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