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