Merge branch 'mr/bisect-in-c-2'
[git] / revision.c
1 #include "cache.h"
2 #include "object-store.h"
3 #include "tag.h"
4 #include "blob.h"
5 #include "tree.h"
6 #include "commit.h"
7 #include "diff.h"
8 #include "refs.h"
9 #include "revision.h"
10 #include "repository.h"
11 #include "graph.h"
12 #include "grep.h"
13 #include "reflog-walk.h"
14 #include "patch-ids.h"
15 #include "decorate.h"
16 #include "log-tree.h"
17 #include "string-list.h"
18 #include "line-log.h"
19 #include "mailmap.h"
20 #include "commit-slab.h"
21 #include "dir.h"
22 #include "cache-tree.h"
23 #include "bisect.h"
24 #include "packfile.h"
25 #include "worktree.h"
26 #include "strvec.h"
27 #include "commit-reach.h"
28 #include "commit-graph.h"
29 #include "prio-queue.h"
30 #include "hashmap.h"
31 #include "utf8.h"
32 #include "bloom.h"
33 #include "json-writer.h"
34
35 volatile show_early_output_fn_t show_early_output;
36
37 static const char *term_bad;
38 static const char *term_good;
39
40 implement_shared_commit_slab(revision_sources, char *);
41
42 static inline int want_ancestry(const struct rev_info *revs);
43
44 void show_object_with_name(FILE *out, struct object *obj, const char *name)
45 {
46         const char *p;
47
48         fprintf(out, "%s ", oid_to_hex(&obj->oid));
49         for (p = name; *p && *p != '\n'; p++)
50                 fputc(*p, out);
51         fputc('\n', out);
52 }
53
54 static void mark_blob_uninteresting(struct blob *blob)
55 {
56         if (!blob)
57                 return;
58         if (blob->object.flags & UNINTERESTING)
59                 return;
60         blob->object.flags |= UNINTERESTING;
61 }
62
63 static void mark_tree_contents_uninteresting(struct repository *r,
64                                              struct tree *tree)
65 {
66         struct tree_desc desc;
67         struct name_entry entry;
68
69         if (parse_tree_gently(tree, 1) < 0)
70                 return;
71
72         init_tree_desc(&desc, tree->buffer, tree->size);
73         while (tree_entry(&desc, &entry)) {
74                 switch (object_type(entry.mode)) {
75                 case OBJ_TREE:
76                         mark_tree_uninteresting(r, lookup_tree(r, &entry.oid));
77                         break;
78                 case OBJ_BLOB:
79                         mark_blob_uninteresting(lookup_blob(r, &entry.oid));
80                         break;
81                 default:
82                         /* Subproject commit - not in this repository */
83                         break;
84                 }
85         }
86
87         /*
88          * We don't care about the tree any more
89          * after it has been marked uninteresting.
90          */
91         free_tree_buffer(tree);
92 }
93
94 void mark_tree_uninteresting(struct repository *r, struct tree *tree)
95 {
96         struct object *obj;
97
98         if (!tree)
99                 return;
100
101         obj = &tree->object;
102         if (obj->flags & UNINTERESTING)
103                 return;
104         obj->flags |= UNINTERESTING;
105         mark_tree_contents_uninteresting(r, tree);
106 }
107
108 struct path_and_oids_entry {
109         struct hashmap_entry ent;
110         char *path;
111         struct oidset trees;
112 };
113
114 static int path_and_oids_cmp(const void *hashmap_cmp_fn_data,
115                              const struct hashmap_entry *eptr,
116                              const struct hashmap_entry *entry_or_key,
117                              const void *keydata)
118 {
119         const struct path_and_oids_entry *e1, *e2;
120
121         e1 = container_of(eptr, const struct path_and_oids_entry, ent);
122         e2 = container_of(entry_or_key, const struct path_and_oids_entry, ent);
123
124         return strcmp(e1->path, e2->path);
125 }
126
127 static void paths_and_oids_init(struct hashmap *map)
128 {
129         hashmap_init(map, path_and_oids_cmp, NULL, 0);
130 }
131
132 static void paths_and_oids_clear(struct hashmap *map)
133 {
134         struct hashmap_iter iter;
135         struct path_and_oids_entry *entry;
136
137         hashmap_for_each_entry(map, &iter, entry, ent /* member name */) {
138                 oidset_clear(&entry->trees);
139                 free(entry->path);
140         }
141
142         hashmap_free_entries(map, struct path_and_oids_entry, ent);
143 }
144
145 static void paths_and_oids_insert(struct hashmap *map,
146                                   const char *path,
147                                   const struct object_id *oid)
148 {
149         int hash = strhash(path);
150         struct path_and_oids_entry key;
151         struct path_and_oids_entry *entry;
152
153         hashmap_entry_init(&key.ent, hash);
154
155         /* use a shallow copy for the lookup */
156         key.path = (char *)path;
157         oidset_init(&key.trees, 0);
158
159         entry = hashmap_get_entry(map, &key, ent, NULL);
160         if (!entry) {
161                 entry = xcalloc(1, sizeof(struct path_and_oids_entry));
162                 hashmap_entry_init(&entry->ent, hash);
163                 entry->path = xstrdup(key.path);
164                 oidset_init(&entry->trees, 16);
165                 hashmap_put(map, &entry->ent);
166         }
167
168         oidset_insert(&entry->trees, oid);
169 }
170
171 static void add_children_by_path(struct repository *r,
172                                  struct tree *tree,
173                                  struct hashmap *map)
174 {
175         struct tree_desc desc;
176         struct name_entry entry;
177
178         if (!tree)
179                 return;
180
181         if (parse_tree_gently(tree, 1) < 0)
182                 return;
183
184         init_tree_desc(&desc, tree->buffer, tree->size);
185         while (tree_entry(&desc, &entry)) {
186                 switch (object_type(entry.mode)) {
187                 case OBJ_TREE:
188                         paths_and_oids_insert(map, entry.path, &entry.oid);
189
190                         if (tree->object.flags & UNINTERESTING) {
191                                 struct tree *child = lookup_tree(r, &entry.oid);
192                                 if (child)
193                                         child->object.flags |= UNINTERESTING;
194                         }
195                         break;
196                 case OBJ_BLOB:
197                         if (tree->object.flags & UNINTERESTING) {
198                                 struct blob *child = lookup_blob(r, &entry.oid);
199                                 if (child)
200                                         child->object.flags |= UNINTERESTING;
201                         }
202                         break;
203                 default:
204                         /* Subproject commit - not in this repository */
205                         break;
206                 }
207         }
208
209         free_tree_buffer(tree);
210 }
211
212 void mark_trees_uninteresting_sparse(struct repository *r,
213                                      struct oidset *trees)
214 {
215         unsigned has_interesting = 0, has_uninteresting = 0;
216         struct hashmap map;
217         struct hashmap_iter map_iter;
218         struct path_and_oids_entry *entry;
219         struct object_id *oid;
220         struct oidset_iter iter;
221
222         oidset_iter_init(trees, &iter);
223         while ((!has_interesting || !has_uninteresting) &&
224                (oid = oidset_iter_next(&iter))) {
225                 struct tree *tree = lookup_tree(r, oid);
226
227                 if (!tree)
228                         continue;
229
230                 if (tree->object.flags & UNINTERESTING)
231                         has_uninteresting = 1;
232                 else
233                         has_interesting = 1;
234         }
235
236         /* Do not walk unless we have both types of trees. */
237         if (!has_uninteresting || !has_interesting)
238                 return;
239
240         paths_and_oids_init(&map);
241
242         oidset_iter_init(trees, &iter);
243         while ((oid = oidset_iter_next(&iter))) {
244                 struct tree *tree = lookup_tree(r, oid);
245                 add_children_by_path(r, tree, &map);
246         }
247
248         hashmap_for_each_entry(&map, &map_iter, entry, ent /* member name */)
249                 mark_trees_uninteresting_sparse(r, &entry->trees);
250
251         paths_and_oids_clear(&map);
252 }
253
254 struct commit_stack {
255         struct commit **items;
256         size_t nr, alloc;
257 };
258 #define COMMIT_STACK_INIT { NULL, 0, 0 }
259
260 static void commit_stack_push(struct commit_stack *stack, struct commit *commit)
261 {
262         ALLOC_GROW(stack->items, stack->nr + 1, stack->alloc);
263         stack->items[stack->nr++] = commit;
264 }
265
266 static struct commit *commit_stack_pop(struct commit_stack *stack)
267 {
268         return stack->nr ? stack->items[--stack->nr] : NULL;
269 }
270
271 static void commit_stack_clear(struct commit_stack *stack)
272 {
273         FREE_AND_NULL(stack->items);
274         stack->nr = stack->alloc = 0;
275 }
276
277 static void mark_one_parent_uninteresting(struct commit *commit,
278                                           struct commit_stack *pending)
279 {
280         struct commit_list *l;
281
282         if (commit->object.flags & UNINTERESTING)
283                 return;
284         commit->object.flags |= UNINTERESTING;
285
286         /*
287          * Normally we haven't parsed the parent
288          * yet, so we won't have a parent of a parent
289          * here. However, it may turn out that we've
290          * reached this commit some other way (where it
291          * wasn't uninteresting), in which case we need
292          * to mark its parents recursively too..
293          */
294         for (l = commit->parents; l; l = l->next)
295                 commit_stack_push(pending, l->item);
296 }
297
298 void mark_parents_uninteresting(struct commit *commit)
299 {
300         struct commit_stack pending = COMMIT_STACK_INIT;
301         struct commit_list *l;
302
303         for (l = commit->parents; l; l = l->next)
304                 mark_one_parent_uninteresting(l->item, &pending);
305
306         while (pending.nr > 0)
307                 mark_one_parent_uninteresting(commit_stack_pop(&pending),
308                                               &pending);
309
310         commit_stack_clear(&pending);
311 }
312
313 static void add_pending_object_with_path(struct rev_info *revs,
314                                          struct object *obj,
315                                          const char *name, unsigned mode,
316                                          const char *path)
317 {
318         struct interpret_branch_name_options options = { 0 };
319         if (!obj)
320                 return;
321         if (revs->no_walk && (obj->flags & UNINTERESTING))
322                 revs->no_walk = 0;
323         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
324                 struct strbuf buf = STRBUF_INIT;
325                 int len = interpret_branch_name(name, 0, &buf, &options);
326
327                 if (0 < len && name[len] && buf.len)
328                         strbuf_addstr(&buf, name + len);
329                 add_reflog_for_walk(revs->reflog_info,
330                                     (struct commit *)obj,
331                                     buf.buf[0] ? buf.buf: name);
332                 strbuf_release(&buf);
333                 return; /* do not add the commit itself */
334         }
335         add_object_array_with_path(obj, name, &revs->pending, mode, path);
336 }
337
338 static void add_pending_object_with_mode(struct rev_info *revs,
339                                          struct object *obj,
340                                          const char *name, unsigned mode)
341 {
342         add_pending_object_with_path(revs, obj, name, mode, NULL);
343 }
344
345 void add_pending_object(struct rev_info *revs,
346                         struct object *obj, const char *name)
347 {
348         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
349 }
350
351 void add_head_to_pending(struct rev_info *revs)
352 {
353         struct object_id oid;
354         struct object *obj;
355         if (get_oid("HEAD", &oid))
356                 return;
357         obj = parse_object(revs->repo, &oid);
358         if (!obj)
359                 return;
360         add_pending_object(revs, obj, "HEAD");
361 }
362
363 static struct object *get_reference(struct rev_info *revs, const char *name,
364                                     const struct object_id *oid,
365                                     unsigned int flags)
366 {
367         struct object *object;
368
369         /*
370          * If the repository has commit graphs, repo_parse_commit() avoids
371          * reading the object buffer, so use it whenever possible.
372          */
373         if (oid_object_info(revs->repo, oid, NULL) == OBJ_COMMIT) {
374                 struct commit *c = lookup_commit(revs->repo, oid);
375                 if (!repo_parse_commit(revs->repo, c))
376                         object = (struct object *) c;
377                 else
378                         object = NULL;
379         } else {
380                 object = parse_object(revs->repo, oid);
381         }
382
383         if (!object) {
384                 if (revs->ignore_missing)
385                         return object;
386                 if (revs->exclude_promisor_objects && is_promisor_object(oid))
387                         return NULL;
388                 die("bad object %s", name);
389         }
390         object->flags |= flags;
391         return object;
392 }
393
394 void add_pending_oid(struct rev_info *revs, const char *name,
395                       const struct object_id *oid, unsigned int flags)
396 {
397         struct object *object = get_reference(revs, name, oid, flags);
398         add_pending_object(revs, object, name);
399 }
400
401 static struct commit *handle_commit(struct rev_info *revs,
402                                     struct object_array_entry *entry)
403 {
404         struct object *object = entry->item;
405         const char *name = entry->name;
406         const char *path = entry->path;
407         unsigned int mode = entry->mode;
408         unsigned long flags = object->flags;
409
410         /*
411          * Tag object? Look what it points to..
412          */
413         while (object->type == OBJ_TAG) {
414                 struct tag *tag = (struct tag *) object;
415                 if (revs->tag_objects && !(flags & UNINTERESTING))
416                         add_pending_object(revs, object, tag->tag);
417                 object = parse_object(revs->repo, get_tagged_oid(tag));
418                 if (!object) {
419                         if (revs->ignore_missing_links || (flags & UNINTERESTING))
420                                 return NULL;
421                         if (revs->exclude_promisor_objects &&
422                             is_promisor_object(&tag->tagged->oid))
423                                 return NULL;
424                         die("bad object %s", oid_to_hex(&tag->tagged->oid));
425                 }
426                 object->flags |= flags;
427                 /*
428                  * We'll handle the tagged object by looping or dropping
429                  * through to the non-tag handlers below. Do not
430                  * propagate path data from the tag's pending entry.
431                  */
432                 path = NULL;
433                 mode = 0;
434         }
435
436         /*
437          * Commit object? Just return it, we'll do all the complex
438          * reachability crud.
439          */
440         if (object->type == OBJ_COMMIT) {
441                 struct commit *commit = (struct commit *)object;
442
443                 if (repo_parse_commit(revs->repo, commit) < 0)
444                         die("unable to parse commit %s", name);
445                 if (flags & UNINTERESTING) {
446                         mark_parents_uninteresting(commit);
447
448                         if (!revs->topo_order || !generation_numbers_enabled(the_repository))
449                                 revs->limited = 1;
450                 }
451                 if (revs->sources) {
452                         char **slot = revision_sources_at(revs->sources, commit);
453
454                         if (!*slot)
455                                 *slot = xstrdup(name);
456                 }
457                 return commit;
458         }
459
460         /*
461          * Tree object? Either mark it uninteresting, or add it
462          * to the list of objects to look at later..
463          */
464         if (object->type == OBJ_TREE) {
465                 struct tree *tree = (struct tree *)object;
466                 if (!revs->tree_objects)
467                         return NULL;
468                 if (flags & UNINTERESTING) {
469                         mark_tree_contents_uninteresting(revs->repo, tree);
470                         return NULL;
471                 }
472                 add_pending_object_with_path(revs, object, name, mode, path);
473                 return NULL;
474         }
475
476         /*
477          * Blob object? You know the drill by now..
478          */
479         if (object->type == OBJ_BLOB) {
480                 if (!revs->blob_objects)
481                         return NULL;
482                 if (flags & UNINTERESTING)
483                         return NULL;
484                 add_pending_object_with_path(revs, object, name, mode, path);
485                 return NULL;
486         }
487         die("%s is unknown object", name);
488 }
489
490 static int everybody_uninteresting(struct commit_list *orig,
491                                    struct commit **interesting_cache)
492 {
493         struct commit_list *list = orig;
494
495         if (*interesting_cache) {
496                 struct commit *commit = *interesting_cache;
497                 if (!(commit->object.flags & UNINTERESTING))
498                         return 0;
499         }
500
501         while (list) {
502                 struct commit *commit = list->item;
503                 list = list->next;
504                 if (commit->object.flags & UNINTERESTING)
505                         continue;
506
507                 *interesting_cache = commit;
508                 return 0;
509         }
510         return 1;
511 }
512
513 /*
514  * A definition of "relevant" commit that we can use to simplify limited graphs
515  * by eliminating side branches.
516  *
517  * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
518  * in our list), or that is a specified BOTTOM commit. Then after computing
519  * a limited list, during processing we can generally ignore boundary merges
520  * coming from outside the graph, (ie from irrelevant parents), and treat
521  * those merges as if they were single-parent. TREESAME is defined to consider
522  * only relevant parents, if any. If we are TREESAME to our on-graph parents,
523  * we don't care if we were !TREESAME to non-graph parents.
524  *
525  * Treating bottom commits as relevant ensures that a limited graph's
526  * connection to the actual bottom commit is not viewed as a side branch, but
527  * treated as part of the graph. For example:
528  *
529  *   ....Z...A---X---o---o---B
530  *        .     /
531  *         W---Y
532  *
533  * When computing "A..B", the A-X connection is at least as important as
534  * Y-X, despite A being flagged UNINTERESTING.
535  *
536  * And when computing --ancestry-path "A..B", the A-X connection is more
537  * important than Y-X, despite both A and Y being flagged UNINTERESTING.
538  */
539 static inline int relevant_commit(struct commit *commit)
540 {
541         return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
542 }
543
544 /*
545  * Return a single relevant commit from a parent list. If we are a TREESAME
546  * commit, and this selects one of our parents, then we can safely simplify to
547  * that parent.
548  */
549 static struct commit *one_relevant_parent(const struct rev_info *revs,
550                                           struct commit_list *orig)
551 {
552         struct commit_list *list = orig;
553         struct commit *relevant = NULL;
554
555         if (!orig)
556                 return NULL;
557
558         /*
559          * For 1-parent commits, or if first-parent-only, then return that
560          * first parent (even if not "relevant" by the above definition).
561          * TREESAME will have been set purely on that parent.
562          */
563         if (revs->first_parent_only || !orig->next)
564                 return orig->item;
565
566         /*
567          * For multi-parent commits, identify a sole relevant parent, if any.
568          * If we have only one relevant parent, then TREESAME will be set purely
569          * with regard to that parent, and we can simplify accordingly.
570          *
571          * If we have more than one relevant parent, or no relevant parents
572          * (and multiple irrelevant ones), then we can't select a parent here
573          * and return NULL.
574          */
575         while (list) {
576                 struct commit *commit = list->item;
577                 list = list->next;
578                 if (relevant_commit(commit)) {
579                         if (relevant)
580                                 return NULL;
581                         relevant = commit;
582                 }
583         }
584         return relevant;
585 }
586
587 /*
588  * The goal is to get REV_TREE_NEW as the result only if the
589  * diff consists of all '+' (and no other changes), REV_TREE_OLD
590  * if the whole diff is removal of old data, and otherwise
591  * REV_TREE_DIFFERENT (of course if the trees are the same we
592  * want REV_TREE_SAME).
593  *
594  * The only time we care about the distinction is when
595  * remove_empty_trees is in effect, in which case we care only about
596  * whether the whole change is REV_TREE_NEW, or if there's another type
597  * of change. Which means we can stop the diff early in either of these
598  * cases:
599  *
600  *   1. We're not using remove_empty_trees at all.
601  *
602  *   2. We saw anything except REV_TREE_NEW.
603  */
604 static int tree_difference = REV_TREE_SAME;
605
606 static void file_add_remove(struct diff_options *options,
607                     int addremove, unsigned mode,
608                     const struct object_id *oid,
609                     int oid_valid,
610                     const char *fullpath, unsigned dirty_submodule)
611 {
612         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
613         struct rev_info *revs = options->change_fn_data;
614
615         tree_difference |= diff;
616         if (!revs->remove_empty_trees || tree_difference != REV_TREE_NEW)
617                 options->flags.has_changes = 1;
618 }
619
620 static void file_change(struct diff_options *options,
621                  unsigned old_mode, unsigned new_mode,
622                  const struct object_id *old_oid,
623                  const struct object_id *new_oid,
624                  int old_oid_valid, int new_oid_valid,
625                  const char *fullpath,
626                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
627 {
628         tree_difference = REV_TREE_DIFFERENT;
629         options->flags.has_changes = 1;
630 }
631
632 static int bloom_filter_atexit_registered;
633 static unsigned int count_bloom_filter_maybe;
634 static unsigned int count_bloom_filter_definitely_not;
635 static unsigned int count_bloom_filter_false_positive;
636 static unsigned int count_bloom_filter_not_present;
637
638 static void trace2_bloom_filter_statistics_atexit(void)
639 {
640         struct json_writer jw = JSON_WRITER_INIT;
641
642         jw_object_begin(&jw, 0);
643         jw_object_intmax(&jw, "filter_not_present", count_bloom_filter_not_present);
644         jw_object_intmax(&jw, "maybe", count_bloom_filter_maybe);
645         jw_object_intmax(&jw, "definitely_not", count_bloom_filter_definitely_not);
646         jw_object_intmax(&jw, "false_positive", count_bloom_filter_false_positive);
647         jw_end(&jw);
648
649         trace2_data_json("bloom", the_repository, "statistics", &jw);
650
651         jw_release(&jw);
652 }
653
654 static int forbid_bloom_filters(struct pathspec *spec)
655 {
656         if (spec->has_wildcard)
657                 return 1;
658         if (spec->nr > 1)
659                 return 1;
660         if (spec->magic & ~PATHSPEC_LITERAL)
661                 return 1;
662         if (spec->nr && (spec->items[0].magic & ~PATHSPEC_LITERAL))
663                 return 1;
664
665         return 0;
666 }
667
668 static void prepare_to_use_bloom_filter(struct rev_info *revs)
669 {
670         struct pathspec_item *pi;
671         char *path_alloc = NULL;
672         const char *path, *p;
673         size_t len;
674         int path_component_nr = 1;
675
676         if (!revs->commits)
677                 return;
678
679         if (forbid_bloom_filters(&revs->prune_data))
680                 return;
681
682         repo_parse_commit(revs->repo, revs->commits->item);
683
684         revs->bloom_filter_settings = get_bloom_filter_settings(revs->repo);
685         if (!revs->bloom_filter_settings)
686                 return;
687
688         if (!revs->pruning.pathspec.nr)
689                 return;
690
691         pi = &revs->pruning.pathspec.items[0];
692
693         /* remove single trailing slash from path, if needed */
694         if (pi->len > 0 && pi->match[pi->len - 1] == '/') {
695                 path_alloc = xmemdupz(pi->match, pi->len - 1);
696                 path = path_alloc;
697         } else
698                 path = pi->match;
699
700         len = strlen(path);
701         if (!len) {
702                 revs->bloom_filter_settings = NULL;
703                 free(path_alloc);
704                 return;
705         }
706
707         p = path;
708         while (*p) {
709                 /*
710                  * At this point, the path is normalized to use Unix-style
711                  * path separators. This is required due to how the
712                  * changed-path Bloom filters store the paths.
713                  */
714                 if (*p == '/')
715                         path_component_nr++;
716                 p++;
717         }
718
719         revs->bloom_keys_nr = path_component_nr;
720         ALLOC_ARRAY(revs->bloom_keys, revs->bloom_keys_nr);
721
722         fill_bloom_key(path, len, &revs->bloom_keys[0],
723                        revs->bloom_filter_settings);
724         path_component_nr = 1;
725
726         p = path + len - 1;
727         while (p > path) {
728                 if (*p == '/')
729                         fill_bloom_key(path, p - path,
730                                        &revs->bloom_keys[path_component_nr++],
731                                        revs->bloom_filter_settings);
732                 p--;
733         }
734
735         if (trace2_is_enabled() && !bloom_filter_atexit_registered) {
736                 atexit(trace2_bloom_filter_statistics_atexit);
737                 bloom_filter_atexit_registered = 1;
738         }
739
740         free(path_alloc);
741 }
742
743 static int check_maybe_different_in_bloom_filter(struct rev_info *revs,
744                                                  struct commit *commit)
745 {
746         struct bloom_filter *filter;
747         int result = 1, j;
748
749         if (!revs->repo->objects->commit_graph)
750                 return -1;
751
752         if (commit_graph_generation(commit) == GENERATION_NUMBER_INFINITY)
753                 return -1;
754
755         filter = get_bloom_filter(revs->repo, commit);
756
757         if (!filter) {
758                 count_bloom_filter_not_present++;
759                 return -1;
760         }
761
762         for (j = 0; result && j < revs->bloom_keys_nr; j++) {
763                 result = bloom_filter_contains(filter,
764                                                &revs->bloom_keys[j],
765                                                revs->bloom_filter_settings);
766         }
767
768         if (result)
769                 count_bloom_filter_maybe++;
770         else
771                 count_bloom_filter_definitely_not++;
772
773         return result;
774 }
775
776 static int rev_compare_tree(struct rev_info *revs,
777                             struct commit *parent, struct commit *commit, int nth_parent)
778 {
779         struct tree *t1 = get_commit_tree(parent);
780         struct tree *t2 = get_commit_tree(commit);
781         int bloom_ret = 1;
782
783         if (!t1)
784                 return REV_TREE_NEW;
785         if (!t2)
786                 return REV_TREE_OLD;
787
788         if (revs->simplify_by_decoration) {
789                 /*
790                  * If we are simplifying by decoration, then the commit
791                  * is worth showing if it has a tag pointing at it.
792                  */
793                 if (get_name_decoration(&commit->object))
794                         return REV_TREE_DIFFERENT;
795                 /*
796                  * A commit that is not pointed by a tag is uninteresting
797                  * if we are not limited by path.  This means that you will
798                  * see the usual "commits that touch the paths" plus any
799                  * tagged commit by specifying both --simplify-by-decoration
800                  * and pathspec.
801                  */
802                 if (!revs->prune_data.nr)
803                         return REV_TREE_SAME;
804         }
805
806         if (revs->bloom_keys_nr && !nth_parent) {
807                 bloom_ret = check_maybe_different_in_bloom_filter(revs, commit);
808
809                 if (bloom_ret == 0)
810                         return REV_TREE_SAME;
811         }
812
813         tree_difference = REV_TREE_SAME;
814         revs->pruning.flags.has_changes = 0;
815         diff_tree_oid(&t1->object.oid, &t2->object.oid, "", &revs->pruning);
816
817         if (!nth_parent)
818                 if (bloom_ret == 1 && tree_difference == REV_TREE_SAME)
819                         count_bloom_filter_false_positive++;
820
821         return tree_difference;
822 }
823
824 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
825 {
826         struct tree *t1 = get_commit_tree(commit);
827
828         if (!t1)
829                 return 0;
830
831         tree_difference = REV_TREE_SAME;
832         revs->pruning.flags.has_changes = 0;
833         diff_tree_oid(NULL, &t1->object.oid, "", &revs->pruning);
834
835         return tree_difference == REV_TREE_SAME;
836 }
837
838 struct treesame_state {
839         unsigned int nparents;
840         unsigned char treesame[FLEX_ARRAY];
841 };
842
843 static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
844 {
845         unsigned n = commit_list_count(commit->parents);
846         struct treesame_state *st = xcalloc(1, st_add(sizeof(*st), n));
847         st->nparents = n;
848         add_decoration(&revs->treesame, &commit->object, st);
849         return st;
850 }
851
852 /*
853  * Must be called immediately after removing the nth_parent from a commit's
854  * parent list, if we are maintaining the per-parent treesame[] decoration.
855  * This does not recalculate the master TREESAME flag - update_treesame()
856  * should be called to update it after a sequence of treesame[] modifications
857  * that may have affected it.
858  */
859 static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
860 {
861         struct treesame_state *st;
862         int old_same;
863
864         if (!commit->parents) {
865                 /*
866                  * Have just removed the only parent from a non-merge.
867                  * Different handling, as we lack decoration.
868                  */
869                 if (nth_parent != 0)
870                         die("compact_treesame %u", nth_parent);
871                 old_same = !!(commit->object.flags & TREESAME);
872                 if (rev_same_tree_as_empty(revs, commit))
873                         commit->object.flags |= TREESAME;
874                 else
875                         commit->object.flags &= ~TREESAME;
876                 return old_same;
877         }
878
879         st = lookup_decoration(&revs->treesame, &commit->object);
880         if (!st || nth_parent >= st->nparents)
881                 die("compact_treesame %u", nth_parent);
882
883         old_same = st->treesame[nth_parent];
884         memmove(st->treesame + nth_parent,
885                 st->treesame + nth_parent + 1,
886                 st->nparents - nth_parent - 1);
887
888         /*
889          * If we've just become a non-merge commit, update TREESAME
890          * immediately, and remove the no-longer-needed decoration.
891          * If still a merge, defer update until update_treesame().
892          */
893         if (--st->nparents == 1) {
894                 if (commit->parents->next)
895                         die("compact_treesame parents mismatch");
896                 if (st->treesame[0] && revs->dense)
897                         commit->object.flags |= TREESAME;
898                 else
899                         commit->object.flags &= ~TREESAME;
900                 free(add_decoration(&revs->treesame, &commit->object, NULL));
901         }
902
903         return old_same;
904 }
905
906 static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
907 {
908         if (commit->parents && commit->parents->next) {
909                 unsigned n;
910                 struct treesame_state *st;
911                 struct commit_list *p;
912                 unsigned relevant_parents;
913                 unsigned relevant_change, irrelevant_change;
914
915                 st = lookup_decoration(&revs->treesame, &commit->object);
916                 if (!st)
917                         die("update_treesame %s", oid_to_hex(&commit->object.oid));
918                 relevant_parents = 0;
919                 relevant_change = irrelevant_change = 0;
920                 for (p = commit->parents, n = 0; p; n++, p = p->next) {
921                         if (relevant_commit(p->item)) {
922                                 relevant_change |= !st->treesame[n];
923                                 relevant_parents++;
924                         } else
925                                 irrelevant_change |= !st->treesame[n];
926                 }
927                 if (relevant_parents ? relevant_change : irrelevant_change)
928                         commit->object.flags &= ~TREESAME;
929                 else
930                         commit->object.flags |= TREESAME;
931         }
932
933         return commit->object.flags & TREESAME;
934 }
935
936 static inline int limiting_can_increase_treesame(const struct rev_info *revs)
937 {
938         /*
939          * TREESAME is irrelevant unless prune && dense;
940          * if simplify_history is set, we can't have a mixture of TREESAME and
941          *    !TREESAME INTERESTING parents (and we don't have treesame[]
942          *    decoration anyway);
943          * if first_parent_only is set, then the TREESAME flag is locked
944          *    against the first parent (and again we lack treesame[] decoration).
945          */
946         return revs->prune && revs->dense &&
947                !revs->simplify_history &&
948                !revs->first_parent_only;
949 }
950
951 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
952 {
953         struct commit_list **pp, *parent;
954         struct treesame_state *ts = NULL;
955         int relevant_change = 0, irrelevant_change = 0;
956         int relevant_parents, nth_parent;
957
958         /*
959          * If we don't do pruning, everything is interesting
960          */
961         if (!revs->prune)
962                 return;
963
964         if (!get_commit_tree(commit))
965                 return;
966
967         if (!commit->parents) {
968                 if (rev_same_tree_as_empty(revs, commit))
969                         commit->object.flags |= TREESAME;
970                 return;
971         }
972
973         /*
974          * Normal non-merge commit? If we don't want to make the
975          * history dense, we consider it always to be a change..
976          */
977         if (!revs->dense && !commit->parents->next)
978                 return;
979
980         for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
981              (parent = *pp) != NULL;
982              pp = &parent->next, nth_parent++) {
983                 struct commit *p = parent->item;
984                 if (relevant_commit(p))
985                         relevant_parents++;
986
987                 if (nth_parent == 1) {
988                         /*
989                          * This our second loop iteration - so we now know
990                          * we're dealing with a merge.
991                          *
992                          * Do not compare with later parents when we care only about
993                          * the first parent chain, in order to avoid derailing the
994                          * traversal to follow a side branch that brought everything
995                          * in the path we are limited to by the pathspec.
996                          */
997                         if (revs->first_parent_only)
998                                 break;
999                         /*
1000                          * If this will remain a potentially-simplifiable
1001                          * merge, remember per-parent treesame if needed.
1002                          * Initialise the array with the comparison from our
1003                          * first iteration.
1004                          */
1005                         if (revs->treesame.name &&
1006                             !revs->simplify_history &&
1007                             !(commit->object.flags & UNINTERESTING)) {
1008                                 ts = initialise_treesame(revs, commit);
1009                                 if (!(irrelevant_change || relevant_change))
1010                                         ts->treesame[0] = 1;
1011                         }
1012                 }
1013                 if (repo_parse_commit(revs->repo, p) < 0)
1014                         die("cannot simplify commit %s (because of %s)",
1015                             oid_to_hex(&commit->object.oid),
1016                             oid_to_hex(&p->object.oid));
1017                 switch (rev_compare_tree(revs, p, commit, nth_parent)) {
1018                 case REV_TREE_SAME:
1019                         if (!revs->simplify_history || !relevant_commit(p)) {
1020                                 /* Even if a merge with an uninteresting
1021                                  * side branch brought the entire change
1022                                  * we are interested in, we do not want
1023                                  * to lose the other branches of this
1024                                  * merge, so we just keep going.
1025                                  */
1026                                 if (ts)
1027                                         ts->treesame[nth_parent] = 1;
1028                                 continue;
1029                         }
1030                         parent->next = NULL;
1031                         commit->parents = parent;
1032
1033                         /*
1034                          * A merge commit is a "diversion" if it is not
1035                          * TREESAME to its first parent but is TREESAME
1036                          * to a later parent. In the simplified history,
1037                          * we "divert" the history walk to the later
1038                          * parent. These commits are shown when "show_pulls"
1039                          * is enabled, so do not mark the object as
1040                          * TREESAME here.
1041                          */
1042                         if (!revs->show_pulls || !nth_parent)
1043                                 commit->object.flags |= TREESAME;
1044
1045                         return;
1046
1047                 case REV_TREE_NEW:
1048                         if (revs->remove_empty_trees &&
1049                             rev_same_tree_as_empty(revs, p)) {
1050                                 /* We are adding all the specified
1051                                  * paths from this parent, so the
1052                                  * history beyond this parent is not
1053                                  * interesting.  Remove its parents
1054                                  * (they are grandparents for us).
1055                                  * IOW, we pretend this parent is a
1056                                  * "root" commit.
1057                                  */
1058                                 if (repo_parse_commit(revs->repo, p) < 0)
1059                                         die("cannot simplify commit %s (invalid %s)",
1060                                             oid_to_hex(&commit->object.oid),
1061                                             oid_to_hex(&p->object.oid));
1062                                 p->parents = NULL;
1063                         }
1064                 /* fallthrough */
1065                 case REV_TREE_OLD:
1066                 case REV_TREE_DIFFERENT:
1067                         if (relevant_commit(p))
1068                                 relevant_change = 1;
1069                         else
1070                                 irrelevant_change = 1;
1071
1072                         if (!nth_parent)
1073                                 commit->object.flags |= PULL_MERGE;
1074
1075                         continue;
1076                 }
1077                 die("bad tree compare for commit %s", oid_to_hex(&commit->object.oid));
1078         }
1079
1080         /*
1081          * TREESAME is straightforward for single-parent commits. For merge
1082          * commits, it is most useful to define it so that "irrelevant"
1083          * parents cannot make us !TREESAME - if we have any relevant
1084          * parents, then we only consider TREESAMEness with respect to them,
1085          * allowing irrelevant merges from uninteresting branches to be
1086          * simplified away. Only if we have only irrelevant parents do we
1087          * base TREESAME on them. Note that this logic is replicated in
1088          * update_treesame, which should be kept in sync.
1089          */
1090         if (relevant_parents ? !relevant_change : !irrelevant_change)
1091                 commit->object.flags |= TREESAME;
1092 }
1093
1094 static int process_parents(struct rev_info *revs, struct commit *commit,
1095                            struct commit_list **list, struct prio_queue *queue)
1096 {
1097         struct commit_list *parent = commit->parents;
1098         unsigned left_flag;
1099
1100         if (commit->object.flags & ADDED)
1101                 return 0;
1102         commit->object.flags |= ADDED;
1103
1104         if (revs->include_check &&
1105             !revs->include_check(commit, revs->include_check_data))
1106                 return 0;
1107
1108         /*
1109          * If the commit is uninteresting, don't try to
1110          * prune parents - we want the maximal uninteresting
1111          * set.
1112          *
1113          * Normally we haven't parsed the parent
1114          * yet, so we won't have a parent of a parent
1115          * here. However, it may turn out that we've
1116          * reached this commit some other way (where it
1117          * wasn't uninteresting), in which case we need
1118          * to mark its parents recursively too..
1119          */
1120         if (commit->object.flags & UNINTERESTING) {
1121                 while (parent) {
1122                         struct commit *p = parent->item;
1123                         parent = parent->next;
1124                         if (p)
1125                                 p->object.flags |= UNINTERESTING;
1126                         if (repo_parse_commit_gently(revs->repo, p, 1) < 0)
1127                                 continue;
1128                         if (p->parents)
1129                                 mark_parents_uninteresting(p);
1130                         if (p->object.flags & SEEN)
1131                                 continue;
1132                         p->object.flags |= SEEN;
1133                         if (list)
1134                                 commit_list_insert_by_date(p, list);
1135                         if (queue)
1136                                 prio_queue_put(queue, p);
1137                 }
1138                 return 0;
1139         }
1140
1141         /*
1142          * Ok, the commit wasn't uninteresting. Try to
1143          * simplify the commit history and find the parent
1144          * that has no differences in the path set if one exists.
1145          */
1146         try_to_simplify_commit(revs, commit);
1147
1148         if (revs->no_walk)
1149                 return 0;
1150
1151         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
1152
1153         for (parent = commit->parents; parent; parent = parent->next) {
1154                 struct commit *p = parent->item;
1155                 int gently = revs->ignore_missing_links ||
1156                              revs->exclude_promisor_objects;
1157                 if (repo_parse_commit_gently(revs->repo, p, gently) < 0) {
1158                         if (revs->exclude_promisor_objects &&
1159                             is_promisor_object(&p->object.oid)) {
1160                                 if (revs->first_parent_only)
1161                                         break;
1162                                 continue;
1163                         }
1164                         return -1;
1165                 }
1166                 if (revs->sources) {
1167                         char **slot = revision_sources_at(revs->sources, p);
1168
1169                         if (!*slot)
1170                                 *slot = *revision_sources_at(revs->sources, commit);
1171                 }
1172                 p->object.flags |= left_flag;
1173                 if (!(p->object.flags & SEEN)) {
1174                         p->object.flags |= SEEN;
1175                         if (list)
1176                                 commit_list_insert_by_date(p, list);
1177                         if (queue)
1178                                 prio_queue_put(queue, p);
1179                 }
1180                 if (revs->first_parent_only)
1181                         break;
1182         }
1183         return 0;
1184 }
1185
1186 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
1187 {
1188         struct commit_list *p;
1189         int left_count = 0, right_count = 0;
1190         int left_first;
1191         struct patch_ids ids;
1192         unsigned cherry_flag;
1193
1194         /* First count the commits on the left and on the right */
1195         for (p = list; p; p = p->next) {
1196                 struct commit *commit = p->item;
1197                 unsigned flags = commit->object.flags;
1198                 if (flags & BOUNDARY)
1199                         ;
1200                 else if (flags & SYMMETRIC_LEFT)
1201                         left_count++;
1202                 else
1203                         right_count++;
1204         }
1205
1206         if (!left_count || !right_count)
1207                 return;
1208
1209         left_first = left_count < right_count;
1210         init_patch_ids(revs->repo, &ids);
1211         ids.diffopts.pathspec = revs->diffopt.pathspec;
1212
1213         /* Compute patch-ids for one side */
1214         for (p = list; p; p = p->next) {
1215                 struct commit *commit = p->item;
1216                 unsigned flags = commit->object.flags;
1217
1218                 if (flags & BOUNDARY)
1219                         continue;
1220                 /*
1221                  * If we have fewer left, left_first is set and we omit
1222                  * commits on the right branch in this loop.  If we have
1223                  * fewer right, we skip the left ones.
1224                  */
1225                 if (left_first != !!(flags & SYMMETRIC_LEFT))
1226                         continue;
1227                 add_commit_patch_id(commit, &ids);
1228         }
1229
1230         /* either cherry_mark or cherry_pick are true */
1231         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
1232
1233         /* Check the other side */
1234         for (p = list; p; p = p->next) {
1235                 struct commit *commit = p->item;
1236                 struct patch_id *id;
1237                 unsigned flags = commit->object.flags;
1238
1239                 if (flags & BOUNDARY)
1240                         continue;
1241                 /*
1242                  * If we have fewer left, left_first is set and we omit
1243                  * commits on the left branch in this loop.
1244                  */
1245                 if (left_first == !!(flags & SYMMETRIC_LEFT))
1246                         continue;
1247
1248                 /*
1249                  * Have we seen the same patch id?
1250                  */
1251                 id = has_commit_patch_id(commit, &ids);
1252                 if (!id)
1253                         continue;
1254
1255                 commit->object.flags |= cherry_flag;
1256                 id->commit->object.flags |= cherry_flag;
1257         }
1258
1259         free_patch_ids(&ids);
1260 }
1261
1262 /* How many extra uninteresting commits we want to see.. */
1263 #define SLOP 5
1264
1265 static int still_interesting(struct commit_list *src, timestamp_t date, int slop,
1266                              struct commit **interesting_cache)
1267 {
1268         /*
1269          * No source list at all? We're definitely done..
1270          */
1271         if (!src)
1272                 return 0;
1273
1274         /*
1275          * Does the destination list contain entries with a date
1276          * before the source list? Definitely _not_ done.
1277          */
1278         if (date <= src->item->date)
1279                 return SLOP;
1280
1281         /*
1282          * Does the source list still have interesting commits in
1283          * it? Definitely not done..
1284          */
1285         if (!everybody_uninteresting(src, interesting_cache))
1286                 return SLOP;
1287
1288         /* Ok, we're closing in.. */
1289         return slop-1;
1290 }
1291
1292 /*
1293  * "rev-list --ancestry-path A..B" computes commits that are ancestors
1294  * of B but not ancestors of A but further limits the result to those
1295  * that are descendants of A.  This takes the list of bottom commits and
1296  * the result of "A..B" without --ancestry-path, and limits the latter
1297  * further to the ones that can reach one of the commits in "bottom".
1298  */
1299 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
1300 {
1301         struct commit_list *p;
1302         struct commit_list *rlist = NULL;
1303         int made_progress;
1304
1305         /*
1306          * Reverse the list so that it will be likely that we would
1307          * process parents before children.
1308          */
1309         for (p = list; p; p = p->next)
1310                 commit_list_insert(p->item, &rlist);
1311
1312         for (p = bottom; p; p = p->next)
1313                 p->item->object.flags |= TMP_MARK;
1314
1315         /*
1316          * Mark the ones that can reach bottom commits in "list",
1317          * in a bottom-up fashion.
1318          */
1319         do {
1320                 made_progress = 0;
1321                 for (p = rlist; p; p = p->next) {
1322                         struct commit *c = p->item;
1323                         struct commit_list *parents;
1324                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
1325                                 continue;
1326                         for (parents = c->parents;
1327                              parents;
1328                              parents = parents->next) {
1329                                 if (!(parents->item->object.flags & TMP_MARK))
1330                                         continue;
1331                                 c->object.flags |= TMP_MARK;
1332                                 made_progress = 1;
1333                                 break;
1334                         }
1335                 }
1336         } while (made_progress);
1337
1338         /*
1339          * NEEDSWORK: decide if we want to remove parents that are
1340          * not marked with TMP_MARK from commit->parents for commits
1341          * in the resulting list.  We may not want to do that, though.
1342          */
1343
1344         /*
1345          * The ones that are not marked with TMP_MARK are uninteresting
1346          */
1347         for (p = list; p; p = p->next) {
1348                 struct commit *c = p->item;
1349                 if (c->object.flags & TMP_MARK)
1350                         continue;
1351                 c->object.flags |= UNINTERESTING;
1352         }
1353
1354         /* We are done with the TMP_MARK */
1355         for (p = list; p; p = p->next)
1356                 p->item->object.flags &= ~TMP_MARK;
1357         for (p = bottom; p; p = p->next)
1358                 p->item->object.flags &= ~TMP_MARK;
1359         free_commit_list(rlist);
1360 }
1361
1362 /*
1363  * Before walking the history, keep the set of "negative" refs the
1364  * caller has asked to exclude.
1365  *
1366  * This is used to compute "rev-list --ancestry-path A..B", as we need
1367  * to filter the result of "A..B" further to the ones that can actually
1368  * reach A.
1369  */
1370 static struct commit_list *collect_bottom_commits(struct commit_list *list)
1371 {
1372         struct commit_list *elem, *bottom = NULL;
1373         for (elem = list; elem; elem = elem->next)
1374                 if (elem->item->object.flags & BOTTOM)
1375                         commit_list_insert(elem->item, &bottom);
1376         return bottom;
1377 }
1378
1379 /* Assumes either left_only or right_only is set */
1380 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1381 {
1382         struct commit_list *p;
1383
1384         for (p = list; p; p = p->next) {
1385                 struct commit *commit = p->item;
1386
1387                 if (revs->right_only) {
1388                         if (commit->object.flags & SYMMETRIC_LEFT)
1389                                 commit->object.flags |= SHOWN;
1390                 } else  /* revs->left_only is set */
1391                         if (!(commit->object.flags & SYMMETRIC_LEFT))
1392                                 commit->object.flags |= SHOWN;
1393         }
1394 }
1395
1396 static int limit_list(struct rev_info *revs)
1397 {
1398         int slop = SLOP;
1399         timestamp_t date = TIME_MAX;
1400         struct commit_list *list = revs->commits;
1401         struct commit_list *newlist = NULL;
1402         struct commit_list **p = &newlist;
1403         struct commit_list *bottom = NULL;
1404         struct commit *interesting_cache = NULL;
1405
1406         if (revs->ancestry_path) {
1407                 bottom = collect_bottom_commits(list);
1408                 if (!bottom)
1409                         die("--ancestry-path given but there are no bottom commits");
1410         }
1411
1412         while (list) {
1413                 struct commit *commit = pop_commit(&list);
1414                 struct object *obj = &commit->object;
1415                 show_early_output_fn_t show;
1416
1417                 if (commit == interesting_cache)
1418                         interesting_cache = NULL;
1419
1420                 if (revs->max_age != -1 && (commit->date < revs->max_age))
1421                         obj->flags |= UNINTERESTING;
1422                 if (process_parents(revs, commit, &list, NULL) < 0)
1423                         return -1;
1424                 if (obj->flags & UNINTERESTING) {
1425                         mark_parents_uninteresting(commit);
1426                         slop = still_interesting(list, date, slop, &interesting_cache);
1427                         if (slop)
1428                                 continue;
1429                         break;
1430                 }
1431                 if (revs->min_age != -1 && (commit->date > revs->min_age) &&
1432                     !revs->line_level_traverse)
1433                         continue;
1434                 date = commit->date;
1435                 p = &commit_list_insert(commit, p)->next;
1436
1437                 show = show_early_output;
1438                 if (!show)
1439                         continue;
1440
1441                 show(revs, newlist);
1442                 show_early_output = NULL;
1443         }
1444         if (revs->cherry_pick || revs->cherry_mark)
1445                 cherry_pick_list(newlist, revs);
1446
1447         if (revs->left_only || revs->right_only)
1448                 limit_left_right(newlist, revs);
1449
1450         if (bottom) {
1451                 limit_to_ancestry(bottom, newlist);
1452                 free_commit_list(bottom);
1453         }
1454
1455         /*
1456          * Check if any commits have become TREESAME by some of their parents
1457          * becoming UNINTERESTING.
1458          */
1459         if (limiting_can_increase_treesame(revs))
1460                 for (list = newlist; list; list = list->next) {
1461                         struct commit *c = list->item;
1462                         if (c->object.flags & (UNINTERESTING | TREESAME))
1463                                 continue;
1464                         update_treesame(revs, c);
1465                 }
1466
1467         revs->commits = newlist;
1468         return 0;
1469 }
1470
1471 /*
1472  * Add an entry to refs->cmdline with the specified information.
1473  * *name is copied.
1474  */
1475 static void add_rev_cmdline(struct rev_info *revs,
1476                             struct object *item,
1477                             const char *name,
1478                             int whence,
1479                             unsigned flags)
1480 {
1481         struct rev_cmdline_info *info = &revs->cmdline;
1482         unsigned int nr = info->nr;
1483
1484         ALLOC_GROW(info->rev, nr + 1, info->alloc);
1485         info->rev[nr].item = item;
1486         info->rev[nr].name = xstrdup(name);
1487         info->rev[nr].whence = whence;
1488         info->rev[nr].flags = flags;
1489         info->nr++;
1490 }
1491
1492 static void add_rev_cmdline_list(struct rev_info *revs,
1493                                  struct commit_list *commit_list,
1494                                  int whence,
1495                                  unsigned flags)
1496 {
1497         while (commit_list) {
1498                 struct object *object = &commit_list->item->object;
1499                 add_rev_cmdline(revs, object, oid_to_hex(&object->oid),
1500                                 whence, flags);
1501                 commit_list = commit_list->next;
1502         }
1503 }
1504
1505 struct all_refs_cb {
1506         int all_flags;
1507         int warned_bad_reflog;
1508         struct rev_info *all_revs;
1509         const char *name_for_errormsg;
1510         struct worktree *wt;
1511 };
1512
1513 int ref_excluded(struct string_list *ref_excludes, const char *path)
1514 {
1515         struct string_list_item *item;
1516
1517         if (!ref_excludes)
1518                 return 0;
1519         for_each_string_list_item(item, ref_excludes) {
1520                 if (!wildmatch(item->string, path, 0))
1521                         return 1;
1522         }
1523         return 0;
1524 }
1525
1526 static int handle_one_ref(const char *path, const struct object_id *oid,
1527                           int flag, void *cb_data)
1528 {
1529         struct all_refs_cb *cb = cb_data;
1530         struct object *object;
1531
1532         if (ref_excluded(cb->all_revs->ref_excludes, path))
1533             return 0;
1534
1535         object = get_reference(cb->all_revs, path, oid, cb->all_flags);
1536         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1537         add_pending_oid(cb->all_revs, path, oid, cb->all_flags);
1538         return 0;
1539 }
1540
1541 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1542         unsigned flags)
1543 {
1544         cb->all_revs = revs;
1545         cb->all_flags = flags;
1546         revs->rev_input_given = 1;
1547         cb->wt = NULL;
1548 }
1549
1550 void clear_ref_exclusion(struct string_list **ref_excludes_p)
1551 {
1552         if (*ref_excludes_p) {
1553                 string_list_clear(*ref_excludes_p, 0);
1554                 free(*ref_excludes_p);
1555         }
1556         *ref_excludes_p = NULL;
1557 }
1558
1559 void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1560 {
1561         if (!*ref_excludes_p) {
1562                 *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1563                 (*ref_excludes_p)->strdup_strings = 1;
1564         }
1565         string_list_append(*ref_excludes_p, exclude);
1566 }
1567
1568 static void handle_refs(struct ref_store *refs,
1569                         struct rev_info *revs, unsigned flags,
1570                         int (*for_each)(struct ref_store *, each_ref_fn, void *))
1571 {
1572         struct all_refs_cb cb;
1573
1574         if (!refs) {
1575                 /* this could happen with uninitialized submodules */
1576                 return;
1577         }
1578
1579         init_all_refs_cb(&cb, revs, flags);
1580         for_each(refs, handle_one_ref, &cb);
1581 }
1582
1583 static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
1584 {
1585         struct all_refs_cb *cb = cb_data;
1586         if (!is_null_oid(oid)) {
1587                 struct object *o = parse_object(cb->all_revs->repo, oid);
1588                 if (o) {
1589                         o->flags |= cb->all_flags;
1590                         /* ??? CMDLINEFLAGS ??? */
1591                         add_pending_object(cb->all_revs, o, "");
1592                 }
1593                 else if (!cb->warned_bad_reflog) {
1594                         warning("reflog of '%s' references pruned commits",
1595                                 cb->name_for_errormsg);
1596                         cb->warned_bad_reflog = 1;
1597                 }
1598         }
1599 }
1600
1601 static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
1602                 const char *email, timestamp_t timestamp, int tz,
1603                 const char *message, void *cb_data)
1604 {
1605         handle_one_reflog_commit(ooid, cb_data);
1606         handle_one_reflog_commit(noid, cb_data);
1607         return 0;
1608 }
1609
1610 static int handle_one_reflog(const char *refname_in_wt,
1611                              const struct object_id *oid,
1612                              int flag, void *cb_data)
1613 {
1614         struct all_refs_cb *cb = cb_data;
1615         struct strbuf refname = STRBUF_INIT;
1616
1617         cb->warned_bad_reflog = 0;
1618         strbuf_worktree_ref(cb->wt, &refname, refname_in_wt);
1619         cb->name_for_errormsg = refname.buf;
1620         refs_for_each_reflog_ent(get_main_ref_store(the_repository),
1621                                  refname.buf,
1622                                  handle_one_reflog_ent, cb_data);
1623         strbuf_release(&refname);
1624         return 0;
1625 }
1626
1627 static void add_other_reflogs_to_pending(struct all_refs_cb *cb)
1628 {
1629         struct worktree **worktrees, **p;
1630
1631         worktrees = get_worktrees();
1632         for (p = worktrees; *p; p++) {
1633                 struct worktree *wt = *p;
1634
1635                 if (wt->is_current)
1636                         continue;
1637
1638                 cb->wt = wt;
1639                 refs_for_each_reflog(get_worktree_ref_store(wt),
1640                                      handle_one_reflog,
1641                                      cb);
1642         }
1643         free_worktrees(worktrees);
1644 }
1645
1646 void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1647 {
1648         struct all_refs_cb cb;
1649
1650         cb.all_revs = revs;
1651         cb.all_flags = flags;
1652         cb.wt = NULL;
1653         for_each_reflog(handle_one_reflog, &cb);
1654
1655         if (!revs->single_worktree)
1656                 add_other_reflogs_to_pending(&cb);
1657 }
1658
1659 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1660                            struct strbuf *path, unsigned int flags)
1661 {
1662         size_t baselen = path->len;
1663         int i;
1664
1665         if (it->entry_count >= 0) {
1666                 struct tree *tree = lookup_tree(revs->repo, &it->oid);
1667                 tree->object.flags |= flags;
1668                 add_pending_object_with_path(revs, &tree->object, "",
1669                                              040000, path->buf);
1670         }
1671
1672         for (i = 0; i < it->subtree_nr; i++) {
1673                 struct cache_tree_sub *sub = it->down[i];
1674                 strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1675                 add_cache_tree(sub->cache_tree, revs, path, flags);
1676                 strbuf_setlen(path, baselen);
1677         }
1678
1679 }
1680
1681 static void do_add_index_objects_to_pending(struct rev_info *revs,
1682                                             struct index_state *istate,
1683                                             unsigned int flags)
1684 {
1685         int i;
1686
1687         for (i = 0; i < istate->cache_nr; i++) {
1688                 struct cache_entry *ce = istate->cache[i];
1689                 struct blob *blob;
1690
1691                 if (S_ISGITLINK(ce->ce_mode))
1692                         continue;
1693
1694                 blob = lookup_blob(revs->repo, &ce->oid);
1695                 if (!blob)
1696                         die("unable to add index blob to traversal");
1697                 blob->object.flags |= flags;
1698                 add_pending_object_with_path(revs, &blob->object, "",
1699                                              ce->ce_mode, ce->name);
1700         }
1701
1702         if (istate->cache_tree) {
1703                 struct strbuf path = STRBUF_INIT;
1704                 add_cache_tree(istate->cache_tree, revs, &path, flags);
1705                 strbuf_release(&path);
1706         }
1707 }
1708
1709 void add_index_objects_to_pending(struct rev_info *revs, unsigned int flags)
1710 {
1711         struct worktree **worktrees, **p;
1712
1713         repo_read_index(revs->repo);
1714         do_add_index_objects_to_pending(revs, revs->repo->index, flags);
1715
1716         if (revs->single_worktree)
1717                 return;
1718
1719         worktrees = get_worktrees();
1720         for (p = worktrees; *p; p++) {
1721                 struct worktree *wt = *p;
1722                 struct index_state istate = { NULL };
1723
1724                 if (wt->is_current)
1725                         continue; /* current index already taken care of */
1726
1727                 if (read_index_from(&istate,
1728                                     worktree_git_path(wt, "index"),
1729                                     get_worktree_git_dir(wt)) > 0)
1730                         do_add_index_objects_to_pending(revs, &istate, flags);
1731                 discard_index(&istate);
1732         }
1733         free_worktrees(worktrees);
1734 }
1735
1736 struct add_alternate_refs_data {
1737         struct rev_info *revs;
1738         unsigned int flags;
1739 };
1740
1741 static void add_one_alternate_ref(const struct object_id *oid,
1742                                   void *vdata)
1743 {
1744         const char *name = ".alternate";
1745         struct add_alternate_refs_data *data = vdata;
1746         struct object *obj;
1747
1748         obj = get_reference(data->revs, name, oid, data->flags);
1749         add_rev_cmdline(data->revs, obj, name, REV_CMD_REV, data->flags);
1750         add_pending_object(data->revs, obj, name);
1751 }
1752
1753 static void add_alternate_refs_to_pending(struct rev_info *revs,
1754                                           unsigned int flags)
1755 {
1756         struct add_alternate_refs_data data;
1757         data.revs = revs;
1758         data.flags = flags;
1759         for_each_alternate_ref(add_one_alternate_ref, &data);
1760 }
1761
1762 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
1763                             int exclude_parent)
1764 {
1765         struct object_id oid;
1766         struct object *it;
1767         struct commit *commit;
1768         struct commit_list *parents;
1769         int parent_number;
1770         const char *arg = arg_;
1771
1772         if (*arg == '^') {
1773                 flags ^= UNINTERESTING | BOTTOM;
1774                 arg++;
1775         }
1776         if (get_oid_committish(arg, &oid))
1777                 return 0;
1778         while (1) {
1779                 it = get_reference(revs, arg, &oid, 0);
1780                 if (!it && revs->ignore_missing)
1781                         return 0;
1782                 if (it->type != OBJ_TAG)
1783                         break;
1784                 if (!((struct tag*)it)->tagged)
1785                         return 0;
1786                 oidcpy(&oid, &((struct tag*)it)->tagged->oid);
1787         }
1788         if (it->type != OBJ_COMMIT)
1789                 return 0;
1790         commit = (struct commit *)it;
1791         if (exclude_parent &&
1792             exclude_parent > commit_list_count(commit->parents))
1793                 return 0;
1794         for (parents = commit->parents, parent_number = 1;
1795              parents;
1796              parents = parents->next, parent_number++) {
1797                 if (exclude_parent && parent_number != exclude_parent)
1798                         continue;
1799
1800                 it = &parents->item->object;
1801                 it->flags |= flags;
1802                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1803                 add_pending_object(revs, it, arg);
1804         }
1805         return 1;
1806 }
1807
1808 void repo_init_revisions(struct repository *r,
1809                          struct rev_info *revs,
1810                          const char *prefix)
1811 {
1812         memset(revs, 0, sizeof(*revs));
1813
1814         revs->repo = r;
1815         revs->abbrev = DEFAULT_ABBREV;
1816         revs->ignore_merges = -1;
1817         revs->simplify_history = 1;
1818         revs->pruning.repo = r;
1819         revs->pruning.flags.recursive = 1;
1820         revs->pruning.flags.quick = 1;
1821         revs->pruning.add_remove = file_add_remove;
1822         revs->pruning.change = file_change;
1823         revs->pruning.change_fn_data = revs;
1824         revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1825         revs->dense = 1;
1826         revs->prefix = prefix;
1827         revs->max_age = -1;
1828         revs->min_age = -1;
1829         revs->skip_count = -1;
1830         revs->max_count = -1;
1831         revs->max_parents = -1;
1832         revs->expand_tabs_in_log = -1;
1833
1834         revs->commit_format = CMIT_FMT_DEFAULT;
1835         revs->expand_tabs_in_log_default = 8;
1836
1837         init_grep_defaults(revs->repo);
1838         grep_init(&revs->grep_filter, revs->repo, prefix);
1839         revs->grep_filter.status_only = 1;
1840
1841         repo_diff_setup(revs->repo, &revs->diffopt);
1842         if (prefix && !revs->diffopt.prefix) {
1843                 revs->diffopt.prefix = prefix;
1844                 revs->diffopt.prefix_length = strlen(prefix);
1845         }
1846
1847         init_display_notes(&revs->notes_opt);
1848 }
1849
1850 static void add_pending_commit_list(struct rev_info *revs,
1851                                     struct commit_list *commit_list,
1852                                     unsigned int flags)
1853 {
1854         while (commit_list) {
1855                 struct object *object = &commit_list->item->object;
1856                 object->flags |= flags;
1857                 add_pending_object(revs, object, oid_to_hex(&object->oid));
1858                 commit_list = commit_list->next;
1859         }
1860 }
1861
1862 static void prepare_show_merge(struct rev_info *revs)
1863 {
1864         struct commit_list *bases;
1865         struct commit *head, *other;
1866         struct object_id oid;
1867         const char **prune = NULL;
1868         int i, prune_num = 1; /* counting terminating NULL */
1869         struct index_state *istate = revs->repo->index;
1870
1871         if (get_oid("HEAD", &oid))
1872                 die("--merge without HEAD?");
1873         head = lookup_commit_or_die(&oid, "HEAD");
1874         if (get_oid("MERGE_HEAD", &oid))
1875                 die("--merge without MERGE_HEAD?");
1876         other = lookup_commit_or_die(&oid, "MERGE_HEAD");
1877         add_pending_object(revs, &head->object, "HEAD");
1878         add_pending_object(revs, &other->object, "MERGE_HEAD");
1879         bases = get_merge_bases(head, other);
1880         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1881         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1882         free_commit_list(bases);
1883         head->object.flags |= SYMMETRIC_LEFT;
1884
1885         if (!istate->cache_nr)
1886                 repo_read_index(revs->repo);
1887         for (i = 0; i < istate->cache_nr; i++) {
1888                 const struct cache_entry *ce = istate->cache[i];
1889                 if (!ce_stage(ce))
1890                         continue;
1891                 if (ce_path_match(istate, ce, &revs->prune_data, NULL)) {
1892                         prune_num++;
1893                         REALLOC_ARRAY(prune, prune_num);
1894                         prune[prune_num-2] = ce->name;
1895                         prune[prune_num-1] = NULL;
1896                 }
1897                 while ((i+1 < istate->cache_nr) &&
1898                        ce_same_name(ce, istate->cache[i+1]))
1899                         i++;
1900         }
1901         clear_pathspec(&revs->prune_data);
1902         parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1903                        PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1904         revs->limited = 1;
1905 }
1906
1907 static int dotdot_missing(const char *arg, char *dotdot,
1908                           struct rev_info *revs, int symmetric)
1909 {
1910         if (revs->ignore_missing)
1911                 return 0;
1912         /* de-munge so we report the full argument */
1913         *dotdot = '.';
1914         die(symmetric
1915             ? "Invalid symmetric difference expression %s"
1916             : "Invalid revision range %s", arg);
1917 }
1918
1919 static int handle_dotdot_1(const char *arg, char *dotdot,
1920                            struct rev_info *revs, int flags,
1921                            int cant_be_filename,
1922                            struct object_context *a_oc,
1923                            struct object_context *b_oc)
1924 {
1925         const char *a_name, *b_name;
1926         struct object_id a_oid, b_oid;
1927         struct object *a_obj, *b_obj;
1928         unsigned int a_flags, b_flags;
1929         int symmetric = 0;
1930         unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1931         unsigned int oc_flags = GET_OID_COMMITTISH | GET_OID_RECORD_PATH;
1932
1933         a_name = arg;
1934         if (!*a_name)
1935                 a_name = "HEAD";
1936
1937         b_name = dotdot + 2;
1938         if (*b_name == '.') {
1939                 symmetric = 1;
1940                 b_name++;
1941         }
1942         if (!*b_name)
1943                 b_name = "HEAD";
1944
1945         if (get_oid_with_context(revs->repo, a_name, oc_flags, &a_oid, a_oc) ||
1946             get_oid_with_context(revs->repo, b_name, oc_flags, &b_oid, b_oc))
1947                 return -1;
1948
1949         if (!cant_be_filename) {
1950                 *dotdot = '.';
1951                 verify_non_filename(revs->prefix, arg);
1952                 *dotdot = '\0';
1953         }
1954
1955         a_obj = parse_object(revs->repo, &a_oid);
1956         b_obj = parse_object(revs->repo, &b_oid);
1957         if (!a_obj || !b_obj)
1958                 return dotdot_missing(arg, dotdot, revs, symmetric);
1959
1960         if (!symmetric) {
1961                 /* just A..B */
1962                 b_flags = flags;
1963                 a_flags = flags_exclude;
1964         } else {
1965                 /* A...B -- find merge bases between the two */
1966                 struct commit *a, *b;
1967                 struct commit_list *exclude;
1968
1969                 a = lookup_commit_reference(revs->repo, &a_obj->oid);
1970                 b = lookup_commit_reference(revs->repo, &b_obj->oid);
1971                 if (!a || !b)
1972                         return dotdot_missing(arg, dotdot, revs, symmetric);
1973
1974                 exclude = get_merge_bases(a, b);
1975                 add_rev_cmdline_list(revs, exclude, REV_CMD_MERGE_BASE,
1976                                      flags_exclude);
1977                 add_pending_commit_list(revs, exclude, flags_exclude);
1978                 free_commit_list(exclude);
1979
1980                 b_flags = flags;
1981                 a_flags = flags | SYMMETRIC_LEFT;
1982         }
1983
1984         a_obj->flags |= a_flags;
1985         b_obj->flags |= b_flags;
1986         add_rev_cmdline(revs, a_obj, a_name, REV_CMD_LEFT, a_flags);
1987         add_rev_cmdline(revs, b_obj, b_name, REV_CMD_RIGHT, b_flags);
1988         add_pending_object_with_path(revs, a_obj, a_name, a_oc->mode, a_oc->path);
1989         add_pending_object_with_path(revs, b_obj, b_name, b_oc->mode, b_oc->path);
1990         return 0;
1991 }
1992
1993 static int handle_dotdot(const char *arg,
1994                          struct rev_info *revs, int flags,
1995                          int cant_be_filename)
1996 {
1997         struct object_context a_oc, b_oc;
1998         char *dotdot = strstr(arg, "..");
1999         int ret;
2000
2001         if (!dotdot)
2002                 return -1;
2003
2004         memset(&a_oc, 0, sizeof(a_oc));
2005         memset(&b_oc, 0, sizeof(b_oc));
2006
2007         *dotdot = '\0';
2008         ret = handle_dotdot_1(arg, dotdot, revs, flags, cant_be_filename,
2009                               &a_oc, &b_oc);
2010         *dotdot = '.';
2011
2012         free(a_oc.path);
2013         free(b_oc.path);
2014
2015         return ret;
2016 }
2017
2018 static int handle_revision_arg_1(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
2019 {
2020         struct object_context oc;
2021         char *mark;
2022         struct object *object;
2023         struct object_id oid;
2024         int local_flags;
2025         const char *arg = arg_;
2026         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
2027         unsigned get_sha1_flags = GET_OID_RECORD_PATH;
2028
2029         flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
2030
2031         if (!cant_be_filename && !strcmp(arg, "..")) {
2032                 /*
2033                  * Just ".."?  That is not a range but the
2034                  * pathspec for the parent directory.
2035                  */
2036                 return -1;
2037         }
2038
2039         if (!handle_dotdot(arg, revs, flags, revarg_opt))
2040                 return 0;
2041
2042         mark = strstr(arg, "^@");
2043         if (mark && !mark[2]) {
2044                 *mark = 0;
2045                 if (add_parents_only(revs, arg, flags, 0))
2046                         return 0;
2047                 *mark = '^';
2048         }
2049         mark = strstr(arg, "^!");
2050         if (mark && !mark[2]) {
2051                 *mark = 0;
2052                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
2053                         *mark = '^';
2054         }
2055         mark = strstr(arg, "^-");
2056         if (mark) {
2057                 int exclude_parent = 1;
2058
2059                 if (mark[2]) {
2060                         char *end;
2061                         exclude_parent = strtoul(mark + 2, &end, 10);
2062                         if (*end != '\0' || !exclude_parent)
2063                                 return -1;
2064                 }
2065
2066                 *mark = 0;
2067                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
2068                         *mark = '^';
2069         }
2070
2071         local_flags = 0;
2072         if (*arg == '^') {
2073                 local_flags = UNINTERESTING | BOTTOM;
2074                 arg++;
2075         }
2076
2077         if (revarg_opt & REVARG_COMMITTISH)
2078                 get_sha1_flags |= GET_OID_COMMITTISH;
2079
2080         if (get_oid_with_context(revs->repo, arg, get_sha1_flags, &oid, &oc))
2081                 return revs->ignore_missing ? 0 : -1;
2082         if (!cant_be_filename)
2083                 verify_non_filename(revs->prefix, arg);
2084         object = get_reference(revs, arg, &oid, flags ^ local_flags);
2085         if (!object)
2086                 return revs->ignore_missing ? 0 : -1;
2087         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
2088         add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
2089         free(oc.path);
2090         return 0;
2091 }
2092
2093 int handle_revision_arg(const char *arg, struct rev_info *revs, int flags, unsigned revarg_opt)
2094 {
2095         int ret = handle_revision_arg_1(arg, revs, flags, revarg_opt);
2096         if (!ret)
2097                 revs->rev_input_given = 1;
2098         return ret;
2099 }
2100
2101 static void read_pathspec_from_stdin(struct strbuf *sb,
2102                                      struct strvec *prune)
2103 {
2104         while (strbuf_getline(sb, stdin) != EOF)
2105                 strvec_push(prune, sb->buf);
2106 }
2107
2108 static void read_revisions_from_stdin(struct rev_info *revs,
2109                                       struct strvec *prune)
2110 {
2111         struct strbuf sb;
2112         int seen_dashdash = 0;
2113         int save_warning;
2114
2115         save_warning = warn_on_object_refname_ambiguity;
2116         warn_on_object_refname_ambiguity = 0;
2117
2118         strbuf_init(&sb, 1000);
2119         while (strbuf_getline(&sb, stdin) != EOF) {
2120                 int len = sb.len;
2121                 if (!len)
2122                         break;
2123                 if (sb.buf[0] == '-') {
2124                         if (len == 2 && sb.buf[1] == '-') {
2125                                 seen_dashdash = 1;
2126                                 break;
2127                         }
2128                         die("options not supported in --stdin mode");
2129                 }
2130                 if (handle_revision_arg(sb.buf, revs, 0,
2131                                         REVARG_CANNOT_BE_FILENAME))
2132                         die("bad revision '%s'", sb.buf);
2133         }
2134         if (seen_dashdash)
2135                 read_pathspec_from_stdin(&sb, prune);
2136
2137         strbuf_release(&sb);
2138         warn_on_object_refname_ambiguity = save_warning;
2139 }
2140
2141 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
2142 {
2143         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
2144 }
2145
2146 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
2147 {
2148         append_header_grep_pattern(&revs->grep_filter, field, pattern);
2149 }
2150
2151 static void add_message_grep(struct rev_info *revs, const char *pattern)
2152 {
2153         add_grep(revs, pattern, GREP_PATTERN_BODY);
2154 }
2155
2156 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
2157                                int *unkc, const char **unkv,
2158                                const struct setup_revision_opt* opt)
2159 {
2160         const char *arg = argv[0];
2161         const char *optarg;
2162         int argcount;
2163         const unsigned hexsz = the_hash_algo->hexsz;
2164
2165         /* pseudo revision arguments */
2166         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
2167             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
2168             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
2169             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
2170             !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
2171             !strcmp(arg, "--indexed-objects") ||
2172             !strcmp(arg, "--alternate-refs") ||
2173             starts_with(arg, "--exclude=") ||
2174             starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
2175             starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
2176         {
2177                 unkv[(*unkc)++] = arg;
2178                 return 1;
2179         }
2180
2181         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
2182                 revs->max_count = atoi(optarg);
2183                 revs->no_walk = 0;
2184                 return argcount;
2185         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
2186                 revs->skip_count = atoi(optarg);
2187                 return argcount;
2188         } else if ((*arg == '-') && isdigit(arg[1])) {
2189                 /* accept -<digit>, like traditional "head" */
2190                 if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
2191                     revs->max_count < 0)
2192                         die("'%s': not a non-negative integer", arg + 1);
2193                 revs->no_walk = 0;
2194         } else if (!strcmp(arg, "-n")) {
2195                 if (argc <= 1)
2196                         return error("-n requires an argument");
2197                 revs->max_count = atoi(argv[1]);
2198                 revs->no_walk = 0;
2199                 return 2;
2200         } else if (skip_prefix(arg, "-n", &optarg)) {
2201                 revs->max_count = atoi(optarg);
2202                 revs->no_walk = 0;
2203         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
2204                 revs->max_age = atoi(optarg);
2205                 return argcount;
2206         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
2207                 revs->max_age = approxidate(optarg);
2208                 return argcount;
2209         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
2210                 revs->max_age = approxidate(optarg);
2211                 return argcount;
2212         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
2213                 revs->min_age = atoi(optarg);
2214                 return argcount;
2215         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
2216                 revs->min_age = approxidate(optarg);
2217                 return argcount;
2218         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
2219                 revs->min_age = approxidate(optarg);
2220                 return argcount;
2221         } else if (!strcmp(arg, "--first-parent")) {
2222                 revs->first_parent_only = 1;
2223         } else if (!strcmp(arg, "--ancestry-path")) {
2224                 revs->ancestry_path = 1;
2225                 revs->simplify_history = 0;
2226                 revs->limited = 1;
2227         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
2228                 init_reflog_walk(&revs->reflog_info);
2229         } else if (!strcmp(arg, "--default")) {
2230                 if (argc <= 1)
2231                         return error("bad --default argument");
2232                 revs->def = argv[1];
2233                 return 2;
2234         } else if (!strcmp(arg, "--merge")) {
2235                 revs->show_merge = 1;
2236         } else if (!strcmp(arg, "--topo-order")) {
2237                 revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
2238                 revs->topo_order = 1;
2239         } else if (!strcmp(arg, "--simplify-merges")) {
2240                 revs->simplify_merges = 1;
2241                 revs->topo_order = 1;
2242                 revs->rewrite_parents = 1;
2243                 revs->simplify_history = 0;
2244                 revs->limited = 1;
2245         } else if (!strcmp(arg, "--simplify-by-decoration")) {
2246                 revs->simplify_merges = 1;
2247                 revs->topo_order = 1;
2248                 revs->rewrite_parents = 1;
2249                 revs->simplify_history = 0;
2250                 revs->simplify_by_decoration = 1;
2251                 revs->limited = 1;
2252                 revs->prune = 1;
2253         } else if (!strcmp(arg, "--date-order")) {
2254                 revs->sort_order = REV_SORT_BY_COMMIT_DATE;
2255                 revs->topo_order = 1;
2256         } else if (!strcmp(arg, "--author-date-order")) {
2257                 revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
2258                 revs->topo_order = 1;
2259         } else if (!strcmp(arg, "--early-output")) {
2260                 revs->early_output = 100;
2261                 revs->topo_order = 1;
2262         } else if (skip_prefix(arg, "--early-output=", &optarg)) {
2263                 if (strtoul_ui(optarg, 10, &revs->early_output) < 0)
2264                         die("'%s': not a non-negative integer", optarg);
2265                 revs->topo_order = 1;
2266         } else if (!strcmp(arg, "--parents")) {
2267                 revs->rewrite_parents = 1;
2268                 revs->print_parents = 1;
2269         } else if (!strcmp(arg, "--dense")) {
2270                 revs->dense = 1;
2271         } else if (!strcmp(arg, "--sparse")) {
2272                 revs->dense = 0;
2273         } else if (!strcmp(arg, "--in-commit-order")) {
2274                 revs->tree_blobs_in_commit_order = 1;
2275         } else if (!strcmp(arg, "--remove-empty")) {
2276                 revs->remove_empty_trees = 1;
2277         } else if (!strcmp(arg, "--merges")) {
2278                 revs->min_parents = 2;
2279         } else if (!strcmp(arg, "--no-merges")) {
2280                 revs->max_parents = 1;
2281         } else if (skip_prefix(arg, "--min-parents=", &optarg)) {
2282                 revs->min_parents = atoi(optarg);
2283         } else if (!strcmp(arg, "--no-min-parents")) {
2284                 revs->min_parents = 0;
2285         } else if (skip_prefix(arg, "--max-parents=", &optarg)) {
2286                 revs->max_parents = atoi(optarg);
2287         } else if (!strcmp(arg, "--no-max-parents")) {
2288                 revs->max_parents = -1;
2289         } else if (!strcmp(arg, "--boundary")) {
2290                 revs->boundary = 1;
2291         } else if (!strcmp(arg, "--left-right")) {
2292                 revs->left_right = 1;
2293         } else if (!strcmp(arg, "--left-only")) {
2294                 if (revs->right_only)
2295                         die("--left-only is incompatible with --right-only"
2296                             " or --cherry");
2297                 revs->left_only = 1;
2298         } else if (!strcmp(arg, "--right-only")) {
2299                 if (revs->left_only)
2300                         die("--right-only is incompatible with --left-only");
2301                 revs->right_only = 1;
2302         } else if (!strcmp(arg, "--cherry")) {
2303                 if (revs->left_only)
2304                         die("--cherry is incompatible with --left-only");
2305                 revs->cherry_mark = 1;
2306                 revs->right_only = 1;
2307                 revs->max_parents = 1;
2308                 revs->limited = 1;
2309         } else if (!strcmp(arg, "--count")) {
2310                 revs->count = 1;
2311         } else if (!strcmp(arg, "--cherry-mark")) {
2312                 if (revs->cherry_pick)
2313                         die("--cherry-mark is incompatible with --cherry-pick");
2314                 revs->cherry_mark = 1;
2315                 revs->limited = 1; /* needs limit_list() */
2316         } else if (!strcmp(arg, "--cherry-pick")) {
2317                 if (revs->cherry_mark)
2318                         die("--cherry-pick is incompatible with --cherry-mark");
2319                 revs->cherry_pick = 1;
2320                 revs->limited = 1;
2321         } else if (!strcmp(arg, "--objects")) {
2322                 revs->tag_objects = 1;
2323                 revs->tree_objects = 1;
2324                 revs->blob_objects = 1;
2325         } else if (!strcmp(arg, "--objects-edge")) {
2326                 revs->tag_objects = 1;
2327                 revs->tree_objects = 1;
2328                 revs->blob_objects = 1;
2329                 revs->edge_hint = 1;
2330         } else if (!strcmp(arg, "--objects-edge-aggressive")) {
2331                 revs->tag_objects = 1;
2332                 revs->tree_objects = 1;
2333                 revs->blob_objects = 1;
2334                 revs->edge_hint = 1;
2335                 revs->edge_hint_aggressive = 1;
2336         } else if (!strcmp(arg, "--verify-objects")) {
2337                 revs->tag_objects = 1;
2338                 revs->tree_objects = 1;
2339                 revs->blob_objects = 1;
2340                 revs->verify_objects = 1;
2341         } else if (!strcmp(arg, "--unpacked")) {
2342                 revs->unpacked = 1;
2343         } else if (starts_with(arg, "--unpacked=")) {
2344                 die(_("--unpacked=<packfile> no longer supported"));
2345         } else if (!strcmp(arg, "-r")) {
2346                 revs->diff = 1;
2347                 revs->diffopt.flags.recursive = 1;
2348         } else if (!strcmp(arg, "-t")) {
2349                 revs->diff = 1;
2350                 revs->diffopt.flags.recursive = 1;
2351                 revs->diffopt.flags.tree_in_recursive = 1;
2352         } else if (!strcmp(arg, "-m")) {
2353                 /*
2354                  * To "diff-index", "-m" means "match missing", and to the "log"
2355                  * family of commands, it means "show full diff for merges". Set
2356                  * both fields appropriately.
2357                  */
2358                 revs->ignore_merges = 0;
2359                 revs->match_missing = 1;
2360         } else if ((argcount = parse_long_opt("diff-merges", argv, &optarg))) {
2361                 if (!strcmp(optarg, "off")) {
2362                         revs->ignore_merges = 1;
2363                 } else {
2364                         die(_("unknown value for --diff-merges: %s"), optarg);
2365                 }
2366                 return argcount;
2367         } else if (!strcmp(arg, "--no-diff-merges")) {
2368                 revs->ignore_merges = 1;
2369         } else if (!strcmp(arg, "-c")) {
2370                 revs->diff = 1;
2371                 revs->dense_combined_merges = 0;
2372                 revs->combine_merges = 1;
2373         } else if (!strcmp(arg, "--combined-all-paths")) {
2374                 revs->diff = 1;
2375                 revs->combined_all_paths = 1;
2376         } else if (!strcmp(arg, "--cc")) {
2377                 revs->diff = 1;
2378                 revs->dense_combined_merges = 1;
2379                 revs->combine_merges = 1;
2380         } else if (!strcmp(arg, "-v")) {
2381                 revs->verbose_header = 1;
2382         } else if (!strcmp(arg, "--pretty")) {
2383                 revs->verbose_header = 1;
2384                 revs->pretty_given = 1;
2385                 get_commit_format(NULL, revs);
2386         } else if (skip_prefix(arg, "--pretty=", &optarg) ||
2387                    skip_prefix(arg, "--format=", &optarg)) {
2388                 /*
2389                  * Detached form ("--pretty X" as opposed to "--pretty=X")
2390                  * not allowed, since the argument is optional.
2391                  */
2392                 revs->verbose_header = 1;
2393                 revs->pretty_given = 1;
2394                 get_commit_format(optarg, revs);
2395         } else if (!strcmp(arg, "--expand-tabs")) {
2396                 revs->expand_tabs_in_log = 8;
2397         } else if (!strcmp(arg, "--no-expand-tabs")) {
2398                 revs->expand_tabs_in_log = 0;
2399         } else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
2400                 int val;
2401                 if (strtol_i(arg, 10, &val) < 0 || val < 0)
2402                         die("'%s': not a non-negative integer", arg);
2403                 revs->expand_tabs_in_log = val;
2404         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
2405                 enable_default_display_notes(&revs->notes_opt, &revs->show_notes);
2406                 revs->show_notes_given = 1;
2407         } else if (!strcmp(arg, "--show-signature")) {
2408                 revs->show_signature = 1;
2409         } else if (!strcmp(arg, "--no-show-signature")) {
2410                 revs->show_signature = 0;
2411         } else if (!strcmp(arg, "--show-linear-break")) {
2412                 revs->break_bar = "                    ..........";
2413                 revs->track_linear = 1;
2414                 revs->track_first_time = 1;
2415         } else if (skip_prefix(arg, "--show-linear-break=", &optarg)) {
2416                 revs->break_bar = xstrdup(optarg);
2417                 revs->track_linear = 1;
2418                 revs->track_first_time = 1;
2419         } else if (skip_prefix(arg, "--show-notes=", &optarg) ||
2420                    skip_prefix(arg, "--notes=", &optarg)) {
2421                 if (starts_with(arg, "--show-notes=") &&
2422                     revs->notes_opt.use_default_notes < 0)
2423                         revs->notes_opt.use_default_notes = 1;
2424                 enable_ref_display_notes(&revs->notes_opt, &revs->show_notes, optarg);
2425                 revs->show_notes_given = 1;
2426         } else if (!strcmp(arg, "--no-notes")) {
2427                 disable_display_notes(&revs->notes_opt, &revs->show_notes);
2428                 revs->show_notes_given = 1;
2429         } else if (!strcmp(arg, "--standard-notes")) {
2430                 revs->show_notes_given = 1;
2431                 revs->notes_opt.use_default_notes = 1;
2432         } else if (!strcmp(arg, "--no-standard-notes")) {
2433                 revs->notes_opt.use_default_notes = 0;
2434         } else if (!strcmp(arg, "--oneline")) {
2435                 revs->verbose_header = 1;
2436                 get_commit_format("oneline", revs);
2437                 revs->pretty_given = 1;
2438                 revs->abbrev_commit = 1;
2439         } else if (!strcmp(arg, "--graph")) {
2440                 revs->topo_order = 1;
2441                 revs->rewrite_parents = 1;
2442                 revs->graph = graph_init(revs);
2443         } else if (!strcmp(arg, "--encode-email-headers")) {
2444                 revs->encode_email_headers = 1;
2445         } else if (!strcmp(arg, "--no-encode-email-headers")) {
2446                 revs->encode_email_headers = 0;
2447         } else if (!strcmp(arg, "--root")) {
2448                 revs->show_root_diff = 1;
2449         } else if (!strcmp(arg, "--no-commit-id")) {
2450                 revs->no_commit_id = 1;
2451         } else if (!strcmp(arg, "--always")) {
2452                 revs->always_show_header = 1;
2453         } else if (!strcmp(arg, "--no-abbrev")) {
2454                 revs->abbrev = 0;
2455         } else if (!strcmp(arg, "--abbrev")) {
2456                 revs->abbrev = DEFAULT_ABBREV;
2457         } else if (skip_prefix(arg, "--abbrev=", &optarg)) {
2458                 revs->abbrev = strtoul(optarg, NULL, 10);
2459                 if (revs->abbrev < MINIMUM_ABBREV)
2460                         revs->abbrev = MINIMUM_ABBREV;
2461                 else if (revs->abbrev > hexsz)
2462                         revs->abbrev = hexsz;
2463         } else if (!strcmp(arg, "--abbrev-commit")) {
2464                 revs->abbrev_commit = 1;
2465                 revs->abbrev_commit_given = 1;
2466         } else if (!strcmp(arg, "--no-abbrev-commit")) {
2467                 revs->abbrev_commit = 0;
2468         } else if (!strcmp(arg, "--full-diff")) {
2469                 revs->diff = 1;
2470                 revs->full_diff = 1;
2471         } else if (!strcmp(arg, "--show-pulls")) {
2472                 revs->show_pulls = 1;
2473         } else if (!strcmp(arg, "--full-history")) {
2474                 revs->simplify_history = 0;
2475         } else if (!strcmp(arg, "--relative-date")) {
2476                 revs->date_mode.type = DATE_RELATIVE;
2477                 revs->date_mode_explicit = 1;
2478         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
2479                 parse_date_format(optarg, &revs->date_mode);
2480                 revs->date_mode_explicit = 1;
2481                 return argcount;
2482         } else if (!strcmp(arg, "--log-size")) {
2483                 revs->show_log_size = 1;
2484         }
2485         /*
2486          * Grepping the commit log
2487          */
2488         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
2489                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
2490                 return argcount;
2491         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
2492                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
2493                 return argcount;
2494         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
2495                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
2496                 return argcount;
2497         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
2498                 add_message_grep(revs, optarg);
2499                 return argcount;
2500         } else if (!strcmp(arg, "--grep-debug")) {
2501                 revs->grep_filter.debug = 1;
2502         } else if (!strcmp(arg, "--basic-regexp")) {
2503                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_BRE;
2504         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
2505                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
2506         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
2507                 revs->grep_filter.ignore_case = 1;
2508                 revs->diffopt.pickaxe_opts |= DIFF_PICKAXE_IGNORE_CASE;
2509         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
2510                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
2511         } else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
2512                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_PCRE;
2513         } else if (!strcmp(arg, "--all-match")) {
2514                 revs->grep_filter.all_match = 1;
2515         } else if (!strcmp(arg, "--invert-grep")) {
2516                 revs->invert_grep = 1;
2517         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2518                 if (strcmp(optarg, "none"))
2519                         git_log_output_encoding = xstrdup(optarg);
2520                 else
2521                         git_log_output_encoding = "";
2522                 return argcount;
2523         } else if (!strcmp(arg, "--reverse")) {
2524                 revs->reverse ^= 1;
2525         } else if (!strcmp(arg, "--children")) {
2526                 revs->children.name = "children";
2527                 revs->limited = 1;
2528         } else if (!strcmp(arg, "--ignore-missing")) {
2529                 revs->ignore_missing = 1;
2530         } else if (opt && opt->allow_exclude_promisor_objects &&
2531                    !strcmp(arg, "--exclude-promisor-objects")) {
2532                 if (fetch_if_missing)
2533                         BUG("exclude_promisor_objects can only be used when fetch_if_missing is 0");
2534                 revs->exclude_promisor_objects = 1;
2535         } else {
2536                 int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
2537                 if (!opts)
2538                         unkv[(*unkc)++] = arg;
2539                 return opts;
2540         }
2541         if (revs->graph && revs->track_linear)
2542                 die("--show-linear-break and --graph are incompatible");
2543
2544         return 1;
2545 }
2546
2547 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2548                         const struct option *options,
2549                         const char * const usagestr[])
2550 {
2551         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2552                                     &ctx->cpidx, ctx->out, NULL);
2553         if (n <= 0) {
2554                 error("unknown option `%s'", ctx->argv[0]);
2555                 usage_with_options(usagestr, options);
2556         }
2557         ctx->argv += n;
2558         ctx->argc -= n;
2559 }
2560
2561 static int for_each_bisect_ref(struct ref_store *refs, each_ref_fn fn,
2562                                void *cb_data, const char *term)
2563 {
2564         struct strbuf bisect_refs = STRBUF_INIT;
2565         int status;
2566         strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2567         status = refs_for_each_fullref_in(refs, bisect_refs.buf, fn, cb_data, 0);
2568         strbuf_release(&bisect_refs);
2569         return status;
2570 }
2571
2572 static int for_each_bad_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2573 {
2574         return for_each_bisect_ref(refs, fn, cb_data, term_bad);
2575 }
2576
2577 static int for_each_good_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2578 {
2579         return for_each_bisect_ref(refs, fn, cb_data, term_good);
2580 }
2581
2582 static int handle_revision_pseudo_opt(const char *submodule,
2583                                 struct rev_info *revs,
2584                                 int argc, const char **argv, int *flags)
2585 {
2586         const char *arg = argv[0];
2587         const char *optarg;
2588         struct ref_store *refs;
2589         int argcount;
2590
2591         if (submodule) {
2592                 /*
2593                  * We need some something like get_submodule_worktrees()
2594                  * before we can go through all worktrees of a submodule,
2595                  * .e.g with adding all HEADs from --all, which is not
2596                  * supported right now, so stick to single worktree.
2597                  */
2598                 if (!revs->single_worktree)
2599                         BUG("--single-worktree cannot be used together with submodule");
2600                 refs = get_submodule_ref_store(submodule);
2601         } else
2602                 refs = get_main_ref_store(revs->repo);
2603
2604         /*
2605          * NOTE!
2606          *
2607          * Commands like "git shortlog" will not accept the options below
2608          * unless parse_revision_opt queues them (as opposed to erroring
2609          * out).
2610          *
2611          * When implementing your new pseudo-option, remember to
2612          * register it in the list at the top of handle_revision_opt.
2613          */
2614         if (!strcmp(arg, "--all")) {
2615                 handle_refs(refs, revs, *flags, refs_for_each_ref);
2616                 handle_refs(refs, revs, *flags, refs_head_ref);
2617                 if (!revs->single_worktree) {
2618                         struct all_refs_cb cb;
2619
2620                         init_all_refs_cb(&cb, revs, *flags);
2621                         other_head_refs(handle_one_ref, &cb);
2622                 }
2623                 clear_ref_exclusion(&revs->ref_excludes);
2624         } else if (!strcmp(arg, "--branches")) {
2625                 handle_refs(refs, revs, *flags, refs_for_each_branch_ref);
2626                 clear_ref_exclusion(&revs->ref_excludes);
2627         } else if (!strcmp(arg, "--bisect")) {
2628                 read_bisect_terms(&term_bad, &term_good);
2629                 handle_refs(refs, revs, *flags, for_each_bad_bisect_ref);
2630                 handle_refs(refs, revs, *flags ^ (UNINTERESTING | BOTTOM),
2631                             for_each_good_bisect_ref);
2632                 revs->bisect = 1;
2633         } else if (!strcmp(arg, "--tags")) {
2634                 handle_refs(refs, revs, *flags, refs_for_each_tag_ref);
2635                 clear_ref_exclusion(&revs->ref_excludes);
2636         } else if (!strcmp(arg, "--remotes")) {
2637                 handle_refs(refs, revs, *flags, refs_for_each_remote_ref);
2638                 clear_ref_exclusion(&revs->ref_excludes);
2639         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2640                 struct all_refs_cb cb;
2641                 init_all_refs_cb(&cb, revs, *flags);
2642                 for_each_glob_ref(handle_one_ref, optarg, &cb);
2643                 clear_ref_exclusion(&revs->ref_excludes);
2644                 return argcount;
2645         } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2646                 add_ref_exclusion(&revs->ref_excludes, optarg);
2647                 return argcount;
2648         } else if (skip_prefix(arg, "--branches=", &optarg)) {
2649                 struct all_refs_cb cb;
2650                 init_all_refs_cb(&cb, revs, *flags);
2651                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/heads/", &cb);
2652                 clear_ref_exclusion(&revs->ref_excludes);
2653         } else if (skip_prefix(arg, "--tags=", &optarg)) {
2654                 struct all_refs_cb cb;
2655                 init_all_refs_cb(&cb, revs, *flags);
2656                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/tags/", &cb);
2657                 clear_ref_exclusion(&revs->ref_excludes);
2658         } else if (skip_prefix(arg, "--remotes=", &optarg)) {
2659                 struct all_refs_cb cb;
2660                 init_all_refs_cb(&cb, revs, *flags);
2661                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/remotes/", &cb);
2662                 clear_ref_exclusion(&revs->ref_excludes);
2663         } else if (!strcmp(arg, "--reflog")) {
2664                 add_reflogs_to_pending(revs, *flags);
2665         } else if (!strcmp(arg, "--indexed-objects")) {
2666                 add_index_objects_to_pending(revs, *flags);
2667         } else if (!strcmp(arg, "--alternate-refs")) {
2668                 add_alternate_refs_to_pending(revs, *flags);
2669         } else if (!strcmp(arg, "--not")) {
2670                 *flags ^= UNINTERESTING | BOTTOM;
2671         } else if (!strcmp(arg, "--no-walk")) {
2672                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2673         } else if (skip_prefix(arg, "--no-walk=", &optarg)) {
2674                 /*
2675                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2676                  * not allowed, since the argument is optional.
2677                  */
2678                 if (!strcmp(optarg, "sorted"))
2679                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2680                 else if (!strcmp(optarg, "unsorted"))
2681                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2682                 else
2683                         return error("invalid argument to --no-walk");
2684         } else if (!strcmp(arg, "--do-walk")) {
2685                 revs->no_walk = 0;
2686         } else if (!strcmp(arg, "--single-worktree")) {
2687                 revs->single_worktree = 1;
2688         } else {
2689                 return 0;
2690         }
2691
2692         return 1;
2693 }
2694
2695 static void NORETURN diagnose_missing_default(const char *def)
2696 {
2697         int flags;
2698         const char *refname;
2699
2700         refname = resolve_ref_unsafe(def, 0, NULL, &flags);
2701         if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2702                 die(_("your current branch appears to be broken"));
2703
2704         skip_prefix(refname, "refs/heads/", &refname);
2705         die(_("your current branch '%s' does not have any commits yet"),
2706             refname);
2707 }
2708
2709 /*
2710  * Parse revision information, filling in the "rev_info" structure,
2711  * and removing the used arguments from the argument list.
2712  *
2713  * Returns the number of arguments left that weren't recognized
2714  * (which are also moved to the head of the argument list)
2715  */
2716 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2717 {
2718         int i, flags, left, seen_dashdash, revarg_opt;
2719         struct strvec prune_data = STRVEC_INIT;
2720         const char *submodule = NULL;
2721         int seen_end_of_options = 0;
2722
2723         if (opt)
2724                 submodule = opt->submodule;
2725
2726         /* First, search for "--" */
2727         if (opt && opt->assume_dashdash) {
2728                 seen_dashdash = 1;
2729         } else {
2730                 seen_dashdash = 0;
2731                 for (i = 1; i < argc; i++) {
2732                         const char *arg = argv[i];
2733                         if (strcmp(arg, "--"))
2734                                 continue;
2735                         argv[i] = NULL;
2736                         argc = i;
2737                         if (argv[i + 1])
2738                                 strvec_pushv(&prune_data, argv + i + 1);
2739                         seen_dashdash = 1;
2740                         break;
2741                 }
2742         }
2743
2744         /* Second, deal with arguments and options */
2745         flags = 0;
2746         revarg_opt = opt ? opt->revarg_opt : 0;
2747         if (seen_dashdash)
2748                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2749         for (left = i = 1; i < argc; i++) {
2750                 const char *arg = argv[i];
2751                 if (!seen_end_of_options && *arg == '-') {
2752                         int opts;
2753
2754                         opts = handle_revision_pseudo_opt(submodule,
2755                                                 revs, argc - i, argv + i,
2756                                                 &flags);
2757                         if (opts > 0) {
2758                                 i += opts - 1;
2759                                 continue;
2760                         }
2761
2762                         if (!strcmp(arg, "--stdin")) {
2763                                 if (revs->disable_stdin) {
2764                                         argv[left++] = arg;
2765                                         continue;
2766                                 }
2767                                 if (revs->read_from_stdin++)
2768                                         die("--stdin given twice?");
2769                                 read_revisions_from_stdin(revs, &prune_data);
2770                                 continue;
2771                         }
2772
2773                         if (!strcmp(arg, "--end-of-options")) {
2774                                 seen_end_of_options = 1;
2775                                 continue;
2776                         }
2777
2778                         opts = handle_revision_opt(revs, argc - i, argv + i,
2779                                                    &left, argv, opt);
2780                         if (opts > 0) {
2781                                 i += opts - 1;
2782                                 continue;
2783                         }
2784                         if (opts < 0)
2785                                 exit(128);
2786                         continue;
2787                 }
2788
2789
2790                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2791                         int j;
2792                         if (seen_dashdash || *arg == '^')
2793                                 die("bad revision '%s'", arg);
2794
2795                         /* If we didn't have a "--":
2796                          * (1) all filenames must exist;
2797                          * (2) all rev-args must not be interpretable
2798                          *     as a valid filename.
2799                          * but the latter we have checked in the main loop.
2800                          */
2801                         for (j = i; j < argc; j++)
2802                                 verify_filename(revs->prefix, argv[j], j == i);
2803
2804                         strvec_pushv(&prune_data, argv + i);
2805                         break;
2806                 }
2807         }
2808
2809         if (prune_data.nr) {
2810                 /*
2811                  * If we need to introduce the magic "a lone ':' means no
2812                  * pathspec whatsoever", here is the place to do so.
2813                  *
2814                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2815                  *      prune_data.nr = 0;
2816                  *      prune_data.alloc = 0;
2817                  *      free(prune_data.path);
2818                  *      prune_data.path = NULL;
2819                  * } else {
2820                  *      terminate prune_data.alloc with NULL and
2821                  *      call init_pathspec() to set revs->prune_data here.
2822                  * }
2823                  */
2824                 parse_pathspec(&revs->prune_data, 0, 0,
2825                                revs->prefix, prune_data.v);
2826         }
2827         strvec_clear(&prune_data);
2828
2829         if (revs->def == NULL)
2830                 revs->def = opt ? opt->def : NULL;
2831         if (opt && opt->tweak)
2832                 opt->tweak(revs, opt);
2833         if (revs->show_merge)
2834                 prepare_show_merge(revs);
2835         if (revs->def && !revs->pending.nr && !revs->rev_input_given) {
2836                 struct object_id oid;
2837                 struct object *object;
2838                 struct object_context oc;
2839                 if (get_oid_with_context(revs->repo, revs->def, 0, &oid, &oc))
2840                         diagnose_missing_default(revs->def);
2841                 object = get_reference(revs, revs->def, &oid, 0);
2842                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2843         }
2844
2845         /* Did the user ask for any diff output? Run the diff! */
2846         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2847                 revs->diff = 1;
2848
2849         /* Pickaxe, diff-filter and rename following need diffs */
2850         if ((revs->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
2851             revs->diffopt.filter ||
2852             revs->diffopt.flags.follow_renames)
2853                 revs->diff = 1;
2854
2855         if (revs->diffopt.objfind)
2856                 revs->simplify_history = 0;
2857
2858         if (revs->line_level_traverse) {
2859                 if (want_ancestry(revs))
2860                         revs->limited = 1;
2861                 revs->topo_order = 1;
2862         }
2863
2864         if (revs->topo_order && !generation_numbers_enabled(the_repository))
2865                 revs->limited = 1;
2866
2867         if (revs->prune_data.nr) {
2868                 copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2869                 /* Can't prune commits with rename following: the paths change.. */
2870                 if (!revs->diffopt.flags.follow_renames)
2871                         revs->prune = 1;
2872                 if (!revs->full_diff)
2873                         copy_pathspec(&revs->diffopt.pathspec,
2874                                       &revs->prune_data);
2875         }
2876         if (revs->combine_merges && revs->ignore_merges < 0)
2877                 revs->ignore_merges = 0;
2878         if (revs->ignore_merges < 0)
2879                 revs->ignore_merges = 1;
2880         if (revs->combined_all_paths && !revs->combine_merges)
2881                 die("--combined-all-paths makes no sense without -c or --cc");
2882
2883         revs->diffopt.abbrev = revs->abbrev;
2884
2885         diff_setup_done(&revs->diffopt);
2886
2887         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2888                                  &revs->grep_filter);
2889         if (!is_encoding_utf8(get_log_output_encoding()))
2890                 revs->grep_filter.ignore_locale = 1;
2891         compile_grep_patterns(&revs->grep_filter);
2892
2893         if (revs->reverse && revs->reflog_info)
2894                 die("cannot combine --reverse with --walk-reflogs");
2895         if (revs->reflog_info && revs->limited)
2896                 die("cannot combine --walk-reflogs with history-limiting options");
2897         if (revs->rewrite_parents && revs->children.name)
2898                 die("cannot combine --parents and --children");
2899
2900         /*
2901          * Limitations on the graph functionality
2902          */
2903         if (revs->reverse && revs->graph)
2904                 die("cannot combine --reverse with --graph");
2905
2906         if (revs->reflog_info && revs->graph)
2907                 die("cannot combine --walk-reflogs with --graph");
2908         if (revs->no_walk && revs->graph)
2909                 die("cannot combine --no-walk with --graph");
2910         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2911                 die("cannot use --grep-reflog without --walk-reflogs");
2912
2913         if (revs->line_level_traverse &&
2914             (revs->diffopt.output_format & ~(DIFF_FORMAT_PATCH | DIFF_FORMAT_NO_OUTPUT)))
2915                 die(_("-L does not yet support diff formats besides -p and -s"));
2916
2917         if (revs->expand_tabs_in_log < 0)
2918                 revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
2919
2920         return left;
2921 }
2922
2923 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2924 {
2925         struct commit_list *l = xcalloc(1, sizeof(*l));
2926
2927         l->item = child;
2928         l->next = add_decoration(&revs->children, &parent->object, l);
2929 }
2930
2931 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2932 {
2933         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2934         struct commit_list **pp, *p;
2935         int surviving_parents;
2936
2937         /* Examine existing parents while marking ones we have seen... */
2938         pp = &commit->parents;
2939         surviving_parents = 0;
2940         while ((p = *pp) != NULL) {
2941                 struct commit *parent = p->item;
2942                 if (parent->object.flags & TMP_MARK) {
2943                         *pp = p->next;
2944                         if (ts)
2945                                 compact_treesame(revs, commit, surviving_parents);
2946                         continue;
2947                 }
2948                 parent->object.flags |= TMP_MARK;
2949                 surviving_parents++;
2950                 pp = &p->next;
2951         }
2952         /* clear the temporary mark */
2953         for (p = commit->parents; p; p = p->next) {
2954                 p->item->object.flags &= ~TMP_MARK;
2955         }
2956         /* no update_treesame() - removing duplicates can't affect TREESAME */
2957         return surviving_parents;
2958 }
2959
2960 struct merge_simplify_state {
2961         struct commit *simplified;
2962 };
2963
2964 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2965 {
2966         struct merge_simplify_state *st;
2967
2968         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2969         if (!st) {
2970                 st = xcalloc(1, sizeof(*st));
2971                 add_decoration(&revs->merge_simplification, &commit->object, st);
2972         }
2973         return st;
2974 }
2975
2976 static int mark_redundant_parents(struct commit *commit)
2977 {
2978         struct commit_list *h = reduce_heads(commit->parents);
2979         int i = 0, marked = 0;
2980         struct commit_list *po, *pn;
2981
2982         /* Want these for sanity-checking only */
2983         int orig_cnt = commit_list_count(commit->parents);
2984         int cnt = commit_list_count(h);
2985
2986         /*
2987          * Not ready to remove items yet, just mark them for now, based
2988          * on the output of reduce_heads(). reduce_heads outputs the reduced
2989          * set in its original order, so this isn't too hard.
2990          */
2991         po = commit->parents;
2992         pn = h;
2993         while (po) {
2994                 if (pn && po->item == pn->item) {
2995                         pn = pn->next;
2996                         i++;
2997                 } else {
2998                         po->item->object.flags |= TMP_MARK;
2999                         marked++;
3000                 }
3001                 po=po->next;
3002         }
3003
3004         if (i != cnt || cnt+marked != orig_cnt)
3005                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
3006
3007         free_commit_list(h);
3008
3009         return marked;
3010 }
3011
3012 static int mark_treesame_root_parents(struct commit *commit)
3013 {
3014         struct commit_list *p;
3015         int marked = 0;
3016
3017         for (p = commit->parents; p; p = p->next) {
3018                 struct commit *parent = p->item;
3019                 if (!parent->parents && (parent->object.flags & TREESAME)) {
3020                         parent->object.flags |= TMP_MARK;
3021                         marked++;
3022                 }
3023         }
3024
3025         return marked;
3026 }
3027
3028 /*
3029  * Awkward naming - this means one parent we are TREESAME to.
3030  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
3031  * empty tree). Better name suggestions?
3032  */
3033 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
3034 {
3035         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
3036         struct commit *unmarked = NULL, *marked = NULL;
3037         struct commit_list *p;
3038         unsigned n;
3039
3040         for (p = commit->parents, n = 0; p; p = p->next, n++) {
3041                 if (ts->treesame[n]) {
3042                         if (p->item->object.flags & TMP_MARK) {
3043                                 if (!marked)
3044                                         marked = p->item;
3045                         } else {
3046                                 if (!unmarked) {
3047                                         unmarked = p->item;
3048                                         break;
3049                                 }
3050                         }
3051                 }
3052         }
3053
3054         /*
3055          * If we are TREESAME to a marked-for-deletion parent, but not to any
3056          * unmarked parents, unmark the first TREESAME parent. This is the
3057          * parent that the default simplify_history==1 scan would have followed,
3058          * and it doesn't make sense to omit that path when asking for a
3059          * simplified full history. Retaining it improves the chances of
3060          * understanding odd missed merges that took an old version of a file.
3061          *
3062          * Example:
3063          *
3064          *   I--------*X       A modified the file, but mainline merge X used
3065          *    \       /        "-s ours", so took the version from I. X is
3066          *     `-*A--'         TREESAME to I and !TREESAME to A.
3067          *
3068          * Default log from X would produce "I". Without this check,
3069          * --full-history --simplify-merges would produce "I-A-X", showing
3070          * the merge commit X and that it changed A, but not making clear that
3071          * it had just taken the I version. With this check, the topology above
3072          * is retained.
3073          *
3074          * Note that it is possible that the simplification chooses a different
3075          * TREESAME parent from the default, in which case this test doesn't
3076          * activate, and we _do_ drop the default parent. Example:
3077          *
3078          *   I------X         A modified the file, but it was reverted in B,
3079          *    \    /          meaning mainline merge X is TREESAME to both
3080          *    *A-*B           parents.
3081          *
3082          * Default log would produce "I" by following the first parent;
3083          * --full-history --simplify-merges will produce "I-A-B". But this is a
3084          * reasonable result - it presents a logical full history leading from
3085          * I to X, and X is not an important merge.
3086          */
3087         if (!unmarked && marked) {
3088                 marked->object.flags &= ~TMP_MARK;
3089                 return 1;
3090         }
3091
3092         return 0;
3093 }
3094
3095 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
3096 {
3097         struct commit_list **pp, *p;
3098         int nth_parent, removed = 0;
3099
3100         pp = &commit->parents;
3101         nth_parent = 0;
3102         while ((p = *pp) != NULL) {
3103                 struct commit *parent = p->item;
3104                 if (parent->object.flags & TMP_MARK) {
3105                         parent->object.flags &= ~TMP_MARK;
3106                         *pp = p->next;
3107                         free(p);
3108                         removed++;
3109                         compact_treesame(revs, commit, nth_parent);
3110                         continue;
3111                 }
3112                 pp = &p->next;
3113                 nth_parent++;
3114         }
3115
3116         /* Removing parents can only increase TREESAMEness */
3117         if (removed && !(commit->object.flags & TREESAME))
3118                 update_treesame(revs, commit);
3119
3120         return nth_parent;
3121 }
3122
3123 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
3124 {
3125         struct commit_list *p;
3126         struct commit *parent;
3127         struct merge_simplify_state *st, *pst;
3128         int cnt;
3129
3130         st = locate_simplify_state(revs, commit);
3131
3132         /*
3133          * Have we handled this one?
3134          */
3135         if (st->simplified)
3136                 return tail;
3137
3138         /*
3139          * An UNINTERESTING commit simplifies to itself, so does a
3140          * root commit.  We do not rewrite parents of such commit
3141          * anyway.
3142          */
3143         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
3144                 st->simplified = commit;
3145                 return tail;
3146         }
3147
3148         /*
3149          * Do we know what commit all of our parents that matter
3150          * should be rewritten to?  Otherwise we are not ready to
3151          * rewrite this one yet.
3152          */
3153         for (cnt = 0, p = commit->parents; p; p = p->next) {
3154                 pst = locate_simplify_state(revs, p->item);
3155                 if (!pst->simplified) {
3156                         tail = &commit_list_insert(p->item, tail)->next;
3157                         cnt++;
3158                 }
3159                 if (revs->first_parent_only)
3160                         break;
3161         }
3162         if (cnt) {
3163                 tail = &commit_list_insert(commit, tail)->next;
3164                 return tail;
3165         }
3166
3167         /*
3168          * Rewrite our list of parents. Note that this cannot
3169          * affect our TREESAME flags in any way - a commit is
3170          * always TREESAME to its simplification.
3171          */
3172         for (p = commit->parents; p; p = p->next) {
3173                 pst = locate_simplify_state(revs, p->item);
3174                 p->item = pst->simplified;
3175                 if (revs->first_parent_only)
3176                         break;
3177         }
3178
3179         if (revs->first_parent_only)
3180                 cnt = 1;
3181         else
3182                 cnt = remove_duplicate_parents(revs, commit);
3183
3184         /*
3185          * It is possible that we are a merge and one side branch
3186          * does not have any commit that touches the given paths;
3187          * in such a case, the immediate parent from that branch
3188          * will be rewritten to be the merge base.
3189          *
3190          *      o----X          X: the commit we are looking at;
3191          *     /    /           o: a commit that touches the paths;
3192          * ---o----'
3193          *
3194          * Further, a merge of an independent branch that doesn't
3195          * touch the path will reduce to a treesame root parent:
3196          *
3197          *  ----o----X          X: the commit we are looking at;
3198          *          /           o: a commit that touches the paths;
3199          *         r            r: a root commit not touching the paths
3200          *
3201          * Detect and simplify both cases.
3202          */
3203         if (1 < cnt) {
3204                 int marked = mark_redundant_parents(commit);
3205                 marked += mark_treesame_root_parents(commit);
3206                 if (marked)
3207                         marked -= leave_one_treesame_to_parent(revs, commit);
3208                 if (marked)
3209                         cnt = remove_marked_parents(revs, commit);
3210         }
3211
3212         /*
3213          * A commit simplifies to itself if it is a root, if it is
3214          * UNINTERESTING, if it touches the given paths, or if it is a
3215          * merge and its parents don't simplify to one relevant commit
3216          * (the first two cases are already handled at the beginning of
3217          * this function).
3218          *
3219          * Otherwise, it simplifies to what its sole relevant parent
3220          * simplifies to.
3221          */
3222         if (!cnt ||
3223             (commit->object.flags & UNINTERESTING) ||
3224             !(commit->object.flags & TREESAME) ||
3225             (parent = one_relevant_parent(revs, commit->parents)) == NULL ||
3226             (revs->show_pulls && (commit->object.flags & PULL_MERGE)))
3227                 st->simplified = commit;
3228         else {
3229                 pst = locate_simplify_state(revs, parent);
3230                 st->simplified = pst->simplified;
3231         }
3232         return tail;
3233 }
3234
3235 static void simplify_merges(struct rev_info *revs)
3236 {
3237         struct commit_list *list, *next;
3238         struct commit_list *yet_to_do, **tail;
3239         struct commit *commit;
3240
3241         if (!revs->prune)
3242                 return;
3243
3244         /* feed the list reversed */
3245         yet_to_do = NULL;
3246         for (list = revs->commits; list; list = next) {
3247                 commit = list->item;
3248                 next = list->next;
3249                 /*
3250                  * Do not free(list) here yet; the original list
3251                  * is used later in this function.
3252                  */
3253                 commit_list_insert(commit, &yet_to_do);
3254         }
3255         while (yet_to_do) {
3256                 list = yet_to_do;
3257                 yet_to_do = NULL;
3258                 tail = &yet_to_do;
3259                 while (list) {
3260                         commit = pop_commit(&list);
3261                         tail = simplify_one(revs, commit, tail);
3262                 }
3263         }
3264
3265         /* clean up the result, removing the simplified ones */
3266         list = revs->commits;
3267         revs->commits = NULL;
3268         tail = &revs->commits;
3269         while (list) {
3270                 struct merge_simplify_state *st;
3271
3272                 commit = pop_commit(&list);
3273                 st = locate_simplify_state(revs, commit);
3274                 if (st->simplified == commit)
3275                         tail = &commit_list_insert(commit, tail)->next;
3276         }
3277 }
3278
3279 static void set_children(struct rev_info *revs)
3280 {
3281         struct commit_list *l;
3282         for (l = revs->commits; l; l = l->next) {
3283                 struct commit *commit = l->item;
3284                 struct commit_list *p;
3285
3286                 for (p = commit->parents; p; p = p->next)
3287                         add_child(revs, p->item, commit);
3288         }
3289 }
3290
3291 void reset_revision_walk(void)
3292 {
3293         clear_object_flags(SEEN | ADDED | SHOWN | TOPO_WALK_EXPLORED | TOPO_WALK_INDEGREE);
3294 }
3295
3296 static int mark_uninteresting(const struct object_id *oid,
3297                               struct packed_git *pack,
3298                               uint32_t pos,
3299                               void *cb)
3300 {
3301         struct rev_info *revs = cb;
3302         struct object *o = parse_object(revs->repo, oid);
3303         o->flags |= UNINTERESTING | SEEN;
3304         return 0;
3305 }
3306
3307 define_commit_slab(indegree_slab, int);
3308 define_commit_slab(author_date_slab, timestamp_t);
3309
3310 struct topo_walk_info {
3311         uint32_t min_generation;
3312         struct prio_queue explore_queue;
3313         struct prio_queue indegree_queue;
3314         struct prio_queue topo_queue;
3315         struct indegree_slab indegree;
3316         struct author_date_slab author_date;
3317 };
3318
3319 static inline void test_flag_and_insert(struct prio_queue *q, struct commit *c, int flag)
3320 {
3321         if (c->object.flags & flag)
3322                 return;
3323
3324         c->object.flags |= flag;
3325         prio_queue_put(q, c);
3326 }
3327
3328 static void explore_walk_step(struct rev_info *revs)
3329 {
3330         struct topo_walk_info *info = revs->topo_walk_info;
3331         struct commit_list *p;
3332         struct commit *c = prio_queue_get(&info->explore_queue);
3333
3334         if (!c)
3335                 return;
3336
3337         if (repo_parse_commit_gently(revs->repo, c, 1) < 0)
3338                 return;
3339
3340         if (revs->sort_order == REV_SORT_BY_AUTHOR_DATE)
3341                 record_author_date(&info->author_date, c);
3342
3343         if (revs->max_age != -1 && (c->date < revs->max_age))
3344                 c->object.flags |= UNINTERESTING;
3345
3346         if (process_parents(revs, c, NULL, NULL) < 0)
3347                 return;
3348
3349         if (c->object.flags & UNINTERESTING)
3350                 mark_parents_uninteresting(c);
3351
3352         for (p = c->parents; p; p = p->next)
3353                 test_flag_and_insert(&info->explore_queue, p->item, TOPO_WALK_EXPLORED);
3354 }
3355
3356 static void explore_to_depth(struct rev_info *revs,
3357                              uint32_t gen_cutoff)
3358 {
3359         struct topo_walk_info *info = revs->topo_walk_info;
3360         struct commit *c;
3361         while ((c = prio_queue_peek(&info->explore_queue)) &&
3362                commit_graph_generation(c) >= gen_cutoff)
3363                 explore_walk_step(revs);
3364 }
3365
3366 static void indegree_walk_step(struct rev_info *revs)
3367 {
3368         struct commit_list *p;
3369         struct topo_walk_info *info = revs->topo_walk_info;
3370         struct commit *c = prio_queue_get(&info->indegree_queue);
3371
3372         if (!c)
3373                 return;
3374
3375         if (repo_parse_commit_gently(revs->repo, c, 1) < 0)
3376                 return;
3377
3378         explore_to_depth(revs, commit_graph_generation(c));
3379
3380         for (p = c->parents; p; p = p->next) {
3381                 struct commit *parent = p->item;
3382                 int *pi = indegree_slab_at(&info->indegree, parent);
3383
3384                 if (*pi)
3385                         (*pi)++;
3386                 else
3387                         *pi = 2;
3388
3389                 test_flag_and_insert(&info->indegree_queue, parent, TOPO_WALK_INDEGREE);
3390
3391                 if (revs->first_parent_only)
3392                         return;
3393         }
3394 }
3395
3396 static void compute_indegrees_to_depth(struct rev_info *revs,
3397                                        uint32_t gen_cutoff)
3398 {
3399         struct topo_walk_info *info = revs->topo_walk_info;
3400         struct commit *c;
3401         while ((c = prio_queue_peek(&info->indegree_queue)) &&
3402                commit_graph_generation(c) >= gen_cutoff)
3403                 indegree_walk_step(revs);
3404 }
3405
3406 static void reset_topo_walk(struct rev_info *revs)
3407 {
3408         struct topo_walk_info *info = revs->topo_walk_info;
3409
3410         clear_prio_queue(&info->explore_queue);
3411         clear_prio_queue(&info->indegree_queue);
3412         clear_prio_queue(&info->topo_queue);
3413         clear_indegree_slab(&info->indegree);
3414         clear_author_date_slab(&info->author_date);
3415
3416         FREE_AND_NULL(revs->topo_walk_info);
3417 }
3418
3419 static void init_topo_walk(struct rev_info *revs)
3420 {
3421         struct topo_walk_info *info;
3422         struct commit_list *list;
3423         if (revs->topo_walk_info)
3424                 reset_topo_walk(revs);
3425
3426         revs->topo_walk_info = xmalloc(sizeof(struct topo_walk_info));
3427         info = revs->topo_walk_info;
3428         memset(info, 0, sizeof(struct topo_walk_info));
3429
3430         init_indegree_slab(&info->indegree);
3431         memset(&info->explore_queue, 0, sizeof(info->explore_queue));
3432         memset(&info->indegree_queue, 0, sizeof(info->indegree_queue));
3433         memset(&info->topo_queue, 0, sizeof(info->topo_queue));
3434
3435         switch (revs->sort_order) {
3436         default: /* REV_SORT_IN_GRAPH_ORDER */
3437                 info->topo_queue.compare = NULL;
3438                 break;
3439         case REV_SORT_BY_COMMIT_DATE:
3440                 info->topo_queue.compare = compare_commits_by_commit_date;
3441                 break;
3442         case REV_SORT_BY_AUTHOR_DATE:
3443                 init_author_date_slab(&info->author_date);
3444                 info->topo_queue.compare = compare_commits_by_author_date;
3445                 info->topo_queue.cb_data = &info->author_date;
3446                 break;
3447         }
3448
3449         info->explore_queue.compare = compare_commits_by_gen_then_commit_date;
3450         info->indegree_queue.compare = compare_commits_by_gen_then_commit_date;
3451
3452         info->min_generation = GENERATION_NUMBER_INFINITY;
3453         for (list = revs->commits; list; list = list->next) {
3454                 struct commit *c = list->item;
3455                 uint32_t generation;
3456
3457                 if (repo_parse_commit_gently(revs->repo, c, 1))
3458                         continue;
3459
3460                 test_flag_and_insert(&info->explore_queue, c, TOPO_WALK_EXPLORED);
3461                 test_flag_and_insert(&info->indegree_queue, c, TOPO_WALK_INDEGREE);
3462
3463                 generation = commit_graph_generation(c);
3464                 if (generation < info->min_generation)
3465                         info->min_generation = generation;
3466
3467                 *(indegree_slab_at(&info->indegree, c)) = 1;
3468
3469                 if (revs->sort_order == REV_SORT_BY_AUTHOR_DATE)
3470                         record_author_date(&info->author_date, c);
3471         }
3472         compute_indegrees_to_depth(revs, info->min_generation);
3473
3474         for (list = revs->commits; list; list = list->next) {
3475                 struct commit *c = list->item;
3476
3477                 if (*(indegree_slab_at(&info->indegree, c)) == 1)
3478                         prio_queue_put(&info->topo_queue, c);
3479         }
3480
3481         /*
3482          * This is unfortunate; the initial tips need to be shown
3483          * in the order given from the revision traversal machinery.
3484          */
3485         if (revs->sort_order == REV_SORT_IN_GRAPH_ORDER)
3486                 prio_queue_reverse(&info->topo_queue);
3487 }
3488
3489 static struct commit *next_topo_commit(struct rev_info *revs)
3490 {
3491         struct commit *c;
3492         struct topo_walk_info *info = revs->topo_walk_info;
3493
3494         /* pop next off of topo_queue */
3495         c = prio_queue_get(&info->topo_queue);
3496
3497         if (c)
3498                 *(indegree_slab_at(&info->indegree, c)) = 0;
3499
3500         return c;
3501 }
3502
3503 static void expand_topo_walk(struct rev_info *revs, struct commit *commit)
3504 {
3505         struct commit_list *p;
3506         struct topo_walk_info *info = revs->topo_walk_info;
3507         if (process_parents(revs, commit, NULL, NULL) < 0) {
3508                 if (!revs->ignore_missing_links)
3509                         die("Failed to traverse parents of commit %s",
3510                             oid_to_hex(&commit->object.oid));
3511         }
3512
3513         for (p = commit->parents; p; p = p->next) {
3514                 struct commit *parent = p->item;
3515                 int *pi;
3516                 uint32_t generation;
3517
3518                 if (parent->object.flags & UNINTERESTING)
3519                         continue;
3520
3521                 if (repo_parse_commit_gently(revs->repo, parent, 1) < 0)
3522                         continue;
3523
3524                 generation = commit_graph_generation(parent);
3525                 if (generation < info->min_generation) {
3526                         info->min_generation = generation;
3527                         compute_indegrees_to_depth(revs, info->min_generation);
3528                 }
3529
3530                 pi = indegree_slab_at(&info->indegree, parent);
3531
3532                 (*pi)--;
3533                 if (*pi == 1)
3534                         prio_queue_put(&info->topo_queue, parent);
3535
3536                 if (revs->first_parent_only)
3537                         return;
3538         }
3539 }
3540
3541 int prepare_revision_walk(struct rev_info *revs)
3542 {
3543         int i;
3544         struct object_array old_pending;
3545         struct commit_list **next = &revs->commits;
3546
3547         memcpy(&old_pending, &revs->pending, sizeof(old_pending));
3548         revs->pending.nr = 0;
3549         revs->pending.alloc = 0;
3550         revs->pending.objects = NULL;
3551         for (i = 0; i < old_pending.nr; i++) {
3552                 struct object_array_entry *e = old_pending.objects + i;
3553                 struct commit *commit = handle_commit(revs, e);
3554                 if (commit) {
3555                         if (!(commit->object.flags & SEEN)) {
3556                                 commit->object.flags |= SEEN;
3557                                 next = commit_list_append(commit, next);
3558                         }
3559                 }
3560         }
3561         object_array_clear(&old_pending);
3562
3563         /* Signal whether we need per-parent treesame decoration */
3564         if (revs->simplify_merges ||
3565             (revs->limited && limiting_can_increase_treesame(revs)))
3566                 revs->treesame.name = "treesame";
3567
3568         if (revs->exclude_promisor_objects) {
3569                 for_each_packed_object(mark_uninteresting, revs,
3570                                        FOR_EACH_OBJECT_PROMISOR_ONLY);
3571         }
3572
3573         if (!revs->reflog_info)
3574                 prepare_to_use_bloom_filter(revs);
3575         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
3576                 commit_list_sort_by_date(&revs->commits);
3577         if (revs->no_walk)
3578                 return 0;
3579         if (revs->limited) {
3580                 if (limit_list(revs) < 0)
3581                         return -1;
3582                 if (revs->topo_order)
3583                         sort_in_topological_order(&revs->commits, revs->sort_order);
3584         } else if (revs->topo_order)
3585                 init_topo_walk(revs);
3586         if (revs->line_level_traverse && want_ancestry(revs))
3587                 /*
3588                  * At the moment we can only do line-level log with parent
3589                  * rewriting by performing this expensive pre-filtering step.
3590                  * If parent rewriting is not requested, then we rather
3591                  * perform the line-level log filtering during the regular
3592                  * history traversal.
3593                  */
3594                 line_log_filter(revs);
3595         if (revs->simplify_merges)
3596                 simplify_merges(revs);
3597         if (revs->children.name)
3598                 set_children(revs);
3599
3600         return 0;
3601 }
3602
3603 static enum rewrite_result rewrite_one_1(struct rev_info *revs,
3604                                          struct commit **pp,
3605                                          struct prio_queue *queue)
3606 {
3607         for (;;) {
3608                 struct commit *p = *pp;
3609                 if (!revs->limited)
3610                         if (process_parents(revs, p, NULL, queue) < 0)
3611                                 return rewrite_one_error;
3612                 if (p->object.flags & UNINTERESTING)
3613                         return rewrite_one_ok;
3614                 if (!(p->object.flags & TREESAME))
3615                         return rewrite_one_ok;
3616                 if (!p->parents)
3617                         return rewrite_one_noparents;
3618                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
3619                         return rewrite_one_ok;
3620                 *pp = p;
3621         }
3622 }
3623
3624 static void merge_queue_into_list(struct prio_queue *q, struct commit_list **list)
3625 {
3626         while (q->nr) {
3627                 struct commit *item = prio_queue_peek(q);
3628                 struct commit_list *p = *list;
3629
3630                 if (p && p->item->date >= item->date)
3631                         list = &p->next;
3632                 else {
3633                         p = commit_list_insert(item, list);
3634                         list = &p->next; /* skip newly added item */
3635                         prio_queue_get(q); /* pop item */
3636                 }
3637         }
3638 }
3639
3640 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
3641 {
3642         struct prio_queue queue = { compare_commits_by_commit_date };
3643         enum rewrite_result ret = rewrite_one_1(revs, pp, &queue);
3644         merge_queue_into_list(&queue, &revs->commits);
3645         clear_prio_queue(&queue);
3646         return ret;
3647 }
3648
3649 int rewrite_parents(struct rev_info *revs, struct commit *commit,
3650         rewrite_parent_fn_t rewrite_parent)
3651 {
3652         struct commit_list **pp = &commit->parents;
3653         while (*pp) {
3654                 struct commit_list *parent = *pp;
3655                 switch (rewrite_parent(revs, &parent->item)) {
3656                 case rewrite_one_ok:
3657                         break;
3658                 case rewrite_one_noparents:
3659                         *pp = parent->next;
3660                         continue;
3661                 case rewrite_one_error:
3662                         return -1;
3663                 }
3664                 pp = &parent->next;
3665         }
3666         remove_duplicate_parents(revs, commit);
3667         return 0;
3668 }
3669
3670 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
3671 {
3672         char *person, *endp;
3673         size_t len, namelen, maillen;
3674         const char *name;
3675         const char *mail;
3676         struct ident_split ident;
3677
3678         person = strstr(buf->buf, what);
3679         if (!person)
3680                 return 0;
3681
3682         person += strlen(what);
3683         endp = strchr(person, '\n');
3684         if (!endp)
3685                 return 0;
3686
3687         len = endp - person;
3688
3689         if (split_ident_line(&ident, person, len))
3690                 return 0;
3691
3692         mail = ident.mail_begin;
3693         maillen = ident.mail_end - ident.mail_begin;
3694         name = ident.name_begin;
3695         namelen = ident.name_end - ident.name_begin;
3696
3697         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
3698                 struct strbuf namemail = STRBUF_INIT;
3699
3700                 strbuf_addf(&namemail, "%.*s <%.*s>",
3701                             (int)namelen, name, (int)maillen, mail);
3702
3703                 strbuf_splice(buf, ident.name_begin - buf->buf,
3704                               ident.mail_end - ident.name_begin + 1,
3705                               namemail.buf, namemail.len);
3706
3707                 strbuf_release(&namemail);
3708
3709                 return 1;
3710         }
3711
3712         return 0;
3713 }
3714
3715 static int commit_match(struct commit *commit, struct rev_info *opt)
3716 {
3717         int retval;
3718         const char *encoding;
3719         const char *message;
3720         struct strbuf buf = STRBUF_INIT;
3721
3722         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
3723                 return 1;
3724
3725         /* Prepend "fake" headers as needed */
3726         if (opt->grep_filter.use_reflog_filter) {
3727                 strbuf_addstr(&buf, "reflog ");
3728                 get_reflog_message(&buf, opt->reflog_info);
3729                 strbuf_addch(&buf, '\n');
3730         }
3731
3732         /*
3733          * We grep in the user's output encoding, under the assumption that it
3734          * is the encoding they are most likely to write their grep pattern
3735          * for. In addition, it means we will match the "notes" encoding below,
3736          * so we will not end up with a buffer that has two different encodings
3737          * in it.
3738          */
3739         encoding = get_log_output_encoding();
3740         message = logmsg_reencode(commit, NULL, encoding);
3741
3742         /* Copy the commit to temporary if we are using "fake" headers */
3743         if (buf.len)
3744                 strbuf_addstr(&buf, message);
3745
3746         if (opt->grep_filter.header_list && opt->mailmap) {
3747                 if (!buf.len)
3748                         strbuf_addstr(&buf, message);
3749
3750                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
3751                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
3752         }
3753
3754         /* Append "fake" message parts as needed */
3755         if (opt->show_notes) {
3756                 if (!buf.len)
3757                         strbuf_addstr(&buf, message);
3758                 format_display_notes(&commit->object.oid, &buf, encoding, 1);
3759         }
3760
3761         /*
3762          * Find either in the original commit message, or in the temporary.
3763          * Note that we cast away the constness of "message" here. It is
3764          * const because it may come from the cached commit buffer. That's OK,
3765          * because we know that it is modifiable heap memory, and that while
3766          * grep_buffer may modify it for speed, it will restore any
3767          * changes before returning.
3768          */
3769         if (buf.len)
3770                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
3771         else
3772                 retval = grep_buffer(&opt->grep_filter,
3773                                      (char *)message, strlen(message));
3774         strbuf_release(&buf);
3775         unuse_commit_buffer(commit, message);
3776         return opt->invert_grep ? !retval : retval;
3777 }
3778
3779 static inline int want_ancestry(const struct rev_info *revs)
3780 {
3781         return (revs->rewrite_parents || revs->children.name);
3782 }
3783
3784 /*
3785  * Return a timestamp to be used for --since/--until comparisons for this
3786  * commit, based on the revision options.
3787  */
3788 static timestamp_t comparison_date(const struct rev_info *revs,
3789                                    struct commit *commit)
3790 {
3791         return revs->reflog_info ?
3792                 get_reflog_timestamp(revs->reflog_info) :
3793                 commit->date;
3794 }
3795
3796 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
3797 {
3798         if (commit->object.flags & SHOWN)
3799                 return commit_ignore;
3800         if (revs->unpacked && has_object_pack(&commit->object.oid))
3801                 return commit_ignore;
3802         if (commit->object.flags & UNINTERESTING)
3803                 return commit_ignore;
3804         if (revs->line_level_traverse && !want_ancestry(revs)) {
3805                 /*
3806                  * In case of line-level log with parent rewriting
3807                  * prepare_revision_walk() already took care of all line-level
3808                  * log filtering, and there is nothing left to do here.
3809                  *
3810                  * If parent rewriting was not requested, then this is the
3811                  * place to perform the line-level log filtering.  Notably,
3812                  * this check, though expensive, must come before the other,
3813                  * cheaper filtering conditions, because the tracked line
3814                  * ranges must be adjusted even when the commit will end up
3815                  * being ignored based on other conditions.
3816                  */
3817                 if (!line_log_process_ranges_arbitrary_commit(revs, commit))
3818                         return commit_ignore;
3819         }
3820         if (revs->min_age != -1 &&
3821             comparison_date(revs, commit) > revs->min_age)
3822                         return commit_ignore;
3823         if (revs->min_parents || (revs->max_parents >= 0)) {
3824                 int n = commit_list_count(commit->parents);
3825                 if ((n < revs->min_parents) ||
3826                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
3827                         return commit_ignore;
3828         }
3829         if (!commit_match(commit, revs))
3830                 return commit_ignore;
3831         if (revs->prune && revs->dense) {
3832                 /* Commit without changes? */
3833                 if (commit->object.flags & TREESAME) {
3834                         int n;
3835                         struct commit_list *p;
3836                         /* drop merges unless we want parenthood */
3837                         if (!want_ancestry(revs))
3838                                 return commit_ignore;
3839
3840                         if (revs->show_pulls && (commit->object.flags & PULL_MERGE))
3841                                 return commit_show;
3842
3843                         /*
3844                          * If we want ancestry, then need to keep any merges
3845                          * between relevant commits to tie together topology.
3846                          * For consistency with TREESAME and simplification
3847                          * use "relevant" here rather than just INTERESTING,
3848                          * to treat bottom commit(s) as part of the topology.
3849                          */
3850                         for (n = 0, p = commit->parents; p; p = p->next)
3851                                 if (relevant_commit(p->item))
3852                                         if (++n >= 2)
3853                                                 return commit_show;
3854                         return commit_ignore;
3855                 }
3856         }
3857         return commit_show;
3858 }
3859
3860 define_commit_slab(saved_parents, struct commit_list *);
3861
3862 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3863
3864 /*
3865  * You may only call save_parents() once per commit (this is checked
3866  * for non-root commits).
3867  */
3868 static void save_parents(struct rev_info *revs, struct commit *commit)
3869 {
3870         struct commit_list **pp;
3871
3872         if (!revs->saved_parents_slab) {
3873                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3874                 init_saved_parents(revs->saved_parents_slab);
3875         }
3876
3877         pp = saved_parents_at(revs->saved_parents_slab, commit);
3878
3879         /*
3880          * When walking with reflogs, we may visit the same commit
3881          * several times: once for each appearance in the reflog.
3882          *
3883          * In this case, save_parents() will be called multiple times.
3884          * We want to keep only the first set of parents.  We need to
3885          * store a sentinel value for an empty (i.e., NULL) parent
3886          * list to distinguish it from a not-yet-saved list, however.
3887          */
3888         if (*pp)
3889                 return;
3890         if (commit->parents)
3891                 *pp = copy_commit_list(commit->parents);
3892         else
3893                 *pp = EMPTY_PARENT_LIST;
3894 }
3895
3896 static void free_saved_parents(struct rev_info *revs)
3897 {
3898         if (revs->saved_parents_slab)
3899                 clear_saved_parents(revs->saved_parents_slab);
3900 }
3901
3902 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3903 {
3904         struct commit_list *parents;
3905
3906         if (!revs->saved_parents_slab)
3907                 return commit->parents;
3908
3909         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3910         if (parents == EMPTY_PARENT_LIST)
3911                 return NULL;
3912         return parents;
3913 }
3914
3915 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3916 {
3917         enum commit_action action = get_commit_action(revs, commit);
3918
3919         if (action == commit_show &&
3920             revs->prune && revs->dense && want_ancestry(revs)) {
3921                 /*
3922                  * --full-diff on simplified parents is no good: it
3923                  * will show spurious changes from the commits that
3924                  * were elided.  So we save the parents on the side
3925                  * when --full-diff is in effect.
3926                  */
3927                 if (revs->full_diff)
3928                         save_parents(revs, commit);
3929                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
3930                         return commit_error;
3931         }
3932         return action;
3933 }
3934
3935 static void track_linear(struct rev_info *revs, struct commit *commit)
3936 {
3937         if (revs->track_first_time) {
3938                 revs->linear = 1;
3939                 revs->track_first_time = 0;
3940         } else {
3941                 struct commit_list *p;
3942                 for (p = revs->previous_parents; p; p = p->next)
3943                         if (p->item == NULL || /* first commit */
3944                             oideq(&p->item->object.oid, &commit->object.oid))
3945                                 break;
3946                 revs->linear = p != NULL;
3947         }
3948         if (revs->reverse) {
3949                 if (revs->linear)
3950                         commit->object.flags |= TRACK_LINEAR;
3951         }
3952         free_commit_list(revs->previous_parents);
3953         revs->previous_parents = copy_commit_list(commit->parents);
3954 }
3955
3956 static struct commit *get_revision_1(struct rev_info *revs)
3957 {
3958         while (1) {
3959                 struct commit *commit;
3960
3961                 if (revs->reflog_info)
3962                         commit = next_reflog_entry(revs->reflog_info);
3963                 else if (revs->topo_walk_info)
3964                         commit = next_topo_commit(revs);
3965                 else
3966                         commit = pop_commit(&revs->commits);
3967
3968                 if (!commit)
3969                         return NULL;
3970
3971                 if (revs->reflog_info)
3972                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3973
3974                 /*
3975                  * If we haven't done the list limiting, we need to look at
3976                  * the parents here. We also need to do the date-based limiting
3977                  * that we'd otherwise have done in limit_list().
3978                  */
3979                 if (!revs->limited) {
3980                         if (revs->max_age != -1 &&
3981                             comparison_date(revs, commit) < revs->max_age)
3982                                 continue;
3983
3984                         if (revs->reflog_info)
3985                                 try_to_simplify_commit(revs, commit);
3986                         else if (revs->topo_walk_info)
3987                                 expand_topo_walk(revs, commit);
3988                         else if (process_parents(revs, commit, &revs->commits, NULL) < 0) {
3989                                 if (!revs->ignore_missing_links)
3990                                         die("Failed to traverse parents of commit %s",
3991                                                 oid_to_hex(&commit->object.oid));
3992                         }
3993                 }
3994
3995                 switch (simplify_commit(revs, commit)) {
3996                 case commit_ignore:
3997                         continue;
3998                 case commit_error:
3999                         die("Failed to simplify parents of commit %s",
4000                             oid_to_hex(&commit->object.oid));
4001                 default:
4002                         if (revs->track_linear)
4003                                 track_linear(revs, commit);
4004                         return commit;
4005                 }
4006         }
4007 }
4008
4009 /*
4010  * Return true for entries that have not yet been shown.  (This is an
4011  * object_array_each_func_t.)
4012  */
4013 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
4014 {
4015         return !(entry->item->flags & SHOWN);
4016 }
4017
4018 /*
4019  * If array is on the verge of a realloc, garbage-collect any entries
4020  * that have already been shown to try to free up some space.
4021  */
4022 static void gc_boundary(struct object_array *array)
4023 {
4024         if (array->nr == array->alloc)
4025                 object_array_filter(array, entry_unshown, NULL);
4026 }
4027
4028 static void create_boundary_commit_list(struct rev_info *revs)
4029 {
4030         unsigned i;
4031         struct commit *c;
4032         struct object_array *array = &revs->boundary_commits;
4033         struct object_array_entry *objects = array->objects;
4034
4035         /*
4036          * If revs->commits is non-NULL at this point, an error occurred in
4037          * get_revision_1().  Ignore the error and continue printing the
4038          * boundary commits anyway.  (This is what the code has always
4039          * done.)
4040          */
4041         if (revs->commits) {
4042                 free_commit_list(revs->commits);
4043                 revs->commits = NULL;
4044         }
4045
4046         /*
4047          * Put all of the actual boundary commits from revs->boundary_commits
4048          * into revs->commits
4049          */
4050         for (i = 0; i < array->nr; i++) {
4051                 c = (struct commit *)(objects[i].item);
4052                 if (!c)
4053                         continue;
4054                 if (!(c->object.flags & CHILD_SHOWN))
4055                         continue;
4056                 if (c->object.flags & (SHOWN | BOUNDARY))
4057                         continue;
4058                 c->object.flags |= BOUNDARY;
4059                 commit_list_insert(c, &revs->commits);
4060         }
4061
4062         /*
4063          * If revs->topo_order is set, sort the boundary commits
4064          * in topological order
4065          */
4066         sort_in_topological_order(&revs->commits, revs->sort_order);
4067 }
4068
4069 static struct commit *get_revision_internal(struct rev_info *revs)
4070 {
4071         struct commit *c = NULL;
4072         struct commit_list *l;
4073
4074         if (revs->boundary == 2) {
4075                 /*
4076                  * All of the normal commits have already been returned,
4077                  * and we are now returning boundary commits.
4078                  * create_boundary_commit_list() has populated
4079                  * revs->commits with the remaining commits to return.
4080                  */
4081                 c = pop_commit(&revs->commits);
4082                 if (c)
4083                         c->object.flags |= SHOWN;
4084                 return c;
4085         }
4086
4087         /*
4088          * If our max_count counter has reached zero, then we are done. We
4089          * don't simply return NULL because we still might need to show
4090          * boundary commits. But we want to avoid calling get_revision_1, which
4091          * might do a considerable amount of work finding the next commit only
4092          * for us to throw it away.
4093          *
4094          * If it is non-zero, then either we don't have a max_count at all
4095          * (-1), or it is still counting, in which case we decrement.
4096          */
4097         if (revs->max_count) {
4098                 c = get_revision_1(revs);
4099                 if (c) {
4100                         while (revs->skip_count > 0) {
4101                                 revs->skip_count--;
4102                                 c = get_revision_1(revs);
4103                                 if (!c)
4104                                         break;
4105                         }
4106                 }
4107
4108                 if (revs->max_count > 0)
4109                         revs->max_count--;
4110         }
4111
4112         if (c)
4113                 c->object.flags |= SHOWN;
4114
4115         if (!revs->boundary)
4116                 return c;
4117
4118         if (!c) {
4119                 /*
4120                  * get_revision_1() runs out the commits, and
4121                  * we are done computing the boundaries.
4122                  * switch to boundary commits output mode.
4123                  */
4124                 revs->boundary = 2;
4125
4126                 /*
4127                  * Update revs->commits to contain the list of
4128                  * boundary commits.
4129                  */
4130                 create_boundary_commit_list(revs);
4131
4132                 return get_revision_internal(revs);
4133         }
4134
4135         /*
4136          * boundary commits are the commits that are parents of the
4137          * ones we got from get_revision_1() but they themselves are
4138          * not returned from get_revision_1().  Before returning
4139          * 'c', we need to mark its parents that they could be boundaries.
4140          */
4141
4142         for (l = c->parents; l; l = l->next) {
4143                 struct object *p;
4144                 p = &(l->item->object);
4145                 if (p->flags & (CHILD_SHOWN | SHOWN))
4146                         continue;
4147                 p->flags |= CHILD_SHOWN;
4148                 gc_boundary(&revs->boundary_commits);
4149                 add_object_array(p, NULL, &revs->boundary_commits);
4150         }
4151
4152         return c;
4153 }
4154
4155 struct commit *get_revision(struct rev_info *revs)
4156 {
4157         struct commit *c;
4158         struct commit_list *reversed;
4159
4160         if (revs->reverse) {
4161                 reversed = NULL;
4162                 while ((c = get_revision_internal(revs)))
4163                         commit_list_insert(c, &reversed);
4164                 revs->commits = reversed;
4165                 revs->reverse = 0;
4166                 revs->reverse_output_stage = 1;
4167         }
4168
4169         if (revs->reverse_output_stage) {
4170                 c = pop_commit(&revs->commits);
4171                 if (revs->track_linear)
4172                         revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
4173                 return c;
4174         }
4175
4176         c = get_revision_internal(revs);
4177         if (c && revs->graph)
4178                 graph_update(revs->graph, c);
4179         if (!c) {
4180                 free_saved_parents(revs);
4181                 if (revs->previous_parents) {
4182                         free_commit_list(revs->previous_parents);
4183                         revs->previous_parents = NULL;
4184                 }
4185         }
4186         return c;
4187 }
4188
4189 const char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
4190 {
4191         if (commit->object.flags & BOUNDARY)
4192                 return "-";
4193         else if (commit->object.flags & UNINTERESTING)
4194                 return "^";
4195         else if (commit->object.flags & PATCHSAME)
4196                 return "=";
4197         else if (!revs || revs->left_right) {
4198                 if (commit->object.flags & SYMMETRIC_LEFT)
4199                         return "<";
4200                 else
4201                         return ">";
4202         } else if (revs->graph)
4203                 return "*";
4204         else if (revs->cherry_mark)
4205                 return "+";
4206         return "";
4207 }
4208
4209 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
4210 {
4211         const char *mark = get_revision_mark(revs, commit);
4212         if (!strlen(mark))
4213                 return;
4214         fputs(mark, stdout);
4215         putchar(' ');
4216 }