Merge branch 'ls/p4-keep-empty-commits'
[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 char *path_name(const struct name_path *path, const char *name)
29 {
30         const struct name_path *p;
31         char *n, *m;
32         int nlen = strlen(name);
33         int len = nlen + 1;
34
35         for (p = path; p; p = p->up) {
36                 if (p->elem_len)
37                         len += p->elem_len + 1;
38         }
39         n = xmalloc(len);
40         m = n + len - (nlen + 1);
41         memcpy(m, name, nlen + 1);
42         for (p = path; p; p = p->up) {
43                 if (p->elem_len) {
44                         m -= p->elem_len + 1;
45                         memcpy(m, p->elem, p->elem_len);
46                         m[p->elem_len] = '/';
47                 }
48         }
49         return n;
50 }
51
52 static int show_path_component_truncated(FILE *out, const char *name, int len)
53 {
54         int cnt;
55         for (cnt = 0; cnt < len; cnt++) {
56                 int ch = name[cnt];
57                 if (!ch || ch == '\n')
58                         return -1;
59                 fputc(ch, out);
60         }
61         return len;
62 }
63
64 static int show_path_truncated(FILE *out, const struct name_path *path)
65 {
66         int emitted, ours;
67
68         if (!path)
69                 return 0;
70         emitted = show_path_truncated(out, path->up);
71         if (emitted < 0)
72                 return emitted;
73         if (emitted)
74                 fputc('/', out);
75         ours = show_path_component_truncated(out, path->elem, path->elem_len);
76         if (ours < 0)
77                 return ours;
78         return ours || emitted;
79 }
80
81 void show_object_with_name(FILE *out, struct object *obj,
82                            const struct name_path *path, const char *component)
83 {
84         struct name_path leaf;
85         leaf.up = (struct name_path *)path;
86         leaf.elem = component;
87         leaf.elem_len = strlen(component);
88
89         fprintf(out, "%s ", oid_to_hex(&obj->oid));
90         show_path_truncated(out, &leaf);
91         fputc('\n', out);
92 }
93
94 static void mark_blob_uninteresting(struct blob *blob)
95 {
96         if (!blob)
97                 return;
98         if (blob->object.flags & UNINTERESTING)
99                 return;
100         blob->object.flags |= UNINTERESTING;
101 }
102
103 static void mark_tree_contents_uninteresting(struct tree *tree)
104 {
105         struct tree_desc desc;
106         struct name_entry entry;
107         struct object *obj = &tree->object;
108
109         if (!has_object_file(&obj->oid))
110                 return;
111         if (parse_tree(tree) < 0)
112                 die("bad tree %s", oid_to_hex(&obj->oid));
113
114         init_tree_desc(&desc, tree->buffer, tree->size);
115         while (tree_entry(&desc, &entry)) {
116                 switch (object_type(entry.mode)) {
117                 case OBJ_TREE:
118                         mark_tree_uninteresting(lookup_tree(entry.sha1));
119                         break;
120                 case OBJ_BLOB:
121                         mark_blob_uninteresting(lookup_blob(entry.sha1));
122                         break;
123                 default:
124                         /* Subproject commit - not in this repository */
125                         break;
126                 }
127         }
128
129         /*
130          * We don't care about the tree any more
131          * after it has been marked uninteresting.
132          */
133         free_tree_buffer(tree);
134 }
135
136 void mark_tree_uninteresting(struct tree *tree)
137 {
138         struct object *obj;
139
140         if (!tree)
141                 return;
142
143         obj = &tree->object;
144         if (obj->flags & UNINTERESTING)
145                 return;
146         obj->flags |= UNINTERESTING;
147         mark_tree_contents_uninteresting(tree);
148 }
149
150 void mark_parents_uninteresting(struct commit *commit)
151 {
152         struct commit_list *parents = NULL, *l;
153
154         for (l = commit->parents; l; l = l->next)
155                 commit_list_insert(l->item, &parents);
156
157         while (parents) {
158                 struct commit *commit = pop_commit(&parents);
159
160                 while (commit) {
161                         /*
162                          * A missing commit is ok iff its parent is marked
163                          * uninteresting.
164                          *
165                          * We just mark such a thing parsed, so that when
166                          * it is popped next time around, we won't be trying
167                          * to parse it and get an error.
168                          */
169                         if (!has_object_file(&commit->object.oid))
170                                 commit->object.parsed = 1;
171
172                         if (commit->object.flags & UNINTERESTING)
173                                 break;
174
175                         commit->object.flags |= UNINTERESTING;
176
177                         /*
178                          * Normally we haven't parsed the parent
179                          * yet, so we won't have a parent of a parent
180                          * here. However, it may turn out that we've
181                          * reached this commit some other way (where it
182                          * wasn't uninteresting), in which case we need
183                          * to mark its parents recursively too..
184                          */
185                         if (!commit->parents)
186                                 break;
187
188                         for (l = commit->parents->next; l; l = l->next)
189                                 commit_list_insert(l->item, &parents);
190                         commit = commit->parents->item;
191                 }
192         }
193 }
194
195 static void add_pending_object_with_path(struct rev_info *revs,
196                                          struct object *obj,
197                                          const char *name, unsigned mode,
198                                          const char *path)
199 {
200         if (!obj)
201                 return;
202         if (revs->no_walk && (obj->flags & UNINTERESTING))
203                 revs->no_walk = 0;
204         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
205                 struct strbuf buf = STRBUF_INIT;
206                 int len = interpret_branch_name(name, 0, &buf);
207                 int st;
208
209                 if (0 < len && name[len] && buf.len)
210                         strbuf_addstr(&buf, name + len);
211                 st = add_reflog_for_walk(revs->reflog_info,
212                                          (struct commit *)obj,
213                                          buf.buf[0] ? buf.buf: name);
214                 strbuf_release(&buf);
215                 if (st)
216                         return;
217         }
218         add_object_array_with_path(obj, name, &revs->pending, mode, path);
219 }
220
221 static void add_pending_object_with_mode(struct rev_info *revs,
222                                          struct object *obj,
223                                          const char *name, unsigned mode)
224 {
225         add_pending_object_with_path(revs, obj, name, mode, NULL);
226 }
227
228 void add_pending_object(struct rev_info *revs,
229                         struct object *obj, const char *name)
230 {
231         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
232 }
233
234 void add_head_to_pending(struct rev_info *revs)
235 {
236         unsigned char sha1[20];
237         struct object *obj;
238         if (get_sha1("HEAD", sha1))
239                 return;
240         obj = parse_object(sha1);
241         if (!obj)
242                 return;
243         add_pending_object(revs, obj, "HEAD");
244 }
245
246 static struct object *get_reference(struct rev_info *revs, const char *name,
247                                     const unsigned char *sha1,
248                                     unsigned int flags)
249 {
250         struct object *object;
251
252         object = parse_object(sha1);
253         if (!object) {
254                 if (revs->ignore_missing)
255                         return object;
256                 die("bad object %s", name);
257         }
258         object->flags |= flags;
259         return object;
260 }
261
262 void add_pending_sha1(struct rev_info *revs, const char *name,
263                       const unsigned char *sha1, unsigned int flags)
264 {
265         struct object *object = get_reference(revs, name, sha1, flags);
266         add_pending_object(revs, object, name);
267 }
268
269 static struct commit *handle_commit(struct rev_info *revs,
270                                     struct object_array_entry *entry)
271 {
272         struct object *object = entry->item;
273         const char *name = entry->name;
274         const char *path = entry->path;
275         unsigned int mode = entry->mode;
276         unsigned long flags = object->flags;
277
278         /*
279          * Tag object? Look what it points to..
280          */
281         while (object->type == OBJ_TAG) {
282                 struct tag *tag = (struct tag *) object;
283                 if (revs->tag_objects && !(flags & UNINTERESTING))
284                         add_pending_object(revs, object, tag->tag);
285                 if (!tag->tagged)
286                         die("bad tag");
287                 object = parse_object(tag->tagged->oid.hash);
288                 if (!object) {
289                         if (flags & UNINTERESTING)
290                                 return NULL;
291                         die("bad object %s", oid_to_hex(&tag->tagged->oid));
292                 }
293                 object->flags |= flags;
294                 /*
295                  * We'll handle the tagged object by looping or dropping
296                  * through to the non-tag handlers below. Do not
297                  * propagate data from the tag's pending entry.
298                  */
299                 name = "";
300                 path = NULL;
301                 mode = 0;
302         }
303
304         /*
305          * Commit object? Just return it, we'll do all the complex
306          * reachability crud.
307          */
308         if (object->type == OBJ_COMMIT) {
309                 struct commit *commit = (struct commit *)object;
310                 if (parse_commit(commit) < 0)
311                         die("unable to parse commit %s", name);
312                 if (flags & UNINTERESTING) {
313                         mark_parents_uninteresting(commit);
314                         revs->limited = 1;
315                 }
316                 if (revs->show_source && !commit->util)
317                         commit->util = xstrdup(name);
318                 return commit;
319         }
320
321         /*
322          * Tree object? Either mark it uninteresting, or add it
323          * to the list of objects to look at later..
324          */
325         if (object->type == OBJ_TREE) {
326                 struct tree *tree = (struct tree *)object;
327                 if (!revs->tree_objects)
328                         return NULL;
329                 if (flags & UNINTERESTING) {
330                         mark_tree_contents_uninteresting(tree);
331                         return NULL;
332                 }
333                 add_pending_object_with_path(revs, object, name, mode, path);
334                 return NULL;
335         }
336
337         /*
338          * Blob object? You know the drill by now..
339          */
340         if (object->type == OBJ_BLOB) {
341                 if (!revs->blob_objects)
342                         return NULL;
343                 if (flags & UNINTERESTING)
344                         return NULL;
345                 add_pending_object_with_path(revs, object, name, mode, path);
346                 return NULL;
347         }
348         die("%s is unknown object", name);
349 }
350
351 static int everybody_uninteresting(struct commit_list *orig,
352                                    struct commit **interesting_cache)
353 {
354         struct commit_list *list = orig;
355
356         if (*interesting_cache) {
357                 struct commit *commit = *interesting_cache;
358                 if (!(commit->object.flags & UNINTERESTING))
359                         return 0;
360         }
361
362         while (list) {
363                 struct commit *commit = list->item;
364                 list = list->next;
365                 if (commit->object.flags & UNINTERESTING)
366                         continue;
367
368                 *interesting_cache = commit;
369                 return 0;
370         }
371         return 1;
372 }
373
374 /*
375  * A definition of "relevant" commit that we can use to simplify limited graphs
376  * by eliminating side branches.
377  *
378  * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
379  * in our list), or that is a specified BOTTOM commit. Then after computing
380  * a limited list, during processing we can generally ignore boundary merges
381  * coming from outside the graph, (ie from irrelevant parents), and treat
382  * those merges as if they were single-parent. TREESAME is defined to consider
383  * only relevant parents, if any. If we are TREESAME to our on-graph parents,
384  * we don't care if we were !TREESAME to non-graph parents.
385  *
386  * Treating bottom commits as relevant ensures that a limited graph's
387  * connection to the actual bottom commit is not viewed as a side branch, but
388  * treated as part of the graph. For example:
389  *
390  *   ....Z...A---X---o---o---B
391  *        .     /
392  *         W---Y
393  *
394  * When computing "A..B", the A-X connection is at least as important as
395  * Y-X, despite A being flagged UNINTERESTING.
396  *
397  * And when computing --ancestry-path "A..B", the A-X connection is more
398  * important than Y-X, despite both A and Y being flagged UNINTERESTING.
399  */
400 static inline int relevant_commit(struct commit *commit)
401 {
402         return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
403 }
404
405 /*
406  * Return a single relevant commit from a parent list. If we are a TREESAME
407  * commit, and this selects one of our parents, then we can safely simplify to
408  * that parent.
409  */
410 static struct commit *one_relevant_parent(const struct rev_info *revs,
411                                           struct commit_list *orig)
412 {
413         struct commit_list *list = orig;
414         struct commit *relevant = NULL;
415
416         if (!orig)
417                 return NULL;
418
419         /*
420          * For 1-parent commits, or if first-parent-only, then return that
421          * first parent (even if not "relevant" by the above definition).
422          * TREESAME will have been set purely on that parent.
423          */
424         if (revs->first_parent_only || !orig->next)
425                 return orig->item;
426
427         /*
428          * For multi-parent commits, identify a sole relevant parent, if any.
429          * If we have only one relevant parent, then TREESAME will be set purely
430          * with regard to that parent, and we can simplify accordingly.
431          *
432          * If we have more than one relevant parent, or no relevant parents
433          * (and multiple irrelevant ones), then we can't select a parent here
434          * and return NULL.
435          */
436         while (list) {
437                 struct commit *commit = list->item;
438                 list = list->next;
439                 if (relevant_commit(commit)) {
440                         if (relevant)
441                                 return NULL;
442                         relevant = commit;
443                 }
444         }
445         return relevant;
446 }
447
448 /*
449  * The goal is to get REV_TREE_NEW as the result only if the
450  * diff consists of all '+' (and no other changes), REV_TREE_OLD
451  * if the whole diff is removal of old data, and otherwise
452  * REV_TREE_DIFFERENT (of course if the trees are the same we
453  * want REV_TREE_SAME).
454  * That means that once we get to REV_TREE_DIFFERENT, we do not
455  * have to look any further.
456  */
457 static int tree_difference = REV_TREE_SAME;
458
459 static void file_add_remove(struct diff_options *options,
460                     int addremove, unsigned mode,
461                     const unsigned char *sha1,
462                     int sha1_valid,
463                     const char *fullpath, unsigned dirty_submodule)
464 {
465         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
466
467         tree_difference |= diff;
468         if (tree_difference == REV_TREE_DIFFERENT)
469                 DIFF_OPT_SET(options, HAS_CHANGES);
470 }
471
472 static void file_change(struct diff_options *options,
473                  unsigned old_mode, unsigned new_mode,
474                  const unsigned char *old_sha1,
475                  const unsigned char *new_sha1,
476                  int old_sha1_valid, int new_sha1_valid,
477                  const char *fullpath,
478                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
479 {
480         tree_difference = REV_TREE_DIFFERENT;
481         DIFF_OPT_SET(options, HAS_CHANGES);
482 }
483
484 static int rev_compare_tree(struct rev_info *revs,
485                             struct commit *parent, struct commit *commit)
486 {
487         struct tree *t1 = parent->tree;
488         struct tree *t2 = commit->tree;
489
490         if (!t1)
491                 return REV_TREE_NEW;
492         if (!t2)
493                 return REV_TREE_OLD;
494
495         if (revs->simplify_by_decoration) {
496                 /*
497                  * If we are simplifying by decoration, then the commit
498                  * is worth showing if it has a tag pointing at it.
499                  */
500                 if (get_name_decoration(&commit->object))
501                         return REV_TREE_DIFFERENT;
502                 /*
503                  * A commit that is not pointed by a tag is uninteresting
504                  * if we are not limited by path.  This means that you will
505                  * see the usual "commits that touch the paths" plus any
506                  * tagged commit by specifying both --simplify-by-decoration
507                  * and pathspec.
508                  */
509                 if (!revs->prune_data.nr)
510                         return REV_TREE_SAME;
511         }
512
513         tree_difference = REV_TREE_SAME;
514         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
515         if (diff_tree_sha1(t1->object.oid.hash, t2->object.oid.hash, "",
516                            &revs->pruning) < 0)
517                 return REV_TREE_DIFFERENT;
518         return tree_difference;
519 }
520
521 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
522 {
523         int retval;
524         struct tree *t1 = commit->tree;
525
526         if (!t1)
527                 return 0;
528
529         tree_difference = REV_TREE_SAME;
530         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
531         retval = diff_tree_sha1(NULL, t1->object.oid.hash, "", &revs->pruning);
532
533         return retval >= 0 && (tree_difference == REV_TREE_SAME);
534 }
535
536 struct treesame_state {
537         unsigned int nparents;
538         unsigned char treesame[FLEX_ARRAY];
539 };
540
541 static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
542 {
543         unsigned n = commit_list_count(commit->parents);
544         struct treesame_state *st = xcalloc(1, sizeof(*st) + n);
545         st->nparents = n;
546         add_decoration(&revs->treesame, &commit->object, st);
547         return st;
548 }
549
550 /*
551  * Must be called immediately after removing the nth_parent from a commit's
552  * parent list, if we are maintaining the per-parent treesame[] decoration.
553  * This does not recalculate the master TREESAME flag - update_treesame()
554  * should be called to update it after a sequence of treesame[] modifications
555  * that may have affected it.
556  */
557 static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
558 {
559         struct treesame_state *st;
560         int old_same;
561
562         if (!commit->parents) {
563                 /*
564                  * Have just removed the only parent from a non-merge.
565                  * Different handling, as we lack decoration.
566                  */
567                 if (nth_parent != 0)
568                         die("compact_treesame %u", nth_parent);
569                 old_same = !!(commit->object.flags & TREESAME);
570                 if (rev_same_tree_as_empty(revs, commit))
571                         commit->object.flags |= TREESAME;
572                 else
573                         commit->object.flags &= ~TREESAME;
574                 return old_same;
575         }
576
577         st = lookup_decoration(&revs->treesame, &commit->object);
578         if (!st || nth_parent >= st->nparents)
579                 die("compact_treesame %u", nth_parent);
580
581         old_same = st->treesame[nth_parent];
582         memmove(st->treesame + nth_parent,
583                 st->treesame + nth_parent + 1,
584                 st->nparents - nth_parent - 1);
585
586         /*
587          * If we've just become a non-merge commit, update TREESAME
588          * immediately, and remove the no-longer-needed decoration.
589          * If still a merge, defer update until update_treesame().
590          */
591         if (--st->nparents == 1) {
592                 if (commit->parents->next)
593                         die("compact_treesame parents mismatch");
594                 if (st->treesame[0] && revs->dense)
595                         commit->object.flags |= TREESAME;
596                 else
597                         commit->object.flags &= ~TREESAME;
598                 free(add_decoration(&revs->treesame, &commit->object, NULL));
599         }
600
601         return old_same;
602 }
603
604 static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
605 {
606         if (commit->parents && commit->parents->next) {
607                 unsigned n;
608                 struct treesame_state *st;
609                 struct commit_list *p;
610                 unsigned relevant_parents;
611                 unsigned relevant_change, irrelevant_change;
612
613                 st = lookup_decoration(&revs->treesame, &commit->object);
614                 if (!st)
615                         die("update_treesame %s", oid_to_hex(&commit->object.oid));
616                 relevant_parents = 0;
617                 relevant_change = irrelevant_change = 0;
618                 for (p = commit->parents, n = 0; p; n++, p = p->next) {
619                         if (relevant_commit(p->item)) {
620                                 relevant_change |= !st->treesame[n];
621                                 relevant_parents++;
622                         } else
623                                 irrelevant_change |= !st->treesame[n];
624                 }
625                 if (relevant_parents ? relevant_change : irrelevant_change)
626                         commit->object.flags &= ~TREESAME;
627                 else
628                         commit->object.flags |= TREESAME;
629         }
630
631         return commit->object.flags & TREESAME;
632 }
633
634 static inline int limiting_can_increase_treesame(const struct rev_info *revs)
635 {
636         /*
637          * TREESAME is irrelevant unless prune && dense;
638          * if simplify_history is set, we can't have a mixture of TREESAME and
639          *    !TREESAME INTERESTING parents (and we don't have treesame[]
640          *    decoration anyway);
641          * if first_parent_only is set, then the TREESAME flag is locked
642          *    against the first parent (and again we lack treesame[] decoration).
643          */
644         return revs->prune && revs->dense &&
645                !revs->simplify_history &&
646                !revs->first_parent_only;
647 }
648
649 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
650 {
651         struct commit_list **pp, *parent;
652         struct treesame_state *ts = NULL;
653         int relevant_change = 0, irrelevant_change = 0;
654         int relevant_parents, nth_parent;
655
656         /*
657          * If we don't do pruning, everything is interesting
658          */
659         if (!revs->prune)
660                 return;
661
662         if (!commit->tree)
663                 return;
664
665         if (!commit->parents) {
666                 if (rev_same_tree_as_empty(revs, commit))
667                         commit->object.flags |= TREESAME;
668                 return;
669         }
670
671         /*
672          * Normal non-merge commit? If we don't want to make the
673          * history dense, we consider it always to be a change..
674          */
675         if (!revs->dense && !commit->parents->next)
676                 return;
677
678         for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
679              (parent = *pp) != NULL;
680              pp = &parent->next, nth_parent++) {
681                 struct commit *p = parent->item;
682                 if (relevant_commit(p))
683                         relevant_parents++;
684
685                 if (nth_parent == 1) {
686                         /*
687                          * This our second loop iteration - so we now know
688                          * we're dealing with a merge.
689                          *
690                          * Do not compare with later parents when we care only about
691                          * the first parent chain, in order to avoid derailing the
692                          * traversal to follow a side branch that brought everything
693                          * in the path we are limited to by the pathspec.
694                          */
695                         if (revs->first_parent_only)
696                                 break;
697                         /*
698                          * If this will remain a potentially-simplifiable
699                          * merge, remember per-parent treesame if needed.
700                          * Initialise the array with the comparison from our
701                          * first iteration.
702                          */
703                         if (revs->treesame.name &&
704                             !revs->simplify_history &&
705                             !(commit->object.flags & UNINTERESTING)) {
706                                 ts = initialise_treesame(revs, commit);
707                                 if (!(irrelevant_change || relevant_change))
708                                         ts->treesame[0] = 1;
709                         }
710                 }
711                 if (parse_commit(p) < 0)
712                         die("cannot simplify commit %s (because of %s)",
713                             oid_to_hex(&commit->object.oid),
714                             oid_to_hex(&p->object.oid));
715                 switch (rev_compare_tree(revs, p, commit)) {
716                 case REV_TREE_SAME:
717                         if (!revs->simplify_history || !relevant_commit(p)) {
718                                 /* Even if a merge with an uninteresting
719                                  * side branch brought the entire change
720                                  * we are interested in, we do not want
721                                  * to lose the other branches of this
722                                  * merge, so we just keep going.
723                                  */
724                                 if (ts)
725                                         ts->treesame[nth_parent] = 1;
726                                 continue;
727                         }
728                         parent->next = NULL;
729                         commit->parents = parent;
730                         commit->object.flags |= TREESAME;
731                         return;
732
733                 case REV_TREE_NEW:
734                         if (revs->remove_empty_trees &&
735                             rev_same_tree_as_empty(revs, p)) {
736                                 /* We are adding all the specified
737                                  * paths from this parent, so the
738                                  * history beyond this parent is not
739                                  * interesting.  Remove its parents
740                                  * (they are grandparents for us).
741                                  * IOW, we pretend this parent is a
742                                  * "root" commit.
743                                  */
744                                 if (parse_commit(p) < 0)
745                                         die("cannot simplify commit %s (invalid %s)",
746                                             oid_to_hex(&commit->object.oid),
747                                             oid_to_hex(&p->object.oid));
748                                 p->parents = NULL;
749                         }
750                 /* fallthrough */
751                 case REV_TREE_OLD:
752                 case REV_TREE_DIFFERENT:
753                         if (relevant_commit(p))
754                                 relevant_change = 1;
755                         else
756                                 irrelevant_change = 1;
757                         continue;
758                 }
759                 die("bad tree compare for commit %s", oid_to_hex(&commit->object.oid));
760         }
761
762         /*
763          * TREESAME is straightforward for single-parent commits. For merge
764          * commits, it is most useful to define it so that "irrelevant"
765          * parents cannot make us !TREESAME - if we have any relevant
766          * parents, then we only consider TREESAMEness with respect to them,
767          * allowing irrelevant merges from uninteresting branches to be
768          * simplified away. Only if we have only irrelevant parents do we
769          * base TREESAME on them. Note that this logic is replicated in
770          * update_treesame, which should be kept in sync.
771          */
772         if (relevant_parents ? !relevant_change : !irrelevant_change)
773                 commit->object.flags |= TREESAME;
774 }
775
776 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
777                     struct commit_list *cached_base, struct commit_list **cache)
778 {
779         struct commit_list *new_entry;
780
781         if (cached_base && p->date < cached_base->item->date)
782                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
783         else
784                 new_entry = commit_list_insert_by_date(p, head);
785
786         if (cache && (!*cache || p->date < (*cache)->item->date))
787                 *cache = new_entry;
788 }
789
790 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
791                     struct commit_list **list, struct commit_list **cache_ptr)
792 {
793         struct commit_list *parent = commit->parents;
794         unsigned left_flag;
795         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
796
797         if (commit->object.flags & ADDED)
798                 return 0;
799         commit->object.flags |= ADDED;
800
801         if (revs->include_check &&
802             !revs->include_check(commit, revs->include_check_data))
803                 return 0;
804
805         /*
806          * If the commit is uninteresting, don't try to
807          * prune parents - we want the maximal uninteresting
808          * set.
809          *
810          * Normally we haven't parsed the parent
811          * yet, so we won't have a parent of a parent
812          * here. However, it may turn out that we've
813          * reached this commit some other way (where it
814          * wasn't uninteresting), in which case we need
815          * to mark its parents recursively too..
816          */
817         if (commit->object.flags & UNINTERESTING) {
818                 while (parent) {
819                         struct commit *p = parent->item;
820                         parent = parent->next;
821                         if (p)
822                                 p->object.flags |= UNINTERESTING;
823                         if (parse_commit_gently(p, 1) < 0)
824                                 continue;
825                         if (p->parents)
826                                 mark_parents_uninteresting(p);
827                         if (p->object.flags & SEEN)
828                                 continue;
829                         p->object.flags |= SEEN;
830                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
831                 }
832                 return 0;
833         }
834
835         /*
836          * Ok, the commit wasn't uninteresting. Try to
837          * simplify the commit history and find the parent
838          * that has no differences in the path set if one exists.
839          */
840         try_to_simplify_commit(revs, commit);
841
842         if (revs->no_walk)
843                 return 0;
844
845         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
846
847         for (parent = commit->parents; parent; parent = parent->next) {
848                 struct commit *p = parent->item;
849
850                 if (parse_commit_gently(p, revs->ignore_missing_links) < 0)
851                         return -1;
852                 if (revs->show_source && !p->util)
853                         p->util = commit->util;
854                 p->object.flags |= left_flag;
855                 if (!(p->object.flags & SEEN)) {
856                         p->object.flags |= SEEN;
857                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
858                 }
859                 if (revs->first_parent_only)
860                         break;
861         }
862         return 0;
863 }
864
865 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
866 {
867         struct commit_list *p;
868         int left_count = 0, right_count = 0;
869         int left_first;
870         struct patch_ids ids;
871         unsigned cherry_flag;
872
873         /* First count the commits on the left and on the right */
874         for (p = list; p; p = p->next) {
875                 struct commit *commit = p->item;
876                 unsigned flags = commit->object.flags;
877                 if (flags & BOUNDARY)
878                         ;
879                 else if (flags & SYMMETRIC_LEFT)
880                         left_count++;
881                 else
882                         right_count++;
883         }
884
885         if (!left_count || !right_count)
886                 return;
887
888         left_first = left_count < right_count;
889         init_patch_ids(&ids);
890         ids.diffopts.pathspec = revs->diffopt.pathspec;
891
892         /* Compute patch-ids for one side */
893         for (p = list; p; p = p->next) {
894                 struct commit *commit = p->item;
895                 unsigned flags = commit->object.flags;
896
897                 if (flags & BOUNDARY)
898                         continue;
899                 /*
900                  * If we have fewer left, left_first is set and we omit
901                  * commits on the right branch in this loop.  If we have
902                  * fewer right, we skip the left ones.
903                  */
904                 if (left_first != !!(flags & SYMMETRIC_LEFT))
905                         continue;
906                 commit->util = add_commit_patch_id(commit, &ids);
907         }
908
909         /* either cherry_mark or cherry_pick are true */
910         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
911
912         /* Check the other side */
913         for (p = list; p; p = p->next) {
914                 struct commit *commit = p->item;
915                 struct patch_id *id;
916                 unsigned flags = commit->object.flags;
917
918                 if (flags & BOUNDARY)
919                         continue;
920                 /*
921                  * If we have fewer left, left_first is set and we omit
922                  * commits on the left branch in this loop.
923                  */
924                 if (left_first == !!(flags & SYMMETRIC_LEFT))
925                         continue;
926
927                 /*
928                  * Have we seen the same patch id?
929                  */
930                 id = has_commit_patch_id(commit, &ids);
931                 if (!id)
932                         continue;
933                 id->seen = 1;
934                 commit->object.flags |= cherry_flag;
935         }
936
937         /* Now check the original side for seen ones */
938         for (p = list; p; p = p->next) {
939                 struct commit *commit = p->item;
940                 struct patch_id *ent;
941
942                 ent = commit->util;
943                 if (!ent)
944                         continue;
945                 if (ent->seen)
946                         commit->object.flags |= cherry_flag;
947                 commit->util = NULL;
948         }
949
950         free_patch_ids(&ids);
951 }
952
953 /* How many extra uninteresting commits we want to see.. */
954 #define SLOP 5
955
956 static int still_interesting(struct commit_list *src, unsigned long date, int slop,
957                              struct commit **interesting_cache)
958 {
959         /*
960          * No source list at all? We're definitely done..
961          */
962         if (!src)
963                 return 0;
964
965         /*
966          * Does the destination list contain entries with a date
967          * before the source list? Definitely _not_ done.
968          */
969         if (date <= src->item->date)
970                 return SLOP;
971
972         /*
973          * Does the source list still have interesting commits in
974          * it? Definitely not done..
975          */
976         if (!everybody_uninteresting(src, interesting_cache))
977                 return SLOP;
978
979         /* Ok, we're closing in.. */
980         return slop-1;
981 }
982
983 /*
984  * "rev-list --ancestry-path A..B" computes commits that are ancestors
985  * of B but not ancestors of A but further limits the result to those
986  * that are descendants of A.  This takes the list of bottom commits and
987  * the result of "A..B" without --ancestry-path, and limits the latter
988  * further to the ones that can reach one of the commits in "bottom".
989  */
990 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
991 {
992         struct commit_list *p;
993         struct commit_list *rlist = NULL;
994         int made_progress;
995
996         /*
997          * Reverse the list so that it will be likely that we would
998          * process parents before children.
999          */
1000         for (p = list; p; p = p->next)
1001                 commit_list_insert(p->item, &rlist);
1002
1003         for (p = bottom; p; p = p->next)
1004                 p->item->object.flags |= TMP_MARK;
1005
1006         /*
1007          * Mark the ones that can reach bottom commits in "list",
1008          * in a bottom-up fashion.
1009          */
1010         do {
1011                 made_progress = 0;
1012                 for (p = rlist; p; p = p->next) {
1013                         struct commit *c = p->item;
1014                         struct commit_list *parents;
1015                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
1016                                 continue;
1017                         for (parents = c->parents;
1018                              parents;
1019                              parents = parents->next) {
1020                                 if (!(parents->item->object.flags & TMP_MARK))
1021                                         continue;
1022                                 c->object.flags |= TMP_MARK;
1023                                 made_progress = 1;
1024                                 break;
1025                         }
1026                 }
1027         } while (made_progress);
1028
1029         /*
1030          * NEEDSWORK: decide if we want to remove parents that are
1031          * not marked with TMP_MARK from commit->parents for commits
1032          * in the resulting list.  We may not want to do that, though.
1033          */
1034
1035         /*
1036          * The ones that are not marked with TMP_MARK are uninteresting
1037          */
1038         for (p = list; p; p = p->next) {
1039                 struct commit *c = p->item;
1040                 if (c->object.flags & TMP_MARK)
1041                         continue;
1042                 c->object.flags |= UNINTERESTING;
1043         }
1044
1045         /* We are done with the TMP_MARK */
1046         for (p = list; p; p = p->next)
1047                 p->item->object.flags &= ~TMP_MARK;
1048         for (p = bottom; p; p = p->next)
1049                 p->item->object.flags &= ~TMP_MARK;
1050         free_commit_list(rlist);
1051 }
1052
1053 /*
1054  * Before walking the history, keep the set of "negative" refs the
1055  * caller has asked to exclude.
1056  *
1057  * This is used to compute "rev-list --ancestry-path A..B", as we need
1058  * to filter the result of "A..B" further to the ones that can actually
1059  * reach A.
1060  */
1061 static struct commit_list *collect_bottom_commits(struct commit_list *list)
1062 {
1063         struct commit_list *elem, *bottom = NULL;
1064         for (elem = list; elem; elem = elem->next)
1065                 if (elem->item->object.flags & BOTTOM)
1066                         commit_list_insert(elem->item, &bottom);
1067         return bottom;
1068 }
1069
1070 /* Assumes either left_only or right_only is set */
1071 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1072 {
1073         struct commit_list *p;
1074
1075         for (p = list; p; p = p->next) {
1076                 struct commit *commit = p->item;
1077
1078                 if (revs->right_only) {
1079                         if (commit->object.flags & SYMMETRIC_LEFT)
1080                                 commit->object.flags |= SHOWN;
1081                 } else  /* revs->left_only is set */
1082                         if (!(commit->object.flags & SYMMETRIC_LEFT))
1083                                 commit->object.flags |= SHOWN;
1084         }
1085 }
1086
1087 static int limit_list(struct rev_info *revs)
1088 {
1089         int slop = SLOP;
1090         unsigned long date = ~0ul;
1091         struct commit_list *list = revs->commits;
1092         struct commit_list *newlist = NULL;
1093         struct commit_list **p = &newlist;
1094         struct commit_list *bottom = NULL;
1095         struct commit *interesting_cache = NULL;
1096
1097         if (revs->ancestry_path) {
1098                 bottom = collect_bottom_commits(list);
1099                 if (!bottom)
1100                         die("--ancestry-path given but there are no bottom commits");
1101         }
1102
1103         while (list) {
1104                 struct commit *commit = pop_commit(&list);
1105                 struct object *obj = &commit->object;
1106                 show_early_output_fn_t show;
1107
1108                 if (commit == interesting_cache)
1109                         interesting_cache = NULL;
1110
1111                 if (revs->max_age != -1 && (commit->date < revs->max_age))
1112                         obj->flags |= UNINTERESTING;
1113                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
1114                         return -1;
1115                 if (obj->flags & UNINTERESTING) {
1116                         mark_parents_uninteresting(commit);
1117                         if (revs->show_all)
1118                                 p = &commit_list_insert(commit, p)->next;
1119                         slop = still_interesting(list, date, slop, &interesting_cache);
1120                         if (slop)
1121                                 continue;
1122                         /* If showing all, add the whole pending list to the end */
1123                         if (revs->show_all)
1124                                 *p = list;
1125                         break;
1126                 }
1127                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1128                         continue;
1129                 date = commit->date;
1130                 p = &commit_list_insert(commit, p)->next;
1131
1132                 show = show_early_output;
1133                 if (!show)
1134                         continue;
1135
1136                 show(revs, newlist);
1137                 show_early_output = NULL;
1138         }
1139         if (revs->cherry_pick || revs->cherry_mark)
1140                 cherry_pick_list(newlist, revs);
1141
1142         if (revs->left_only || revs->right_only)
1143                 limit_left_right(newlist, revs);
1144
1145         if (bottom) {
1146                 limit_to_ancestry(bottom, newlist);
1147                 free_commit_list(bottom);
1148         }
1149
1150         /*
1151          * Check if any commits have become TREESAME by some of their parents
1152          * becoming UNINTERESTING.
1153          */
1154         if (limiting_can_increase_treesame(revs))
1155                 for (list = newlist; list; list = list->next) {
1156                         struct commit *c = list->item;
1157                         if (c->object.flags & (UNINTERESTING | TREESAME))
1158                                 continue;
1159                         update_treesame(revs, c);
1160                 }
1161
1162         revs->commits = newlist;
1163         return 0;
1164 }
1165
1166 /*
1167  * Add an entry to refs->cmdline with the specified information.
1168  * *name is copied.
1169  */
1170 static void add_rev_cmdline(struct rev_info *revs,
1171                             struct object *item,
1172                             const char *name,
1173                             int whence,
1174                             unsigned flags)
1175 {
1176         struct rev_cmdline_info *info = &revs->cmdline;
1177         int nr = info->nr;
1178
1179         ALLOC_GROW(info->rev, nr + 1, info->alloc);
1180         info->rev[nr].item = item;
1181         info->rev[nr].name = xstrdup(name);
1182         info->rev[nr].whence = whence;
1183         info->rev[nr].flags = flags;
1184         info->nr++;
1185 }
1186
1187 static void add_rev_cmdline_list(struct rev_info *revs,
1188                                  struct commit_list *commit_list,
1189                                  int whence,
1190                                  unsigned flags)
1191 {
1192         while (commit_list) {
1193                 struct object *object = &commit_list->item->object;
1194                 add_rev_cmdline(revs, object, oid_to_hex(&object->oid),
1195                                 whence, flags);
1196                 commit_list = commit_list->next;
1197         }
1198 }
1199
1200 struct all_refs_cb {
1201         int all_flags;
1202         int warned_bad_reflog;
1203         struct rev_info *all_revs;
1204         const char *name_for_errormsg;
1205 };
1206
1207 int ref_excluded(struct string_list *ref_excludes, const char *path)
1208 {
1209         struct string_list_item *item;
1210
1211         if (!ref_excludes)
1212                 return 0;
1213         for_each_string_list_item(item, ref_excludes) {
1214                 if (!wildmatch(item->string, path, 0, NULL))
1215                         return 1;
1216         }
1217         return 0;
1218 }
1219
1220 static int handle_one_ref(const char *path, const struct object_id *oid,
1221                           int flag, void *cb_data)
1222 {
1223         struct all_refs_cb *cb = cb_data;
1224         struct object *object;
1225
1226         if (ref_excluded(cb->all_revs->ref_excludes, path))
1227             return 0;
1228
1229         object = get_reference(cb->all_revs, path, oid->hash, cb->all_flags);
1230         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1231         add_pending_sha1(cb->all_revs, path, oid->hash, cb->all_flags);
1232         return 0;
1233 }
1234
1235 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1236         unsigned flags)
1237 {
1238         cb->all_revs = revs;
1239         cb->all_flags = flags;
1240 }
1241
1242 void clear_ref_exclusion(struct string_list **ref_excludes_p)
1243 {
1244         if (*ref_excludes_p) {
1245                 string_list_clear(*ref_excludes_p, 0);
1246                 free(*ref_excludes_p);
1247         }
1248         *ref_excludes_p = NULL;
1249 }
1250
1251 void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1252 {
1253         if (!*ref_excludes_p) {
1254                 *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1255                 (*ref_excludes_p)->strdup_strings = 1;
1256         }
1257         string_list_append(*ref_excludes_p, exclude);
1258 }
1259
1260 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
1261                 int (*for_each)(const char *, each_ref_fn, void *))
1262 {
1263         struct all_refs_cb cb;
1264         init_all_refs_cb(&cb, revs, flags);
1265         for_each(submodule, handle_one_ref, &cb);
1266 }
1267
1268 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
1269 {
1270         struct all_refs_cb *cb = cb_data;
1271         if (!is_null_sha1(sha1)) {
1272                 struct object *o = parse_object(sha1);
1273                 if (o) {
1274                         o->flags |= cb->all_flags;
1275                         /* ??? CMDLINEFLAGS ??? */
1276                         add_pending_object(cb->all_revs, o, "");
1277                 }
1278                 else if (!cb->warned_bad_reflog) {
1279                         warning("reflog of '%s' references pruned commits",
1280                                 cb->name_for_errormsg);
1281                         cb->warned_bad_reflog = 1;
1282                 }
1283         }
1284 }
1285
1286 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
1287                 const char *email, unsigned long timestamp, int tz,
1288                 const char *message, void *cb_data)
1289 {
1290         handle_one_reflog_commit(osha1, cb_data);
1291         handle_one_reflog_commit(nsha1, cb_data);
1292         return 0;
1293 }
1294
1295 static int handle_one_reflog(const char *path, const struct object_id *oid,
1296                              int flag, void *cb_data)
1297 {
1298         struct all_refs_cb *cb = cb_data;
1299         cb->warned_bad_reflog = 0;
1300         cb->name_for_errormsg = path;
1301         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
1302         return 0;
1303 }
1304
1305 void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1306 {
1307         struct all_refs_cb cb;
1308
1309         cb.all_revs = revs;
1310         cb.all_flags = flags;
1311         for_each_reflog(handle_one_reflog, &cb);
1312 }
1313
1314 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1315                            struct strbuf *path)
1316 {
1317         size_t baselen = path->len;
1318         int i;
1319
1320         if (it->entry_count >= 0) {
1321                 struct tree *tree = lookup_tree(it->sha1);
1322                 add_pending_object_with_path(revs, &tree->object, "",
1323                                              040000, path->buf);
1324         }
1325
1326         for (i = 0; i < it->subtree_nr; i++) {
1327                 struct cache_tree_sub *sub = it->down[i];
1328                 strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1329                 add_cache_tree(sub->cache_tree, revs, path);
1330                 strbuf_setlen(path, baselen);
1331         }
1332
1333 }
1334
1335 void add_index_objects_to_pending(struct rev_info *revs, unsigned flags)
1336 {
1337         int i;
1338
1339         read_cache();
1340         for (i = 0; i < active_nr; i++) {
1341                 struct cache_entry *ce = active_cache[i];
1342                 struct blob *blob;
1343
1344                 if (S_ISGITLINK(ce->ce_mode))
1345                         continue;
1346
1347                 blob = lookup_blob(ce->sha1);
1348                 if (!blob)
1349                         die("unable to add index blob to traversal");
1350                 add_pending_object_with_path(revs, &blob->object, "",
1351                                              ce->ce_mode, ce->name);
1352         }
1353
1354         if (active_cache_tree) {
1355                 struct strbuf path = STRBUF_INIT;
1356                 add_cache_tree(active_cache_tree, revs, &path);
1357                 strbuf_release(&path);
1358         }
1359 }
1360
1361 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
1362 {
1363         unsigned char sha1[20];
1364         struct object *it;
1365         struct commit *commit;
1366         struct commit_list *parents;
1367         const char *arg = arg_;
1368
1369         if (*arg == '^') {
1370                 flags ^= UNINTERESTING | BOTTOM;
1371                 arg++;
1372         }
1373         if (get_sha1_committish(arg, sha1))
1374                 return 0;
1375         while (1) {
1376                 it = get_reference(revs, arg, sha1, 0);
1377                 if (!it && revs->ignore_missing)
1378                         return 0;
1379                 if (it->type != OBJ_TAG)
1380                         break;
1381                 if (!((struct tag*)it)->tagged)
1382                         return 0;
1383                 hashcpy(sha1, ((struct tag*)it)->tagged->oid.hash);
1384         }
1385         if (it->type != OBJ_COMMIT)
1386                 return 0;
1387         commit = (struct commit *)it;
1388         for (parents = commit->parents; parents; parents = parents->next) {
1389                 it = &parents->item->object;
1390                 it->flags |= flags;
1391                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1392                 add_pending_object(revs, it, arg);
1393         }
1394         return 1;
1395 }
1396
1397 void init_revisions(struct rev_info *revs, const char *prefix)
1398 {
1399         memset(revs, 0, sizeof(*revs));
1400
1401         revs->abbrev = DEFAULT_ABBREV;
1402         revs->ignore_merges = 1;
1403         revs->simplify_history = 1;
1404         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1405         DIFF_OPT_SET(&revs->pruning, QUICK);
1406         revs->pruning.add_remove = file_add_remove;
1407         revs->pruning.change = file_change;
1408         revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1409         revs->dense = 1;
1410         revs->prefix = prefix;
1411         revs->max_age = -1;
1412         revs->min_age = -1;
1413         revs->skip_count = -1;
1414         revs->max_count = -1;
1415         revs->max_parents = -1;
1416
1417         revs->commit_format = CMIT_FMT_DEFAULT;
1418
1419         init_grep_defaults();
1420         grep_init(&revs->grep_filter, prefix);
1421         revs->grep_filter.status_only = 1;
1422         revs->grep_filter.regflags = REG_NEWLINE;
1423
1424         diff_setup(&revs->diffopt);
1425         if (prefix && !revs->diffopt.prefix) {
1426                 revs->diffopt.prefix = prefix;
1427                 revs->diffopt.prefix_length = strlen(prefix);
1428         }
1429
1430         revs->notes_opt.use_default_notes = -1;
1431 }
1432
1433 static void add_pending_commit_list(struct rev_info *revs,
1434                                     struct commit_list *commit_list,
1435                                     unsigned int flags)
1436 {
1437         while (commit_list) {
1438                 struct object *object = &commit_list->item->object;
1439                 object->flags |= flags;
1440                 add_pending_object(revs, object, oid_to_hex(&object->oid));
1441                 commit_list = commit_list->next;
1442         }
1443 }
1444
1445 static void prepare_show_merge(struct rev_info *revs)
1446 {
1447         struct commit_list *bases;
1448         struct commit *head, *other;
1449         unsigned char sha1[20];
1450         const char **prune = NULL;
1451         int i, prune_num = 1; /* counting terminating NULL */
1452
1453         if (get_sha1("HEAD", sha1))
1454                 die("--merge without HEAD?");
1455         head = lookup_commit_or_die(sha1, "HEAD");
1456         if (get_sha1("MERGE_HEAD", sha1))
1457                 die("--merge without MERGE_HEAD?");
1458         other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1459         add_pending_object(revs, &head->object, "HEAD");
1460         add_pending_object(revs, &other->object, "MERGE_HEAD");
1461         bases = get_merge_bases(head, other);
1462         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1463         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1464         free_commit_list(bases);
1465         head->object.flags |= SYMMETRIC_LEFT;
1466
1467         if (!active_nr)
1468                 read_cache();
1469         for (i = 0; i < active_nr; i++) {
1470                 const struct cache_entry *ce = active_cache[i];
1471                 if (!ce_stage(ce))
1472                         continue;
1473                 if (ce_path_match(ce, &revs->prune_data, NULL)) {
1474                         prune_num++;
1475                         REALLOC_ARRAY(prune, prune_num);
1476                         prune[prune_num-2] = ce->name;
1477                         prune[prune_num-1] = NULL;
1478                 }
1479                 while ((i+1 < active_nr) &&
1480                        ce_same_name(ce, active_cache[i+1]))
1481                         i++;
1482         }
1483         free_pathspec(&revs->prune_data);
1484         parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1485                        PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1486         revs->limited = 1;
1487 }
1488
1489 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1490 {
1491         struct object_context oc;
1492         char *dotdot;
1493         struct object *object;
1494         unsigned char sha1[20];
1495         int local_flags;
1496         const char *arg = arg_;
1497         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1498         unsigned get_sha1_flags = 0;
1499
1500         flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1501
1502         dotdot = strstr(arg, "..");
1503         if (dotdot) {
1504                 unsigned char from_sha1[20];
1505                 const char *next = dotdot + 2;
1506                 const char *this = arg;
1507                 int symmetric = *next == '.';
1508                 unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1509                 static const char head_by_default[] = "HEAD";
1510                 unsigned int a_flags;
1511
1512                 *dotdot = 0;
1513                 next += symmetric;
1514
1515                 if (!*next)
1516                         next = head_by_default;
1517                 if (dotdot == arg)
1518                         this = head_by_default;
1519                 if (this == head_by_default && next == head_by_default &&
1520                     !symmetric) {
1521                         /*
1522                          * Just ".."?  That is not a range but the
1523                          * pathspec for the parent directory.
1524                          */
1525                         if (!cant_be_filename) {
1526                                 *dotdot = '.';
1527                                 return -1;
1528                         }
1529                 }
1530                 if (!get_sha1_committish(this, from_sha1) &&
1531                     !get_sha1_committish(next, sha1)) {
1532                         struct object *a_obj, *b_obj;
1533
1534                         if (!cant_be_filename) {
1535                                 *dotdot = '.';
1536                                 verify_non_filename(revs->prefix, arg);
1537                         }
1538
1539                         a_obj = parse_object(from_sha1);
1540                         b_obj = parse_object(sha1);
1541                         if (!a_obj || !b_obj) {
1542                         missing:
1543                                 if (revs->ignore_missing)
1544                                         return 0;
1545                                 die(symmetric
1546                                     ? "Invalid symmetric difference expression %s"
1547                                     : "Invalid revision range %s", arg);
1548                         }
1549
1550                         if (!symmetric) {
1551                                 /* just A..B */
1552                                 a_flags = flags_exclude;
1553                         } else {
1554                                 /* A...B -- find merge bases between the two */
1555                                 struct commit *a, *b;
1556                                 struct commit_list *exclude;
1557
1558                                 a = (a_obj->type == OBJ_COMMIT
1559                                      ? (struct commit *)a_obj
1560                                      : lookup_commit_reference(a_obj->oid.hash));
1561                                 b = (b_obj->type == OBJ_COMMIT
1562                                      ? (struct commit *)b_obj
1563                                      : lookup_commit_reference(b_obj->oid.hash));
1564                                 if (!a || !b)
1565                                         goto missing;
1566                                 exclude = get_merge_bases(a, b);
1567                                 add_rev_cmdline_list(revs, exclude,
1568                                                      REV_CMD_MERGE_BASE,
1569                                                      flags_exclude);
1570                                 add_pending_commit_list(revs, exclude,
1571                                                         flags_exclude);
1572                                 free_commit_list(exclude);
1573
1574                                 a_flags = flags | SYMMETRIC_LEFT;
1575                         }
1576
1577                         a_obj->flags |= a_flags;
1578                         b_obj->flags |= flags;
1579                         add_rev_cmdline(revs, a_obj, this,
1580                                         REV_CMD_LEFT, a_flags);
1581                         add_rev_cmdline(revs, b_obj, next,
1582                                         REV_CMD_RIGHT, flags);
1583                         add_pending_object(revs, a_obj, this);
1584                         add_pending_object(revs, b_obj, next);
1585                         return 0;
1586                 }
1587                 *dotdot = '.';
1588         }
1589         dotdot = strstr(arg, "^@");
1590         if (dotdot && !dotdot[2]) {
1591                 *dotdot = 0;
1592                 if (add_parents_only(revs, arg, flags))
1593                         return 0;
1594                 *dotdot = '^';
1595         }
1596         dotdot = strstr(arg, "^!");
1597         if (dotdot && !dotdot[2]) {
1598                 *dotdot = 0;
1599                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM)))
1600                         *dotdot = '^';
1601         }
1602
1603         local_flags = 0;
1604         if (*arg == '^') {
1605                 local_flags = UNINTERESTING | BOTTOM;
1606                 arg++;
1607         }
1608
1609         if (revarg_opt & REVARG_COMMITTISH)
1610                 get_sha1_flags = GET_SHA1_COMMITTISH;
1611
1612         if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1613                 return revs->ignore_missing ? 0 : -1;
1614         if (!cant_be_filename)
1615                 verify_non_filename(revs->prefix, arg);
1616         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1617         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1618         add_pending_object_with_mode(revs, object, arg, oc.mode);
1619         return 0;
1620 }
1621
1622 struct cmdline_pathspec {
1623         int alloc;
1624         int nr;
1625         const char **path;
1626 };
1627
1628 static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1629 {
1630         while (*av) {
1631                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1632                 prune->path[prune->nr++] = *(av++);
1633         }
1634 }
1635
1636 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1637                                      struct cmdline_pathspec *prune)
1638 {
1639         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1640                 int len = sb->len;
1641                 if (len && sb->buf[len - 1] == '\n')
1642                         sb->buf[--len] = '\0';
1643                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1644                 prune->path[prune->nr++] = xstrdup(sb->buf);
1645         }
1646 }
1647
1648 static void read_revisions_from_stdin(struct rev_info *revs,
1649                                       struct cmdline_pathspec *prune)
1650 {
1651         struct strbuf sb;
1652         int seen_dashdash = 0;
1653         int save_warning;
1654
1655         save_warning = warn_on_object_refname_ambiguity;
1656         warn_on_object_refname_ambiguity = 0;
1657
1658         strbuf_init(&sb, 1000);
1659         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1660                 int len = sb.len;
1661                 if (len && sb.buf[len - 1] == '\n')
1662                         sb.buf[--len] = '\0';
1663                 if (!len)
1664                         break;
1665                 if (sb.buf[0] == '-') {
1666                         if (len == 2 && sb.buf[1] == '-') {
1667                                 seen_dashdash = 1;
1668                                 break;
1669                         }
1670                         die("options not supported in --stdin mode");
1671                 }
1672                 if (handle_revision_arg(sb.buf, revs, 0,
1673                                         REVARG_CANNOT_BE_FILENAME))
1674                         die("bad revision '%s'", sb.buf);
1675         }
1676         if (seen_dashdash)
1677                 read_pathspec_from_stdin(revs, &sb, prune);
1678
1679         strbuf_release(&sb);
1680         warn_on_object_refname_ambiguity = save_warning;
1681 }
1682
1683 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1684 {
1685         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1686 }
1687
1688 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1689 {
1690         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1691 }
1692
1693 static void add_message_grep(struct rev_info *revs, const char *pattern)
1694 {
1695         add_grep(revs, pattern, GREP_PATTERN_BODY);
1696 }
1697
1698 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1699                                int *unkc, const char **unkv)
1700 {
1701         const char *arg = argv[0];
1702         const char *optarg;
1703         int argcount;
1704
1705         /* pseudo revision arguments */
1706         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1707             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1708             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1709             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1710             !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
1711             !strcmp(arg, "--indexed-objects") ||
1712             starts_with(arg, "--exclude=") ||
1713             starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
1714             starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
1715         {
1716                 unkv[(*unkc)++] = arg;
1717                 return 1;
1718         }
1719
1720         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1721                 revs->max_count = atoi(optarg);
1722                 revs->no_walk = 0;
1723                 return argcount;
1724         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1725                 revs->skip_count = atoi(optarg);
1726                 return argcount;
1727         } else if ((*arg == '-') && isdigit(arg[1])) {
1728                 /* accept -<digit>, like traditional "head" */
1729                 if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
1730                     revs->max_count < 0)
1731                         die("'%s': not a non-negative integer", arg + 1);
1732                 revs->no_walk = 0;
1733         } else if (!strcmp(arg, "-n")) {
1734                 if (argc <= 1)
1735                         return error("-n requires an argument");
1736                 revs->max_count = atoi(argv[1]);
1737                 revs->no_walk = 0;
1738                 return 2;
1739         } else if (starts_with(arg, "-n")) {
1740                 revs->max_count = atoi(arg + 2);
1741                 revs->no_walk = 0;
1742         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1743                 revs->max_age = atoi(optarg);
1744                 return argcount;
1745         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1746                 revs->max_age = approxidate(optarg);
1747                 return argcount;
1748         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1749                 revs->max_age = approxidate(optarg);
1750                 return argcount;
1751         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1752                 revs->min_age = atoi(optarg);
1753                 return argcount;
1754         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1755                 revs->min_age = approxidate(optarg);
1756                 return argcount;
1757         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1758                 revs->min_age = approxidate(optarg);
1759                 return argcount;
1760         } else if (!strcmp(arg, "--first-parent")) {
1761                 revs->first_parent_only = 1;
1762         } else if (!strcmp(arg, "--ancestry-path")) {
1763                 revs->ancestry_path = 1;
1764                 revs->simplify_history = 0;
1765                 revs->limited = 1;
1766         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1767                 init_reflog_walk(&revs->reflog_info);
1768         } else if (!strcmp(arg, "--default")) {
1769                 if (argc <= 1)
1770                         return error("bad --default argument");
1771                 revs->def = argv[1];
1772                 return 2;
1773         } else if (!strcmp(arg, "--merge")) {
1774                 revs->show_merge = 1;
1775         } else if (!strcmp(arg, "--topo-order")) {
1776                 revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1777                 revs->topo_order = 1;
1778         } else if (!strcmp(arg, "--simplify-merges")) {
1779                 revs->simplify_merges = 1;
1780                 revs->topo_order = 1;
1781                 revs->rewrite_parents = 1;
1782                 revs->simplify_history = 0;
1783                 revs->limited = 1;
1784         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1785                 revs->simplify_merges = 1;
1786                 revs->topo_order = 1;
1787                 revs->rewrite_parents = 1;
1788                 revs->simplify_history = 0;
1789                 revs->simplify_by_decoration = 1;
1790                 revs->limited = 1;
1791                 revs->prune = 1;
1792                 load_ref_decorations(DECORATE_SHORT_REFS);
1793         } else if (!strcmp(arg, "--date-order")) {
1794                 revs->sort_order = REV_SORT_BY_COMMIT_DATE;
1795                 revs->topo_order = 1;
1796         } else if (!strcmp(arg, "--author-date-order")) {
1797                 revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
1798                 revs->topo_order = 1;
1799         } else if (starts_with(arg, "--early-output")) {
1800                 int count = 100;
1801                 switch (arg[14]) {
1802                 case '=':
1803                         count = atoi(arg+15);
1804                         /* Fallthrough */
1805                 case 0:
1806                         revs->topo_order = 1;
1807                        revs->early_output = count;
1808                 }
1809         } else if (!strcmp(arg, "--parents")) {
1810                 revs->rewrite_parents = 1;
1811                 revs->print_parents = 1;
1812         } else if (!strcmp(arg, "--dense")) {
1813                 revs->dense = 1;
1814         } else if (!strcmp(arg, "--sparse")) {
1815                 revs->dense = 0;
1816         } else if (!strcmp(arg, "--show-all")) {
1817                 revs->show_all = 1;
1818         } else if (!strcmp(arg, "--remove-empty")) {
1819                 revs->remove_empty_trees = 1;
1820         } else if (!strcmp(arg, "--merges")) {
1821                 revs->min_parents = 2;
1822         } else if (!strcmp(arg, "--no-merges")) {
1823                 revs->max_parents = 1;
1824         } else if (starts_with(arg, "--min-parents=")) {
1825                 revs->min_parents = atoi(arg+14);
1826         } else if (starts_with(arg, "--no-min-parents")) {
1827                 revs->min_parents = 0;
1828         } else if (starts_with(arg, "--max-parents=")) {
1829                 revs->max_parents = atoi(arg+14);
1830         } else if (starts_with(arg, "--no-max-parents")) {
1831                 revs->max_parents = -1;
1832         } else if (!strcmp(arg, "--boundary")) {
1833                 revs->boundary = 1;
1834         } else if (!strcmp(arg, "--left-right")) {
1835                 revs->left_right = 1;
1836         } else if (!strcmp(arg, "--left-only")) {
1837                 if (revs->right_only)
1838                         die("--left-only is incompatible with --right-only"
1839                             " or --cherry");
1840                 revs->left_only = 1;
1841         } else if (!strcmp(arg, "--right-only")) {
1842                 if (revs->left_only)
1843                         die("--right-only is incompatible with --left-only");
1844                 revs->right_only = 1;
1845         } else if (!strcmp(arg, "--cherry")) {
1846                 if (revs->left_only)
1847                         die("--cherry is incompatible with --left-only");
1848                 revs->cherry_mark = 1;
1849                 revs->right_only = 1;
1850                 revs->max_parents = 1;
1851                 revs->limited = 1;
1852         } else if (!strcmp(arg, "--count")) {
1853                 revs->count = 1;
1854         } else if (!strcmp(arg, "--cherry-mark")) {
1855                 if (revs->cherry_pick)
1856                         die("--cherry-mark is incompatible with --cherry-pick");
1857                 revs->cherry_mark = 1;
1858                 revs->limited = 1; /* needs limit_list() */
1859         } else if (!strcmp(arg, "--cherry-pick")) {
1860                 if (revs->cherry_mark)
1861                         die("--cherry-pick is incompatible with --cherry-mark");
1862                 revs->cherry_pick = 1;
1863                 revs->limited = 1;
1864         } else if (!strcmp(arg, "--objects")) {
1865                 revs->tag_objects = 1;
1866                 revs->tree_objects = 1;
1867                 revs->blob_objects = 1;
1868         } else if (!strcmp(arg, "--objects-edge")) {
1869                 revs->tag_objects = 1;
1870                 revs->tree_objects = 1;
1871                 revs->blob_objects = 1;
1872                 revs->edge_hint = 1;
1873         } else if (!strcmp(arg, "--objects-edge-aggressive")) {
1874                 revs->tag_objects = 1;
1875                 revs->tree_objects = 1;
1876                 revs->blob_objects = 1;
1877                 revs->edge_hint = 1;
1878                 revs->edge_hint_aggressive = 1;
1879         } else if (!strcmp(arg, "--verify-objects")) {
1880                 revs->tag_objects = 1;
1881                 revs->tree_objects = 1;
1882                 revs->blob_objects = 1;
1883                 revs->verify_objects = 1;
1884         } else if (!strcmp(arg, "--unpacked")) {
1885                 revs->unpacked = 1;
1886         } else if (starts_with(arg, "--unpacked=")) {
1887                 die("--unpacked=<packfile> no longer supported.");
1888         } else if (!strcmp(arg, "-r")) {
1889                 revs->diff = 1;
1890                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1891         } else if (!strcmp(arg, "-t")) {
1892                 revs->diff = 1;
1893                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1894                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1895         } else if (!strcmp(arg, "-m")) {
1896                 revs->ignore_merges = 0;
1897         } else if (!strcmp(arg, "-c")) {
1898                 revs->diff = 1;
1899                 revs->dense_combined_merges = 0;
1900                 revs->combine_merges = 1;
1901         } else if (!strcmp(arg, "--cc")) {
1902                 revs->diff = 1;
1903                 revs->dense_combined_merges = 1;
1904                 revs->combine_merges = 1;
1905         } else if (!strcmp(arg, "-v")) {
1906                 revs->verbose_header = 1;
1907         } else if (!strcmp(arg, "--pretty")) {
1908                 revs->verbose_header = 1;
1909                 revs->pretty_given = 1;
1910                 get_commit_format(NULL, revs);
1911         } else if (starts_with(arg, "--pretty=") || starts_with(arg, "--format=")) {
1912                 /*
1913                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1914                  * not allowed, since the argument is optional.
1915                  */
1916                 revs->verbose_header = 1;
1917                 revs->pretty_given = 1;
1918                 get_commit_format(arg+9, revs);
1919         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1920                 revs->show_notes = 1;
1921                 revs->show_notes_given = 1;
1922                 revs->notes_opt.use_default_notes = 1;
1923         } else if (!strcmp(arg, "--show-signature")) {
1924                 revs->show_signature = 1;
1925         } else if (!strcmp(arg, "--show-linear-break") ||
1926                    starts_with(arg, "--show-linear-break=")) {
1927                 if (starts_with(arg, "--show-linear-break="))
1928                         revs->break_bar = xstrdup(arg + 20);
1929                 else
1930                         revs->break_bar = "                    ..........";
1931                 revs->track_linear = 1;
1932                 revs->track_first_time = 1;
1933         } else if (starts_with(arg, "--show-notes=") ||
1934                    starts_with(arg, "--notes=")) {
1935                 struct strbuf buf = STRBUF_INIT;
1936                 revs->show_notes = 1;
1937                 revs->show_notes_given = 1;
1938                 if (starts_with(arg, "--show-notes")) {
1939                         if (revs->notes_opt.use_default_notes < 0)
1940                                 revs->notes_opt.use_default_notes = 1;
1941                         strbuf_addstr(&buf, arg+13);
1942                 }
1943                 else
1944                         strbuf_addstr(&buf, arg+8);
1945                 expand_notes_ref(&buf);
1946                 string_list_append(&revs->notes_opt.extra_notes_refs,
1947                                    strbuf_detach(&buf, NULL));
1948         } else if (!strcmp(arg, "--no-notes")) {
1949                 revs->show_notes = 0;
1950                 revs->show_notes_given = 1;
1951                 revs->notes_opt.use_default_notes = -1;
1952                 /* we have been strdup'ing ourselves, so trick
1953                  * string_list into free()ing strings */
1954                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1955                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1956                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1957         } else if (!strcmp(arg, "--standard-notes")) {
1958                 revs->show_notes_given = 1;
1959                 revs->notes_opt.use_default_notes = 1;
1960         } else if (!strcmp(arg, "--no-standard-notes")) {
1961                 revs->notes_opt.use_default_notes = 0;
1962         } else if (!strcmp(arg, "--oneline")) {
1963                 revs->verbose_header = 1;
1964                 get_commit_format("oneline", revs);
1965                 revs->pretty_given = 1;
1966                 revs->abbrev_commit = 1;
1967         } else if (!strcmp(arg, "--graph")) {
1968                 revs->topo_order = 1;
1969                 revs->rewrite_parents = 1;
1970                 revs->graph = graph_init(revs);
1971         } else if (!strcmp(arg, "--root")) {
1972                 revs->show_root_diff = 1;
1973         } else if (!strcmp(arg, "--no-commit-id")) {
1974                 revs->no_commit_id = 1;
1975         } else if (!strcmp(arg, "--always")) {
1976                 revs->always_show_header = 1;
1977         } else if (!strcmp(arg, "--no-abbrev")) {
1978                 revs->abbrev = 0;
1979         } else if (!strcmp(arg, "--abbrev")) {
1980                 revs->abbrev = DEFAULT_ABBREV;
1981         } else if (starts_with(arg, "--abbrev=")) {
1982                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1983                 if (revs->abbrev < MINIMUM_ABBREV)
1984                         revs->abbrev = MINIMUM_ABBREV;
1985                 else if (revs->abbrev > 40)
1986                         revs->abbrev = 40;
1987         } else if (!strcmp(arg, "--abbrev-commit")) {
1988                 revs->abbrev_commit = 1;
1989                 revs->abbrev_commit_given = 1;
1990         } else if (!strcmp(arg, "--no-abbrev-commit")) {
1991                 revs->abbrev_commit = 0;
1992         } else if (!strcmp(arg, "--full-diff")) {
1993                 revs->diff = 1;
1994                 revs->full_diff = 1;
1995         } else if (!strcmp(arg, "--full-history")) {
1996                 revs->simplify_history = 0;
1997         } else if (!strcmp(arg, "--relative-date")) {
1998                 revs->date_mode.type = DATE_RELATIVE;
1999                 revs->date_mode_explicit = 1;
2000         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
2001                 parse_date_format(optarg, &revs->date_mode);
2002                 revs->date_mode_explicit = 1;
2003                 return argcount;
2004         } else if (!strcmp(arg, "--log-size")) {
2005                 revs->show_log_size = 1;
2006         }
2007         /*
2008          * Grepping the commit log
2009          */
2010         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
2011                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
2012                 return argcount;
2013         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
2014                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
2015                 return argcount;
2016         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
2017                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
2018                 return argcount;
2019         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
2020                 add_message_grep(revs, optarg);
2021                 return argcount;
2022         } else if (!strcmp(arg, "--grep-debug")) {
2023                 revs->grep_filter.debug = 1;
2024         } else if (!strcmp(arg, "--basic-regexp")) {
2025                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_BRE, &revs->grep_filter);
2026         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
2027                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, &revs->grep_filter);
2028         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
2029                 revs->grep_filter.regflags |= REG_ICASE;
2030                 DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
2031         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
2032                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_FIXED, &revs->grep_filter);
2033         } else if (!strcmp(arg, "--perl-regexp")) {
2034                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_PCRE, &revs->grep_filter);
2035         } else if (!strcmp(arg, "--all-match")) {
2036                 revs->grep_filter.all_match = 1;
2037         } else if (!strcmp(arg, "--invert-grep")) {
2038                 revs->invert_grep = 1;
2039         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2040                 if (strcmp(optarg, "none"))
2041                         git_log_output_encoding = xstrdup(optarg);
2042                 else
2043                         git_log_output_encoding = "";
2044                 return argcount;
2045         } else if (!strcmp(arg, "--reverse")) {
2046                 revs->reverse ^= 1;
2047         } else if (!strcmp(arg, "--children")) {
2048                 revs->children.name = "children";
2049                 revs->limited = 1;
2050         } else if (!strcmp(arg, "--ignore-missing")) {
2051                 revs->ignore_missing = 1;
2052         } else {
2053                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
2054                 if (!opts)
2055                         unkv[(*unkc)++] = arg;
2056                 return opts;
2057         }
2058         if (revs->graph && revs->track_linear)
2059                 die("--show-linear-break and --graph are incompatible");
2060
2061         return 1;
2062 }
2063
2064 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2065                         const struct option *options,
2066                         const char * const usagestr[])
2067 {
2068         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2069                                     &ctx->cpidx, ctx->out);
2070         if (n <= 0) {
2071                 error("unknown option `%s'", ctx->argv[0]);
2072                 usage_with_options(usagestr, options);
2073         }
2074         ctx->argv += n;
2075         ctx->argc -= n;
2076 }
2077
2078 static int for_each_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data, const char *term) {
2079         struct strbuf bisect_refs = STRBUF_INIT;
2080         int status;
2081         strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2082         status = for_each_ref_in_submodule(submodule, bisect_refs.buf, fn, cb_data);
2083         strbuf_release(&bisect_refs);
2084         return status;
2085 }
2086
2087 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2088 {
2089         return for_each_bisect_ref(submodule, fn, cb_data, term_bad);
2090 }
2091
2092 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2093 {
2094         return for_each_bisect_ref(submodule, fn, cb_data, term_good);
2095 }
2096
2097 static int handle_revision_pseudo_opt(const char *submodule,
2098                                 struct rev_info *revs,
2099                                 int argc, const char **argv, int *flags)
2100 {
2101         const char *arg = argv[0];
2102         const char *optarg;
2103         int argcount;
2104
2105         /*
2106          * NOTE!
2107          *
2108          * Commands like "git shortlog" will not accept the options below
2109          * unless parse_revision_opt queues them (as opposed to erroring
2110          * out).
2111          *
2112          * When implementing your new pseudo-option, remember to
2113          * register it in the list at the top of handle_revision_opt.
2114          */
2115         if (!strcmp(arg, "--all")) {
2116                 handle_refs(submodule, revs, *flags, for_each_ref_submodule);
2117                 handle_refs(submodule, revs, *flags, head_ref_submodule);
2118                 clear_ref_exclusion(&revs->ref_excludes);
2119         } else if (!strcmp(arg, "--branches")) {
2120                 handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
2121                 clear_ref_exclusion(&revs->ref_excludes);
2122         } else if (!strcmp(arg, "--bisect")) {
2123                 read_bisect_terms(&term_bad, &term_good);
2124                 handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
2125                 handle_refs(submodule, revs, *flags ^ (UNINTERESTING | BOTTOM), for_each_good_bisect_ref);
2126                 revs->bisect = 1;
2127         } else if (!strcmp(arg, "--tags")) {
2128                 handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
2129                 clear_ref_exclusion(&revs->ref_excludes);
2130         } else if (!strcmp(arg, "--remotes")) {
2131                 handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
2132                 clear_ref_exclusion(&revs->ref_excludes);
2133         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2134                 struct all_refs_cb cb;
2135                 init_all_refs_cb(&cb, revs, *flags);
2136                 for_each_glob_ref(handle_one_ref, optarg, &cb);
2137                 clear_ref_exclusion(&revs->ref_excludes);
2138                 return argcount;
2139         } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2140                 add_ref_exclusion(&revs->ref_excludes, optarg);
2141                 return argcount;
2142         } else if (starts_with(arg, "--branches=")) {
2143                 struct all_refs_cb cb;
2144                 init_all_refs_cb(&cb, revs, *flags);
2145                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
2146                 clear_ref_exclusion(&revs->ref_excludes);
2147         } else if (starts_with(arg, "--tags=")) {
2148                 struct all_refs_cb cb;
2149                 init_all_refs_cb(&cb, revs, *flags);
2150                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
2151                 clear_ref_exclusion(&revs->ref_excludes);
2152         } else if (starts_with(arg, "--remotes=")) {
2153                 struct all_refs_cb cb;
2154                 init_all_refs_cb(&cb, revs, *flags);
2155                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
2156                 clear_ref_exclusion(&revs->ref_excludes);
2157         } else if (!strcmp(arg, "--reflog")) {
2158                 add_reflogs_to_pending(revs, *flags);
2159         } else if (!strcmp(arg, "--indexed-objects")) {
2160                 add_index_objects_to_pending(revs, *flags);
2161         } else if (!strcmp(arg, "--not")) {
2162                 *flags ^= UNINTERESTING | BOTTOM;
2163         } else if (!strcmp(arg, "--no-walk")) {
2164                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2165         } else if (starts_with(arg, "--no-walk=")) {
2166                 /*
2167                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2168                  * not allowed, since the argument is optional.
2169                  */
2170                 if (!strcmp(arg + 10, "sorted"))
2171                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2172                 else if (!strcmp(arg + 10, "unsorted"))
2173                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2174                 else
2175                         return error("invalid argument to --no-walk");
2176         } else if (!strcmp(arg, "--do-walk")) {
2177                 revs->no_walk = 0;
2178         } else {
2179                 return 0;
2180         }
2181
2182         return 1;
2183 }
2184
2185 static void NORETURN diagnose_missing_default(const char *def)
2186 {
2187         unsigned char sha1[20];
2188         int flags;
2189         const char *refname;
2190
2191         refname = resolve_ref_unsafe(def, 0, sha1, &flags);
2192         if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2193                 die(_("your current branch appears to be broken"));
2194
2195         skip_prefix(refname, "refs/heads/", &refname);
2196         die(_("your current branch '%s' does not have any commits yet"),
2197             refname);
2198 }
2199
2200 /*
2201  * Parse revision information, filling in the "rev_info" structure,
2202  * and removing the used arguments from the argument list.
2203  *
2204  * Returns the number of arguments left that weren't recognized
2205  * (which are also moved to the head of the argument list)
2206  */
2207 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2208 {
2209         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
2210         struct cmdline_pathspec prune_data;
2211         const char *submodule = NULL;
2212
2213         memset(&prune_data, 0, sizeof(prune_data));
2214         if (opt)
2215                 submodule = opt->submodule;
2216
2217         /* First, search for "--" */
2218         if (opt && opt->assume_dashdash) {
2219                 seen_dashdash = 1;
2220         } else {
2221                 seen_dashdash = 0;
2222                 for (i = 1; i < argc; i++) {
2223                         const char *arg = argv[i];
2224                         if (strcmp(arg, "--"))
2225                                 continue;
2226                         argv[i] = NULL;
2227                         argc = i;
2228                         if (argv[i + 1])
2229                                 append_prune_data(&prune_data, argv + i + 1);
2230                         seen_dashdash = 1;
2231                         break;
2232                 }
2233         }
2234
2235         /* Second, deal with arguments and options */
2236         flags = 0;
2237         revarg_opt = opt ? opt->revarg_opt : 0;
2238         if (seen_dashdash)
2239                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2240         read_from_stdin = 0;
2241         for (left = i = 1; i < argc; i++) {
2242                 const char *arg = argv[i];
2243                 if (*arg == '-') {
2244                         int opts;
2245
2246                         opts = handle_revision_pseudo_opt(submodule,
2247                                                 revs, argc - i, argv + i,
2248                                                 &flags);
2249                         if (opts > 0) {
2250                                 i += opts - 1;
2251                                 continue;
2252                         }
2253
2254                         if (!strcmp(arg, "--stdin")) {
2255                                 if (revs->disable_stdin) {
2256                                         argv[left++] = arg;
2257                                         continue;
2258                                 }
2259                                 if (read_from_stdin++)
2260                                         die("--stdin given twice?");
2261                                 read_revisions_from_stdin(revs, &prune_data);
2262                                 continue;
2263                         }
2264
2265                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
2266                         if (opts > 0) {
2267                                 i += opts - 1;
2268                                 continue;
2269                         }
2270                         if (opts < 0)
2271                                 exit(128);
2272                         continue;
2273                 }
2274
2275
2276                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2277                         int j;
2278                         if (seen_dashdash || *arg == '^')
2279                                 die("bad revision '%s'", arg);
2280
2281                         /* If we didn't have a "--":
2282                          * (1) all filenames must exist;
2283                          * (2) all rev-args must not be interpretable
2284                          *     as a valid filename.
2285                          * but the latter we have checked in the main loop.
2286                          */
2287                         for (j = i; j < argc; j++)
2288                                 verify_filename(revs->prefix, argv[j], j == i);
2289
2290                         append_prune_data(&prune_data, argv + i);
2291                         break;
2292                 }
2293                 else
2294                         got_rev_arg = 1;
2295         }
2296
2297         if (prune_data.nr) {
2298                 /*
2299                  * If we need to introduce the magic "a lone ':' means no
2300                  * pathspec whatsoever", here is the place to do so.
2301                  *
2302                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2303                  *      prune_data.nr = 0;
2304                  *      prune_data.alloc = 0;
2305                  *      free(prune_data.path);
2306                  *      prune_data.path = NULL;
2307                  * } else {
2308                  *      terminate prune_data.alloc with NULL and
2309                  *      call init_pathspec() to set revs->prune_data here.
2310                  * }
2311                  */
2312                 ALLOC_GROW(prune_data.path, prune_data.nr + 1, prune_data.alloc);
2313                 prune_data.path[prune_data.nr++] = NULL;
2314                 parse_pathspec(&revs->prune_data, 0, 0,
2315                                revs->prefix, prune_data.path);
2316         }
2317
2318         if (revs->def == NULL)
2319                 revs->def = opt ? opt->def : NULL;
2320         if (opt && opt->tweak)
2321                 opt->tweak(revs, opt);
2322         if (revs->show_merge)
2323                 prepare_show_merge(revs);
2324         if (revs->def && !revs->pending.nr && !got_rev_arg) {
2325                 unsigned char sha1[20];
2326                 struct object *object;
2327                 struct object_context oc;
2328                 if (get_sha1_with_context(revs->def, 0, sha1, &oc))
2329                         diagnose_missing_default(revs->def);
2330                 object = get_reference(revs, revs->def, sha1, 0);
2331                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2332         }
2333
2334         /* Did the user ask for any diff output? Run the diff! */
2335         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2336                 revs->diff = 1;
2337
2338         /* Pickaxe, diff-filter and rename following need diffs */
2339         if (revs->diffopt.pickaxe ||
2340             revs->diffopt.filter ||
2341             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2342                 revs->diff = 1;
2343
2344         if (revs->topo_order)
2345                 revs->limited = 1;
2346
2347         if (revs->prune_data.nr) {
2348                 copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2349                 /* Can't prune commits with rename following: the paths change.. */
2350                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2351                         revs->prune = 1;
2352                 if (!revs->full_diff)
2353                         copy_pathspec(&revs->diffopt.pathspec,
2354                                       &revs->prune_data);
2355         }
2356         if (revs->combine_merges)
2357                 revs->ignore_merges = 0;
2358         revs->diffopt.abbrev = revs->abbrev;
2359
2360         if (revs->line_level_traverse) {
2361                 revs->limited = 1;
2362                 revs->topo_order = 1;
2363         }
2364
2365         diff_setup_done(&revs->diffopt);
2366
2367         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2368                                  &revs->grep_filter);
2369         compile_grep_patterns(&revs->grep_filter);
2370
2371         if (revs->reverse && revs->reflog_info)
2372                 die("cannot combine --reverse with --walk-reflogs");
2373         if (revs->rewrite_parents && revs->children.name)
2374                 die("cannot combine --parents and --children");
2375
2376         /*
2377          * Limitations on the graph functionality
2378          */
2379         if (revs->reverse && revs->graph)
2380                 die("cannot combine --reverse with --graph");
2381
2382         if (revs->reflog_info && revs->graph)
2383                 die("cannot combine --walk-reflogs with --graph");
2384         if (revs->no_walk && revs->graph)
2385                 die("cannot combine --no-walk with --graph");
2386         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2387                 die("cannot use --grep-reflog without --walk-reflogs");
2388
2389         if (revs->first_parent_only && revs->bisect)
2390                 die(_("--first-parent is incompatible with --bisect"));
2391
2392         return left;
2393 }
2394
2395 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2396 {
2397         struct commit_list *l = xcalloc(1, sizeof(*l));
2398
2399         l->item = child;
2400         l->next = add_decoration(&revs->children, &parent->object, l);
2401 }
2402
2403 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2404 {
2405         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2406         struct commit_list **pp, *p;
2407         int surviving_parents;
2408
2409         /* Examine existing parents while marking ones we have seen... */
2410         pp = &commit->parents;
2411         surviving_parents = 0;
2412         while ((p = *pp) != NULL) {
2413                 struct commit *parent = p->item;
2414                 if (parent->object.flags & TMP_MARK) {
2415                         *pp = p->next;
2416                         if (ts)
2417                                 compact_treesame(revs, commit, surviving_parents);
2418                         continue;
2419                 }
2420                 parent->object.flags |= TMP_MARK;
2421                 surviving_parents++;
2422                 pp = &p->next;
2423         }
2424         /* clear the temporary mark */
2425         for (p = commit->parents; p; p = p->next) {
2426                 p->item->object.flags &= ~TMP_MARK;
2427         }
2428         /* no update_treesame() - removing duplicates can't affect TREESAME */
2429         return surviving_parents;
2430 }
2431
2432 struct merge_simplify_state {
2433         struct commit *simplified;
2434 };
2435
2436 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2437 {
2438         struct merge_simplify_state *st;
2439
2440         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2441         if (!st) {
2442                 st = xcalloc(1, sizeof(*st));
2443                 add_decoration(&revs->merge_simplification, &commit->object, st);
2444         }
2445         return st;
2446 }
2447
2448 static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2449 {
2450         struct commit_list *h = reduce_heads(commit->parents);
2451         int i = 0, marked = 0;
2452         struct commit_list *po, *pn;
2453
2454         /* Want these for sanity-checking only */
2455         int orig_cnt = commit_list_count(commit->parents);
2456         int cnt = commit_list_count(h);
2457
2458         /*
2459          * Not ready to remove items yet, just mark them for now, based
2460          * on the output of reduce_heads(). reduce_heads outputs the reduced
2461          * set in its original order, so this isn't too hard.
2462          */
2463         po = commit->parents;
2464         pn = h;
2465         while (po) {
2466                 if (pn && po->item == pn->item) {
2467                         pn = pn->next;
2468                         i++;
2469                 } else {
2470                         po->item->object.flags |= TMP_MARK;
2471                         marked++;
2472                 }
2473                 po=po->next;
2474         }
2475
2476         if (i != cnt || cnt+marked != orig_cnt)
2477                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2478
2479         free_commit_list(h);
2480
2481         return marked;
2482 }
2483
2484 static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2485 {
2486         struct commit_list *p;
2487         int marked = 0;
2488
2489         for (p = commit->parents; p; p = p->next) {
2490                 struct commit *parent = p->item;
2491                 if (!parent->parents && (parent->object.flags & TREESAME)) {
2492                         parent->object.flags |= TMP_MARK;
2493                         marked++;
2494                 }
2495         }
2496
2497         return marked;
2498 }
2499
2500 /*
2501  * Awkward naming - this means one parent we are TREESAME to.
2502  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2503  * empty tree). Better name suggestions?
2504  */
2505 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2506 {
2507         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2508         struct commit *unmarked = NULL, *marked = NULL;
2509         struct commit_list *p;
2510         unsigned n;
2511
2512         for (p = commit->parents, n = 0; p; p = p->next, n++) {
2513                 if (ts->treesame[n]) {
2514                         if (p->item->object.flags & TMP_MARK) {
2515                                 if (!marked)
2516                                         marked = p->item;
2517                         } else {
2518                                 if (!unmarked) {
2519                                         unmarked = p->item;
2520                                         break;
2521                                 }
2522                         }
2523                 }
2524         }
2525
2526         /*
2527          * If we are TREESAME to a marked-for-deletion parent, but not to any
2528          * unmarked parents, unmark the first TREESAME parent. This is the
2529          * parent that the default simplify_history==1 scan would have followed,
2530          * and it doesn't make sense to omit that path when asking for a
2531          * simplified full history. Retaining it improves the chances of
2532          * understanding odd missed merges that took an old version of a file.
2533          *
2534          * Example:
2535          *
2536          *   I--------*X       A modified the file, but mainline merge X used
2537          *    \       /        "-s ours", so took the version from I. X is
2538          *     `-*A--'         TREESAME to I and !TREESAME to A.
2539          *
2540          * Default log from X would produce "I". Without this check,
2541          * --full-history --simplify-merges would produce "I-A-X", showing
2542          * the merge commit X and that it changed A, but not making clear that
2543          * it had just taken the I version. With this check, the topology above
2544          * is retained.
2545          *
2546          * Note that it is possible that the simplification chooses a different
2547          * TREESAME parent from the default, in which case this test doesn't
2548          * activate, and we _do_ drop the default parent. Example:
2549          *
2550          *   I------X         A modified the file, but it was reverted in B,
2551          *    \    /          meaning mainline merge X is TREESAME to both
2552          *    *A-*B           parents.
2553          *
2554          * Default log would produce "I" by following the first parent;
2555          * --full-history --simplify-merges will produce "I-A-B". But this is a
2556          * reasonable result - it presents a logical full history leading from
2557          * I to X, and X is not an important merge.
2558          */
2559         if (!unmarked && marked) {
2560                 marked->object.flags &= ~TMP_MARK;
2561                 return 1;
2562         }
2563
2564         return 0;
2565 }
2566
2567 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2568 {
2569         struct commit_list **pp, *p;
2570         int nth_parent, removed = 0;
2571
2572         pp = &commit->parents;
2573         nth_parent = 0;
2574         while ((p = *pp) != NULL) {
2575                 struct commit *parent = p->item;
2576                 if (parent->object.flags & TMP_MARK) {
2577                         parent->object.flags &= ~TMP_MARK;
2578                         *pp = p->next;
2579                         free(p);
2580                         removed++;
2581                         compact_treesame(revs, commit, nth_parent);
2582                         continue;
2583                 }
2584                 pp = &p->next;
2585                 nth_parent++;
2586         }
2587
2588         /* Removing parents can only increase TREESAMEness */
2589         if (removed && !(commit->object.flags & TREESAME))
2590                 update_treesame(revs, commit);
2591
2592         return nth_parent;
2593 }
2594
2595 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2596 {
2597         struct commit_list *p;
2598         struct commit *parent;
2599         struct merge_simplify_state *st, *pst;
2600         int cnt;
2601
2602         st = locate_simplify_state(revs, commit);
2603
2604         /*
2605          * Have we handled this one?
2606          */
2607         if (st->simplified)
2608                 return tail;
2609
2610         /*
2611          * An UNINTERESTING commit simplifies to itself, so does a
2612          * root commit.  We do not rewrite parents of such commit
2613          * anyway.
2614          */
2615         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2616                 st->simplified = commit;
2617                 return tail;
2618         }
2619
2620         /*
2621          * Do we know what commit all of our parents that matter
2622          * should be rewritten to?  Otherwise we are not ready to
2623          * rewrite this one yet.
2624          */
2625         for (cnt = 0, p = commit->parents; p; p = p->next) {
2626                 pst = locate_simplify_state(revs, p->item);
2627                 if (!pst->simplified) {
2628                         tail = &commit_list_insert(p->item, tail)->next;
2629                         cnt++;
2630                 }
2631                 if (revs->first_parent_only)
2632                         break;
2633         }
2634         if (cnt) {
2635                 tail = &commit_list_insert(commit, tail)->next;
2636                 return tail;
2637         }
2638
2639         /*
2640          * Rewrite our list of parents. Note that this cannot
2641          * affect our TREESAME flags in any way - a commit is
2642          * always TREESAME to its simplification.
2643          */
2644         for (p = commit->parents; p; p = p->next) {
2645                 pst = locate_simplify_state(revs, p->item);
2646                 p->item = pst->simplified;
2647                 if (revs->first_parent_only)
2648                         break;
2649         }
2650
2651         if (revs->first_parent_only)
2652                 cnt = 1;
2653         else
2654                 cnt = remove_duplicate_parents(revs, commit);
2655
2656         /*
2657          * It is possible that we are a merge and one side branch
2658          * does not have any commit that touches the given paths;
2659          * in such a case, the immediate parent from that branch
2660          * will be rewritten to be the merge base.
2661          *
2662          *      o----X          X: the commit we are looking at;
2663          *     /    /           o: a commit that touches the paths;
2664          * ---o----'
2665          *
2666          * Further, a merge of an independent branch that doesn't
2667          * touch the path will reduce to a treesame root parent:
2668          *
2669          *  ----o----X          X: the commit we are looking at;
2670          *          /           o: a commit that touches the paths;
2671          *         r            r: a root commit not touching the paths
2672          *
2673          * Detect and simplify both cases.
2674          */
2675         if (1 < cnt) {
2676                 int marked = mark_redundant_parents(revs, commit);
2677                 marked += mark_treesame_root_parents(revs, commit);
2678                 if (marked)
2679                         marked -= leave_one_treesame_to_parent(revs, commit);
2680                 if (marked)
2681                         cnt = remove_marked_parents(revs, commit);
2682         }
2683
2684         /*
2685          * A commit simplifies to itself if it is a root, if it is
2686          * UNINTERESTING, if it touches the given paths, or if it is a
2687          * merge and its parents don't simplify to one relevant commit
2688          * (the first two cases are already handled at the beginning of
2689          * this function).
2690          *
2691          * Otherwise, it simplifies to what its sole relevant parent
2692          * simplifies to.
2693          */
2694         if (!cnt ||
2695             (commit->object.flags & UNINTERESTING) ||
2696             !(commit->object.flags & TREESAME) ||
2697             (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2698                 st->simplified = commit;
2699         else {
2700                 pst = locate_simplify_state(revs, parent);
2701                 st->simplified = pst->simplified;
2702         }
2703         return tail;
2704 }
2705
2706 static void simplify_merges(struct rev_info *revs)
2707 {
2708         struct commit_list *list, *next;
2709         struct commit_list *yet_to_do, **tail;
2710         struct commit *commit;
2711
2712         if (!revs->prune)
2713                 return;
2714
2715         /* feed the list reversed */
2716         yet_to_do = NULL;
2717         for (list = revs->commits; list; list = next) {
2718                 commit = list->item;
2719                 next = list->next;
2720                 /*
2721                  * Do not free(list) here yet; the original list
2722                  * is used later in this function.
2723                  */
2724                 commit_list_insert(commit, &yet_to_do);
2725         }
2726         while (yet_to_do) {
2727                 list = yet_to_do;
2728                 yet_to_do = NULL;
2729                 tail = &yet_to_do;
2730                 while (list) {
2731                         commit = pop_commit(&list);
2732                         tail = simplify_one(revs, commit, tail);
2733                 }
2734         }
2735
2736         /* clean up the result, removing the simplified ones */
2737         list = revs->commits;
2738         revs->commits = NULL;
2739         tail = &revs->commits;
2740         while (list) {
2741                 struct merge_simplify_state *st;
2742
2743                 commit = pop_commit(&list);
2744                 st = locate_simplify_state(revs, commit);
2745                 if (st->simplified == commit)
2746                         tail = &commit_list_insert(commit, tail)->next;
2747         }
2748 }
2749
2750 static void set_children(struct rev_info *revs)
2751 {
2752         struct commit_list *l;
2753         for (l = revs->commits; l; l = l->next) {
2754                 struct commit *commit = l->item;
2755                 struct commit_list *p;
2756
2757                 for (p = commit->parents; p; p = p->next)
2758                         add_child(revs, p->item, commit);
2759         }
2760 }
2761
2762 void reset_revision_walk(void)
2763 {
2764         clear_object_flags(SEEN | ADDED | SHOWN);
2765 }
2766
2767 int prepare_revision_walk(struct rev_info *revs)
2768 {
2769         int i;
2770         struct object_array old_pending;
2771         struct commit_list **next = &revs->commits;
2772
2773         memcpy(&old_pending, &revs->pending, sizeof(old_pending));
2774         revs->pending.nr = 0;
2775         revs->pending.alloc = 0;
2776         revs->pending.objects = NULL;
2777         for (i = 0; i < old_pending.nr; i++) {
2778                 struct object_array_entry *e = old_pending.objects + i;
2779                 struct commit *commit = handle_commit(revs, e);
2780                 if (commit) {
2781                         if (!(commit->object.flags & SEEN)) {
2782                                 commit->object.flags |= SEEN;
2783                                 next = commit_list_append(commit, next);
2784                         }
2785                 }
2786         }
2787         if (!revs->leak_pending)
2788                 object_array_clear(&old_pending);
2789
2790         /* Signal whether we need per-parent treesame decoration */
2791         if (revs->simplify_merges ||
2792             (revs->limited && limiting_can_increase_treesame(revs)))
2793                 revs->treesame.name = "treesame";
2794
2795         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2796                 commit_list_sort_by_date(&revs->commits);
2797         if (revs->no_walk)
2798                 return 0;
2799         if (revs->limited)
2800                 if (limit_list(revs) < 0)
2801                         return -1;
2802         if (revs->topo_order)
2803                 sort_in_topological_order(&revs->commits, revs->sort_order);
2804         if (revs->line_level_traverse)
2805                 line_log_filter(revs);
2806         if (revs->simplify_merges)
2807                 simplify_merges(revs);
2808         if (revs->children.name)
2809                 set_children(revs);
2810         return 0;
2811 }
2812
2813 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2814 {
2815         struct commit_list *cache = NULL;
2816
2817         for (;;) {
2818                 struct commit *p = *pp;
2819                 if (!revs->limited)
2820                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2821                                 return rewrite_one_error;
2822                 if (p->object.flags & UNINTERESTING)
2823                         return rewrite_one_ok;
2824                 if (!(p->object.flags & TREESAME))
2825                         return rewrite_one_ok;
2826                 if (!p->parents)
2827                         return rewrite_one_noparents;
2828                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2829                         return rewrite_one_ok;
2830                 *pp = p;
2831         }
2832 }
2833
2834 int rewrite_parents(struct rev_info *revs, struct commit *commit,
2835         rewrite_parent_fn_t rewrite_parent)
2836 {
2837         struct commit_list **pp = &commit->parents;
2838         while (*pp) {
2839                 struct commit_list *parent = *pp;
2840                 switch (rewrite_parent(revs, &parent->item)) {
2841                 case rewrite_one_ok:
2842                         break;
2843                 case rewrite_one_noparents:
2844                         *pp = parent->next;
2845                         continue;
2846                 case rewrite_one_error:
2847                         return -1;
2848                 }
2849                 pp = &parent->next;
2850         }
2851         remove_duplicate_parents(revs, commit);
2852         return 0;
2853 }
2854
2855 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2856 {
2857         char *person, *endp;
2858         size_t len, namelen, maillen;
2859         const char *name;
2860         const char *mail;
2861         struct ident_split ident;
2862
2863         person = strstr(buf->buf, what);
2864         if (!person)
2865                 return 0;
2866
2867         person += strlen(what);
2868         endp = strchr(person, '\n');
2869         if (!endp)
2870                 return 0;
2871
2872         len = endp - person;
2873
2874         if (split_ident_line(&ident, person, len))
2875                 return 0;
2876
2877         mail = ident.mail_begin;
2878         maillen = ident.mail_end - ident.mail_begin;
2879         name = ident.name_begin;
2880         namelen = ident.name_end - ident.name_begin;
2881
2882         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2883                 struct strbuf namemail = STRBUF_INIT;
2884
2885                 strbuf_addf(&namemail, "%.*s <%.*s>",
2886                             (int)namelen, name, (int)maillen, mail);
2887
2888                 strbuf_splice(buf, ident.name_begin - buf->buf,
2889                               ident.mail_end - ident.name_begin + 1,
2890                               namemail.buf, namemail.len);
2891
2892                 strbuf_release(&namemail);
2893
2894                 return 1;
2895         }
2896
2897         return 0;
2898 }
2899
2900 static int commit_match(struct commit *commit, struct rev_info *opt)
2901 {
2902         int retval;
2903         const char *encoding;
2904         const char *message;
2905         struct strbuf buf = STRBUF_INIT;
2906
2907         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2908                 return 1;
2909
2910         /* Prepend "fake" headers as needed */
2911         if (opt->grep_filter.use_reflog_filter) {
2912                 strbuf_addstr(&buf, "reflog ");
2913                 get_reflog_message(&buf, opt->reflog_info);
2914                 strbuf_addch(&buf, '\n');
2915         }
2916
2917         /*
2918          * We grep in the user's output encoding, under the assumption that it
2919          * is the encoding they are most likely to write their grep pattern
2920          * for. In addition, it means we will match the "notes" encoding below,
2921          * so we will not end up with a buffer that has two different encodings
2922          * in it.
2923          */
2924         encoding = get_log_output_encoding();
2925         message = logmsg_reencode(commit, NULL, encoding);
2926
2927         /* Copy the commit to temporary if we are using "fake" headers */
2928         if (buf.len)
2929                 strbuf_addstr(&buf, message);
2930
2931         if (opt->grep_filter.header_list && opt->mailmap) {
2932                 if (!buf.len)
2933                         strbuf_addstr(&buf, message);
2934
2935                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2936                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2937         }
2938
2939         /* Append "fake" message parts as needed */
2940         if (opt->show_notes) {
2941                 if (!buf.len)
2942                         strbuf_addstr(&buf, message);
2943                 format_display_notes(commit->object.oid.hash, &buf, encoding, 1);
2944         }
2945
2946         /*
2947          * Find either in the original commit message, or in the temporary.
2948          * Note that we cast away the constness of "message" here. It is
2949          * const because it may come from the cached commit buffer. That's OK,
2950          * because we know that it is modifiable heap memory, and that while
2951          * grep_buffer may modify it for speed, it will restore any
2952          * changes before returning.
2953          */
2954         if (buf.len)
2955                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2956         else
2957                 retval = grep_buffer(&opt->grep_filter,
2958                                      (char *)message, strlen(message));
2959         strbuf_release(&buf);
2960         unuse_commit_buffer(commit, message);
2961         return opt->invert_grep ? !retval : retval;
2962 }
2963
2964 static inline int want_ancestry(const struct rev_info *revs)
2965 {
2966         return (revs->rewrite_parents || revs->children.name);
2967 }
2968
2969 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2970 {
2971         if (commit->object.flags & SHOWN)
2972                 return commit_ignore;
2973         if (revs->unpacked && has_sha1_pack(commit->object.oid.hash))
2974                 return commit_ignore;
2975         if (revs->show_all)
2976                 return commit_show;
2977         if (commit->object.flags & UNINTERESTING)
2978                 return commit_ignore;
2979         if (revs->min_age != -1 && (commit->date > revs->min_age))
2980                 return commit_ignore;
2981         if (revs->min_parents || (revs->max_parents >= 0)) {
2982                 int n = commit_list_count(commit->parents);
2983                 if ((n < revs->min_parents) ||
2984                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2985                         return commit_ignore;
2986         }
2987         if (!commit_match(commit, revs))
2988                 return commit_ignore;
2989         if (revs->prune && revs->dense) {
2990                 /* Commit without changes? */
2991                 if (commit->object.flags & TREESAME) {
2992                         int n;
2993                         struct commit_list *p;
2994                         /* drop merges unless we want parenthood */
2995                         if (!want_ancestry(revs))
2996                                 return commit_ignore;
2997                         /*
2998                          * If we want ancestry, then need to keep any merges
2999                          * between relevant commits to tie together topology.
3000                          * For consistency with TREESAME and simplification
3001                          * use "relevant" here rather than just INTERESTING,
3002                          * to treat bottom commit(s) as part of the topology.
3003                          */
3004                         for (n = 0, p = commit->parents; p; p = p->next)
3005                                 if (relevant_commit(p->item))
3006                                         if (++n >= 2)
3007                                                 return commit_show;
3008                         return commit_ignore;
3009                 }
3010         }
3011         return commit_show;
3012 }
3013
3014 define_commit_slab(saved_parents, struct commit_list *);
3015
3016 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3017
3018 /*
3019  * You may only call save_parents() once per commit (this is checked
3020  * for non-root commits).
3021  */
3022 static void save_parents(struct rev_info *revs, struct commit *commit)
3023 {
3024         struct commit_list **pp;
3025
3026         if (!revs->saved_parents_slab) {
3027                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3028                 init_saved_parents(revs->saved_parents_slab);
3029         }
3030
3031         pp = saved_parents_at(revs->saved_parents_slab, commit);
3032
3033         /*
3034          * When walking with reflogs, we may visit the same commit
3035          * several times: once for each appearance in the reflog.
3036          *
3037          * In this case, save_parents() will be called multiple times.
3038          * We want to keep only the first set of parents.  We need to
3039          * store a sentinel value for an empty (i.e., NULL) parent
3040          * list to distinguish it from a not-yet-saved list, however.
3041          */
3042         if (*pp)
3043                 return;
3044         if (commit->parents)
3045                 *pp = copy_commit_list(commit->parents);
3046         else
3047                 *pp = EMPTY_PARENT_LIST;
3048 }
3049
3050 static void free_saved_parents(struct rev_info *revs)
3051 {
3052         if (revs->saved_parents_slab)
3053                 clear_saved_parents(revs->saved_parents_slab);
3054 }
3055
3056 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3057 {
3058         struct commit_list *parents;
3059
3060         if (!revs->saved_parents_slab)
3061                 return commit->parents;
3062
3063         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3064         if (parents == EMPTY_PARENT_LIST)
3065                 return NULL;
3066         return parents;
3067 }
3068
3069 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3070 {
3071         enum commit_action action = get_commit_action(revs, commit);
3072
3073         if (action == commit_show &&
3074             !revs->show_all &&
3075             revs->prune && revs->dense && want_ancestry(revs)) {
3076                 /*
3077                  * --full-diff on simplified parents is no good: it
3078                  * will show spurious changes from the commits that
3079                  * were elided.  So we save the parents on the side
3080                  * when --full-diff is in effect.
3081                  */
3082                 if (revs->full_diff)
3083                         save_parents(revs, commit);
3084                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
3085                         return commit_error;
3086         }
3087         return action;
3088 }
3089
3090 static void track_linear(struct rev_info *revs, struct commit *commit)
3091 {
3092         if (revs->track_first_time) {
3093                 revs->linear = 1;
3094                 revs->track_first_time = 0;
3095         } else {
3096                 struct commit_list *p;
3097                 for (p = revs->previous_parents; p; p = p->next)
3098                         if (p->item == NULL || /* first commit */
3099                             !oidcmp(&p->item->object.oid, &commit->object.oid))
3100                                 break;
3101                 revs->linear = p != NULL;
3102         }
3103         if (revs->reverse) {
3104                 if (revs->linear)
3105                         commit->object.flags |= TRACK_LINEAR;
3106         }
3107         free_commit_list(revs->previous_parents);
3108         revs->previous_parents = copy_commit_list(commit->parents);
3109 }
3110
3111 static struct commit *get_revision_1(struct rev_info *revs)
3112 {
3113         if (!revs->commits)
3114                 return NULL;
3115
3116         do {
3117                 struct commit *commit = pop_commit(&revs->commits);
3118
3119                 if (revs->reflog_info) {
3120                         save_parents(revs, commit);
3121                         fake_reflog_parent(revs->reflog_info, commit);
3122                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3123                 }
3124
3125                 /*
3126                  * If we haven't done the list limiting, we need to look at
3127                  * the parents here. We also need to do the date-based limiting
3128                  * that we'd otherwise have done in limit_list().
3129                  */
3130                 if (!revs->limited) {
3131                         if (revs->max_age != -1 &&
3132                             (commit->date < revs->max_age))
3133                                 continue;
3134                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
3135                                 if (!revs->ignore_missing_links)
3136                                         die("Failed to traverse parents of commit %s",
3137                                                 oid_to_hex(&commit->object.oid));
3138                         }
3139                 }
3140
3141                 switch (simplify_commit(revs, commit)) {
3142                 case commit_ignore:
3143                         continue;
3144                 case commit_error:
3145                         die("Failed to simplify parents of commit %s",
3146                             oid_to_hex(&commit->object.oid));
3147                 default:
3148                         if (revs->track_linear)
3149                                 track_linear(revs, commit);
3150                         return commit;
3151                 }
3152         } while (revs->commits);
3153         return NULL;
3154 }
3155
3156 /*
3157  * Return true for entries that have not yet been shown.  (This is an
3158  * object_array_each_func_t.)
3159  */
3160 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3161 {
3162         return !(entry->item->flags & SHOWN);
3163 }
3164
3165 /*
3166  * If array is on the verge of a realloc, garbage-collect any entries
3167  * that have already been shown to try to free up some space.
3168  */
3169 static void gc_boundary(struct object_array *array)
3170 {
3171         if (array->nr == array->alloc)
3172                 object_array_filter(array, entry_unshown, NULL);
3173 }
3174
3175 static void create_boundary_commit_list(struct rev_info *revs)
3176 {
3177         unsigned i;
3178         struct commit *c;
3179         struct object_array *array = &revs->boundary_commits;
3180         struct object_array_entry *objects = array->objects;
3181
3182         /*
3183          * If revs->commits is non-NULL at this point, an error occurred in
3184          * get_revision_1().  Ignore the error and continue printing the
3185          * boundary commits anyway.  (This is what the code has always
3186          * done.)
3187          */
3188         if (revs->commits) {
3189                 free_commit_list(revs->commits);
3190                 revs->commits = NULL;
3191         }
3192
3193         /*
3194          * Put all of the actual boundary commits from revs->boundary_commits
3195          * into revs->commits
3196          */
3197         for (i = 0; i < array->nr; i++) {
3198                 c = (struct commit *)(objects[i].item);
3199                 if (!c)
3200                         continue;
3201                 if (!(c->object.flags & CHILD_SHOWN))
3202                         continue;
3203                 if (c->object.flags & (SHOWN | BOUNDARY))
3204                         continue;
3205                 c->object.flags |= BOUNDARY;
3206                 commit_list_insert(c, &revs->commits);
3207         }
3208
3209         /*
3210          * If revs->topo_order is set, sort the boundary commits
3211          * in topological order
3212          */
3213         sort_in_topological_order(&revs->commits, revs->sort_order);
3214 }
3215
3216 static struct commit *get_revision_internal(struct rev_info *revs)
3217 {
3218         struct commit *c = NULL;
3219         struct commit_list *l;
3220
3221         if (revs->boundary == 2) {
3222                 /*
3223                  * All of the normal commits have already been returned,
3224                  * and we are now returning boundary commits.
3225                  * create_boundary_commit_list() has populated
3226                  * revs->commits with the remaining commits to return.
3227                  */
3228                 c = pop_commit(&revs->commits);
3229                 if (c)
3230                         c->object.flags |= SHOWN;
3231                 return c;
3232         }
3233
3234         /*
3235          * If our max_count counter has reached zero, then we are done. We
3236          * don't simply return NULL because we still might need to show
3237          * boundary commits. But we want to avoid calling get_revision_1, which
3238          * might do a considerable amount of work finding the next commit only
3239          * for us to throw it away.
3240          *
3241          * If it is non-zero, then either we don't have a max_count at all
3242          * (-1), or it is still counting, in which case we decrement.
3243          */
3244         if (revs->max_count) {
3245                 c = get_revision_1(revs);
3246                 if (c) {
3247                         while (revs->skip_count > 0) {
3248                                 revs->skip_count--;
3249                                 c = get_revision_1(revs);
3250                                 if (!c)
3251                                         break;
3252                         }
3253                 }
3254
3255                 if (revs->max_count > 0)
3256                         revs->max_count--;
3257         }
3258
3259         if (c)
3260                 c->object.flags |= SHOWN;
3261
3262         if (!revs->boundary)
3263                 return c;
3264
3265         if (!c) {
3266                 /*
3267                  * get_revision_1() runs out the commits, and
3268                  * we are done computing the boundaries.
3269                  * switch to boundary commits output mode.
3270                  */
3271                 revs->boundary = 2;
3272
3273                 /*
3274                  * Update revs->commits to contain the list of
3275                  * boundary commits.
3276                  */
3277                 create_boundary_commit_list(revs);
3278
3279                 return get_revision_internal(revs);
3280         }
3281
3282         /*
3283          * boundary commits are the commits that are parents of the
3284          * ones we got from get_revision_1() but they themselves are
3285          * not returned from get_revision_1().  Before returning
3286          * 'c', we need to mark its parents that they could be boundaries.
3287          */
3288
3289         for (l = c->parents; l; l = l->next) {
3290                 struct object *p;
3291                 p = &(l->item->object);
3292                 if (p->flags & (CHILD_SHOWN | SHOWN))
3293                         continue;
3294                 p->flags |= CHILD_SHOWN;
3295                 gc_boundary(&revs->boundary_commits);
3296                 add_object_array(p, NULL, &revs->boundary_commits);
3297         }
3298
3299         return c;
3300 }
3301
3302 struct commit *get_revision(struct rev_info *revs)
3303 {
3304         struct commit *c;
3305         struct commit_list *reversed;
3306
3307         if (revs->reverse) {
3308                 reversed = NULL;
3309                 while ((c = get_revision_internal(revs)))
3310                         commit_list_insert(c, &reversed);
3311                 revs->commits = reversed;
3312                 revs->reverse = 0;
3313                 revs->reverse_output_stage = 1;
3314         }
3315
3316         if (revs->reverse_output_stage) {
3317                 c = pop_commit(&revs->commits);
3318                 if (revs->track_linear)
3319                         revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
3320                 return c;
3321         }
3322
3323         c = get_revision_internal(revs);
3324         if (c && revs->graph)
3325                 graph_update(revs->graph, c);
3326         if (!c) {
3327                 free_saved_parents(revs);
3328                 if (revs->previous_parents) {
3329                         free_commit_list(revs->previous_parents);
3330                         revs->previous_parents = NULL;
3331                 }
3332         }
3333         return c;
3334 }
3335
3336 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3337 {
3338         if (commit->object.flags & BOUNDARY)
3339                 return "-";
3340         else if (commit->object.flags & UNINTERESTING)
3341                 return "^";
3342         else if (commit->object.flags & PATCHSAME)
3343                 return "=";
3344         else if (!revs || revs->left_right) {
3345                 if (commit->object.flags & SYMMETRIC_LEFT)
3346                         return "<";
3347                 else
3348                         return ">";
3349         } else if (revs->graph)
3350                 return "*";
3351         else if (revs->cherry_mark)
3352                 return "+";
3353         return "";
3354 }
3355
3356 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3357 {
3358         char *mark = get_revision_mark(revs, commit);
3359         if (!strlen(mark))
3360                 return;
3361         fputs(mark, stdout);
3362         putchar(' ');
3363 }