep-debug")) {
1972                 revs->grep_filter.debug = 1;
1973         } else if (!strcmp(arg, "--basic-regexp")) {
1974                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_BRE, &revs->grep_filter);
1975         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1976                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, &revs->grep_filter);
1977         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1978                 revs->grep_filter.regflags |= REG_ICASE;
1979                 DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
1980         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1981                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_FIXED, &revs->grep_filter);
1982         } else if (!strcmp(arg, "--perl-regexp")) {
1983                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_PCRE, &revs->grep_filter);
1984         } else if (!strcmp(arg, "--all-match")) {
1985                 revs->grep_filter.all_match = 1;
1986         } else if (!strcmp(arg, "--invert-grep")) {
1987                 revs->invert_grep = 1;
1988         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1989                 if (strcmp(optarg, "none"))
1990                         git_log_output_encoding = xstrdup(optarg);
1991                 else
1992                         git_log_output_encoding = "";
1993                 return argcount;
1994         } else if (!strcmp(arg, "--reverse")) {
1995                 revs->reverse ^= 1;
1996         } else if (!strcmp(arg, "--children")) {
1997                 revs->children.name = "children";
1998                 revs->limited = 1;
1999         } else if (!strcmp(arg, "--ignore-missing")) {
2000                 revs->ignore_missing = 1;
2001         } else {
2002                 int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
2003                 if (!opts)
2004                         unkv[(*unkc)++] = arg;
2005                 return opts;
2006         }
2007         if (revs->graph && revs->track_linear)
2008                 die("--show-linear-break and --graph are incompatible");
2009
2010         return 1;
2011 }
2012
2013 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2014                         const struct option *options,
2015                         const char * const usagestr[])
2016 {
2017         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2018                                     &ctx->cpidx, ctx->out);
2019         if (n <= 0) {
2020                 error("unknown option `%s'", ctx->argv[0]);
2021                 usage_with_options(usagestr, options);
2022         }
2023         ctx->argv += n;
2024         ctx->argc -= n;
2025 }
2026
2027 static int for_each_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data, const char *term) {
2028         struct strbuf bisect_refs = STRBUF_INIT;
2029         int status;
2030         strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2031         status = for_each_ref_in_submodule(submodule, bisect_refs.buf, fn, cb_data);
2032         strbuf_release(&bisect_refs);
2033         return status;
2034 }
2035
2036 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2037 {
2038         return for_each_bisect_ref(submodule, fn, cb_data, term_bad);
2039 }
2040
2041 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2042 {
2043         return for_each_bisect_ref(submodule, fn, cb_data, term_good);
2044 }
2045
2046 static int handle_revision_pseudo_opt(const char *submodule,
2047                                 struct rev_info *revs,
2048                                 int argc, const char **argv, int *flags)
2049 {
2050         const char *arg = argv[0];
2051         const char *optarg;
2052         int argcount;
2053
2054         /*
2055          * NOTE!
2056          *
2057          * Commands like "git shortlog" will not accept the options below
2058          * unless parse_revision_opt queues them (as opposed to erroring
2059          * out).
2060          *
2061          * When implementing your new pseudo-option, remember to
2062          * register it in the list at the top of handle_revision_opt.
2063          */
2064         if (!strcmp(arg, "--all")) {
2065                 handle_refs(submodule, revs, *flags, for_each_ref_submodule);
2066                 handle_refs(submodule, revs, *flags, head_ref_submodule);
2067                 clear_ref_exclusion(&revs->ref_excludes);
2068         } else if (!strcmp(arg, "--branches")) {
2069                 handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
2070                 clear_ref_exclusion(&revs->ref_excludes);
2071         } else if (!strcmp(arg, "--bisect")) {
2072                 read_bisect_terms(&term_bad, &term_good);
2073                 handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
2074                 handle_refs(submodule, revs, *flags ^ (UNINTERESTING | BOTTOM), for_each_good_bisect_ref);
2075                 revs->bisect = 1;
2076         } else if (!strcmp(arg, "--tags")) {
2077                 handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
2078                 clear_ref_exclusion(&revs->ref_excludes);
2079         } else if (!strcmp(arg, "--remotes")) {
2080                 handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
2081                 clear_ref_exclusion(&revs->ref_excludes);
2082         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2083                 struct all_refs_cb cb;
2084                 init_all_refs_cb(&cb, revs, *flags);
2085                 for_each_glob_ref(handle_one_ref, optarg, &cb);
2086                 clear_ref_exclusion(&revs->ref_excludes);
2087                 return argcount;
2088         } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2089                 add_ref_exclusion(&revs->ref_excludes, optarg);
2090                 return argcount;
2091         } else if (starts_with(arg, "--branches=")) {
2092                 struct all_refs_cb cb;
2093                 init_all_refs_cb(&cb, revs, *flags);
2094                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
2095                 clear_ref_exclusion(&revs->ref_excludes);
2096         } else if (starts_with(arg, "--tags=")) {
2097                 struct all_refs_cb cb;
2098                 init_all_refs_cb(&cb, revs, *flags);
2099                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
2100                 clear_ref_exclusion(&revs->ref_excludes);
2101         } else if (starts_with(arg, "--remotes=")) {
2102                 struct all_refs_cb cb;
2103                 init_all_refs_cb(&cb, revs, *flags);
2104                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
2105                 clear_ref_exclusion(&revs->ref_excludes);
2106         } else if (!strcmp(arg, "--reflog")) {
2107                 add_reflogs_to_pending(revs, *flags);
2108         } else if (!strcmp(arg, "--indexed-objects")) {
2109                 add_index_objects_to_pending(revs, *flags);
2110         } else if (!strcmp(arg, "--not")) {
2111                 *flags ^= UNINTERESTING | BOTTOM;
2112         } else if (!strcmp(arg, "--no-walk")) {
2113                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2114         } else if (starts_with(arg, "--no-walk=")) {
2115                 /*
2116                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2117                  * not allowed, since the argument is optional.
2118                  */
2119                 if (!strcmp(arg + 10, "sorted"))
2120                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2121                 else if (!strcmp(arg + 10, "unsorted"))
2122                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2123                 else
2124                         return error("invalid argument to --no-walk");
2125         } else if (!strcmp(arg, "--do-walk")) {
2126                 revs->no_walk = 0;
2127         } else {
2128                 return 0;
2129         }
2130
2131         return 1;
2132 }
2133
2134 static void NORETURN diagnose_missing_default(const char *def)
2135 {
2136         unsigned char sha1[20];
2137         int flags;
2138         const char *refname;
2139
2140         refname = resolve_ref_unsafe(def, 0, sha1, &flags);
2141         if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2142                 die(_("your current branch appears to be broken"));
2143
2144         skip_prefix(refname, "refs/heads/", &refname);
2145         die(_("your current branch '%s' does not have any commits yet"),
2146             refname);
2147 }
2148
2149 /*
2150  * Parse revision information, filling in the "rev_info" structure,
2151  * and removing the used arguments from the argument list.
2152  *
2153  * Returns the number of arguments left that weren't recognized
2154  * (which are also moved to the head of the argument list)
2155  */
2156 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2157 {
2158         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
2159         struct cmdline_pathspec prune_data;
2160         const char *submodule = NULL;
2161
2162         memset(&prune_data, 0, sizeof(prune_data));
2163         if (opt)
2164                 submodule = opt->submodule;
2165
2166         /* First, search for "--" */
2167         if (opt && opt->assume_dashdash) {
2168                 seen_dashdash = 1;
2169         } else {
2170                 seen_dashdash = 0;
2171                 for (i = 1; i < argc; i++) {
2172                         const char *arg = argv[i];
2173                         if (strcmp(arg, "--"))
2174                                 continue;
2175                         argv[i] = NULL;
2176                         argc = i;
2177                         if (argv[i + 1])
2178                                 append_prune_data(&prune_data, argv + i + 1);
2179                         seen_dashdash = 1;
2180                         break;
2181                 }
2182         }
2183
2184         /* Second, deal with arguments and options */
2185         flags = 0;
2186         revarg_opt = opt ? opt->revarg_opt : 0;
2187         if (seen_dashdash)
2188                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2189         read_from_stdin = 0;
2190         for (left = i = 1; i < argc; i++) {
2191                 const char *arg = argv[i];
2192                 if (*arg == '-') {
2193                         int opts;
2194
2195                         opts = handle_revision_pseudo_opt(submodule,
2196                                                 revs, argc - i, argv + i,
2197                                                 &flags);
2198                         if (opts > 0) {
2199                                 i += opts - 1;
2200                                 continue;
2201                         }
2202
2203                         if (!strcmp(arg, "--stdin")) {
2204                                 if (revs->disable_stdin) {
2205                                         argv[left++] = arg;
2206                                         continue;
2207                                 }
2208                                 if (read_from_stdin++)
2209                                         die("--stdin given twice?");
2210                                 read_revisions_from_stdin(revs, &prune_data);
2211                                 continue;
2212                         }
2213
2214                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
2215                         if (opts > 0) {
2216                                 i += opts - 1;
2217                                 continue;
2218                         }
2219                         if (opts < 0)
2220                                 exit(128);
2221                         continue;
2222                 }
2223
2224
2225                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2226                         int j;
2227                         if (seen_dashdash || *arg == '^')
2228                                 die("bad revision '%s'", arg);
2229
2230                         /* If we didn't have a "--":
2231                          * (1) all filenames must exist;
2232                          * (2) all rev-args must not be interpretable
2233                          *     as a valid filename.
2234                          * but the latter we have checked in the main loop.
2235                          */
2236                         for (j = i; j < argc; j++)
2237                                 verify_filename(revs->prefix, argv[j], j == i);
2238
2239                         append_prune_data(&prune_data, argv + i);
2240                         break;
2241                 }
2242                 else
2243                         got_rev_arg = 1;
2244         }
2245
2246         if (prune_data.nr) {
2247                 /*
2248                  * If we need to introduce the magic "a lone ':' means no
2249                  * pathspec whatsoever", here is the place to do so.
2250                  *
2251                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2252                  *      prune_data.nr = 0;
2253                  *      prune_data.alloc = 0;
2254                  *      free(prune_data.path);
2255                  *      prune_data.path = NULL;
2256                  * } else {
2257                  *      terminate prune_data.alloc with NULL and
2258                  *      call init_pathspec() to set revs->prune_data here.
2259                  * }
2260                  */
2261                 ALLOC_GROW(prune_data.path, prune_data.nr + 1, prune_data.alloc);
2262                 prune_data.path[prune_data.nr++] = NULL;
2263                 parse_pathspec(&revs->prune_data, 0, 0,
2264                                revs->prefix, prune_data.path);
2265         }
2266
2267         if (revs->def == NULL)
2268                 revs->def = opt ? opt->def : NULL;
2269         if (opt && opt->tweak)
2270                 opt->tweak(revs, opt);
2271         if (revs->show_merge)
2272                 prepare_show_merge(revs);
2273         if (revs->def && !revs->pending.nr && !got_rev_arg) {
2274                 unsigned char sha1[20];
2275                 struct object *object;
2276                 struct object_context oc;
2277                 if (get_sha1_with_context(revs->def, 0, sha1, &oc))
2278                         diagnose_missing_default(revs->def);
2279                 object = get_reference(revs, revs->def, sha1, 0);
2280                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2281         }
2282
2283         /* Did the user ask for any diff output? Run the diff! */
2284         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2285                 revs->diff = 1;
2286
2287         /* Pickaxe, diff-filter and rename following need diffs */
2288         if (revs->diffopt.pickaxe ||
2289             revs->diffopt.filter ||
2290             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2291                 revs->diff = 1;
2292
2293         if (revs->topo_order)
2294                 revs->limited = 1;
2295
2296         if (revs->prune_data.nr) {
2297                 copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2298                 /* Can't prune commits with rename following: the paths change.. */
2299                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2300                         revs->prune = 1;
2301                 if (!revs->full_diff)
2302                         copy_pathspec(&revs->diffopt.pathspec,
2303                                       &revs->prune_data);
2304         }
2305         if (revs->combine_merges)
2306                 revs->ignore_merges = 0;
2307         revs->diffopt.abbrev = revs->abbrev;
2308
2309         if (revs->line_level_traverse) {
2310                 revs->limited = 1;
2311                 revs->topo_order = 1;
2312         }
2313
2314         diff_setup_done(&revs->diffopt);
2315
2316         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2317                                  &revs->grep_filter);
2318         compile_grep_patterns(&revs->grep_filter);
2319
2320         if (revs->reverse && revs->reflog_info)
2321                 die("cannot combine --reverse with --walk-reflogs");
2322         if (revs->rewrite_parents && revs->children.name)
2323                 die("cannot combine --parents and --children");
2324
2325         /*
2326          * Limitations on the graph functionality
2327          */
2328         if (revs->reverse && revs->graph)
2329                 die("cannot combine --reverse with --graph");
2330
2331         if (revs->reflog_info && revs->graph)
2332                 die("cannot combine --walk-reflogs with --graph");
2333         if (revs->no_walk && revs->graph)
2334                 die("cannot combine --no-walk with --graph");
2335         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2336                 die("cannot use --grep-reflog without --walk-reflogs");
2337
2338         if (revs->first_parent_only && revs->bisect)
2339                 die(_("--first-parent is incompatible with --bisect"));
2340
2341         if (revs->expand_tabs_in_log < 0)
2342                 revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
2343
2344         return left;
2345 }
2346
2347 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2348 {
2349         struct commit_list *l = xcalloc(1, sizeof(*l));
2350
2351         l->item = child;
2352         l->next = add_decoration(&revs->children, &parent->object, l);
2353 }
2354
2355 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2356 {
2357         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2358         struct commit_list **pp, *p;
2359         int surviving_parents;
2360
2361         /* Examine existing parents while marking ones we have seen... */
2362         pp = &commit->parents;
2363         surviving_parents = 0;
2364         while ((p = *pp) != NULL) {
2365                 struct commit *parent = p->item;
2366                 if (parent->object.flags & TMP_MARK) {
2367                         *pp = p->next;
2368                         if (ts)
2369                                 compact_treesame(revs, commit, surviving_parents);
2370                         continue;
2371                 }
2372                 parent->object.flags |= TMP_MARK;
2373                 surviving_parents++;
2374                 pp = &p->next;
2375         }
2376         /* clear the temporary mark */
2377         for (p = commit->parents; p; p = p->next) {
2378                 p->item->object.flags &= ~TMP_MARK;
2379         }
2380         /* no update_treesame() - removing duplicates can't affect TREESAME */
2381         return surviving_parents;
2382 }
2383
2384 struct merge_simplify_state {
2385         struct commit *simplified;
2386 };
2387
2388 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2389 {
2390         struct merge_simplify_state *st;
2391
2392         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2393         if (!st) {
2394                 st = xcalloc(1, sizeof(*st));
2395                 add_decoration(&revs->merge_simplification, &commit->object, st);
2396         }
2397         return st;
2398 }
2399
2400 static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2401 {
2402         struct commit_list *h = reduce_heads(commit->parents);
2403         int i = 0, marked = 0;
2404         struct commit_list *po, *pn;
2405
2406         /* Want these for sanity-checking only */
2407         int orig_cnt = commit_list_count(commit->parents);
2408         int cnt = commit_list_count(h);
2409
2410         /*
2411          * Not ready to remove items yet, just mark them for now, based
2412          * on the output of reduce_heads(). reduce_heads outputs the reduced
2413          * set in its original order, so this isn't too hard.
2414          */
2415         po = commit->parents;
2416         pn = h;
2417         while (po) {
2418                 if (pn && po->item == pn->item) {
2419                         pn = pn->next;
2420                         i++;
2421                 } else {
2422                         po->item->object.flags |= TMP_MARK;
2423                         marked++;
2424                 }
2425                 po=po->next;
2426         }
2427
2428         if (i != cnt || cnt+marked != orig_cnt)
2429                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2430
2431         free_commit_list(h);
2432
2433         return marked;
2434 }
2435
2436 static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2437 {
2438         struct commit_list *p;
2439         int marked = 0;
2440
2441         for (p = commit->parents; p; p = p->next) {
2442                 struct commit *parent = p->item;
2443                 if (!parent->parents && (parent->object.flags & TREESAME)) {
2444                         parent->object.flags |= TMP_MARK;
2445                         marked++;
2446                 }
2447         }
2448
2449         return marked;
2450 }
2451
2452 /*
2453  * Awkward naming - this means one parent we are TREESAME to.
2454  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2455  * empty tree). Better name suggestions?
2456  */
2457 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2458 {
2459         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2460         struct commit *unmarked = NULL, *marked = NULL;
2461         struct commit_list *p;
2462         unsigned n;
2463
2464         for (p = commit->parents, n = 0; p; p = p->next, n++) {
2465                 if (ts->treesame[n]) {
2466                         if (p->item->object.flags & TMP_MARK) {
2467                                 if (!marked)
2468                                         marked = p->item;
2469                         } else {
2470                                 if (!unmarked) {
2471                                         unmarked = p->item;
2472                                         break;
2473                                 }
2474                         }
2475                 }
2476         }
2477
2478         /*
2479          * If we are TREESAME to a marked-for-deletion parent, but not to any
2480          * unmarked parents, unmark the first TREESAME parent. This is the
2481          * parent that the default simplify_history==1 scan would have followed,
2482          * and it doesn't make sense to omit that path when asking for a
2483          * simplified full history. Retaining it improves the chances of
2484          * understanding odd missed merges that took an old version of a file.
2485          *
2486          * Example:
2487          *
2488          *   I--------*X       A modified the file, but mainline merge X used
2489          *    \       /        "-s ours", so took the version from I. X is
2490          *     `-*A--'         TREESAME to I and !TREESAME to A.
2491          *
2492          * Default log from X would produce "I". Without this check,
2493          * --full-history --simplify-merges would produce "I-A-X", showing
2494          * the merge commit X and that it changed A, but not making clear that
2495          * it had just taken the I version. With this check, the topology above
2496          * is retained.
2497          *
2498          * Note that it is possible that the simplification chooses a different
2499          * TREESAME parent from the default, in which case this test doesn't
2500          * activate, and we _do_ drop the default parent. Example:
2501          *
2502          *   I------X         A modified the file, but it was reverted in B,
2503          *    \    /          meaning mainline merge X is TREESAME to both
2504          *    *A-*B           parents.
2505          *
2506          * Default log would produce "I" by following the first parent;
2507          * --full-history --simplify-merges will produce "I-A-B". But this is a
2508          * reasonable result - it presents a logical full history leading from
2509          * I to X, and X is not an important merge.
2510          */
2511         if (!unmarked && marked) {
2512                 marked->object.flags &= ~TMP_MARK;
2513                 return 1;
2514         }
2515
2516         return 0;
2517 }
2518
2519 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2520 {
2521         struct commit_list **pp, *p;
2522         int nth_parent, removed = 0;
2523
2524         pp = &commit->parents;
2525         nth_parent = 0;
2526         while ((p = *pp) != NULL) {
2527                 struct commit *parent = p->item;
2528                 if (parent->object.flags & TMP_MARK) {
2529                         parent->object.flags &= ~TMP_MARK;
2530                         *pp = p->next;
2531                         free(p);
2532                         removed++;
2533                         compact_treesame(revs, commit, nth_parent);
2534                         continue;
2535                 }
2536                 pp = &p->next;
2537                 nth_parent++;
2538         }
2539
2540         /* Removing parents can only increase TREESAMEness */
2541         if (removed && !(commit->object.flags & TREESAME))
2542                 update_treesame(revs, commit);
2543
2544         return nth_parent;
2545 }
2546
2547 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2548 {
2549         struct commit_list *p;
2550         struct commit *parent;
2551         struct merge_simplify_state *st, *pst;
2552         int cnt;
2553
2554         st = locate_simplify_state(revs, commit);
2555
2556         /*
2557          * Have we handled this one?
2558          */
2559         if (st->simplified)
2560                 return tail;
2561
2562         /*
2563          * An UNINTERESTING commit simplifies to itself, so does a
2564          * root commit.  We do not rewrite parents of such commit
2565          * anyway.
2566          */
2567         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2568                 st->simplified = commit;
2569                 return tail;
2570         }
2571
2572         /*
2573          * Do we know what commit all of our parents that matter
2574          * should be rewritten to?  Otherwise we are not ready to
2575          * rewrite this one yet.
2576          */
2577         for (cnt = 0, p = commit->parents; p; p = p->next) {
2578                 pst = locate_simplify_state(revs, p->item);
2579                 if (!pst->simplified) {
2580                         tail = &commit_list_insert(p->item, tail)->next;
2581                         cnt++;
2582                 }
2583                 if (revs->first_parent_only)
2584                         break;
2585         }
2586         if (cnt) {
2587                 tail = &commit_list_insert(commit, tail)->next;
2588                 return tail;
2589         }
2590
2591         /*
2592          * Rewrite our list of parents. Note that this cannot
2593          * affect our TREESAME flags in any way - a commit is
2594          * always TREESAME to its simplification.
2595          */
2596         for (p = commit->parents; p; p = p->next) {
2597                 pst = locate_simplify_state(revs, p->item);
2598                 p->item = pst->simplified;
2599                 if (revs->first_parent_only)
2600                         break;
2601         }
2602
2603         if (revs->first_parent_only)
2604                 cnt = 1;
2605         else
2606                 cnt = remove_duplicate_parents(revs, commit);
2607
2608         /*
2609          * It is possible that we are a merge and one side branch
2610          * does not have any commit that touches the given paths;
2611          * in such a case, the immediate parent from that branch
2612          * will be rewritten to be the merge base.
2613          *
2614          *      o----X          X: the commit we are looking at;
2615          *     /    /           o: a commit that touches the paths;
2616          * ---o----'
2617          *
2618          * Further, a merge of an independent branch that doesn't
2619          * touch the path will reduce to a treesame root parent:
2620          *
2621          *  ----o----X          X: the commit we are looking at;
2622          *          /           o: a commit that touches the paths;
2623          *         r            r: a root commit not touching the paths
2624          *
2625          * Detect and simplify both cases.
2626          */
2627         if (1 < cnt) {
2628                 int marked = mark_redundant_parents(revs, commit);
2629                 marked += mark_treesame_root_parents(revs, commit);
2630                 if (marked)
2631                         marked -= leave_one_treesame_to_parent(revs, commit);
2632                 if (marked)
2633                         cnt = remove_marked_parents(revs, commit);
2634         }
2635
2636         /*
2637          * A commit simplifies to itself if it is a root, if it is
2638          * UNINTERESTING, if it touches the given paths, or if it is a
2639          * merge and its parents don't simplify to one relevant commit
2640          * (the first two cases are already handled at the beginning of
2641          * this function).
2642          *
2643          * Otherwise, it simplifies to what its sole relevant parent
2644          * simplifies to.
2645          */
2646         if (!cnt ||
2647             (commit->object.flags & UNINTERESTING) ||
2648             !(commit->object.flags & TREESAME) ||
2649             (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2650                 st->simplified = commit;
2651         else {
2652                 pst = locate_simplify_state(revs, parent);
2653                 st->simplified = pst->simplified;
2654         }
2655         return tail;
2656 }
2657
2658 static void simplify_merges(struct rev_info *revs)
2659 {
2660         struct commit_list *list, *next;
2661         struct commit_list *yet_to_do, **tail;
2662         struct commit *commit;
2663
2664         if (!revs->prune)
2665                 return;
2666
2667         /* feed the list reversed */
2668         yet_to_do = NULL;
2669         for (list = revs->commits; list; list = next) {
2670                 commit = list->item;
2671                 next = list->next;
2672                 /*
2673                  * Do not free(list) here yet; the original list
2674                  * is used later in this function.
2675                  */
2676                 commit_list_insert(commit, &yet_to_do);
2677         }
2678         while (yet_to_do) {
2679                 list = yet_to_do;
2680                 yet_to_do = NULL;
2681                 tail = &yet_to_do;
2682                 while (list) {
2683                         commit = pop_commit(&list);
2684                         tail = simplify_one(revs, commit, tail);
2685                 }
2686         }
2687
2688         /* clean up the result, removing the simplified ones */
2689         list = revs->commits;
2690         revs->commits = NULL;
2691         tail = &revs->commits;
2692         while (list) {
2693                 struct merge_simplify_state *st;
2694
2695                 commit = pop_commit(&list);
2696                 st = locate_simplify_state(revs, commit);
2697                 if (st->simplified == commit)
2698                         tail = &commit_list_insert(commit, tail)->next;
2699         }
2700 }
2701
2702 static void set_children(struct rev_info *revs)
2703 {
2704         struct commit_list *l;
2705         for (l = revs->commits; l; l = l->next) {
2706                 struct commit *commit = l->item;
2707                 struct commit_list *p;
2708
2709                 for (p = commit->parents; p; p = p->next)
2710                         add_child(revs, p->item, commit);
2711         }
2712 }
2713
2714 void reset_revision_walk(void)
2715 {
2716         clear_object_flags(SEEN | ADDED | SHOWN);
2717 }
2718
2719 int prepare_revision_walk(struct rev_info *revs)
2720 {
2721         int i;
2722         struct object_array old_pending;
2723         struct commit_list **next = &revs->commits;
2724
2725         memcpy(&old_pending, &revs->pending, sizeof(old_pending));
2726         revs->pending.nr = 0;
2727         revs->pending.alloc = 0;
2728         revs->pending.objects = NULL;
2729         for (i = 0; i < old_pending.nr; i++) {
2730                 struct object_array_entry *e = old_pending.objects + i;
2731                 struct commit *commit = handle_commit(revs, e);
2732                 if (commit) {
2733                         if (!(commit->object.flags & SEEN)) {
2734                                 commit->object.flags |= SEEN;
2735                                 next = commit_list_append(commit, next);
2736                         }
2737                 }
2738         }
2739         if (!revs->leak_pending)
2740                 object_array_clear(&old_pending);
2741
2742         /* Signal whether we need per-parent treesame decoration */
2743         if (revs->simplify_merges ||
2744             (revs->limited && limiting_can_increase_treesame(revs)))
2745                 revs->treesame.name = "treesame";
2746
2747         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2748                 commit_list_sort_by_date(&revs->commits);
2749         if (revs->no_walk)
2750                 return 0;
2751         if (revs->limited)
2752                 if (limit_list(revs) < 0)
2753                         return -1;
2754         if (revs->topo_order)
2755                 sort_in_topological_order(&revs->commits, revs->sort_order);
2756         if (revs->line_level_traverse)
2757                 line_log_filter(revs);
2758         if (revs->simplify_merges)
2759                 simplify_merges(revs);
2760         if (revs->children.name)
2761                 set_children(revs);
2762         return 0;
2763 }
2764
2765 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2766 {
2767         struct commit_list *cache = NULL;
2768
2769         for (;;) {
2770                 struct commit *p = *pp;
2771                 if (!revs->limited)
2772                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2773                                 return rewrite_one_error;
2774                 if (p->object.flags & UNINTERESTING)
2775                         return rewrite_one_ok;
2776                 if (!(p->object.flags & TREESAME))
2777                         return rewrite_one_ok;
2778                 if (!p->parents)
2779                         return rewrite_one_noparents;
2780                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2781                         return rewrite_one_ok;
2782                 *pp = p;
2783         }
2784 }
2785
2786 int rewrite_parents(struct rev_info *revs, struct commit *commit,
2787         rewrite_parent_fn_t rewrite_parent)
2788 {
2789         struct commit_list **pp = &commit->parents;
2790         while (*pp) {
2791                 struct commit_list *parent = *pp;
2792                 switch (rewrite_parent(revs, &parent->item)) {
2793                 case rewrite_one_ok:
2794                         break;
2795                 case rewrite_one_noparents:
2796                         *pp = parent->next;
2797                         continue;
2798                 case rewrite_one_error:
2799                         return -1;
2800                 }
2801                 pp = &parent->next;
2802         }
2803         remove_duplicate_parents(revs, commit);
2804         return 0;
2805 }
2806
2807 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2808 {
2809         char *person, *endp;
2810         size_t len, namelen, maillen;
2811         const char *name;
2812         const char *mail;
2813         struct ident_split ident;
2814
2815         person = strstr(buf->buf, what);
2816         if (!person)
2817                 return 0;
2818
2819         person += strlen(what);
2820         endp = strchr(person, '\n');
2821         if (!endp)
2822                 return 0;
2823
2824         len = endp - person;
2825
2826         if (split_ident_line(&ident, person, len))
2827                 return 0;
2828
2829         mail = ident.mail_begin;
2830         maillen = ident.mail_end - ident.mail_begin;
2831         name = ident.name_begin;
2832         namelen = ident.name_end - ident.name_begin;
2833
2834         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2835                 struct strbuf namemail = STRBUF_INIT;
2836
2837                 strbuf_addf(&namemail, "%.*s <%.*s>",
2838                             (int)namelen, name, (int)maillen, mail);
2839
2840                 strbuf_splice(buf, ident.name_begin - buf->buf,
2841                               ident.mail_end - ident.name_begin + 1,
2842                               namemail.buf, namemail.len);
2843
2844                 strbuf_release(&namemail);
2845
2846                 return 1;
2847         }
2848
2849         return 0;
2850 }
2851
2852 static int commit_match(struct commit *commit, struct rev_info *opt)
2853 {
2854         int retval;
2855         const char *encoding;
2856         const char *message;
2857         struct strbuf buf = STRBUF_INIT;
2858
2859         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2860                 return 1;
2861
2862         /* Prepend "fake" headers as needed */
2863         if (opt->grep_filter.use_reflog_filter) {
2864                 strbuf_addstr(&buf, "reflog ");
2865                 get_reflog_message(&buf, opt->reflog_info);
2866                 strbuf_addch(&buf, '\n');
2867         }
2868
2869         /*
2870          * We grep in the user's output encoding, under the assumption that it
2871          * is the encoding they are most likely to write their grep pattern
2872          * for. In addition, it means we will match the "notes" encoding below,
2873          * so we will not end up with a buffer that has two different encodings
2874          * in it.
2875          */
2876         encoding = get_log_output_encoding();
2877         message = logmsg_reencode(commit, NULL, encoding);
2878
2879         /* Copy the commit to temporary if we are using "fake" headers */
2880         if (buf.len)
2881                 strbuf_addstr(&buf, message);
2882
2883         if (opt->grep_filter.header_list && opt->mailmap) {
2884                 if (!buf.len)
2885                         strbuf_addstr(&buf, message);
2886
2887                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2888                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2889         }
2890
2891         /* Append "fake" message parts as needed */
2892         if (opt->show_notes) {
2893                 if (!buf.len)
2894                         strbuf_addstr(&buf, message);
2895                 format_display_notes(commit->object.oid.hash, &buf, encoding, 1);
2896         }
2897
2898         /*
2899          * Find either in the original commit message, or in the temporary.
2900          * Note that we cast away the constness of "message" here. It is
2901          * const because it may come from the cached commit buffer. That's OK,
2902          * because we know that it is modifiable heap memory, and that while
2903          * grep_buffer may modify it for speed, it will restore any
2904          * changes before returning.
2905          */
2906         if (buf.len)
2907                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2908         else
2909                 retval = grep_buffer(&opt->grep_filter,
2910                                      (char *)message, strlen(message));
2911         strbuf_release(&buf);
2912         unuse_commit_buffer(commit, message);
2913         return opt->invert_grep ? !retval : retval;
2914 }
2915
2916 static inline int want_ancestry(const struct rev_info *revs)
2917 {
2918         return (revs->rewrite_parents || revs->children.name);
2919 }
2920
2921 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2922 {
2923         if (commit->object.flags & SHOWN)
2924                 return commit_ignore;
2925         if (revs->unpacked && has_sha1_pack(commit->object.oid.hash))
2926                 return commit_ignore;
2927         if (revs->show_all)
2928                 return commit_show;
2929         if (commit->object.flags & UNINTERESTING)
2930                 return commit_ignore;
2931         if (revs->min_age != -1 && (commit->date > revs->min_age))
2932                 return commit_ignore;
2933         if (revs->min_parents || (revs->max_parents >= 0)) {
2934                 int n = commit_list_count(commit->parents);
2935                 if ((n < revs->min_parents) ||
2936                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2937                         return commit_ignore;
2938         }
2939         if (!commit_match(commit, revs))
2940                 return commit_ignore;
2941         if (revs->prune && revs->dense) {
2942                 /* Commit without changes? */
2943                 if (commit->object.flags & TREESAME) {
2944                         int n;
2945                         struct commit_list *p;
2946                         /* drop merges unless we want parenthood */
2947                         if (!want_ancestry(revs))
2948                                 return commit_ignore;
2949                         /*
2950                          * If we want ancestry, then need to keep any merges
2951                          * between relevant commits to tie together topology.
2952                          * For consistency with TREESAME and simplification
2953                          * use "relevant" here rather than just INTERESTING,
2954                          * to treat bottom commit(s) as part of the topology.
2955                          */
2956                         for (n = 0, p = commit->parents; p; p = p->next)
2957                                 if (relevant_commit(p->item))
2958                                         if (++n >= 2)
2959                                                 return commit_show;
2960                         return commit_ignore;
2961                 }
2962         }
2963         return commit_show;
2964 }
2965
2966 define_commit_slab(saved_parents, struct commit_list *);
2967
2968 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
2969
2970 /*
2971  * You may only call save_parents() once per commit (this is checked
2972  * for non-root commits).
2973  */
2974 static void save_parents(struct rev_info *revs, struct commit *commit)
2975 {
2976         struct commit_list **pp;
2977
2978         if (!revs->saved_parents_slab) {
2979                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
2980                 init_saved_parents(revs->saved_parents_slab);
2981         }
2982
2983         pp = saved_parents_at(revs->saved_parents_slab, commit);
2984
2985         /*
2986          * When walking with reflogs, we may visit the same commit
2987          * several times: once for each appearance in the reflog.
2988          *
2989          * In this case, save_parents() will be called multiple times.
2990          * We want to keep only the first set of parents.  We need to
2991          * store a sentinel value for an empty (i.e., NULL) parent
2992          * list to distinguish it from a not-yet-saved list, however.
2993          */
2994         if (*pp)
2995                 return;
2996         if (commit->parents)
2997                 *pp = copy_commit_list(commit->parents);
2998         else
2999                 *pp = EMPTY_PARENT_LIST;
3000 }
3001
3002 static void free_saved_parents(struct rev_info *revs)
3003 {
3004         if (revs->saved_parents_slab)
3005                 clear_saved_parents(revs->saved_parents_slab);
3006 }
3007
3008 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3009 {
3010         struct commit_list *parents;
3011
3012         if (!revs->saved_parents_slab)
3013                 return commit->parents;
3014
3015         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3016         if (parents == EMPTY_PARENT_LIST)
3017                 return NULL;
3018         return parents;
3019 }
3020
3021 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3022 {
3023         enum commit_action action = get_commit_action(revs, commit);
3024
3025         if (action == commit_show &&
3026             !revs->show_all &&
3027             revs->prune && revs->dense && want_ancestry(revs)) {
3028                 /*
3029                  * --full-diff on simplified parents is no good: it
3030                  * will show spurious changes from the commits that
3031                  * were elided.  So we save the parents on the side
3032                  * when --full-diff is in effect.
3033                  */
3034                 if (revs->full_diff)
3035                         save_parents(revs, commit);
3036                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
3037                         return commit_error;
3038         }
3039         return action;
3040 }
3041
3042 static void track_linear(struct rev_info *revs, struct commit *commit)
3043 {
3044         if (revs->track_first_time) {
3045                 revs->linear = 1;
3046                 revs->track_first_time = 0;
3047         } else {
3048                 struct commit_list *p;
3049                 for (p = revs->previous_parents; p; p = p->next)
3050                         if (p->item == NULL || /* first commit */
3051                             !oidcmp(&p->item->object.oid, &commit->object.oid))
3052                                 break;
3053                 revs->linear = p != NULL;
3054         }
3055         if (revs->reverse) {
3056                 if (revs->linear)
3057                         commit->object.flags |= TRACK_LINEAR;
3058         }
3059         free_commit_list(revs->previous_parents);
3060         revs->previous_parents = copy_commit_list(commit->parents);
3061 }
3062
3063 static struct commit *get_revision_1(struct rev_info *revs)
3064 {
3065         if (!revs->commits)
3066                 return NULL;
3067
3068         do {
3069                 struct commit *commit = pop_commit(&revs->commits);
3070
3071                 if (revs->reflog_info) {
3072                         save_parents(revs, commit);
3073                         fake_reflog_parent(revs->reflog_info, commit);
3074                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3075                 }
3076
3077                 /*
3078                  * If we haven't done the list limiting, we need to look at
3079                  * the parents here. We also need to do the date-based limiting
3080                  * that we'd otherwise have done in limit_list().
3081                  */
3082                 if (!revs->limited) {
3083                         if (revs->max_age != -1 &&
3084                             (commit->date < revs->max_age))
3085                                 continue;
3086                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
3087                                 if (!revs->ignore_missing_links)
3088                                         die("Failed to traverse parents of commit %s",
3089                                                 oid_to_hex(&commit->object.oid));
3090                         }
3091                 }
3092
3093                 switch (simplify_commit(revs, commit)) {
3094                 case commit_ignore:
3095                         continue;
3096                 case commit_error:
3097                         die("Failed to simplify parents of commit %s",
3098                             oid_to_hex(&commit->object.oid));
3099                 default:
3100                         if (revs->track_linear)
3101                                 track_linear(revs, commit);
3102                         return commit;
3103                 }
3104         } while (revs->commits);
3105         return NULL;
3106 }
3107
3108 /*
3109  * Return true for entries that have not yet been shown.  (This is an
3110  * object_array_each_func_t.)
3111  */
3112 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3113 {
3114         return !(entry->item->flags & SHOWN);
3115 }
3116
3117 /*
3118  * If array is on the verge of a realloc, garbage-collect any entries
3119  * that have already been shown to try to free up some space.
3120  */
3121 static void gc_boundary(struct object_array *array)
3122 {
3123         if (array->nr == array->alloc)
3124                 object_array_filter(array, entry_unshown, NULL);
3125 }
3126
3127 static void create_boundary_commit_list(struct rev_info *revs)
3128 {
3129         unsigned i;
3130         struct commit *c;
3131         struct object_array *array = &revs->boundary_commits;
3132         struct object_array_entry *objects = array->objects;
3133
3134         /*
3135          * If revs->commits is non-NULL at this point, an error occurred in
3136          * get_revision_1().  Ignore the error and continue printing the
3137          * boundary commits anyway.  (This is what the code has always
3138          * done.)
3139          */
3140         if (revs->commits) {
3141                 free_commit_list(revs->commits);
3142                 revs->commits = NULL;
3143         }
3144
3145         /*
3146          * Put all of the actual boundary commits from revs->boundary_commits
3147          * into revs->commits
3148          */
3149         for (i = 0; i < array->nr; i++) {
3150                 c = (struct commit *)(objects[i].item);
3151                 if (!c)
3152                         continue;
3153                 if (!(c->object.flags & CHILD_SHOWN))
3154                         continue;
3155                 if (c->object.flags & (SHOWN | BOUNDARY))
3156                         continue;
3157                 c->object.flags |= BOUNDARY;
3158                 commit_list_insert(c, &revs->commits);
3159         }
3160
3161         /*
3162          * If revs->topo_order is set, sort the boundary commits
3163          * in topological order
3164          */
3165         sort_in_topological_order(&revs->commits, revs->sort_order);
3166 }
3167
3168 static struct commit *get_revision_internal(struct rev_info *revs)
3169 {
3170         struct commit *c = NULL;
3171         struct commit_list *l;
3172
3173         if (revs->boundary == 2) {
3174                 /*
3175                  * All of the normal commits have already been returned,
3176                  * and we are now returning boundary commits.
3177                  * create_boundary_commit_list() has populated
3178                  * revs->commits with the remaining commits to return.
3179                  */
3180                 c = pop_commit(&revs->commits);
3181                 if (c)
3182                         c->object.flags |= SHOWN;
3183                 return c;
3184         }
3185
3186         /*
3187          * If our max_count counter has reached zero, then we are done. We
3188          * don't simply return NULL because we still might need to show
3189          * boundary commits. But we want to avoid calling get_revision_1, which
3190          * might do a considerable amount of work finding the next commit only
3191          * for us to throw it away.
3192          *
3193          * If it is non-zero, then either we don't have a max_count at all
3194          * (-1), or it is still counting, in which case we decrement.
3195          */
3196         if (revs->max_count) {
3197                 c = get_revision_1(revs);
3198                 if (c) {
3199                         while (revs->skip_count > 0) {
3200                                 revs->skip_count--;
3201                                 c = get_revision_1(revs);
3202                                 if (!c)
3203                                         break;
3204                         }
3205                 }
3206
3207                 if (revs->max_count > 0)
3208                         revs->max_count--;
3209         }
3210
3211         if (c)
3212                 c->object.flags |= SHOWN;
3213
3214         if (!revs->boundary)
3215                 return c;
3216
3217         if (!c) {
3218                 /*
3219                  * get_revision_1() runs out the commits, and
3220                  * we are done computing the boundaries.
3221                  * switch to boundary commits output mode.
3222                  */
3223                 revs->boundary = 2;
3224
3225                 /*
3226                  * Update revs->commits to contain the list of
3227                  * boundary commits.
3228                  */
3229                 create_boundary_commit_list(revs);
3230
3231                 return get_revision_internal(revs);
3232         }
3233
3234         /*
3235          * boundary commits are the commits that are parents of the
3236          * ones we got from get_revision_1() but they themselves are
3237          * not returned from get_revision_1().  Before returning
3238          * 'c', we need to mark its parents that they could be boundaries.
3239          */
3240
3241         for (l = c->parents; l; l = l->next) {
3242                 struct object *p;
3243                 p = &(l->item->object);
3244                 if (p->flags & (CHILD_SHOWN | SHOWN))
3245                         continue;
3246                 p->flags |= CHILD_SHOWN;
3247                 gc_boundary(&revs->boundary_commits);
3248                 add_object_array(p, NULL, &revs->boundary_commits);
3249         }
3250
3251         return c;
3252 }
3253
3254 struct commit *get_revision(struct rev_info *revs)
3255 {
3256         struct commit *c;
3257         struct commit_list *reversed;
3258
3259         if (revs->reverse) {
3260                 reversed = NULL;
3261                 while ((c = get_revision_internal(revs)))
3262                         commit_list_insert(c, &reversed);
3263                 revs->commits = reversed;
3264                 revs->reverse = 0;
3265                 revs->reverse_output_stage = 1;
3266         }
3267
3268         if (revs->reverse_output_stage) {
3269                 c = pop_commit(&revs->commits);
3270                 if (revs->track_linear)
3271                         revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
3272                 return c;
3273         }
3274
3275         c = get_revision_internal(revs);
3276         if (c && revs->graph)
3277                 graph_update(revs->graph, c);
3278         if (!c) {
3279                 free_saved_parents(revs);
3280                 if (revs->previous_parents) {
3281                         free_commit_list(revs->previous_parents);
3282                         revs->previous_parents = NULL;
3283                 }
3284         }
3285         return c;
3286 }
3287
3288 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3289 {
3290         if (commit->object.flags & BOUNDARY)
3291                 return "-";
3292         else if (commit->object.flags & UNINTERESTING)
3293                 return "^";
3294         else if (commit->object.flags & PATCHSAME)
3295                 return "=";
3296         else if (!revs || revs->left_right) {
3297                 if (commit->object.flags & SYMMETRIC_LEFT)
3298                         return "<";
3299                 else
3300                         return ">";
3301         } else if (revs->graph)
3302                 return "*";
3303         else if (revs->cherry_mark)
3304                 return "+";
3305         return "";
3306 }
3307
3308 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3309 {
3310         char *mark = get_revision_mark(revs, commit);
3311         if (!strlen(mark))
3312                 return;
3313         fputs(mark, stdout);
3314         putchar(' ');
3315 }