show-ref: stop using PARSE_OPT_NO_INTERNAL_HELP
[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 ", sha1_to_hex(obj->sha1));
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_sha1_file(obj->sha1))
110                 return;
111         if (parse_tree(tree) < 0)
112                 die("bad tree %s", sha1_to_hex(obj->sha1));
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 = &tree->object;
139
140         if (!tree)
141                 return;
142         if (obj->flags & UNINTERESTING)
143                 return;
144         obj->flags |= UNINTERESTING;
145         mark_tree_contents_uninteresting(tree);
146 }
147
148 void mark_parents_uninteresting(struct commit *commit)
149 {
150         struct commit_list *parents = NULL, *l;
151
152         for (l = commit->parents; l; l = l->next)
153                 commit_list_insert(l->item, &parents);
154
155         while (parents) {
156                 struct commit *commit = pop_commit(&parents);
157
158                 while (commit) {
159                         /*
160                          * A missing commit is ok iff its parent is marked
161                          * uninteresting.
162                          *
163                          * We just mark such a thing parsed, so that when
164                          * it is popped next time around, we won't be trying
165                          * to parse it and get an error.
166                          */
167                         if (!has_sha1_file(commit->object.sha1))
168                                 commit->object.parsed = 1;
169
170                         if (commit->object.flags & UNINTERESTING)
171                                 break;
172
173                         commit->object.flags |= UNINTERESTING;
174
175                         /*
176                          * Normally we haven't parsed the parent
177                          * yet, so we won't have a parent of a parent
178                          * here. However, it may turn out that we've
179                          * reached this commit some other way (where it
180                          * wasn't uninteresting), in which case we need
181                          * to mark its parents recursively too..
182                          */
183                         if (!commit->parents)
184                                 break;
185
186                         for (l = commit->parents->next; l; l = l->next)
187                                 commit_list_insert(l->item, &parents);
188                         commit = commit->parents->item;
189                 }
190         }
191 }
192
193 static void add_pending_object_with_path(struct rev_info *revs,
194                                          struct object *obj,
195                                          const char *name, unsigned mode,
196                                          const char *path)
197 {
198         if (!obj)
199                 return;
200         if (revs->no_walk && (obj->flags & UNINTERESTING))
201                 revs->no_walk = 0;
202         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
203                 struct strbuf buf = STRBUF_INIT;
204                 int len = interpret_branch_name(name, 0, &buf);
205                 int st;
206
207                 if (0 < len && name[len] && buf.len)
208                         strbuf_addstr(&buf, name + len);
209                 st = add_reflog_for_walk(revs->reflog_info,
210                                          (struct commit *)obj,
211                                          buf.buf[0] ? buf.buf: name);
212                 strbuf_release(&buf);
213                 if (st)
214                         return;
215         }
216         add_object_array_with_path(obj, name, &revs->pending, mode, path);
217 }
218
219 static void add_pending_object_with_mode(struct rev_info *revs,
220                                          struct object *obj,
221                                          const char *name, unsigned mode)
222 {
223         add_pending_object_with_path(revs, obj, name, mode, NULL);
224 }
225
226 void add_pending_object(struct rev_info *revs,
227                         struct object *obj, const char *name)
228 {
229         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
230 }
231
232 void add_head_to_pending(struct rev_info *revs)
233 {
234         unsigned char sha1[20];
235         struct object *obj;
236         if (get_sha1("HEAD", sha1))
237                 return;
238         obj = parse_object(sha1);
239         if (!obj)
240                 return;
241         add_pending_object(revs, obj, "HEAD");
242 }
243
244 static struct object *get_reference(struct rev_info *revs, const char *name,
245                                     const unsigned char *sha1,
246                                     unsigned int flags)
247 {
248         struct object *object;
249
250         object = parse_object(sha1);
251         if (!object) {
252                 if (revs->ignore_missing)
253                         return object;
254                 die("bad object %s", name);
255         }
256         object->flags |= flags;
257         return object;
258 }
259
260 void add_pending_sha1(struct rev_info *revs, const char *name,
261                       const unsigned char *sha1, unsigned int flags)
262 {
263         struct object *object = get_reference(revs, name, sha1, flags);
264         add_pending_object(revs, object, name);
265 }
266
267 static struct commit *handle_commit(struct rev_info *revs,
268                                     struct object_array_entry *entry)
269 {
270         struct object *object = entry->item;
271         const char *name = entry->name;
272         const char *path = entry->path;
273         unsigned int mode = entry->mode;
274         unsigned long flags = object->flags;
275
276         /*
277          * Tag object? Look what it points to..
278          */
279         while (object->type == OBJ_TAG) {
280                 struct tag *tag = (struct tag *) object;
281                 if (revs->tag_objects && !(flags & UNINTERESTING))
282                         add_pending_object(revs, object, tag->tag);
283                 if (!tag->tagged)
284                         die("bad tag");
285                 object = parse_object(tag->tagged->sha1);
286                 if (!object) {
287                         if (flags & UNINTERESTING)
288                                 return NULL;
289                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
290                 }
291                 object->flags |= flags;
292                 /*
293                  * We'll handle the tagged object by looping or dropping
294                  * through to the non-tag handlers below. Do not
295                  * propagate data from the tag's pending entry.
296                  */
297                 name = "";
298                 path = NULL;
299                 mode = 0;
300         }
301
302         /*
303          * Commit object? Just return it, we'll do all the complex
304          * reachability crud.
305          */
306         if (object->type == OBJ_COMMIT) {
307                 struct commit *commit = (struct commit *)object;
308                 if (parse_commit(commit) < 0)
309                         die("unable to parse commit %s", name);
310                 if (flags & UNINTERESTING) {
311                         mark_parents_uninteresting(commit);
312                         revs->limited = 1;
313                 }
314                 if (revs->show_source && !commit->util)
315                         commit->util = xstrdup(name);
316                 return commit;
317         }
318
319         /*
320          * Tree object? Either mark it uninteresting, or add it
321          * to the list of objects to look at later..
322          */
323         if (object->type == OBJ_TREE) {
324                 struct tree *tree = (struct tree *)object;
325                 if (!revs->tree_objects)
326                         return NULL;
327                 if (flags & UNINTERESTING) {
328                         mark_tree_contents_uninteresting(tree);
329                         return NULL;
330                 }
331                 add_pending_object_with_path(revs, object, name, mode, path);
332                 return NULL;
333         }
334
335         /*
336          * Blob object? You know the drill by now..
337          */
338         if (object->type == OBJ_BLOB) {
339                 if (!revs->blob_objects)
340                         return NULL;
341                 if (flags & UNINTERESTING)
342                         return NULL;
343                 add_pending_object_with_path(revs, object, name, mode, path);
344                 return NULL;
345         }
346         die("%s is unknown object", name);
347 }
348
349 static int everybody_uninteresting(struct commit_list *orig,
350                                    struct commit **interesting_cache)
351 {
352         struct commit_list *list = orig;
353
354         if (*interesting_cache) {
355                 struct commit *commit = *interesting_cache;
356                 if (!(commit->object.flags & UNINTERESTING))
357                         return 0;
358         }
359
360         while (list) {
361                 struct commit *commit = list->item;
362                 list = list->next;
363                 if (commit->object.flags & UNINTERESTING)
364                         continue;
365
366                 *interesting_cache = commit;
367                 return 0;
368         }
369         return 1;
370 }
371
372 /*
373  * A definition of "relevant" commit that we can use to simplify limited graphs
374  * by eliminating side branches.
375  *
376  * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
377  * in our list), or that is a specified BOTTOM commit. Then after computing
378  * a limited list, during processing we can generally ignore boundary merges
379  * coming from outside the graph, (ie from irrelevant parents), and treat
380  * those merges as if they were single-parent. TREESAME is defined to consider
381  * only relevant parents, if any. If we are TREESAME to our on-graph parents,
382  * we don't care if we were !TREESAME to non-graph parents.
383  *
384  * Treating bottom commits as relevant ensures that a limited graph's
385  * connection to the actual bottom commit is not viewed as a side branch, but
386  * treated as part of the graph. For example:
387  *
388  *   ....Z...A---X---o---o---B
389  *        .     /
390  *         W---Y
391  *
392  * When computing "A..B", the A-X connection is at least as important as
393  * Y-X, despite A being flagged UNINTERESTING.
394  *
395  * And when computing --ancestry-path "A..B", the A-X connection is more
396  * important than Y-X, despite both A and Y being flagged UNINTERESTING.
397  */
398 static inline int relevant_commit(struct commit *commit)
399 {
400         return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
401 }
402
403 /*
404  * Return a single relevant commit from a parent list. If we are a TREESAME
405  * commit, and this selects one of our parents, then we can safely simplify to
406  * that parent.
407  */
408 static struct commit *one_relevant_parent(const struct rev_info *revs,
409                                           struct commit_list *orig)
410 {
411         struct commit_list *list = orig;
412         struct commit *relevant = NULL;
413
414         if (!orig)
415                 return NULL;
416
417         /*
418          * For 1-parent commits, or if first-parent-only, then return that
419          * first parent (even if not "relevant" by the above definition).
420          * TREESAME will have been set purely on that parent.
421          */
422         if (revs->first_parent_only || !orig->next)
423                 return orig->item;
424
425         /*
426          * For multi-parent commits, identify a sole relevant parent, if any.
427          * If we have only one relevant parent, then TREESAME will be set purely
428          * with regard to that parent, and we can simplify accordingly.
429          *
430          * If we have more than one relevant parent, or no relevant parents
431          * (and multiple irrelevant ones), then we can't select a parent here
432          * and return NULL.
433          */
434         while (list) {
435                 struct commit *commit = list->item;
436                 list = list->next;
437                 if (relevant_commit(commit)) {
438                         if (relevant)
439                                 return NULL;
440                         relevant = commit;
441                 }
442         }
443         return relevant;
444 }
445
446 /*
447  * The goal is to get REV_TREE_NEW as the result only if the
448  * diff consists of all '+' (and no other changes), REV_TREE_OLD
449  * if the whole diff is removal of old data, and otherwise
450  * REV_TREE_DIFFERENT (of course if the trees are the same we
451  * want REV_TREE_SAME).
452  * That means that once we get to REV_TREE_DIFFERENT, we do not
453  * have to look any further.
454  */
455 static int tree_difference = REV_TREE_SAME;
456
457 static void file_add_remove(struct diff_options *options,
458                     int addremove, unsigned mode,
459                     const unsigned char *sha1,
460                     int sha1_valid,
461                     const char *fullpath, unsigned dirty_submodule)
462 {
463         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
464
465         tree_difference |= diff;
466         if (tree_difference == REV_TREE_DIFFERENT)
467                 DIFF_OPT_SET(options, HAS_CHANGES);
468 }
469
470 static void file_change(struct diff_options *options,
471                  unsigned old_mode, unsigned new_mode,
472                  const unsigned char *old_sha1,
473                  const unsigned char *new_sha1,
474                  int old_sha1_valid, int new_sha1_valid,
475                  const char *fullpath,
476                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
477 {
478         tree_difference = REV_TREE_DIFFERENT;
479         DIFF_OPT_SET(options, HAS_CHANGES);
480 }
481
482 static int rev_compare_tree(struct rev_info *revs,
483                             struct commit *parent, struct commit *commit)
484 {
485         struct tree *t1 = parent->tree;
486         struct tree *t2 = commit->tree;
487
488         if (!t1)
489                 return REV_TREE_NEW;
490         if (!t2)
491                 return REV_TREE_OLD;
492
493         if (revs->simplify_by_decoration) {
494                 /*
495                  * If we are simplifying by decoration, then the commit
496                  * is worth showing if it has a tag pointing at it.
497                  */
498                 if (get_name_decoration(&commit->object))
499                         return REV_TREE_DIFFERENT;
500                 /*
501                  * A commit that is not pointed by a tag is uninteresting
502                  * if we are not limited by path.  This means that you will
503                  * see the usual "commits that touch the paths" plus any
504                  * tagged commit by specifying both --simplify-by-decoration
505                  * and pathspec.
506                  */
507                 if (!revs->prune_data.nr)
508                         return REV_TREE_SAME;
509         }
510
511         tree_difference = REV_TREE_SAME;
512         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
513         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
514                            &revs->pruning) < 0)
515                 return REV_TREE_DIFFERENT;
516         return tree_difference;
517 }
518
519 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
520 {
521         int retval;
522         struct tree *t1 = commit->tree;
523
524         if (!t1)
525                 return 0;
526
527         tree_difference = REV_TREE_SAME;
528         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
529         retval = diff_tree_sha1(NULL, t1->object.sha1, "", &revs->pruning);
530
531         return retval >= 0 && (tree_difference == REV_TREE_SAME);
532 }
533
534 struct treesame_state {
535         unsigned int nparents;
536         unsigned char treesame[FLEX_ARRAY];
537 };
538
539 static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
540 {
541         unsigned n = commit_list_count(commit->parents);
542         struct treesame_state *st = xcalloc(1, sizeof(*st) + n);
543         st->nparents = n;
544         add_decoration(&revs->treesame, &commit->object, st);
545         return st;
546 }
547
548 /*
549  * Must be called immediately after removing the nth_parent from a commit's
550  * parent list, if we are maintaining the per-parent treesame[] decoration.
551  * This does not recalculate the master TREESAME flag - update_treesame()
552  * should be called to update it after a sequence of treesame[] modifications
553  * that may have affected it.
554  */
555 static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
556 {
557         struct treesame_state *st;
558         int old_same;
559
560         if (!commit->parents) {
561                 /*
562                  * Have just removed the only parent from a non-merge.
563                  * Different handling, as we lack decoration.
564                  */
565                 if (nth_parent != 0)
566                         die("compact_treesame %u", nth_parent);
567                 old_same = !!(commit->object.flags & TREESAME);
568                 if (rev_same_tree_as_empty(revs, commit))
569                         commit->object.flags |= TREESAME;
570                 else
571                         commit->object.flags &= ~TREESAME;
572                 return old_same;
573         }
574
575         st = lookup_decoration(&revs->treesame, &commit->object);
576         if (!st || nth_parent >= st->nparents)
577                 die("compact_treesame %u", nth_parent);
578
579         old_same = st->treesame[nth_parent];
580         memmove(st->treesame + nth_parent,
581                 st->treesame + nth_parent + 1,
582                 st->nparents - nth_parent - 1);
583
584         /*
585          * If we've just become a non-merge commit, update TREESAME
586          * immediately, and remove the no-longer-needed decoration.
587          * If still a merge, defer update until update_treesame().
588          */
589         if (--st->nparents == 1) {
590                 if (commit->parents->next)
591                         die("compact_treesame parents mismatch");
592                 if (st->treesame[0] && revs->dense)
593                         commit->object.flags |= TREESAME;
594                 else
595                         commit->object.flags &= ~TREESAME;
596                 free(add_decoration(&revs->treesame, &commit->object, NULL));
597         }
598
599         return old_same;
600 }
601
602 static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
603 {
604         if (commit->parents && commit->parents->next) {
605                 unsigned n;
606                 struct treesame_state *st;
607                 struct commit_list *p;
608                 unsigned relevant_parents;
609                 unsigned relevant_change, irrelevant_change;
610
611                 st = lookup_decoration(&revs->treesame, &commit->object);
612                 if (!st)
613                         die("update_treesame %s", sha1_to_hex(commit->object.sha1));
614                 relevant_parents = 0;
615                 relevant_change = irrelevant_change = 0;
616                 for (p = commit->parents, n = 0; p; n++, p = p->next) {
617                         if (relevant_commit(p->item)) {
618                                 relevant_change |= !st->treesame[n];
619                                 relevant_parents++;
620                         } else
621                                 irrelevant_change |= !st->treesame[n];
622                 }
623                 if (relevant_parents ? relevant_change : irrelevant_change)
624                         commit->object.flags &= ~TREESAME;
625                 else
626                         commit->object.flags |= TREESAME;
627         }
628
629         return commit->object.flags & TREESAME;
630 }
631
632 static inline int limiting_can_increase_treesame(const struct rev_info *revs)
633 {
634         /*
635          * TREESAME is irrelevant unless prune && dense;
636          * if simplify_history is set, we can't have a mixture of TREESAME and
637          *    !TREESAME INTERESTING parents (and we don't have treesame[]
638          *    decoration anyway);
639          * if first_parent_only is set, then the TREESAME flag is locked
640          *    against the first parent (and again we lack treesame[] decoration).
641          */
642         return revs->prune && revs->dense &&
643                !revs->simplify_history &&
644                !revs->first_parent_only;
645 }
646
647 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
648 {
649         struct commit_list **pp, *parent;
650         struct treesame_state *ts = NULL;
651         int relevant_change = 0, irrelevant_change = 0;
652         int relevant_parents, nth_parent;
653
654         /*
655          * If we don't do pruning, everything is interesting
656          */
657         if (!revs->prune)
658                 return;
659
660         if (!commit->tree)
661                 return;
662
663         if (!commit->parents) {
664                 if (rev_same_tree_as_empty(revs, commit))
665                         commit->object.flags |= TREESAME;
666                 return;
667         }
668
669         /*
670          * Normal non-merge commit? If we don't want to make the
671          * history dense, we consider it always to be a change..
672          */
673         if (!revs->dense && !commit->parents->next)
674                 return;
675
676         for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
677              (parent = *pp) != NULL;
678              pp = &parent->next, nth_parent++) {
679                 struct commit *p = parent->item;
680                 if (relevant_commit(p))
681                         relevant_parents++;
682
683                 if (nth_parent == 1) {
684                         /*
685                          * This our second loop iteration - so we now know
686                          * we're dealing with a merge.
687                          *
688                          * Do not compare with later parents when we care only about
689                          * the first parent chain, in order to avoid derailing the
690                          * traversal to follow a side branch that brought everything
691                          * in the path we are limited to by the pathspec.
692                          */
693                         if (revs->first_parent_only)
694                                 break;
695                         /*
696                          * If this will remain a potentially-simplifiable
697                          * merge, remember per-parent treesame if needed.
698                          * Initialise the array with the comparison from our
699                          * first iteration.
700                          */
701                         if (revs->treesame.name &&
702                             !revs->simplify_history &&
703                             !(commit->object.flags & UNINTERESTING)) {
704                                 ts = initialise_treesame(revs, commit);
705                                 if (!(irrelevant_change || relevant_change))
706                                         ts->treesame[0] = 1;
707                         }
708                 }
709                 if (parse_commit(p) < 0)
710                         die("cannot simplify commit %s (because of %s)",
711                             sha1_to_hex(commit->object.sha1),
712                             sha1_to_hex(p->object.sha1));
713                 switch (rev_compare_tree(revs, p, commit)) {
714                 case REV_TREE_SAME:
715                         if (!revs->simplify_history || !relevant_commit(p)) {
716                                 /* Even if a merge with an uninteresting
717                                  * side branch brought the entire change
718                                  * we are interested in, we do not want
719                                  * to lose the other branches of this
720                                  * merge, so we just keep going.
721                                  */
722                                 if (ts)
723                                         ts->treesame[nth_parent] = 1;
724                                 continue;
725                         }
726                         parent->next = NULL;
727                         commit->parents = parent;
728                         commit->object.flags |= TREESAME;
729                         return;
730
731                 case REV_TREE_NEW:
732                         if (revs->remove_empty_trees &&
733                             rev_same_tree_as_empty(revs, p)) {
734                                 /* We are adding all the specified
735                                  * paths from this parent, so the
736                                  * history beyond this parent is not
737                                  * interesting.  Remove its parents
738                                  * (they are grandparents for us).
739                                  * IOW, we pretend this parent is a
740                                  * "root" commit.
741                                  */
742                                 if (parse_commit(p) < 0)
743                                         die("cannot simplify commit %s (invalid %s)",
744                                             sha1_to_hex(commit->object.sha1),
745                                             sha1_to_hex(p->object.sha1));
746                                 p->parents = NULL;
747                         }
748                 /* fallthrough */
749                 case REV_TREE_OLD:
750                 case REV_TREE_DIFFERENT:
751                         if (relevant_commit(p))
752                                 relevant_change = 1;
753                         else
754                                 irrelevant_change = 1;
755                         continue;
756                 }
757                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
758         }
759
760         /*
761          * TREESAME is straightforward for single-parent commits. For merge
762          * commits, it is most useful to define it so that "irrelevant"
763          * parents cannot make us !TREESAME - if we have any relevant
764          * parents, then we only consider TREESAMEness with respect to them,
765          * allowing irrelevant merges from uninteresting branches to be
766          * simplified away. Only if we have only irrelevant parents do we
767          * base TREESAME on them. Note that this logic is replicated in
768          * update_treesame, which should be kept in sync.
769          */
770         if (relevant_parents ? !relevant_change : !irrelevant_change)
771                 commit->object.flags |= TREESAME;
772 }
773
774 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
775                     struct commit_list *cached_base, struct commit_list **cache)
776 {
777         struct commit_list *new_entry;
778
779         if (cached_base && p->date < cached_base->item->date)
780                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
781         else
782                 new_entry = commit_list_insert_by_date(p, head);
783
784         if (cache && (!*cache || p->date < (*cache)->item->date))
785                 *cache = new_entry;
786 }
787
788 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
789                     struct commit_list **list, struct commit_list **cache_ptr)
790 {
791         struct commit_list *parent = commit->parents;
792         unsigned left_flag;
793         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
794
795         if (commit->object.flags & ADDED)
796                 return 0;
797         commit->object.flags |= ADDED;
798
799         if (revs->include_check &&
800             !revs->include_check(commit, revs->include_check_data))
801                 return 0;
802
803         /*
804          * If the commit is uninteresting, don't try to
805          * prune parents - we want the maximal uninteresting
806          * set.
807          *
808          * Normally we haven't parsed the parent
809          * yet, so we won't have a parent of a parent
810          * here. However, it may turn out that we've
811          * reached this commit some other way (where it
812          * wasn't uninteresting), in which case we need
813          * to mark its parents recursively too..
814          */
815         if (commit->object.flags & UNINTERESTING) {
816                 while (parent) {
817                         struct commit *p = parent->item;
818                         parent = parent->next;
819                         if (p)
820                                 p->object.flags |= UNINTERESTING;
821                         if (parse_commit_gently(p, 1) < 0)
822                                 continue;
823                         if (p->parents)
824                                 mark_parents_uninteresting(p);
825                         if (p->object.flags & SEEN)
826                                 continue;
827                         p->object.flags |= SEEN;
828                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
829                 }
830                 return 0;
831         }
832
833         /*
834          * Ok, the commit wasn't uninteresting. Try to
835          * simplify the commit history and find the parent
836          * that has no differences in the path set if one exists.
837          */
838         try_to_simplify_commit(revs, commit);
839
840         if (revs->no_walk)
841                 return 0;
842
843         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
844
845         for (parent = commit->parents; parent; parent = parent->next) {
846                 struct commit *p = parent->item;
847
848                 if (parse_commit_gently(p, revs->ignore_missing_links) < 0)
849                         return -1;
850                 if (revs->show_source && !p->util)
851                         p->util = commit->util;
852                 p->object.flags |= left_flag;
853                 if (!(p->object.flags & SEEN)) {
854                         p->object.flags |= SEEN;
855                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
856                 }
857                 if (revs->first_parent_only)
858                         break;
859         }
860         return 0;
861 }
862
863 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
864 {
865         struct commit_list *p;
866         int left_count = 0, right_count = 0;
867         int left_first;
868         struct patch_ids ids;
869         unsigned cherry_flag;
870
871         /* First count the commits on the left and on the right */
872         for (p = list; p; p = p->next) {
873                 struct commit *commit = p->item;
874                 unsigned flags = commit->object.flags;
875                 if (flags & BOUNDARY)
876                         ;
877                 else if (flags & SYMMETRIC_LEFT)
878                         left_count++;
879                 else
880                         right_count++;
881         }
882
883         if (!left_count || !right_count)
884                 return;
885
886         left_first = left_count < right_count;
887         init_patch_ids(&ids);
888         ids.diffopts.pathspec = revs->diffopt.pathspec;
889
890         /* Compute patch-ids for one side */
891         for (p = list; p; p = p->next) {
892                 struct commit *commit = p->item;
893                 unsigned flags = commit->object.flags;
894
895                 if (flags & BOUNDARY)
896                         continue;
897                 /*
898                  * If we have fewer left, left_first is set and we omit
899                  * commits on the right branch in this loop.  If we have
900                  * fewer right, we skip the left ones.
901                  */
902                 if (left_first != !!(flags & SYMMETRIC_LEFT))
903                         continue;
904                 commit->util = add_commit_patch_id(commit, &ids);
905         }
906
907         /* either cherry_mark or cherry_pick are true */
908         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
909
910         /* Check the other side */
911         for (p = list; p; p = p->next) {
912                 struct commit *commit = p->item;
913                 struct patch_id *id;
914                 unsigned flags = commit->object.flags;
915
916                 if (flags & BOUNDARY)
917                         continue;
918                 /*
919                  * If we have fewer left, left_first is set and we omit
920                  * commits on the left branch in this loop.
921                  */
922                 if (left_first == !!(flags & SYMMETRIC_LEFT))
923                         continue;
924
925                 /*
926                  * Have we seen the same patch id?
927                  */
928                 id = has_commit_patch_id(commit, &ids);
929                 if (!id)
930                         continue;
931                 id->seen = 1;
932                 commit->object.flags |= cherry_flag;
933         }
934
935         /* Now check the original side for seen ones */
936         for (p = list; p; p = p->next) {
937                 struct commit *commit = p->item;
938                 struct patch_id *ent;
939
940                 ent = commit->util;
941                 if (!ent)
942                         continue;
943                 if (ent->seen)
944                         commit->object.flags |= cherry_flag;
945                 commit->util = NULL;
946         }
947
948         free_patch_ids(&ids);
949 }
950
951 /* How many extra uninteresting commits we want to see.. */
952 #define SLOP 5
953
954 static int still_interesting(struct commit_list *src, unsigned long date, int slop,
955                              struct commit **interesting_cache)
956 {
957         /*
958          * No source list at all? We're definitely done..
959          */
960         if (!src)
961                 return 0;
962
963         /*
964          * Does the destination list contain entries with a date
965          * before the source list? Definitely _not_ done.
966          */
967         if (date <= src->item->date)
968                 return SLOP;
969
970         /*
971          * Does the source list still have interesting commits in
972          * it? Definitely not done..
973          */
974         if (!everybody_uninteresting(src, interesting_cache))
975                 return SLOP;
976
977         /* Ok, we're closing in.. */
978         return slop-1;
979 }
980
981 /*
982  * "rev-list --ancestry-path A..B" computes commits that are ancestors
983  * of B but not ancestors of A but further limits the result to those
984  * that are descendants of A.  This takes the list of bottom commits and
985  * the result of "A..B" without --ancestry-path, and limits the latter
986  * further to the ones that can reach one of the commits in "bottom".
987  */
988 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
989 {
990         struct commit_list *p;
991         struct commit_list *rlist = NULL;
992         int made_progress;
993
994         /*
995          * Reverse the list so that it will be likely that we would
996          * process parents before children.
997          */
998         for (p = list; p; p = p->next)
999                 commit_list_insert(p->item, &rlist);
1000
1001         for (p = bottom; p; p = p->next)
1002                 p->item->object.flags |= TMP_MARK;
1003
1004         /*
1005          * Mark the ones that can reach bottom commits in "list",
1006          * in a bottom-up fashion.
1007          */
1008         do {
1009                 made_progress = 0;
1010                 for (p = rlist; p; p = p->next) {
1011                         struct commit *c = p->item;
1012                         struct commit_list *parents;
1013                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
1014                                 continue;
1015                         for (parents = c->parents;
1016                              parents;
1017                              parents = parents->next) {
1018                                 if (!(parents->item->object.flags & TMP_MARK))
1019                                         continue;
1020                                 c->object.flags |= TMP_MARK;
1021                                 made_progress = 1;
1022                                 break;
1023                         }
1024                 }
1025         } while (made_progress);
1026
1027         /*
1028          * NEEDSWORK: decide if we want to remove parents that are
1029          * not marked with TMP_MARK from commit->parents for commits
1030          * in the resulting list.  We may not want to do that, though.
1031          */
1032
1033         /*
1034          * The ones that are not marked with TMP_MARK are uninteresting
1035          */
1036         for (p = list; p; p = p->next) {
1037                 struct commit *c = p->item;
1038                 if (c->object.flags & TMP_MARK)
1039                         continue;
1040                 c->object.flags |= UNINTERESTING;
1041         }
1042
1043         /* We are done with the TMP_MARK */
1044         for (p = list; p; p = p->next)
1045                 p->item->object.flags &= ~TMP_MARK;
1046         for (p = bottom; p; p = p->next)
1047                 p->item->object.flags &= ~TMP_MARK;
1048         free_commit_list(rlist);
1049 }
1050
1051 /*
1052  * Before walking the history, keep the set of "negative" refs the
1053  * caller has asked to exclude.
1054  *
1055  * This is used to compute "rev-list --ancestry-path A..B", as we need
1056  * to filter the result of "A..B" further to the ones that can actually
1057  * reach A.
1058  */
1059 static struct commit_list *collect_bottom_commits(struct commit_list *list)
1060 {
1061         struct commit_list *elem, *bottom = NULL;
1062         for (elem = list; elem; elem = elem->next)
1063                 if (elem->item->object.flags & BOTTOM)
1064                         commit_list_insert(elem->item, &bottom);
1065         return bottom;
1066 }
1067
1068 /* Assumes either left_only or right_only is set */
1069 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1070 {
1071         struct commit_list *p;
1072
1073         for (p = list; p; p = p->next) {
1074                 struct commit *commit = p->item;
1075
1076                 if (revs->right_only) {
1077                         if (commit->object.flags & SYMMETRIC_LEFT)
1078                                 commit->object.flags |= SHOWN;
1079                 } else  /* revs->left_only is set */
1080                         if (!(commit->object.flags & SYMMETRIC_LEFT))
1081                                 commit->object.flags |= SHOWN;
1082         }
1083 }
1084
1085 static int limit_list(struct rev_info *revs)
1086 {
1087         int slop = SLOP;
1088         unsigned long date = ~0ul;
1089         struct commit_list *list = revs->commits;
1090         struct commit_list *newlist = NULL;
1091         struct commit_list **p = &newlist;
1092         struct commit_list *bottom = NULL;
1093         struct commit *interesting_cache = NULL;
1094
1095         if (revs->ancestry_path) {
1096                 bottom = collect_bottom_commits(list);
1097                 if (!bottom)
1098                         die("--ancestry-path given but there are no bottom commits");
1099         }
1100
1101         while (list) {
1102                 struct commit *commit = pop_commit(&list);
1103                 struct object *obj = &commit->object;
1104                 show_early_output_fn_t show;
1105
1106                 if (commit == interesting_cache)
1107                         interesting_cache = NULL;
1108
1109                 if (revs->max_age != -1 && (commit->date < revs->max_age))
1110                         obj->flags |= UNINTERESTING;
1111                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
1112                         return -1;
1113                 if (obj->flags & UNINTERESTING) {
1114                         mark_parents_uninteresting(commit);
1115                         if (revs->show_all)
1116                                 p = &commit_list_insert(commit, p)->next;
1117                         slop = still_interesting(list, date, slop, &interesting_cache);
1118                         if (slop)
1119                                 continue;
1120                         /* If showing all, add the whole pending list to the end */
1121                         if (revs->show_all)
1122                                 *p = list;
1123                         break;
1124                 }
1125                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1126                         continue;
1127                 date = commit->date;
1128                 p = &commit_list_insert(commit, p)->next;
1129
1130                 show = show_early_output;
1131                 if (!show)
1132                         continue;
1133
1134                 show(revs, newlist);
1135                 show_early_output = NULL;
1136         }
1137         if (revs->cherry_pick || revs->cherry_mark)
1138                 cherry_pick_list(newlist, revs);
1139
1140         if (revs->left_only || revs->right_only)
1141                 limit_left_right(newlist, revs);
1142
1143         if (bottom) {
1144                 limit_to_ancestry(bottom, newlist);
1145                 free_commit_list(bottom);
1146         }
1147
1148         /*
1149          * Check if any commits have become TREESAME by some of their parents
1150          * becoming UNINTERESTING.
1151          */
1152         if (limiting_can_increase_treesame(revs))
1153                 for (list = newlist; list; list = list->next) {
1154                         struct commit *c = list->item;
1155                         if (c->object.flags & (UNINTERESTING | TREESAME))
1156                                 continue;
1157                         update_treesame(revs, c);
1158                 }
1159
1160         revs->commits = newlist;
1161         return 0;
1162 }
1163
1164 /*
1165  * Add an entry to refs->cmdline with the specified information.
1166  * *name is copied.
1167  */
1168 static void add_rev_cmdline(struct rev_info *revs,
1169                             struct object *item,
1170                             const char *name,
1171                             int whence,
1172                             unsigned flags)
1173 {
1174         struct rev_cmdline_info *info = &revs->cmdline;
1175         int nr = info->nr;
1176
1177         ALLOC_GROW(info->rev, nr + 1, info->alloc);
1178         info->rev[nr].item = item;
1179         info->rev[nr].name = xstrdup(name);
1180         info->rev[nr].whence = whence;
1181         info->rev[nr].flags = flags;
1182         info->nr++;
1183 }
1184
1185 static void add_rev_cmdline_list(struct rev_info *revs,
1186                                  struct commit_list *commit_list,
1187                                  int whence,
1188                                  unsigned flags)
1189 {
1190         while (commit_list) {
1191                 struct object *object = &commit_list->item->object;
1192                 add_rev_cmdline(revs, object, sha1_to_hex(object->sha1),
1193                                 whence, flags);
1194                 commit_list = commit_list->next;
1195         }
1196 }
1197
1198 struct all_refs_cb {
1199         int all_flags;
1200         int warned_bad_reflog;
1201         struct rev_info *all_revs;
1202         const char *name_for_errormsg;
1203 };
1204
1205 int ref_excluded(struct string_list *ref_excludes, const char *path)
1206 {
1207         struct string_list_item *item;
1208
1209         if (!ref_excludes)
1210                 return 0;
1211         for_each_string_list_item(item, ref_excludes) {
1212                 if (!wildmatch(item->string, path, 0, NULL))
1213                         return 1;
1214         }
1215         return 0;
1216 }
1217
1218 static int handle_one_ref(const char *path, const struct object_id *oid,
1219                           int flag, void *cb_data)
1220 {
1221         struct all_refs_cb *cb = cb_data;
1222         struct object *object;
1223
1224         if (ref_excluded(cb->all_revs->ref_excludes, path))
1225             return 0;
1226
1227         object = get_reference(cb->all_revs, path, oid->hash, cb->all_flags);
1228         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1229         add_pending_sha1(cb->all_revs, path, oid->hash, cb->all_flags);
1230         return 0;
1231 }
1232
1233 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1234         unsigned flags)
1235 {
1236         cb->all_revs = revs;
1237         cb->all_flags = flags;
1238 }
1239
1240 void clear_ref_exclusion(struct string_list **ref_excludes_p)
1241 {
1242         if (*ref_excludes_p) {
1243                 string_list_clear(*ref_excludes_p, 0);
1244                 free(*ref_excludes_p);
1245         }
1246         *ref_excludes_p = NULL;
1247 }
1248
1249 void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1250 {
1251         if (!*ref_excludes_p) {
1252                 *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1253                 (*ref_excludes_p)->strdup_strings = 1;
1254         }
1255         string_list_append(*ref_excludes_p, exclude);
1256 }
1257
1258 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
1259                 int (*for_each)(const char *, each_ref_fn, void *))
1260 {
1261         struct all_refs_cb cb;
1262         init_all_refs_cb(&cb, revs, flags);
1263         for_each(submodule, handle_one_ref, &cb);
1264 }
1265
1266 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
1267 {
1268         struct all_refs_cb *cb = cb_data;
1269         if (!is_null_sha1(sha1)) {
1270                 struct object *o = parse_object(sha1);
1271                 if (o) {
1272                         o->flags |= cb->all_flags;
1273                         /* ??? CMDLINEFLAGS ??? */
1274                         add_pending_object(cb->all_revs, o, "");
1275                 }
1276                 else if (!cb->warned_bad_reflog) {
1277                         warning("reflog of '%s' references pruned commits",
1278                                 cb->name_for_errormsg);
1279                         cb->warned_bad_reflog = 1;
1280                 }
1281         }
1282 }
1283
1284 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
1285                 const char *email, unsigned long timestamp, int tz,
1286                 const char *message, void *cb_data)
1287 {
1288         handle_one_reflog_commit(osha1, cb_data);
1289         handle_one_reflog_commit(nsha1, cb_data);
1290         return 0;
1291 }
1292
1293 static int handle_one_reflog(const char *path, const struct object_id *oid,
1294                              int flag, void *cb_data)
1295 {
1296         struct all_refs_cb *cb = cb_data;
1297         cb->warned_bad_reflog = 0;
1298         cb->name_for_errormsg = path;
1299         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
1300         return 0;
1301 }
1302
1303 void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1304 {
1305         struct all_refs_cb cb;
1306
1307         cb.all_revs = revs;
1308         cb.all_flags = flags;
1309         for_each_reflog(handle_one_reflog, &cb);
1310 }
1311
1312 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1313                            struct strbuf *path)
1314 {
1315         size_t baselen = path->len;
1316         int i;
1317
1318         if (it->entry_count >= 0) {
1319                 struct tree *tree = lookup_tree(it->sha1);
1320                 add_pending_object_with_path(revs, &tree->object, "",
1321                                              040000, path->buf);
1322         }
1323
1324         for (i = 0; i < it->subtree_nr; i++) {
1325                 struct cache_tree_sub *sub = it->down[i];
1326                 strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1327                 add_cache_tree(sub->cache_tree, revs, path);
1328                 strbuf_setlen(path, baselen);
1329         }
1330
1331 }
1332
1333 void add_index_objects_to_pending(struct rev_info *revs, unsigned flags)
1334 {
1335         int i;
1336
1337         read_cache();
1338         for (i = 0; i < active_nr; i++) {
1339                 struct cache_entry *ce = active_cache[i];
1340                 struct blob *blob;
1341
1342                 if (S_ISGITLINK(ce->ce_mode))
1343                         continue;
1344
1345                 blob = lookup_blob(ce->sha1);
1346                 if (!blob)
1347                         die("unable to add index blob to traversal");
1348                 add_pending_object_with_path(revs, &blob->object, "",
1349                                              ce->ce_mode, ce->name);
1350         }
1351
1352         if (active_cache_tree) {
1353                 struct strbuf path = STRBUF_INIT;
1354                 add_cache_tree(active_cache_tree, revs, &path);
1355                 strbuf_release(&path);
1356         }
1357 }
1358
1359 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
1360 {
1361         unsigned char sha1[20];
1362         struct object *it;
1363         struct commit *commit;
1364         struct commit_list *parents;
1365         const char *arg = arg_;
1366
1367         if (*arg == '^') {
1368                 flags ^= UNINTERESTING | BOTTOM;
1369                 arg++;
1370         }
1371         if (get_sha1_committish(arg, sha1))
1372                 return 0;
1373         while (1) {
1374                 it = get_reference(revs, arg, sha1, 0);
1375                 if (!it && revs->ignore_missing)
1376                         return 0;
1377                 if (it->type != OBJ_TAG)
1378                         break;
1379                 if (!((struct tag*)it)->tagged)
1380                         return 0;
1381                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1382         }
1383         if (it->type != OBJ_COMMIT)
1384                 return 0;
1385         commit = (struct commit *)it;
1386         for (parents = commit->parents; parents; parents = parents->next) {
1387                 it = &parents->item->object;
1388                 it->flags |= flags;
1389                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1390                 add_pending_object(revs, it, arg);
1391         }
1392         return 1;
1393 }
1394
1395 void init_revisions(struct rev_info *revs, const char *prefix)
1396 {
1397         memset(revs, 0, sizeof(*revs));
1398
1399         revs->abbrev = DEFAULT_ABBREV;
1400         revs->ignore_merges = 1;
1401         revs->simplify_history = 1;
1402         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1403         DIFF_OPT_SET(&revs->pruning, QUICK);
1404         revs->pruning.add_remove = file_add_remove;
1405         revs->pruning.change = file_change;
1406         revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1407         revs->dense = 1;
1408         revs->prefix = prefix;
1409         revs->max_age = -1;
1410         revs->min_age = -1;
1411         revs->skip_count = -1;
1412         revs->max_count = -1;
1413         revs->max_parents = -1;
1414
1415         revs->commit_format = CMIT_FMT_DEFAULT;
1416
1417         init_grep_defaults();
1418         grep_init(&revs->grep_filter, prefix);
1419         revs->grep_filter.status_only = 1;
1420         revs->grep_filter.regflags = REG_NEWLINE;
1421
1422         diff_setup(&revs->diffopt);
1423         if (prefix && !revs->diffopt.prefix) {
1424                 revs->diffopt.prefix = prefix;
1425                 revs->diffopt.prefix_length = strlen(prefix);
1426         }
1427
1428         revs->notes_opt.use_default_notes = -1;
1429 }
1430
1431 static void add_pending_commit_list(struct rev_info *revs,
1432                                     struct commit_list *commit_list,
1433                                     unsigned int flags)
1434 {
1435         while (commit_list) {
1436                 struct object *object = &commit_list->item->object;
1437                 object->flags |= flags;
1438                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
1439                 commit_list = commit_list->next;
1440         }
1441 }
1442
1443 static void prepare_show_merge(struct rev_info *revs)
1444 {
1445         struct commit_list *bases;
1446         struct commit *head, *other;
1447         unsigned char sha1[20];
1448         const char **prune = NULL;
1449         int i, prune_num = 1; /* counting terminating NULL */
1450
1451         if (get_sha1("HEAD", sha1))
1452                 die("--merge without HEAD?");
1453         head = lookup_commit_or_die(sha1, "HEAD");
1454         if (get_sha1("MERGE_HEAD", sha1))
1455                 die("--merge without MERGE_HEAD?");
1456         other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1457         add_pending_object(revs, &head->object, "HEAD");
1458         add_pending_object(revs, &other->object, "MERGE_HEAD");
1459         bases = get_merge_bases(head, other);
1460         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1461         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1462         free_commit_list(bases);
1463         head->object.flags |= SYMMETRIC_LEFT;
1464
1465         if (!active_nr)
1466                 read_cache();
1467         for (i = 0; i < active_nr; i++) {
1468                 const struct cache_entry *ce = active_cache[i];
1469                 if (!ce_stage(ce))
1470                         continue;
1471                 if (ce_path_match(ce, &revs->prune_data, NULL)) {
1472                         prune_num++;
1473                         REALLOC_ARRAY(prune, prune_num);
1474                         prune[prune_num-2] = ce->name;
1475                         prune[prune_num-1] = NULL;
1476                 }
1477                 while ((i+1 < active_nr) &&
1478                        ce_same_name(ce, active_cache[i+1]))
1479                         i++;
1480         }
1481         free_pathspec(&revs->prune_data);
1482         parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1483                        PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1484         revs->limited = 1;
1485 }
1486
1487 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1488 {
1489         struct object_context oc;
1490         char *dotdot;
1491         struct object *object;
1492         unsigned char sha1[20];
1493         int local_flags;
1494         const char *arg = arg_;
1495         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1496         unsigned get_sha1_flags = 0;
1497
1498         flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1499
1500         dotdot = strstr(arg, "..");
1501         if (dotdot) {
1502                 unsigned char from_sha1[20];
1503                 const char *next = dotdot + 2;
1504                 const char *this = arg;
1505                 int symmetric = *next == '.';
1506                 unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1507                 static const char head_by_default[] = "HEAD";
1508                 unsigned int a_flags;
1509
1510                 *dotdot = 0;
1511                 next += symmetric;
1512
1513                 if (!*next)
1514                         next = head_by_default;
1515                 if (dotdot == arg)
1516                         this = head_by_default;
1517                 if (this == head_by_default && next == head_by_default &&
1518                     !symmetric) {
1519                         /*
1520                          * Just ".."?  That is not a range but the
1521                          * pathspec for the parent directory.
1522                          */
1523                         if (!cant_be_filename) {
1524                                 *dotdot = '.';
1525                                 return -1;
1526                         }
1527                 }
1528                 if (!get_sha1_committish(this, from_sha1) &&
1529                     !get_sha1_committish(next, sha1)) {
1530                         struct object *a_obj, *b_obj;
1531
1532                         if (!cant_be_filename) {
1533                                 *dotdot = '.';
1534                                 verify_non_filename(revs->prefix, arg);
1535                         }
1536
1537                         a_obj = parse_object(from_sha1);
1538                         b_obj = parse_object(sha1);
1539                         if (!a_obj || !b_obj) {
1540                         missing:
1541                                 if (revs->ignore_missing)
1542                                         return 0;
1543                                 die(symmetric
1544                                     ? "Invalid symmetric difference expression %s"
1545                                     : "Invalid revision range %s", arg);
1546                         }
1547
1548                         if (!symmetric) {
1549                                 /* just A..B */
1550                                 a_flags = flags_exclude;
1551                         } else {
1552                                 /* A...B -- find merge bases between the two */
1553                                 struct commit *a, *b;
1554                                 struct commit_list *exclude;
1555
1556                                 a = (a_obj->type == OBJ_COMMIT
1557                                      ? (struct commit *)a_obj
1558                                      : lookup_commit_reference(a_obj->sha1));
1559                                 b = (b_obj->type == OBJ_COMMIT
1560                                      ? (struct commit *)b_obj
1561                                      : lookup_commit_reference(b_obj->sha1));
1562                                 if (!a || !b)
1563                                         goto missing;
1564                                 exclude = get_merge_bases(a, b);
1565                                 add_rev_cmdline_list(revs, exclude,
1566                                                      REV_CMD_MERGE_BASE,
1567                                                      flags_exclude);
1568                                 add_pending_commit_list(revs, exclude,
1569                                                         flags_exclude);
1570                                 free_commit_list(exclude);
1571
1572                                 a_flags = flags | SYMMETRIC_LEFT;
1573                         }
1574
1575                         a_obj->flags |= a_flags;
1576                         b_obj->flags |= flags;
1577                         add_rev_cmdline(revs, a_obj, this,
1578                                         REV_CMD_LEFT, a_flags);
1579                         add_rev_cmdline(revs, b_obj, next,
1580                                         REV_CMD_RIGHT, flags);
1581                         add_pending_object(revs, a_obj, this);
1582                         add_pending_object(revs, b_obj, next);
1583                         return 0;
1584                 }
1585                 *dotdot = '.';
1586         }
1587         dotdot = strstr(arg, "^@");
1588         if (dotdot && !dotdot[2]) {
1589                 *dotdot = 0;
1590                 if (add_parents_only(revs, arg, flags))
1591                         return 0;
1592                 *dotdot = '^';
1593         }
1594         dotdot = strstr(arg, "^!");
1595         if (dotdot && !dotdot[2]) {
1596                 *dotdot = 0;
1597                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM)))
1598                         *dotdot = '^';
1599         }
1600
1601         local_flags = 0;
1602         if (*arg == '^') {
1603                 local_flags = UNINTERESTING | BOTTOM;
1604                 arg++;
1605         }
1606
1607         if (revarg_opt & REVARG_COMMITTISH)
1608                 get_sha1_flags = GET_SHA1_COMMITTISH;
1609
1610         if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1611                 return revs->ignore_missing ? 0 : -1;
1612         if (!cant_be_filename)
1613                 verify_non_filename(revs->prefix, arg);
1614         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1615         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1616         add_pending_object_with_mode(revs, object, arg, oc.mode);
1617         return 0;
1618 }
1619
1620 struct cmdline_pathspec {
1621         int alloc;
1622         int nr;
1623         const char **path;
1624 };
1625
1626 static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1627 {
1628         while (*av) {
1629                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1630                 prune->path[prune->nr++] = *(av++);
1631         }
1632 }
1633
1634 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1635                                      struct cmdline_pathspec *prune)
1636 {
1637         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1638                 int len = sb->len;
1639                 if (len && sb->buf[len - 1] == '\n')
1640                         sb->buf[--len] = '\0';
1641                 ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
1642                 prune->path[prune->nr++] = xstrdup(sb->buf);
1643         }
1644 }
1645
1646 static void read_revisions_from_stdin(struct rev_info *revs,
1647                                       struct cmdline_pathspec *prune)
1648 {
1649         struct strbuf sb;
1650         int seen_dashdash = 0;
1651         int save_warning;
1652
1653         save_warning = warn_on_object_refname_ambiguity;
1654         warn_on_object_refname_ambiguity = 0;
1655
1656         strbuf_init(&sb, 1000);
1657         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1658                 int len = sb.len;
1659                 if (len && sb.buf[len - 1] == '\n')
1660                         sb.buf[--len] = '\0';
1661                 if (!len)
1662                         break;
1663                 if (sb.buf[0] == '-') {
1664                         if (len == 2 && sb.buf[1] == '-') {
1665                                 seen_dashdash = 1;
1666                                 break;
1667                         }
1668                         die("options not supported in --stdin mode");
1669                 }
1670                 if (handle_revision_arg(sb.buf, revs, 0,
1671                                         REVARG_CANNOT_BE_FILENAME))
1672                         die("bad revision '%s'", sb.buf);
1673         }
1674         if (seen_dashdash)
1675                 read_pathspec_from_stdin(revs, &sb, prune);
1676
1677         strbuf_release(&sb);
1678         warn_on_object_refname_ambiguity = save_warning;
1679 }
1680
1681 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1682 {
1683         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1684 }
1685
1686 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1687 {
1688         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1689 }
1690
1691 static void add_message_grep(struct rev_info *revs, const char *pattern)
1692 {
1693         add_grep(revs, pattern, GREP_PATTERN_BODY);
1694 }
1695
1696 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1697                                int *unkc, const char **unkv)
1698 {
1699         const char *arg = argv[0];
1700         const char *optarg;
1701         int argcount;
1702
1703         /* pseudo revision arguments */
1704         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1705             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1706             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1707             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1708             !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
1709             !strcmp(arg, "--indexed-objects") ||
1710             starts_with(arg, "--exclude=") ||
1711             starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
1712             starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
1713         {
1714                 unkv[(*unkc)++] = arg;
1715                 return 1;
1716         }
1717
1718         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1719                 revs->max_count = atoi(optarg);
1720                 revs->no_walk = 0;
1721                 return argcount;
1722         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1723                 revs->skip_count = atoi(optarg);
1724                 return argcount;
1725         } else if ((*arg == '-') && isdigit(arg[1])) {
1726                 /* accept -<digit>, like traditional "head" */
1727                 if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
1728                     revs->max_count < 0)
1729                         die("'%s': not a non-negative integer", arg + 1);
1730                 revs->no_walk = 0;
1731         } else if (!strcmp(arg, "-n")) {
1732                 if (argc <= 1)
1733                         return error("-n requires an argument");
1734                 revs->max_count = atoi(argv[1]);
1735                 revs->no_walk = 0;
1736                 return 2;
1737         } else if (starts_with(arg, "-n")) {
1738                 revs->max_count = atoi(arg + 2);
1739                 revs->no_walk = 0;
1740         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1741                 revs->max_age = atoi(optarg);
1742                 return argcount;
1743         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1744                 revs->max_age = approxidate(optarg);
1745                 return argcount;
1746         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1747                 revs->max_age = approxidate(optarg);
1748                 return argcount;
1749         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1750                 revs->min_age = atoi(optarg);
1751                 return argcount;
1752         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1753                 revs->min_age = approxidate(optarg);
1754                 return argcount;
1755         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1756                 revs->min_age = approxidate(optarg);
1757                 return argcount;
1758         } else if (!strcmp(arg, "--first-parent")) {
1759                 revs->first_parent_only = 1;
1760         } else if (!strcmp(arg, "--ancestry-path")) {
1761                 revs->ancestry_path = 1;
1762                 revs->simplify_history = 0;
1763                 revs->limited = 1;
1764         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1765                 init_reflog_walk(&revs->reflog_info);
1766         } else if (!strcmp(arg, "--default")) {
1767                 if (argc <= 1)
1768                         return error("bad --default argument");
1769                 revs->def = argv[1];
1770                 return 2;
1771         } else if (!strcmp(arg, "--merge")) {
1772                 revs->show_merge = 1;
1773         } else if (!strcmp(arg, "--topo-order")) {
1774                 revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1775                 revs->topo_order = 1;
1776         } else if (!strcmp(arg, "--simplify-merges")) {
1777                 revs->simplify_merges = 1;
1778                 revs->topo_order = 1;
1779                 revs->rewrite_parents = 1;
1780                 revs->simplify_history = 0;
1781                 revs->limited = 1;
1782         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1783                 revs->simplify_merges = 1;
1784                 revs->topo_order = 1;
1785                 revs->rewrite_parents = 1;
1786                 revs->simplify_history = 0;
1787                 revs->simplify_by_decoration = 1;
1788                 revs->limited = 1;
1789                 revs->prune = 1;
1790                 load_ref_decorations(DECORATE_SHORT_REFS);
1791         } else if (!strcmp(arg, "--date-order")) {
1792                 revs->sort_order = REV_SORT_BY_COMMIT_DATE;
1793                 revs->topo_order = 1;
1794         } else if (!strcmp(arg, "--author-date-order")) {
1795                 revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
1796                 revs->topo_order = 1;
1797         } else if (starts_with(arg, "--early-output")) {
1798                 int count = 100;
1799                 switch (arg[14]) {
1800                 case '=':
1801                         count = atoi(arg+15);
1802                         /* Fallthrough */
1803                 case 0:
1804                         revs->topo_order = 1;
1805                        revs->early_output = count;
1806                 }
1807         } else if (!strcmp(arg, "--parents")) {
1808                 revs->rewrite_parents = 1;
1809                 revs->print_parents = 1;
1810         } else if (!strcmp(arg, "--dense")) {
1811                 revs->dense = 1;
1812         } else if (!strcmp(arg, "--sparse")) {
1813                 revs->dense = 0;
1814         } else if (!strcmp(arg, "--show-all")) {
1815                 revs->show_all = 1;
1816         } else if (!strcmp(arg, "--remove-empty")) {
1817                 revs->remove_empty_trees = 1;
1818         } else if (!strcmp(arg, "--merges")) {
1819                 revs->min_parents = 2;
1820         } else if (!strcmp(arg, "--no-merges")) {
1821                 revs->max_parents = 1;
1822         } else if (starts_with(arg, "--min-parents=")) {
1823                 revs->min_parents = atoi(arg+14);
1824         } else if (starts_with(arg, "--no-min-parents")) {
1825                 revs->min_parents = 0;
1826         } else if (starts_with(arg, "--max-parents=")) {
1827                 revs->max_parents = atoi(arg+14);
1828         } else if (starts_with(arg, "--no-max-parents")) {
1829                 revs->max_parents = -1;
1830         } else if (!strcmp(arg, "--boundary")) {
1831                 revs->boundary = 1;
1832         } else if (!strcmp(arg, "--left-right")) {
1833                 revs->left_right = 1;
1834         } else if (!strcmp(arg, "--left-only")) {
1835                 if (revs->right_only)
1836                         die("--left-only is incompatible with --right-only"
1837                             " or --cherry");
1838                 revs->left_only = 1;
1839         } else if (!strcmp(arg, "--right-only")) {
1840                 if (revs->left_only)
1841                         die("--right-only is incompatible with --left-only");
1842                 revs->right_only = 1;
1843         } else if (!strcmp(arg, "--cherry")) {
1844                 if (revs->left_only)
1845                         die("--cherry is incompatible with --left-only");
1846                 revs->cherry_mark = 1;
1847                 revs->right_only = 1;
1848                 revs->max_parents = 1;
1849                 revs->limited = 1;
1850         } else if (!strcmp(arg, "--count")) {
1851                 revs->count = 1;
1852         } else if (!strcmp(arg, "--cherry-mark")) {
1853                 if (revs->cherry_pick)
1854                         die("--cherry-mark is incompatible with --cherry-pick");
1855                 revs->cherry_mark = 1;
1856                 revs->limited = 1; /* needs limit_list() */
1857         } else if (!strcmp(arg, "--cherry-pick")) {
1858                 if (revs->cherry_mark)
1859                         die("--cherry-pick is incompatible with --cherry-mark");
1860                 revs->cherry_pick = 1;
1861                 revs->limited = 1;
1862         } else if (!strcmp(arg, "--objects")) {
1863                 revs->tag_objects = 1;
1864                 revs->tree_objects = 1;
1865                 revs->blob_objects = 1;
1866         } else if (!strcmp(arg, "--objects-edge")) {
1867                 revs->tag_objects = 1;
1868                 revs->tree_objects = 1;
1869                 revs->blob_objects = 1;
1870                 revs->edge_hint = 1;
1871         } else if (!strcmp(arg, "--objects-edge-aggressive")) {
1872                 revs->tag_objects = 1;
1873                 revs->tree_objects = 1;
1874                 revs->blob_objects = 1;
1875                 revs->edge_hint = 1;
1876                 revs->edge_hint_aggressive = 1;
1877         } else if (!strcmp(arg, "--verify-objects")) {
1878                 revs->tag_objects = 1;
1879                 revs->tree_objects = 1;
1880                 revs->blob_objects = 1;
1881                 revs->verify_objects = 1;
1882         } else if (!strcmp(arg, "--unpacked")) {
1883                 revs->unpacked = 1;
1884         } else if (starts_with(arg, "--unpacked=")) {
1885                 die("--unpacked=<packfile> no longer supported.");
1886         } else if (!strcmp(arg, "-r")) {
1887                 revs->diff = 1;
1888                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1889         } else if (!strcmp(arg, "-t")) {
1890                 revs->diff = 1;
1891                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1892                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1893         } else if (!strcmp(arg, "-m")) {
1894                 revs->ignore_merges = 0;
1895         } else if (!strcmp(arg, "-c")) {
1896                 revs->diff = 1;
1897                 revs->dense_combined_merges = 0;
1898                 revs->combine_merges = 1;
1899         } else if (!strcmp(arg, "--cc")) {
1900                 revs->diff = 1;
1901                 revs->dense_combined_merges = 1;
1902                 revs->combine_merges = 1;
1903         } else if (!strcmp(arg, "-v")) {
1904                 revs->verbose_header = 1;
1905         } else if (!strcmp(arg, "--pretty")) {
1906                 revs->verbose_header = 1;
1907                 revs->pretty_given = 1;
1908                 get_commit_format(NULL, revs);
1909         } else if (starts_with(arg, "--pretty=") || starts_with(arg, "--format=")) {
1910                 /*
1911                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1912                  * not allowed, since the argument is optional.
1913                  */
1914                 revs->verbose_header = 1;
1915                 revs->pretty_given = 1;
1916                 get_commit_format(arg+9, revs);
1917         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1918                 revs->show_notes = 1;
1919                 revs->show_notes_given = 1;
1920                 revs->notes_opt.use_default_notes = 1;
1921         } else if (!strcmp(arg, "--show-signature")) {
1922                 revs->show_signature = 1;
1923         } else if (!strcmp(arg, "--show-linear-break") ||
1924                    starts_with(arg, "--show-linear-break=")) {
1925                 if (starts_with(arg, "--show-linear-break="))
1926                         revs->break_bar = xstrdup(arg + 20);
1927                 else
1928                         revs->break_bar = "                    ..........";
1929                 revs->track_linear = 1;
1930                 revs->track_first_time = 1;
1931         } else if (starts_with(arg, "--show-notes=") ||
1932                    starts_with(arg, "--notes=")) {
1933                 struct strbuf buf = STRBUF_INIT;
1934                 revs->show_notes = 1;
1935                 revs->show_notes_given = 1;
1936                 if (starts_with(arg, "--show-notes")) {
1937                         if (revs->notes_opt.use_default_notes < 0)
1938                                 revs->notes_opt.use_default_notes = 1;
1939                         strbuf_addstr(&buf, arg+13);
1940                 }
1941                 else
1942                         strbuf_addstr(&buf, arg+8);
1943                 expand_notes_ref(&buf);
1944                 string_list_append(&revs->notes_opt.extra_notes_refs,
1945                                    strbuf_detach(&buf, NULL));
1946         } else if (!strcmp(arg, "--no-notes")) {
1947                 revs->show_notes = 0;
1948                 revs->show_notes_given = 1;
1949                 revs->notes_opt.use_default_notes = -1;
1950                 /* we have been strdup'ing ourselves, so trick
1951                  * string_list into free()ing strings */
1952                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1953                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1954                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1955         } else if (!strcmp(arg, "--standard-notes")) {
1956                 revs->show_notes_given = 1;
1957                 revs->notes_opt.use_default_notes = 1;
1958         } else if (!strcmp(arg, "--no-standard-notes")) {
1959                 revs->notes_opt.use_default_notes = 0;
1960         } else if (!strcmp(arg, "--oneline")) {
1961                 revs->verbose_header = 1;
1962                 get_commit_format("oneline", revs);
1963                 revs->pretty_given = 1;
1964                 revs->abbrev_commit = 1;
1965         } else if (!strcmp(arg, "--graph")) {
1966                 revs->topo_order = 1;
1967                 revs->rewrite_parents = 1;
1968                 revs->graph = graph_init(revs);
1969         } else if (!strcmp(arg, "--root")) {
1970                 revs->show_root_diff = 1;
1971         } else if (!strcmp(arg, "--no-commit-id")) {
1972                 revs->no_commit_id = 1;
1973         } else if (!strcmp(arg, "--always")) {
1974                 revs->always_show_header = 1;
1975         } else if (!strcmp(arg, "--no-abbrev")) {
1976                 revs->abbrev = 0;
1977         } else if (!strcmp(arg, "--abbrev")) {
1978                 revs->abbrev = DEFAULT_ABBREV;
1979         } else if (starts_with(arg, "--abbrev=")) {
1980                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1981                 if (revs->abbrev < MINIMUM_ABBREV)
1982                         revs->abbrev = MINIMUM_ABBREV;
1983                 else if (revs->abbrev > 40)
1984                         revs->abbrev = 40;
1985         } else if (!strcmp(arg, "--abbrev-commit")) {
1986                 revs->abbrev_commit = 1;
1987                 revs->abbrev_commit_given = 1;
1988         } else if (!strcmp(arg, "--no-abbrev-commit")) {
1989                 revs->abbrev_commit = 0;
1990         } else if (!strcmp(arg, "--full-diff")) {
1991                 revs->diff = 1;
1992                 revs->full_diff = 1;
1993         } else if (!strcmp(arg, "--full-history")) {
1994                 revs->simplify_history = 0;
1995         } else if (!strcmp(arg, "--relative-date")) {
1996                 revs->date_mode.type = DATE_RELATIVE;
1997                 revs->date_mode_explicit = 1;
1998         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1999                 parse_date_format(optarg, &revs->date_mode);
2000                 revs->date_mode_explicit = 1;
2001                 return argcount;
2002         } else if (!strcmp(arg, "--log-size")) {
2003                 revs->show_log_size = 1;
2004         }
2005         /*
2006          * Grepping the commit log
2007          */
2008         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
2009                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
2010                 return argcount;
2011         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
2012                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
2013                 return argcount;
2014         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
2015                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
2016                 return argcount;
2017         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
2018                 add_message_grep(revs, optarg);
2019                 return argcount;
2020         } else if (!strcmp(arg, "--grep-debug")) {
2021                 revs->grep_filter.debug = 1;
2022         } else if (!strcmp(arg, "--basic-regexp")) {
2023                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_BRE, &revs->grep_filter);
2024         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
2025                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, &revs->grep_filter);
2026         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
2027                 revs->grep_filter.regflags |= REG_ICASE;
2028                 DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
2029         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
2030                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_FIXED, &revs->grep_filter);
2031         } else if (!strcmp(arg, "--perl-regexp")) {
2032                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_PCRE, &revs->grep_filter);
2033         } else if (!strcmp(arg, "--all-match")) {
2034                 revs->grep_filter.all_match = 1;
2035         } else if (!strcmp(arg, "--invert-grep")) {
2036                 revs->invert_grep = 1;
2037         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2038                 if (strcmp(optarg, "none"))
2039                         git_log_output_encoding = xstrdup(optarg);
2040                 else
2041                         git_log_output_encoding = "";
2042                 return argcount;
2043         } else if (!strcmp(arg, "--reverse")) {
2044                 revs->reverse ^= 1;
2045         } else if (!strcmp(arg, "--children")) {
2046                 revs->children.name = "children";
2047                 revs->limited = 1;
2048         } else if (!strcmp(arg, "--ignore-missing")) {
2049                 revs->ignore_missing = 1;
2050         } else {
2051                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
2052                 if (!opts)
2053                         unkv[(*unkc)++] = arg;
2054                 return opts;
2055         }
2056         if (revs->graph && revs->track_linear)
2057                 die("--show-linear-break and --graph are incompatible");
2058
2059         return 1;
2060 }
2061
2062 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2063                         const struct option *options,
2064                         const char * const usagestr[])
2065 {
2066         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2067                                     &ctx->cpidx, ctx->out);
2068         if (n <= 0) {
2069                 error("unknown option `%s'", ctx->argv[0]);
2070                 usage_with_options(usagestr, options);
2071         }
2072         ctx->argv += n;
2073         ctx->argc -= n;
2074 }
2075
2076 static int for_each_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data, const char *term) {
2077         struct strbuf bisect_refs = STRBUF_INIT;
2078         int status;
2079         strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2080         status = for_each_ref_in_submodule(submodule, bisect_refs.buf, fn, cb_data);
2081         strbuf_release(&bisect_refs);
2082         return status;
2083 }
2084
2085 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2086 {
2087         return for_each_bisect_ref(submodule, fn, cb_data, term_bad);
2088 }
2089
2090 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
2091 {
2092         return for_each_bisect_ref(submodule, fn, cb_data, term_good);
2093 }
2094
2095 static int handle_revision_pseudo_opt(const char *submodule,
2096                                 struct rev_info *revs,
2097                                 int argc, const char **argv, int *flags)
2098 {
2099         const char *arg = argv[0];
2100         const char *optarg;
2101         int argcount;
2102
2103         /*
2104          * NOTE!
2105          *
2106          * Commands like "git shortlog" will not accept the options below
2107          * unless parse_revision_opt queues them (as opposed to erroring
2108          * out).
2109          *
2110          * When implementing your new pseudo-option, remember to
2111          * register it in the list at the top of handle_revision_opt.
2112          */
2113         if (!strcmp(arg, "--all")) {
2114                 handle_refs(submodule, revs, *flags, for_each_ref_submodule);
2115                 handle_refs(submodule, revs, *flags, head_ref_submodule);
2116                 clear_ref_exclusion(&revs->ref_excludes);
2117         } else if (!strcmp(arg, "--branches")) {
2118                 handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
2119                 clear_ref_exclusion(&revs->ref_excludes);
2120         } else if (!strcmp(arg, "--bisect")) {
2121                 read_bisect_terms(&term_bad, &term_good);
2122                 handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
2123                 handle_refs(submodule, revs, *flags ^ (UNINTERESTING | BOTTOM), for_each_good_bisect_ref);
2124                 revs->bisect = 1;
2125         } else if (!strcmp(arg, "--tags")) {
2126                 handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
2127                 clear_ref_exclusion(&revs->ref_excludes);
2128         } else if (!strcmp(arg, "--remotes")) {
2129                 handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
2130                 clear_ref_exclusion(&revs->ref_excludes);
2131         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2132                 struct all_refs_cb cb;
2133                 init_all_refs_cb(&cb, revs, *flags);
2134                 for_each_glob_ref(handle_one_ref, optarg, &cb);
2135                 clear_ref_exclusion(&revs->ref_excludes);
2136                 return argcount;
2137         } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2138                 add_ref_exclusion(&revs->ref_excludes, optarg);
2139                 return argcount;
2140         } else if (starts_with(arg, "--branches=")) {
2141                 struct all_refs_cb cb;
2142                 init_all_refs_cb(&cb, revs, *flags);
2143                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
2144                 clear_ref_exclusion(&revs->ref_excludes);
2145         } else if (starts_with(arg, "--tags=")) {
2146                 struct all_refs_cb cb;
2147                 init_all_refs_cb(&cb, revs, *flags);
2148                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
2149                 clear_ref_exclusion(&revs->ref_excludes);
2150         } else if (starts_with(arg, "--remotes=")) {
2151                 struct all_refs_cb cb;
2152                 init_all_refs_cb(&cb, revs, *flags);
2153                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
2154                 clear_ref_exclusion(&revs->ref_excludes);
2155         } else if (!strcmp(arg, "--reflog")) {
2156                 add_reflogs_to_pending(revs, *flags);
2157         } else if (!strcmp(arg, "--indexed-objects")) {
2158                 add_index_objects_to_pending(revs, *flags);
2159         } else if (!strcmp(arg, "--not")) {
2160                 *flags ^= UNINTERESTING | BOTTOM;
2161         } else if (!strcmp(arg, "--no-walk")) {
2162                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2163         } else if (starts_with(arg, "--no-walk=")) {
2164                 /*
2165                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2166                  * not allowed, since the argument is optional.
2167                  */
2168                 if (!strcmp(arg + 10, "sorted"))
2169                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2170                 else if (!strcmp(arg + 10, "unsorted"))
2171                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2172                 else
2173                         return error("invalid argument to --no-walk");
2174         } else if (!strcmp(arg, "--do-walk")) {
2175                 revs->no_walk = 0;
2176         } else {
2177                 return 0;
2178         }
2179
2180         return 1;
2181 }
2182
2183 static void NORETURN diagnose_missing_default(const char *def)
2184 {
2185         unsigned char sha1[20];
2186         int flags;
2187         const char *refname;
2188
2189         refname = resolve_ref_unsafe(def, 0, sha1, &flags);
2190         if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2191                 die(_("your current branch appears to be broken"));
2192
2193         skip_prefix(refname, "refs/heads/", &refname);
2194         die(_("your current branch '%s' does not have any commits yet"),
2195             refname);
2196 }
2197
2198 /*
2199  * Parse revision information, filling in the "rev_info" structure,
2200  * and removing the used arguments from the argument list.
2201  *
2202  * Returns the number of arguments left that weren't recognized
2203  * (which are also moved to the head of the argument list)
2204  */
2205 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2206 {
2207         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
2208         struct cmdline_pathspec prune_data;
2209         const char *submodule = NULL;
2210
2211         memset(&prune_data, 0, sizeof(prune_data));
2212         if (opt)
2213                 submodule = opt->submodule;
2214
2215         /* First, search for "--" */
2216         if (opt && opt->assume_dashdash) {
2217                 seen_dashdash = 1;
2218         } else {
2219                 seen_dashdash = 0;
2220                 for (i = 1; i < argc; i++) {
2221                         const char *arg = argv[i];
2222                         if (strcmp(arg, "--"))
2223                                 continue;
2224                         argv[i] = NULL;
2225                         argc = i;
2226                         if (argv[i + 1])
2227                                 append_prune_data(&prune_data, argv + i + 1);
2228                         seen_dashdash = 1;
2229                         break;
2230                 }
2231         }
2232
2233         /* Second, deal with arguments and options */
2234         flags = 0;
2235         revarg_opt = opt ? opt->revarg_opt : 0;
2236         if (seen_dashdash)
2237                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2238         read_from_stdin = 0;
2239         for (left = i = 1; i < argc; i++) {
2240                 const char *arg = argv[i];
2241                 if (*arg == '-') {
2242                         int opts;
2243
2244                         opts = handle_revision_pseudo_opt(submodule,
2245                                                 revs, argc - i, argv + i,
2246                                                 &flags);
2247                         if (opts > 0) {
2248                                 i += opts - 1;
2249                                 continue;
2250                         }
2251
2252                         if (!strcmp(arg, "--stdin")) {
2253                                 if (revs->disable_stdin) {
2254                                         argv[left++] = arg;
2255                                         continue;
2256                                 }
2257                                 if (read_from_stdin++)
2258                                         die("--stdin given twice?");
2259                                 read_revisions_from_stdin(revs, &prune_data);
2260                                 continue;
2261                         }
2262
2263                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
2264                         if (opts > 0) {
2265                                 i += opts - 1;
2266                                 continue;
2267                         }
2268                         if (opts < 0)
2269                                 exit(128);
2270                         continue;
2271                 }
2272
2273
2274                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2275                         int j;
2276                         if (seen_dashdash || *arg == '^')
2277                                 die("bad revision '%s'", arg);
2278
2279                         /* If we didn't have a "--":
2280                          * (1) all filenames must exist;
2281                          * (2) all rev-args must not be interpretable
2282                          *     as a valid filename.
2283                          * but the latter we have checked in the main loop.
2284                          */
2285                         for (j = i; j < argc; j++)
2286                                 verify_filename(revs->prefix, argv[j], j == i);
2287
2288                         append_prune_data(&prune_data, argv + i);
2289                         break;
2290                 }
2291                 else
2292                         got_rev_arg = 1;
2293         }
2294
2295         if (prune_data.nr) {
2296                 /*
2297                  * If we need to introduce the magic "a lone ':' means no
2298                  * pathspec whatsoever", here is the place to do so.
2299                  *
2300                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2301                  *      prune_data.nr = 0;
2302                  *      prune_data.alloc = 0;
2303                  *      free(prune_data.path);
2304                  *      prune_data.path = NULL;
2305                  * } else {
2306                  *      terminate prune_data.alloc with NULL and
2307                  *      call init_pathspec() to set revs->prune_data here.
2308                  * }
2309                  */
2310                 ALLOC_GROW(prune_data.path, prune_data.nr + 1, prune_data.alloc);
2311                 prune_data.path[prune_data.nr++] = NULL;
2312                 parse_pathspec(&revs->prune_data, 0, 0,
2313                                revs->prefix, prune_data.path);
2314         }
2315
2316         if (revs->def == NULL)
2317                 revs->def = opt ? opt->def : NULL;
2318         if (opt && opt->tweak)
2319                 opt->tweak(revs, opt);
2320         if (revs->show_merge)
2321                 prepare_show_merge(revs);
2322         if (revs->def && !revs->pending.nr && !got_rev_arg) {
2323                 unsigned char sha1[20];
2324                 struct object *object;
2325                 struct object_context oc;
2326                 if (get_sha1_with_context(revs->def, 0, sha1, &oc))
2327                         diagnose_missing_default(revs->def);
2328                 object = get_reference(revs, revs->def, sha1, 0);
2329                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2330         }
2331
2332         /* Did the user ask for any diff output? Run the diff! */
2333         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2334                 revs->diff = 1;
2335
2336         /* Pickaxe, diff-filter and rename following need diffs */
2337         if (revs->diffopt.pickaxe ||
2338             revs->diffopt.filter ||
2339             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2340                 revs->diff = 1;
2341
2342         if (revs->topo_order)
2343                 revs->limited = 1;
2344
2345         if (revs->prune_data.nr) {
2346                 copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2347                 /* Can't prune commits with rename following: the paths change.. */
2348                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2349                         revs->prune = 1;
2350                 if (!revs->full_diff)
2351                         copy_pathspec(&revs->diffopt.pathspec,
2352                                       &revs->prune_data);
2353         }
2354         if (revs->combine_merges)
2355                 revs->ignore_merges = 0;
2356         revs->diffopt.abbrev = revs->abbrev;
2357
2358         if (revs->line_level_traverse) {
2359                 revs->limited = 1;
2360                 revs->topo_order = 1;
2361         }
2362
2363         diff_setup_done(&revs->diffopt);
2364
2365         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2366                                  &revs->grep_filter);
2367         compile_grep_patterns(&revs->grep_filter);
2368
2369         if (revs->reverse && revs->reflog_info)
2370                 die("cannot combine --reverse with --walk-reflogs");
2371         if (revs->rewrite_parents && revs->children.name)
2372                 die("cannot combine --parents and --children");
2373
2374         /*
2375          * Limitations on the graph functionality
2376          */
2377         if (revs->reverse && revs->graph)
2378                 die("cannot combine --reverse with --graph");
2379
2380         if (revs->reflog_info && revs->graph)
2381                 die("cannot combine --walk-reflogs with --graph");
2382         if (revs->no_walk && revs->graph)
2383                 die("cannot combine --no-walk with --graph");
2384         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2385                 die("cannot use --grep-reflog without --walk-reflogs");
2386
2387         if (revs->first_parent_only && revs->bisect)
2388                 die(_("--first-parent is incompatible with --bisect"));
2389
2390         return left;
2391 }
2392
2393 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2394 {
2395         struct commit_list *l = xcalloc(1, sizeof(*l));
2396
2397         l->item = child;
2398         l->next = add_decoration(&revs->children, &parent->object, l);
2399 }
2400
2401 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2402 {
2403         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2404         struct commit_list **pp, *p;
2405         int surviving_parents;
2406
2407         /* Examine existing parents while marking ones we have seen... */
2408         pp = &commit->parents;
2409         surviving_parents = 0;
2410         while ((p = *pp) != NULL) {
2411                 struct commit *parent = p->item;
2412                 if (parent->object.flags & TMP_MARK) {
2413                         *pp = p->next;
2414                         if (ts)
2415                                 compact_treesame(revs, commit, surviving_parents);
2416                         continue;
2417                 }
2418                 parent->object.flags |= TMP_MARK;
2419                 surviving_parents++;
2420                 pp = &p->next;
2421         }
2422         /* clear the temporary mark */
2423         for (p = commit->parents; p; p = p->next) {
2424                 p->item->object.flags &= ~TMP_MARK;
2425         }
2426         /* no update_treesame() - removing duplicates can't affect TREESAME */
2427         return surviving_parents;
2428 }
2429
2430 struct merge_simplify_state {
2431         struct commit *simplified;
2432 };
2433
2434 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2435 {
2436         struct merge_simplify_state *st;
2437
2438         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2439         if (!st) {
2440                 st = xcalloc(1, sizeof(*st));
2441                 add_decoration(&revs->merge_simplification, &commit->object, st);
2442         }
2443         return st;
2444 }
2445
2446 static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2447 {
2448         struct commit_list *h = reduce_heads(commit->parents);
2449         int i = 0, marked = 0;
2450         struct commit_list *po, *pn;
2451
2452         /* Want these for sanity-checking only */
2453         int orig_cnt = commit_list_count(commit->parents);
2454         int cnt = commit_list_count(h);
2455
2456         /*
2457          * Not ready to remove items yet, just mark them for now, based
2458          * on the output of reduce_heads(). reduce_heads outputs the reduced
2459          * set in its original order, so this isn't too hard.
2460          */
2461         po = commit->parents;
2462         pn = h;
2463         while (po) {
2464                 if (pn && po->item == pn->item) {
2465                         pn = pn->next;
2466                         i++;
2467                 } else {
2468                         po->item->object.flags |= TMP_MARK;
2469                         marked++;
2470                 }
2471                 po=po->next;
2472         }
2473
2474         if (i != cnt || cnt+marked != orig_cnt)
2475                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2476
2477         free_commit_list(h);
2478
2479         return marked;
2480 }
2481
2482 static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2483 {
2484         struct commit_list *p;
2485         int marked = 0;
2486
2487         for (p = commit->parents; p; p = p->next) {
2488                 struct commit *parent = p->item;
2489                 if (!parent->parents && (parent->object.flags & TREESAME)) {
2490                         parent->object.flags |= TMP_MARK;
2491                         marked++;
2492                 }
2493         }
2494
2495         return marked;
2496 }
2497
2498 /*
2499  * Awkward naming - this means one parent we are TREESAME to.
2500  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2501  * empty tree). Better name suggestions?
2502  */
2503 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2504 {
2505         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2506         struct commit *unmarked = NULL, *marked = NULL;
2507         struct commit_list *p;
2508         unsigned n;
2509
2510         for (p = commit->parents, n = 0; p; p = p->next, n++) {
2511                 if (ts->treesame[n]) {
2512                         if (p->item->object.flags & TMP_MARK) {
2513                                 if (!marked)
2514                                         marked = p->item;
2515                         } else {
2516                                 if (!unmarked) {
2517                                         unmarked = p->item;
2518                                         break;
2519                                 }
2520                         }
2521                 }
2522         }
2523
2524         /*
2525          * If we are TREESAME to a marked-for-deletion parent, but not to any
2526          * unmarked parents, unmark the first TREESAME parent. This is the
2527          * parent that the default simplify_history==1 scan would have followed,
2528          * and it doesn't make sense to omit that path when asking for a
2529          * simplified full history. Retaining it improves the chances of
2530          * understanding odd missed merges that took an old version of a file.
2531          *
2532          * Example:
2533          *
2534          *   I--------*X       A modified the file, but mainline merge X used
2535          *    \       /        "-s ours", so took the version from I. X is
2536          *     `-*A--'         TREESAME to I and !TREESAME to A.
2537          *
2538          * Default log from X would produce "I". Without this check,
2539          * --full-history --simplify-merges would produce "I-A-X", showing
2540          * the merge commit X and that it changed A, but not making clear that
2541          * it had just taken the I version. With this check, the topology above
2542          * is retained.
2543          *
2544          * Note that it is possible that the simplification chooses a different
2545          * TREESAME parent from the default, in which case this test doesn't
2546          * activate, and we _do_ drop the default parent. Example:
2547          *
2548          *   I------X         A modified the file, but it was reverted in B,
2549          *    \    /          meaning mainline merge X is TREESAME to both
2550          *    *A-*B           parents.
2551          *
2552          * Default log would produce "I" by following the first parent;
2553          * --full-history --simplify-merges will produce "I-A-B". But this is a
2554          * reasonable result - it presents a logical full history leading from
2555          * I to X, and X is not an important merge.
2556          */
2557         if (!unmarked && marked) {
2558                 marked->object.flags &= ~TMP_MARK;
2559                 return 1;
2560         }
2561
2562         return 0;
2563 }
2564
2565 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2566 {
2567         struct commit_list **pp, *p;
2568         int nth_parent, removed = 0;
2569
2570         pp = &commit->parents;
2571         nth_parent = 0;
2572         while ((p = *pp) != NULL) {
2573                 struct commit *parent = p->item;
2574                 if (parent->object.flags & TMP_MARK) {
2575                         parent->object.flags &= ~TMP_MARK;
2576                         *pp = p->next;
2577                         free(p);
2578                         removed++;
2579                         compact_treesame(revs, commit, nth_parent);
2580                         continue;
2581                 }
2582                 pp = &p->next;
2583                 nth_parent++;
2584         }
2585
2586         /* Removing parents can only increase TREESAMEness */
2587         if (removed && !(commit->object.flags & TREESAME))
2588                 update_treesame(revs, commit);
2589
2590         return nth_parent;
2591 }
2592
2593 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2594 {
2595         struct commit_list *p;
2596         struct commit *parent;
2597         struct merge_simplify_state *st, *pst;
2598         int cnt;
2599
2600         st = locate_simplify_state(revs, commit);
2601
2602         /*
2603          * Have we handled this one?
2604          */
2605         if (st->simplified)
2606                 return tail;
2607
2608         /*
2609          * An UNINTERESTING commit simplifies to itself, so does a
2610          * root commit.  We do not rewrite parents of such commit
2611          * anyway.
2612          */
2613         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2614                 st->simplified = commit;
2615                 return tail;
2616         }
2617
2618         /*
2619          * Do we know what commit all of our parents that matter
2620          * should be rewritten to?  Otherwise we are not ready to
2621          * rewrite this one yet.
2622          */
2623         for (cnt = 0, p = commit->parents; p; p = p->next) {
2624                 pst = locate_simplify_state(revs, p->item);
2625                 if (!pst->simplified) {
2626                         tail = &commit_list_insert(p->item, tail)->next;
2627                         cnt++;
2628                 }
2629                 if (revs->first_parent_only)
2630                         break;
2631         }
2632         if (cnt) {
2633                 tail = &commit_list_insert(commit, tail)->next;
2634                 return tail;
2635         }
2636
2637         /*
2638          * Rewrite our list of parents. Note that this cannot
2639          * affect our TREESAME flags in any way - a commit is
2640          * always TREESAME to its simplification.
2641          */
2642         for (p = commit->parents; p; p = p->next) {
2643                 pst = locate_simplify_state(revs, p->item);
2644                 p->item = pst->simplified;
2645                 if (revs->first_parent_only)
2646                         break;
2647         }
2648
2649         if (revs->first_parent_only)
2650                 cnt = 1;
2651         else
2652                 cnt = remove_duplicate_parents(revs, commit);
2653
2654         /*
2655          * It is possible that we are a merge and one side branch
2656          * does not have any commit that touches the given paths;
2657          * in such a case, the immediate parent from that branch
2658          * will be rewritten to be the merge base.
2659          *
2660          *      o----X          X: the commit we are looking at;
2661          *     /    /           o: a commit that touches the paths;
2662          * ---o----'
2663          *
2664          * Further, a merge of an independent branch that doesn't
2665          * touch the path will reduce to a treesame root parent:
2666          *
2667          *  ----o----X          X: the commit we are looking at;
2668          *          /           o: a commit that touches the paths;
2669          *         r            r: a root commit not touching the paths
2670          *
2671          * Detect and simplify both cases.
2672          */
2673         if (1 < cnt) {
2674                 int marked = mark_redundant_parents(revs, commit);
2675                 marked += mark_treesame_root_parents(revs, commit);
2676                 if (marked)
2677                         marked -= leave_one_treesame_to_parent(revs, commit);
2678                 if (marked)
2679                         cnt = remove_marked_parents(revs, commit);
2680         }
2681
2682         /*
2683          * A commit simplifies to itself if it is a root, if it is
2684          * UNINTERESTING, if it touches the given paths, or if it is a
2685          * merge and its parents don't simplify to one relevant commit
2686          * (the first two cases are already handled at the beginning of
2687          * this function).
2688          *
2689          * Otherwise, it simplifies to what its sole relevant parent
2690          * simplifies to.
2691          */
2692         if (!cnt ||
2693             (commit->object.flags & UNINTERESTING) ||
2694             !(commit->object.flags & TREESAME) ||
2695             (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2696                 st->simplified = commit;
2697         else {
2698                 pst = locate_simplify_state(revs, parent);
2699                 st->simplified = pst->simplified;
2700         }
2701         return tail;
2702 }
2703
2704 static void simplify_merges(struct rev_info *revs)
2705 {
2706         struct commit_list *list, *next;
2707         struct commit_list *yet_to_do, **tail;
2708         struct commit *commit;
2709
2710         if (!revs->prune)
2711                 return;
2712
2713         /* feed the list reversed */
2714         yet_to_do = NULL;
2715         for (list = revs->commits; list; list = next) {
2716                 commit = list->item;
2717                 next = list->next;
2718                 /*
2719                  * Do not free(list) here yet; the original list
2720                  * is used later in this function.
2721                  */
2722                 commit_list_insert(commit, &yet_to_do);
2723         }
2724         while (yet_to_do) {
2725                 list = yet_to_do;
2726                 yet_to_do = NULL;
2727                 tail = &yet_to_do;
2728                 while (list) {
2729                         commit = pop_commit(&list);
2730                         tail = simplify_one(revs, commit, tail);
2731                 }
2732         }
2733
2734         /* clean up the result, removing the simplified ones */
2735         list = revs->commits;
2736         revs->commits = NULL;
2737         tail = &revs->commits;
2738         while (list) {
2739                 struct merge_simplify_state *st;
2740
2741                 commit = pop_commit(&list);
2742                 st = locate_simplify_state(revs, commit);
2743                 if (st->simplified == commit)
2744                         tail = &commit_list_insert(commit, tail)->next;
2745         }
2746 }
2747
2748 static void set_children(struct rev_info *revs)
2749 {
2750         struct commit_list *l;
2751         for (l = revs->commits; l; l = l->next) {
2752                 struct commit *commit = l->item;
2753                 struct commit_list *p;
2754
2755                 for (p = commit->parents; p; p = p->next)
2756                         add_child(revs, p->item, commit);
2757         }
2758 }
2759
2760 void reset_revision_walk(void)
2761 {
2762         clear_object_flags(SEEN | ADDED | SHOWN);
2763 }
2764
2765 int prepare_revision_walk(struct rev_info *revs)
2766 {
2767         int i;
2768         struct object_array old_pending;
2769         struct commit_list **next = &revs->commits;
2770
2771         memcpy(&old_pending, &revs->pending, sizeof(old_pending));
2772         revs->pending.nr = 0;
2773         revs->pending.alloc = 0;
2774         revs->pending.objects = NULL;
2775         for (i = 0; i < old_pending.nr; i++) {
2776                 struct object_array_entry *e = old_pending.objects + i;
2777                 struct commit *commit = handle_commit(revs, e);
2778                 if (commit) {
2779                         if (!(commit->object.flags & SEEN)) {
2780                                 commit->object.flags |= SEEN;
2781                                 next = commit_list_append(commit, next);
2782                         }
2783                 }
2784         }
2785         if (!revs->leak_pending)
2786                 object_array_clear(&old_pending);
2787
2788         /* Signal whether we need per-parent treesame decoration */
2789         if (revs->simplify_merges ||
2790             (revs->limited && limiting_can_increase_treesame(revs)))
2791                 revs->treesame.name = "treesame";
2792
2793         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2794                 commit_list_sort_by_date(&revs->commits);
2795         if (revs->no_walk)
2796                 return 0;
2797         if (revs->limited)
2798                 if (limit_list(revs) < 0)
2799                         return -1;
2800         if (revs->topo_order)
2801                 sort_in_topological_order(&revs->commits, revs->sort_order);
2802         if (revs->line_level_traverse)
2803                 line_log_filter(revs);
2804         if (revs->simplify_merges)
2805                 simplify_merges(revs);
2806         if (revs->children.name)
2807                 set_children(revs);
2808         return 0;
2809 }
2810
2811 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2812 {
2813         struct commit_list *cache = NULL;
2814
2815         for (;;) {
2816                 struct commit *p = *pp;
2817                 if (!revs->limited)
2818                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2819                                 return rewrite_one_error;
2820                 if (p->object.flags & UNINTERESTING)
2821                         return rewrite_one_ok;
2822                 if (!(p->object.flags & TREESAME))
2823                         return rewrite_one_ok;
2824                 if (!p->parents)
2825                         return rewrite_one_noparents;
2826                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2827                         return rewrite_one_ok;
2828                 *pp = p;
2829         }
2830 }
2831
2832 int rewrite_parents(struct rev_info *revs, struct commit *commit,
2833         rewrite_parent_fn_t rewrite_parent)
2834 {
2835         struct commit_list **pp = &commit->parents;
2836         while (*pp) {
2837                 struct commit_list *parent = *pp;
2838                 switch (rewrite_parent(revs, &parent->item)) {
2839                 case rewrite_one_ok:
2840                         break;
2841                 case rewrite_one_noparents:
2842                         *pp = parent->next;
2843                         continue;
2844                 case rewrite_one_error:
2845                         return -1;
2846                 }
2847                 pp = &parent->next;
2848         }
2849         remove_duplicate_parents(revs, commit);
2850         return 0;
2851 }
2852
2853 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2854 {
2855         char *person, *endp;
2856         size_t len, namelen, maillen;
2857         const char *name;
2858         const char *mail;
2859         struct ident_split ident;
2860
2861         person = strstr(buf->buf, what);
2862         if (!person)
2863                 return 0;
2864
2865         person += strlen(what);
2866         endp = strchr(person, '\n');
2867         if (!endp)
2868                 return 0;
2869
2870         len = endp - person;
2871
2872         if (split_ident_line(&ident, person, len))
2873                 return 0;
2874
2875         mail = ident.mail_begin;
2876         maillen = ident.mail_end - ident.mail_begin;
2877         name = ident.name_begin;
2878         namelen = ident.name_end - ident.name_begin;
2879
2880         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2881                 struct strbuf namemail = STRBUF_INIT;
2882
2883                 strbuf_addf(&namemail, "%.*s <%.*s>",
2884                             (int)namelen, name, (int)maillen, mail);
2885
2886                 strbuf_splice(buf, ident.name_begin - buf->buf,
2887                               ident.mail_end - ident.name_begin + 1,
2888                               namemail.buf, namemail.len);
2889
2890                 strbuf_release(&namemail);
2891
2892                 return 1;
2893         }
2894
2895         return 0;
2896 }
2897
2898 static int commit_match(struct commit *commit, struct rev_info *opt)
2899 {
2900         int retval;
2901         const char *encoding;
2902         const char *message;
2903         struct strbuf buf = STRBUF_INIT;
2904
2905         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2906                 return 1;
2907
2908         /* Prepend "fake" headers as needed */
2909         if (opt->grep_filter.use_reflog_filter) {
2910                 strbuf_addstr(&buf, "reflog ");
2911                 get_reflog_message(&buf, opt->reflog_info);
2912                 strbuf_addch(&buf, '\n');
2913         }
2914
2915         /*
2916          * We grep in the user's output encoding, under the assumption that it
2917          * is the encoding they are most likely to write their grep pattern
2918          * for. In addition, it means we will match the "notes" encoding below,
2919          * so we will not end up with a buffer that has two different encodings
2920          * in it.
2921          */
2922         encoding = get_log_output_encoding();
2923         message = logmsg_reencode(commit, NULL, encoding);
2924
2925         /* Copy the commit to temporary if we are using "fake" headers */
2926         if (buf.len)
2927                 strbuf_addstr(&buf, message);
2928
2929         if (opt->grep_filter.header_list && opt->mailmap) {
2930                 if (!buf.len)
2931                         strbuf_addstr(&buf, message);
2932
2933                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2934                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2935         }
2936
2937         /* Append "fake" message parts as needed */
2938         if (opt->show_notes) {
2939                 if (!buf.len)
2940                         strbuf_addstr(&buf, message);
2941                 format_display_notes(commit->object.sha1, &buf, encoding, 1);
2942         }
2943
2944         /*
2945          * Find either in the original commit message, or in the temporary.
2946          * Note that we cast away the constness of "message" here. It is
2947          * const because it may come from the cached commit buffer. That's OK,
2948          * because we know that it is modifiable heap memory, and that while
2949          * grep_buffer may modify it for speed, it will restore any
2950          * changes before returning.
2951          */
2952         if (buf.len)
2953                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2954         else
2955                 retval = grep_buffer(&opt->grep_filter,
2956                                      (char *)message, strlen(message));
2957         strbuf_release(&buf);
2958         unuse_commit_buffer(commit, message);
2959         return opt->invert_grep ? !retval : retval;
2960 }
2961
2962 static inline int want_ancestry(const struct rev_info *revs)
2963 {
2964         return (revs->rewrite_parents || revs->children.name);
2965 }
2966
2967 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2968 {
2969         if (commit->object.flags & SHOWN)
2970                 return commit_ignore;
2971         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2972                 return commit_ignore;
2973         if (revs->show_all)
2974                 return commit_show;
2975         if (commit->object.flags & UNINTERESTING)
2976                 return commit_ignore;
2977         if (revs->min_age != -1 && (commit->date > revs->min_age))
2978                 return commit_ignore;
2979         if (revs->min_parents || (revs->max_parents >= 0)) {
2980                 int n = commit_list_count(commit->parents);
2981                 if ((n < revs->min_parents) ||
2982                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2983                         return commit_ignore;
2984         }
2985         if (!commit_match(commit, revs))
2986                 return commit_ignore;
2987         if (revs->prune && revs->dense) {
2988                 /* Commit without changes? */
2989                 if (commit->object.flags & TREESAME) {
2990                         int n;
2991                         struct commit_list *p;
2992                         /* drop merges unless we want parenthood */
2993                         if (!want_ancestry(revs))
2994                                 return commit_ignore;
2995                         /*
2996                          * If we want ancestry, then need to keep any merges
2997                          * between relevant commits to tie together topology.
2998                          * For consistency with TREESAME and simplification
2999                          * use "relevant" here rather than just INTERESTING,
3000                          * to treat bottom commit(s) as part of the topology.
3001                          */
3002                         for (n = 0, p = commit->parents; p; p = p->next)
3003                                 if (relevant_commit(p->item))
3004                                         if (++n >= 2)
3005                                                 return commit_show;
3006                         return commit_ignore;
3007                 }
3008         }
3009         return commit_show;
3010 }
3011
3012 define_commit_slab(saved_parents, struct commit_list *);
3013
3014 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3015
3016 /*
3017  * You may only call save_parents() once per commit (this is checked
3018  * for non-root commits).
3019  */
3020 static void save_parents(struct rev_info *revs, struct commit *commit)
3021 {
3022         struct commit_list **pp;
3023
3024         if (!revs->saved_parents_slab) {
3025                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3026                 init_saved_parents(revs->saved_parents_slab);
3027         }
3028
3029         pp = saved_parents_at(revs->saved_parents_slab, commit);
3030
3031         /*
3032          * When walking with reflogs, we may visit the same commit
3033          * several times: once for each appearance in the reflog.
3034          *
3035          * In this case, save_parents() will be called multiple times.
3036          * We want to keep only the first set of parents.  We need to
3037          * store a sentinel value for an empty (i.e., NULL) parent
3038          * list to distinguish it from a not-yet-saved list, however.
3039          */
3040         if (*pp)
3041                 return;
3042         if (commit->parents)
3043                 *pp = copy_commit_list(commit->parents);
3044         else
3045                 *pp = EMPTY_PARENT_LIST;
3046 }
3047
3048 static void free_saved_parents(struct rev_info *revs)
3049 {
3050         if (revs->saved_parents_slab)
3051                 clear_saved_parents(revs->saved_parents_slab);
3052 }
3053
3054 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3055 {
3056         struct commit_list *parents;
3057
3058         if (!revs->saved_parents_slab)
3059                 return commit->parents;
3060
3061         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3062         if (parents == EMPTY_PARENT_LIST)
3063                 return NULL;
3064         return parents;
3065 }
3066
3067 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3068 {
3069         enum commit_action action = get_commit_action(revs, commit);
3070
3071         if (action == commit_show &&
3072             !revs->show_all &&
3073             revs->prune && revs->dense && want_ancestry(revs)) {
3074                 /*
3075                  * --full-diff on simplified parents is no good: it
3076                  * will show spurious changes from the commits that
3077                  * were elided.  So we save the parents on the side
3078                  * when --full-diff is in effect.
3079                  */
3080                 if (revs->full_diff)
3081                         save_parents(revs, commit);
3082                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
3083                         return commit_error;
3084         }
3085         return action;
3086 }
3087
3088 static void track_linear(struct rev_info *revs, struct commit *commit)
3089 {
3090         if (revs->track_first_time) {
3091                 revs->linear = 1;
3092                 revs->track_first_time = 0;
3093         } else {
3094                 struct commit_list *p;
3095                 for (p = revs->previous_parents; p; p = p->next)
3096                         if (p->item == NULL || /* first commit */
3097                             !hashcmp(p->item->object.sha1, commit->object.sha1))
3098                                 break;
3099                 revs->linear = p != NULL;
3100         }
3101         if (revs->reverse) {
3102                 if (revs->linear)
3103                         commit->object.flags |= TRACK_LINEAR;
3104         }
3105         free_commit_list(revs->previous_parents);
3106         revs->previous_parents = copy_commit_list(commit->parents);
3107 }
3108
3109 static struct commit *get_revision_1(struct rev_info *revs)
3110 {
3111         if (!revs->commits)
3112                 return NULL;
3113
3114         do {
3115                 struct commit *commit = pop_commit(&revs->commits);
3116
3117                 if (revs->reflog_info) {
3118                         save_parents(revs, commit);
3119                         fake_reflog_parent(revs->reflog_info, commit);
3120                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3121                 }
3122
3123                 /*
3124                  * If we haven't done the list limiting, we need to look at
3125                  * the parents here. We also need to do the date-based limiting
3126                  * that we'd otherwise have done in limit_list().
3127                  */
3128                 if (!revs->limited) {
3129                         if (revs->max_age != -1 &&
3130                             (commit->date < revs->max_age))
3131                                 continue;
3132                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
3133                                 if (!revs->ignore_missing_links)
3134                                         die("Failed to traverse parents of commit %s",
3135                                                 sha1_to_hex(commit->object.sha1));
3136                         }
3137                 }
3138
3139                 switch (simplify_commit(revs, commit)) {
3140                 case commit_ignore:
3141                         continue;
3142                 case commit_error:
3143                         die("Failed to simplify parents of commit %s",
3144                             sha1_to_hex(commit->object.sha1));
3145                 default:
3146                         if (revs->track_linear)
3147                                 track_linear(revs, commit);
3148                         return commit;
3149                 }
3150         } while (revs->commits);
3151         return NULL;
3152 }
3153
3154 /*
3155  * Return true for entries that have not yet been shown.  (This is an
3156  * object_array_each_func_t.)
3157  */
3158 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3159 {
3160         return !(entry->item->flags & SHOWN);
3161 }
3162
3163 /*
3164  * If array is on the verge of a realloc, garbage-collect any entries
3165  * that have already been shown to try to free up some space.
3166  */
3167 static void gc_boundary(struct object_array *array)
3168 {
3169         if (array->nr == array->alloc)
3170                 object_array_filter(array, entry_unshown, NULL);
3171 }
3172
3173 static void create_boundary_commit_list(struct rev_info *revs)
3174 {
3175         unsigned i;
3176         struct commit *c;
3177         struct object_array *array = &revs->boundary_commits;
3178         struct object_array_entry *objects = array->objects;
3179
3180         /*
3181          * If revs->commits is non-NULL at this point, an error occurred in
3182          * get_revision_1().  Ignore the error and continue printing the
3183          * boundary commits anyway.  (This is what the code has always
3184          * done.)
3185          */
3186         if (revs->commits) {
3187                 free_commit_list(revs->commits);
3188                 revs->commits = NULL;
3189         }
3190
3191         /*
3192          * Put all of the actual boundary commits from revs->boundary_commits
3193          * into revs->commits
3194          */
3195         for (i = 0; i < array->nr; i++) {
3196                 c = (struct commit *)(objects[i].item);
3197                 if (!c)
3198                         continue;
3199                 if (!(c->object.flags & CHILD_SHOWN))
3200                         continue;
3201                 if (c->object.flags & (SHOWN | BOUNDARY))
3202                         continue;
3203                 c->object.flags |= BOUNDARY;
3204                 commit_list_insert(c, &revs->commits);
3205         }
3206
3207         /*
3208          * If revs->topo_order is set, sort the boundary commits
3209          * in topological order
3210          */
3211         sort_in_topological_order(&revs->commits, revs->sort_order);
3212 }
3213
3214 static struct commit *get_revision_internal(struct rev_info *revs)
3215 {
3216         struct commit *c = NULL;
3217         struct commit_list *l;
3218
3219         if (revs->boundary == 2) {
3220                 /*
3221                  * All of the normal commits have already been returned,
3222                  * and we are now returning boundary commits.
3223                  * create_boundary_commit_list() has populated
3224                  * revs->commits with the remaining commits to return.
3225                  */
3226                 c = pop_commit(&revs->commits);
3227                 if (c)
3228                         c->object.flags |= SHOWN;
3229                 return c;
3230         }
3231
3232         /*
3233          * If our max_count counter has reached zero, then we are done. We
3234          * don't simply return NULL because we still might need to show
3235          * boundary commits. But we want to avoid calling get_revision_1, which
3236          * might do a considerable amount of work finding the next commit only
3237          * for us to throw it away.
3238          *
3239          * If it is non-zero, then either we don't have a max_count at all
3240          * (-1), or it is still counting, in which case we decrement.
3241          */
3242         if (revs->max_count) {
3243                 c = get_revision_1(revs);
3244                 if (c) {
3245                         while (revs->skip_count > 0) {
3246                                 revs->skip_count--;
3247                                 c = get_revision_1(revs);
3248                                 if (!c)
3249                                         break;
3250                         }
3251                 }
3252
3253                 if (revs->max_count > 0)
3254                         revs->max_count--;
3255         }
3256
3257         if (c)
3258                 c->object.flags |= SHOWN;
3259
3260         if (!revs->boundary)
3261                 return c;
3262
3263         if (!c) {
3264                 /*
3265                  * get_revision_1() runs out the commits, and
3266                  * we are done computing the boundaries.
3267                  * switch to boundary commits output mode.
3268                  */
3269                 revs->boundary = 2;
3270
3271                 /*
3272                  * Update revs->commits to contain the list of
3273                  * boundary commits.
3274                  */
3275                 create_boundary_commit_list(revs);
3276
3277                 return get_revision_internal(revs);
3278         }
3279
3280         /*
3281          * boundary commits are the commits that are parents of the
3282          * ones we got from get_revision_1() but they themselves are
3283          * not returned from get_revision_1().  Before returning
3284          * 'c', we need to mark its parents that they could be boundaries.
3285          */
3286
3287         for (l = c->parents; l; l = l->next) {
3288                 struct object *p;
3289                 p = &(l->item->object);
3290                 if (p->flags & (CHILD_SHOWN | SHOWN))
3291                         continue;
3292                 p->flags |= CHILD_SHOWN;
3293                 gc_boundary(&revs->boundary_commits);
3294                 add_object_array(p, NULL, &revs->boundary_commits);
3295         }
3296
3297         return c;
3298 }
3299
3300 struct commit *get_revision(struct rev_info *revs)
3301 {
3302         struct commit *c;
3303         struct commit_list *reversed;
3304
3305         if (revs->reverse) {
3306                 reversed = NULL;
3307                 while ((c = get_revision_internal(revs)))
3308                         commit_list_insert(c, &reversed);
3309                 revs->commits = reversed;
3310                 revs->reverse = 0;
3311                 revs->reverse_output_stage = 1;
3312         }
3313
3314         if (revs->reverse_output_stage) {
3315                 c = pop_commit(&revs->commits);
3316                 if (revs->track_linear)
3317                         revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
3318                 return c;
3319         }
3320
3321         c = get_revision_internal(revs);
3322         if (c && revs->graph)
3323                 graph_update(revs->graph, c);
3324         if (!c) {
3325                 free_saved_parents(revs);
3326                 if (revs->previous_parents) {
3327                         free_commit_list(revs->previous_parents);
3328                         revs->previous_parents = NULL;
3329                 }
3330         }
3331         return c;
3332 }
3333
3334 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3335 {
3336         if (commit->object.flags & BOUNDARY)
3337                 return "-";
3338         else if (commit->object.flags & UNINTERESTING)
3339                 return "^";
3340         else if (commit->object.flags & PATCHSAME)
3341                 return "=";
3342         else if (!revs || revs->left_right) {
3343                 if (commit->object.flags & SYMMETRIC_LEFT)
3344                         return "<";
3345                 else
3346                         return ">";
3347         } else if (revs->graph)
3348                 return "*";
3349         else if (revs->cherry_mark)
3350                 return "+";
3351         return "";
3352 }
3353
3354 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3355 {
3356         char *mark = get_revision_mark(revs, commit);
3357         if (!strlen(mark))
3358                 return;
3359         fputs(mark, stdout);
3360         putchar(' ');
3361 }