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