git-log --author and --committer are not left-anchored by default
[git] / revision.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "refs.h"
8 #include "revision.h"
9 #include <regex.h>
10 #include "grep.h"
11
12 static char *path_name(struct name_path *path, const char *name)
13 {
14         struct name_path *p;
15         char *n, *m;
16         int nlen = strlen(name);
17         int len = nlen + 1;
18
19         for (p = path; p; p = p->up) {
20                 if (p->elem_len)
21                         len += p->elem_len + 1;
22         }
23         n = xmalloc(len);
24         m = n + len - (nlen + 1);
25         strcpy(m, name);
26         for (p = path; p; p = p->up) {
27                 if (p->elem_len) {
28                         m -= p->elem_len + 1;
29                         memcpy(m, p->elem, p->elem_len);
30                         m[p->elem_len] = '/';
31                 }
32         }
33         return n;
34 }
35
36 void add_object(struct object *obj,
37                 struct object_array *p,
38                 struct name_path *path,
39                 const char *name)
40 {
41         add_object_array(obj, path_name(path, name), p);
42 }
43
44 static void mark_blob_uninteresting(struct blob *blob)
45 {
46         if (blob->object.flags & UNINTERESTING)
47                 return;
48         blob->object.flags |= UNINTERESTING;
49 }
50
51 void mark_tree_uninteresting(struct tree *tree)
52 {
53         struct tree_desc desc;
54         struct name_entry entry;
55         struct object *obj = &tree->object;
56
57         if (obj->flags & UNINTERESTING)
58                 return;
59         obj->flags |= UNINTERESTING;
60         if (!has_sha1_file(obj->sha1))
61                 return;
62         if (parse_tree(tree) < 0)
63                 die("bad tree %s", sha1_to_hex(obj->sha1));
64
65         desc.buf = tree->buffer;
66         desc.size = tree->size;
67         while (tree_entry(&desc, &entry)) {
68                 if (S_ISDIR(entry.mode))
69                         mark_tree_uninteresting(lookup_tree(entry.sha1));
70                 else
71                         mark_blob_uninteresting(lookup_blob(entry.sha1));
72         }
73
74         /*
75          * We don't care about the tree any more
76          * after it has been marked uninteresting.
77          */
78         free(tree->buffer);
79         tree->buffer = NULL;
80 }
81
82 void mark_parents_uninteresting(struct commit *commit)
83 {
84         struct commit_list *parents = commit->parents;
85
86         while (parents) {
87                 struct commit *commit = parents->item;
88                 if (!(commit->object.flags & UNINTERESTING)) {
89                         commit->object.flags |= UNINTERESTING;
90
91                         /*
92                          * Normally we haven't parsed the parent
93                          * yet, so we won't have a parent of a parent
94                          * here. However, it may turn out that we've
95                          * reached this commit some other way (where it
96                          * wasn't uninteresting), in which case we need
97                          * to mark its parents recursively too..
98                          */
99                         if (commit->parents)
100                                 mark_parents_uninteresting(commit);
101                 }
102
103                 /*
104                  * A missing commit is ok iff its parent is marked
105                  * uninteresting.
106                  *
107                  * We just mark such a thing parsed, so that when
108                  * it is popped next time around, we won't be trying
109                  * to parse it and get an error.
110                  */
111                 if (!has_sha1_file(commit->object.sha1))
112                         commit->object.parsed = 1;
113                 parents = parents->next;
114         }
115 }
116
117 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
118 {
119         add_object_array(obj, name, &revs->pending);
120 }
121
122 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
123 {
124         struct object *object;
125
126         object = parse_object(sha1);
127         if (!object)
128                 die("bad object %s", name);
129         object->flags |= flags;
130         return object;
131 }
132
133 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
134 {
135         unsigned long flags = object->flags;
136
137         /*
138          * Tag object? Look what it points to..
139          */
140         while (object->type == OBJ_TAG) {
141                 struct tag *tag = (struct tag *) object;
142                 if (revs->tag_objects && !(flags & UNINTERESTING))
143                         add_pending_object(revs, object, tag->tag);
144                 object = parse_object(tag->tagged->sha1);
145                 if (!object)
146                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
147         }
148
149         /*
150          * Commit object? Just return it, we'll do all the complex
151          * reachability crud.
152          */
153         if (object->type == OBJ_COMMIT) {
154                 struct commit *commit = (struct commit *)object;
155                 if (parse_commit(commit) < 0)
156                         die("unable to parse commit %s", name);
157                 if (flags & UNINTERESTING) {
158                         commit->object.flags |= UNINTERESTING;
159                         mark_parents_uninteresting(commit);
160                         revs->limited = 1;
161                 }
162                 return commit;
163         }
164
165         /*
166          * Tree object? Either mark it uniniteresting, or add it
167          * to the list of objects to look at later..
168          */
169         if (object->type == OBJ_TREE) {
170                 struct tree *tree = (struct tree *)object;
171                 if (!revs->tree_objects)
172                         return NULL;
173                 if (flags & UNINTERESTING) {
174                         mark_tree_uninteresting(tree);
175                         return NULL;
176                 }
177                 add_pending_object(revs, object, "");
178                 return NULL;
179         }
180
181         /*
182          * Blob object? You know the drill by now..
183          */
184         if (object->type == OBJ_BLOB) {
185                 struct blob *blob = (struct blob *)object;
186                 if (!revs->blob_objects)
187                         return NULL;
188                 if (flags & UNINTERESTING) {
189                         mark_blob_uninteresting(blob);
190                         return NULL;
191                 }
192                 add_pending_object(revs, object, "");
193                 return NULL;
194         }
195         die("%s is unknown object", name);
196 }
197
198 static int everybody_uninteresting(struct commit_list *orig)
199 {
200         struct commit_list *list = orig;
201         while (list) {
202                 struct commit *commit = list->item;
203                 list = list->next;
204                 if (commit->object.flags & UNINTERESTING)
205                         continue;
206                 return 0;
207         }
208         return 1;
209 }
210
211 static int tree_difference = REV_TREE_SAME;
212
213 static void file_add_remove(struct diff_options *options,
214                     int addremove, unsigned mode,
215                     const unsigned char *sha1,
216                     const char *base, const char *path)
217 {
218         int diff = REV_TREE_DIFFERENT;
219
220         /*
221          * Is it an add of a new file? It means that the old tree
222          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
223          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
224          * (and if it already was "REV_TREE_NEW", we'll keep it
225          * "REV_TREE_NEW" of course).
226          */
227         if (addremove == '+') {
228                 diff = tree_difference;
229                 if (diff != REV_TREE_SAME)
230                         return;
231                 diff = REV_TREE_NEW;
232         }
233         tree_difference = diff;
234 }
235
236 static void file_change(struct diff_options *options,
237                  unsigned old_mode, unsigned new_mode,
238                  const unsigned char *old_sha1,
239                  const unsigned char *new_sha1,
240                  const char *base, const char *path)
241 {
242         tree_difference = REV_TREE_DIFFERENT;
243 }
244
245 int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
246 {
247         if (!t1)
248                 return REV_TREE_NEW;
249         if (!t2)
250                 return REV_TREE_DIFFERENT;
251         tree_difference = REV_TREE_SAME;
252         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
253                            &revs->pruning) < 0)
254                 return REV_TREE_DIFFERENT;
255         return tree_difference;
256 }
257
258 int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
259 {
260         int retval;
261         void *tree;
262         struct tree_desc empty, real;
263
264         if (!t1)
265                 return 0;
266
267         tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
268         if (!tree)
269                 return 0;
270         real.buf = tree;
271
272         empty.buf = "";
273         empty.size = 0;
274
275         tree_difference = 0;
276         retval = diff_tree(&empty, &real, "", &revs->pruning);
277         free(tree);
278
279         return retval >= 0 && !tree_difference;
280 }
281
282 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
283 {
284         struct commit_list **pp, *parent;
285         int tree_changed = 0, tree_same = 0;
286
287         if (!commit->tree)
288                 return;
289
290         if (!commit->parents) {
291                 if (!rev_same_tree_as_empty(revs, commit->tree))
292                         commit->object.flags |= TREECHANGE;
293                 return;
294         }
295
296         pp = &commit->parents;
297         while ((parent = *pp) != NULL) {
298                 struct commit *p = parent->item;
299
300                 parse_commit(p);
301                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
302                 case REV_TREE_SAME:
303                         tree_same = 1;
304                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
305                                 /* Even if a merge with an uninteresting
306                                  * side branch brought the entire change
307                                  * we are interested in, we do not want
308                                  * to lose the other branches of this
309                                  * merge, so we just keep going.
310                                  */
311                                 pp = &parent->next;
312                                 continue;
313                         }
314                         parent->next = NULL;
315                         commit->parents = parent;
316                         return;
317
318                 case REV_TREE_NEW:
319                         if (revs->remove_empty_trees &&
320                             rev_same_tree_as_empty(revs, p->tree)) {
321                                 /* We are adding all the specified
322                                  * paths from this parent, so the
323                                  * history beyond this parent is not
324                                  * interesting.  Remove its parents
325                                  * (they are grandparents for us).
326                                  * IOW, we pretend this parent is a
327                                  * "root" commit.
328                                  */
329                                 parse_commit(p);
330                                 p->parents = NULL;
331                         }
332                 /* fallthrough */
333                 case REV_TREE_DIFFERENT:
334                         tree_changed = 1;
335                         pp = &parent->next;
336                         continue;
337                 }
338                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
339         }
340         if (tree_changed && !tree_same)
341                 commit->object.flags |= TREECHANGE;
342 }
343
344 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
345 {
346         struct commit_list *parent = commit->parents;
347
348         if (commit->object.flags & ADDED)
349                 return;
350         commit->object.flags |= ADDED;
351
352         /*
353          * If the commit is uninteresting, don't try to
354          * prune parents - we want the maximal uninteresting
355          * set.
356          *
357          * Normally we haven't parsed the parent
358          * yet, so we won't have a parent of a parent
359          * here. However, it may turn out that we've
360          * reached this commit some other way (where it
361          * wasn't uninteresting), in which case we need
362          * to mark its parents recursively too..
363          */
364         if (commit->object.flags & UNINTERESTING) {
365                 while (parent) {
366                         struct commit *p = parent->item;
367                         parent = parent->next;
368                         parse_commit(p);
369                         p->object.flags |= UNINTERESTING;
370                         if (p->parents)
371                                 mark_parents_uninteresting(p);
372                         if (p->object.flags & SEEN)
373                                 continue;
374                         p->object.flags |= SEEN;
375                         insert_by_date(p, list);
376                 }
377                 return;
378         }
379
380         /*
381          * Ok, the commit wasn't uninteresting. Try to
382          * simplify the commit history and find the parent
383          * that has no differences in the path set if one exists.
384          */
385         if (revs->prune_fn)
386                 revs->prune_fn(revs, commit);
387
388         if (revs->no_walk)
389                 return;
390
391         parent = commit->parents;
392         while (parent) {
393                 struct commit *p = parent->item;
394
395                 parent = parent->next;
396
397                 parse_commit(p);
398                 if (p->object.flags & SEEN)
399                         continue;
400                 p->object.flags |= SEEN;
401                 insert_by_date(p, list);
402         }
403 }
404
405 static void limit_list(struct rev_info *revs)
406 {
407         struct commit_list *list = revs->commits;
408         struct commit_list *newlist = NULL;
409         struct commit_list **p = &newlist;
410
411         while (list) {
412                 struct commit_list *entry = list;
413                 struct commit *commit = list->item;
414                 struct object *obj = &commit->object;
415
416                 list = list->next;
417                 free(entry);
418
419                 if (revs->max_age != -1 && (commit->date < revs->max_age))
420                         obj->flags |= UNINTERESTING;
421                 if (revs->unpacked &&
422                     has_sha1_pack(obj->sha1, revs->ignore_packed))
423                         obj->flags |= UNINTERESTING;
424                 add_parents_to_list(revs, commit, &list);
425                 if (obj->flags & UNINTERESTING) {
426                         mark_parents_uninteresting(commit);
427                         if (everybody_uninteresting(list))
428                                 break;
429                         continue;
430                 }
431                 if (revs->min_age != -1 && (commit->date > revs->min_age))
432                         continue;
433                 p = &commit_list_insert(commit, p)->next;
434         }
435         if (revs->boundary) {
436                 /* mark the ones that are on the result list first */
437                 for (list = newlist; list; list = list->next) {
438                         struct commit *commit = list->item;
439                         commit->object.flags |= TMP_MARK;
440                 }
441                 for (list = newlist; list; list = list->next) {
442                         struct commit *commit = list->item;
443                         struct object *obj = &commit->object;
444                         struct commit_list *parent;
445                         if (obj->flags & UNINTERESTING)
446                                 continue;
447                         for (parent = commit->parents;
448                              parent;
449                              parent = parent->next) {
450                                 struct commit *pcommit = parent->item;
451                                 if (!(pcommit->object.flags & UNINTERESTING))
452                                         continue;
453                                 pcommit->object.flags |= BOUNDARY;
454                                 if (pcommit->object.flags & TMP_MARK)
455                                         continue;
456                                 pcommit->object.flags |= TMP_MARK;
457                                 p = &commit_list_insert(pcommit, p)->next;
458                         }
459                 }
460                 for (list = newlist; list; list = list->next) {
461                         struct commit *commit = list->item;
462                         commit->object.flags &= ~TMP_MARK;
463                 }
464         }
465         revs->commits = newlist;
466 }
467
468 static int all_flags;
469 static struct rev_info *all_revs;
470
471 static int handle_one_ref(const char *path, const unsigned char *sha1)
472 {
473         struct object *object = get_reference(all_revs, path, sha1, all_flags);
474         add_pending_object(all_revs, object, "");
475         return 0;
476 }
477
478 static void handle_all(struct rev_info *revs, unsigned flags)
479 {
480         all_revs = revs;
481         all_flags = flags;
482         for_each_ref(handle_one_ref);
483 }
484
485 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
486 {
487         unsigned char sha1[20];
488         struct object *it;
489         struct commit *commit;
490         struct commit_list *parents;
491
492         if (*arg == '^') {
493                 flags ^= UNINTERESTING;
494                 arg++;
495         }
496         if (get_sha1(arg, sha1))
497                 return 0;
498         while (1) {
499                 it = get_reference(revs, arg, sha1, 0);
500                 if (it->type != OBJ_TAG)
501                         break;
502                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
503         }
504         if (it->type != OBJ_COMMIT)
505                 return 0;
506         commit = (struct commit *)it;
507         for (parents = commit->parents; parents; parents = parents->next) {
508                 it = &parents->item->object;
509                 it->flags |= flags;
510                 add_pending_object(revs, it, arg);
511         }
512         return 1;
513 }
514
515 void init_revisions(struct rev_info *revs, const char *prefix)
516 {
517         memset(revs, 0, sizeof(*revs));
518
519         revs->abbrev = DEFAULT_ABBREV;
520         revs->ignore_merges = 1;
521         revs->simplify_history = 1;
522         revs->pruning.recursive = 1;
523         revs->pruning.add_remove = file_add_remove;
524         revs->pruning.change = file_change;
525         revs->lifo = 1;
526         revs->dense = 1;
527         revs->prefix = prefix;
528         revs->max_age = -1;
529         revs->min_age = -1;
530         revs->max_count = -1;
531
532         revs->prune_fn = NULL;
533         revs->prune_data = NULL;
534
535         revs->topo_setter = topo_sort_default_setter;
536         revs->topo_getter = topo_sort_default_getter;
537
538         revs->commit_format = CMIT_FMT_DEFAULT;
539
540         diff_setup(&revs->diffopt);
541 }
542
543 static void add_pending_commit_list(struct rev_info *revs,
544                                     struct commit_list *commit_list,
545                                     unsigned int flags)
546 {
547         while (commit_list) {
548                 struct object *object = &commit_list->item->object;
549                 object->flags |= flags;
550                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
551                 commit_list = commit_list->next;
552         }
553 }
554
555 static void prepare_show_merge(struct rev_info *revs)
556 {
557         struct commit_list *bases;
558         struct commit *head, *other;
559         unsigned char sha1[20];
560         const char **prune = NULL;
561         int i, prune_num = 1; /* counting terminating NULL */
562
563         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
564                 die("--merge without HEAD?");
565         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
566                 die("--merge without MERGE_HEAD?");
567         add_pending_object(revs, &head->object, "HEAD");
568         add_pending_object(revs, &other->object, "MERGE_HEAD");
569         bases = get_merge_bases(head, other, 1);
570         while (bases) {
571                 struct commit *it = bases->item;
572                 struct commit_list *n = bases->next;
573                 free(bases);
574                 bases = n;
575                 it->object.flags |= UNINTERESTING;
576                 add_pending_object(revs, &it->object, "(merge-base)");
577         }
578
579         if (!active_nr)
580                 read_cache();
581         for (i = 0; i < active_nr; i++) {
582                 struct cache_entry *ce = active_cache[i];
583                 if (!ce_stage(ce))
584                         continue;
585                 if (ce_path_match(ce, revs->prune_data)) {
586                         prune_num++;
587                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
588                         prune[prune_num-2] = ce->name;
589                         prune[prune_num-1] = NULL;
590                 }
591                 while ((i+1 < active_nr) &&
592                        ce_same_name(ce, active_cache[i+1]))
593                         i++;
594         }
595         revs->prune_data = prune;
596 }
597
598 int handle_revision_arg(const char *arg, struct rev_info *revs,
599                         int flags,
600                         int cant_be_filename)
601 {
602         char *dotdot;
603         struct object *object;
604         unsigned char sha1[20];
605         int local_flags;
606
607         dotdot = strstr(arg, "..");
608         if (dotdot) {
609                 unsigned char from_sha1[20];
610                 const char *next = dotdot + 2;
611                 const char *this = arg;
612                 int symmetric = *next == '.';
613                 unsigned int flags_exclude = flags ^ UNINTERESTING;
614
615                 *dotdot = 0;
616                 next += symmetric;
617
618                 if (!*next)
619                         next = "HEAD";
620                 if (dotdot == arg)
621                         this = "HEAD";
622                 if (!get_sha1(this, from_sha1) &&
623                     !get_sha1(next, sha1)) {
624                         struct commit *a, *b;
625                         struct commit_list *exclude;
626
627                         a = lookup_commit_reference(from_sha1);
628                         b = lookup_commit_reference(sha1);
629                         if (!a || !b) {
630                                 die(symmetric ?
631                                     "Invalid symmetric difference expression %s...%s" :
632                                     "Invalid revision range %s..%s",
633                                     arg, next);
634                         }
635
636                         if (!cant_be_filename) {
637                                 *dotdot = '.';
638                                 verify_non_filename(revs->prefix, arg);
639                         }
640
641                         if (symmetric) {
642                                 exclude = get_merge_bases(a, b, 1);
643                                 add_pending_commit_list(revs, exclude,
644                                                         flags_exclude);
645                                 free_commit_list(exclude);
646                                 a->object.flags |= flags;
647                         } else
648                                 a->object.flags |= flags_exclude;
649                         b->object.flags |= flags;
650                         add_pending_object(revs, &a->object, this);
651                         add_pending_object(revs, &b->object, next);
652                         return 0;
653                 }
654                 *dotdot = '.';
655         }
656         dotdot = strstr(arg, "^@");
657         if (dotdot && !dotdot[2]) {
658                 *dotdot = 0;
659                 if (add_parents_only(revs, arg, flags))
660                         return 0;
661                 *dotdot = '^';
662         }
663         local_flags = 0;
664         if (*arg == '^') {
665                 local_flags = UNINTERESTING;
666                 arg++;
667         }
668         if (get_sha1(arg, sha1))
669                 return -1;
670         if (!cant_be_filename)
671                 verify_non_filename(revs->prefix, arg);
672         object = get_reference(revs, arg, sha1, flags ^ local_flags);
673         add_pending_object(revs, object, arg);
674         return 0;
675 }
676
677 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
678 {
679         char *pat;
680         const char *prefix;
681         int patlen, fldlen;
682
683         if (!revs->header_filter) {
684                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
685                 opt->status_only = 1;
686                 opt->pattern_tail = &(opt->pattern_list);
687                 opt->regflags = REG_NEWLINE;
688                 revs->header_filter = opt;
689         }
690
691         fldlen = strlen(field);
692         patlen = strlen(pattern);
693         pat = xmalloc(patlen + fldlen + 10);
694         prefix = ".*";
695         if (*pattern == '^') {
696                 prefix = "";
697                 pattern++;
698         }
699         sprintf(pat, "^%s %s%s", field, prefix, pattern);
700         append_grep_pattern(revs->header_filter, pat,
701                             "command line", 0, GREP_PATTERN);
702 }
703
704 static void add_message_grep(struct rev_info *revs, const char *pattern)
705 {
706         if (!revs->message_filter) {
707                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
708                 opt->status_only = 1;
709                 opt->pattern_tail = &(opt->pattern_list);
710                 opt->regflags = REG_NEWLINE;
711                 revs->message_filter = opt;
712         }
713         append_grep_pattern(revs->message_filter, pattern,
714                             "command line", 0, GREP_PATTERN);
715 }
716
717 static void add_ignore_packed(struct rev_info *revs, const char *name)
718 {
719         int num = ++revs->num_ignore_packed;
720
721         revs->ignore_packed = xrealloc(revs->ignore_packed,
722                                        sizeof(const char **) * (num + 1));
723         revs->ignore_packed[num-1] = name;
724         revs->ignore_packed[num] = NULL;
725 }
726
727 /*
728  * Parse revision information, filling in the "rev_info" structure,
729  * and removing the used arguments from the argument list.
730  *
731  * Returns the number of arguments left that weren't recognized
732  * (which are also moved to the head of the argument list)
733  */
734 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
735 {
736         int i, flags, seen_dashdash, show_merge;
737         const char **unrecognized = argv + 1;
738         int left = 1;
739
740         /* First, search for "--" */
741         seen_dashdash = 0;
742         for (i = 1; i < argc; i++) {
743                 const char *arg = argv[i];
744                 if (strcmp(arg, "--"))
745                         continue;
746                 argv[i] = NULL;
747                 argc = i;
748                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
749                 seen_dashdash = 1;
750                 break;
751         }
752
753         flags = show_merge = 0;
754         for (i = 1; i < argc; i++) {
755                 const char *arg = argv[i];
756                 if (*arg == '-') {
757                         int opts;
758                         if (!strncmp(arg, "--max-count=", 12)) {
759                                 revs->max_count = atoi(arg + 12);
760                                 continue;
761                         }
762                         /* accept -<digit>, like traditional "head" */
763                         if ((*arg == '-') && isdigit(arg[1])) {
764                                 revs->max_count = atoi(arg + 1);
765                                 continue;
766                         }
767                         if (!strcmp(arg, "-n")) {
768                                 if (argc <= i + 1)
769                                         die("-n requires an argument");
770                                 revs->max_count = atoi(argv[++i]);
771                                 continue;
772                         }
773                         if (!strncmp(arg,"-n",2)) {
774                                 revs->max_count = atoi(arg + 2);
775                                 continue;
776                         }
777                         if (!strncmp(arg, "--max-age=", 10)) {
778                                 revs->max_age = atoi(arg + 10);
779                                 continue;
780                         }
781                         if (!strncmp(arg, "--since=", 8)) {
782                                 revs->max_age = approxidate(arg + 8);
783                                 continue;
784                         }
785                         if (!strncmp(arg, "--after=", 8)) {
786                                 revs->max_age = approxidate(arg + 8);
787                                 continue;
788                         }
789                         if (!strncmp(arg, "--min-age=", 10)) {
790                                 revs->min_age = atoi(arg + 10);
791                                 continue;
792                         }
793                         if (!strncmp(arg, "--before=", 9)) {
794                                 revs->min_age = approxidate(arg + 9);
795                                 continue;
796                         }
797                         if (!strncmp(arg, "--until=", 8)) {
798                                 revs->min_age = approxidate(arg + 8);
799                                 continue;
800                         }
801                         if (!strcmp(arg, "--all")) {
802                                 handle_all(revs, flags);
803                                 continue;
804                         }
805                         if (!strcmp(arg, "--not")) {
806                                 flags ^= UNINTERESTING;
807                                 continue;
808                         }
809                         if (!strcmp(arg, "--default")) {
810                                 if (++i >= argc)
811                                         die("bad --default argument");
812                                 def = argv[i];
813                                 continue;
814                         }
815                         if (!strcmp(arg, "--merge")) {
816                                 show_merge = 1;
817                                 continue;
818                         }
819                         if (!strcmp(arg, "--topo-order")) {
820                                 revs->topo_order = 1;
821                                 continue;
822                         }
823                         if (!strcmp(arg, "--date-order")) {
824                                 revs->lifo = 0;
825                                 revs->topo_order = 1;
826                                 continue;
827                         }
828                         if (!strcmp(arg, "--parents")) {
829                                 revs->parents = 1;
830                                 continue;
831                         }
832                         if (!strcmp(arg, "--dense")) {
833                                 revs->dense = 1;
834                                 continue;
835                         }
836                         if (!strcmp(arg, "--sparse")) {
837                                 revs->dense = 0;
838                                 continue;
839                         }
840                         if (!strcmp(arg, "--remove-empty")) {
841                                 revs->remove_empty_trees = 1;
842                                 continue;
843                         }
844                         if (!strcmp(arg, "--no-merges")) {
845                                 revs->no_merges = 1;
846                                 continue;
847                         }
848                         if (!strcmp(arg, "--boundary")) {
849                                 revs->boundary = 1;
850                                 continue;
851                         }
852                         if (!strcmp(arg, "--objects")) {
853                                 revs->tag_objects = 1;
854                                 revs->tree_objects = 1;
855                                 revs->blob_objects = 1;
856                                 continue;
857                         }
858                         if (!strcmp(arg, "--objects-edge")) {
859                                 revs->tag_objects = 1;
860                                 revs->tree_objects = 1;
861                                 revs->blob_objects = 1;
862                                 revs->edge_hint = 1;
863                                 continue;
864                         }
865                         if (!strcmp(arg, "--unpacked")) {
866                                 revs->unpacked = 1;
867                                 free(revs->ignore_packed);
868                                 revs->ignore_packed = NULL;
869                                 revs->num_ignore_packed = 0;
870                                 continue;
871                         }
872                         if (!strncmp(arg, "--unpacked=", 11)) {
873                                 revs->unpacked = 1;
874                                 add_ignore_packed(revs, arg+11);
875                                 continue;
876                         }
877                         if (!strcmp(arg, "-r")) {
878                                 revs->diff = 1;
879                                 revs->diffopt.recursive = 1;
880                                 continue;
881                         }
882                         if (!strcmp(arg, "-t")) {
883                                 revs->diff = 1;
884                                 revs->diffopt.recursive = 1;
885                                 revs->diffopt.tree_in_recursive = 1;
886                                 continue;
887                         }
888                         if (!strcmp(arg, "-m")) {
889                                 revs->ignore_merges = 0;
890                                 continue;
891                         }
892                         if (!strcmp(arg, "-c")) {
893                                 revs->diff = 1;
894                                 revs->dense_combined_merges = 0;
895                                 revs->combine_merges = 1;
896                                 continue;
897                         }
898                         if (!strcmp(arg, "--cc")) {
899                                 revs->diff = 1;
900                                 revs->dense_combined_merges = 1;
901                                 revs->combine_merges = 1;
902                                 continue;
903                         }
904                         if (!strcmp(arg, "-v")) {
905                                 revs->verbose_header = 1;
906                                 continue;
907                         }
908                         if (!strncmp(arg, "--pretty", 8)) {
909                                 revs->verbose_header = 1;
910                                 revs->commit_format = get_commit_format(arg+8);
911                                 continue;
912                         }
913                         if (!strcmp(arg, "--root")) {
914                                 revs->show_root_diff = 1;
915                                 continue;
916                         }
917                         if (!strcmp(arg, "--no-commit-id")) {
918                                 revs->no_commit_id = 1;
919                                 continue;
920                         }
921                         if (!strcmp(arg, "--always")) {
922                                 revs->always_show_header = 1;
923                                 continue;
924                         }
925                         if (!strcmp(arg, "--no-abbrev")) {
926                                 revs->abbrev = 0;
927                                 continue;
928                         }
929                         if (!strcmp(arg, "--abbrev")) {
930                                 revs->abbrev = DEFAULT_ABBREV;
931                                 continue;
932                         }
933                         if (!strncmp(arg, "--abbrev=", 9)) {
934                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
935                                 if (revs->abbrev < MINIMUM_ABBREV)
936                                         revs->abbrev = MINIMUM_ABBREV;
937                                 else if (revs->abbrev > 40)
938                                         revs->abbrev = 40;
939                                 continue;
940                         }
941                         if (!strcmp(arg, "--abbrev-commit")) {
942                                 revs->abbrev_commit = 1;
943                                 continue;
944                         }
945                         if (!strcmp(arg, "--full-diff")) {
946                                 revs->diff = 1;
947                                 revs->full_diff = 1;
948                                 continue;
949                         }
950                         if (!strcmp(arg, "--full-history")) {
951                                 revs->simplify_history = 0;
952                                 continue;
953                         }
954                         if (!strcmp(arg, "--relative-date")) {
955                                 revs->relative_date = 1;
956                                 continue;
957                         }
958                         if (!strncmp(arg, "--author=", 9)) {
959                                 add_header_grep(revs, "author", arg+9);
960                                 continue;
961                         }
962                         if (!strncmp(arg, "--committer=", 12)) {
963                                 add_header_grep(revs, "committer", arg+12);
964                                 continue;
965                         }
966                         if (!strncmp(arg, "--grep=", 7)) {
967                                 add_message_grep(revs, arg+7);
968                                 continue;
969                         }
970                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
971                         if (opts > 0) {
972                                 revs->diff = 1;
973                                 i += opts - 1;
974                                 continue;
975                         }
976                         *unrecognized++ = arg;
977                         left++;
978                         continue;
979                 }
980
981                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
982                         int j;
983                         if (seen_dashdash || *arg == '^')
984                                 die("bad revision '%s'", arg);
985
986                         /* If we didn't have a "--":
987                          * (1) all filenames must exist;
988                          * (2) all rev-args must not be interpretable
989                          *     as a valid filename.
990                          * but the latter we have checked in the main loop.
991                          */
992                         for (j = i; j < argc; j++)
993                                 verify_filename(revs->prefix, argv[j]);
994
995                         revs->prune_data = get_pathspec(revs->prefix,
996                                                         argv + i);
997                         break;
998                 }
999         }
1000
1001         if (show_merge)
1002                 prepare_show_merge(revs);
1003         if (def && !revs->pending.nr) {
1004                 unsigned char sha1[20];
1005                 struct object *object;
1006                 if (get_sha1(def, sha1))
1007                         die("bad default revision '%s'", def);
1008                 object = get_reference(revs, def, sha1, 0);
1009                 add_pending_object(revs, object, def);
1010         }
1011
1012         if (revs->topo_order || revs->unpacked)
1013                 revs->limited = 1;
1014
1015         if (revs->prune_data) {
1016                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1017                 revs->prune_fn = try_to_simplify_commit;
1018                 if (!revs->full_diff)
1019                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1020         }
1021         if (revs->combine_merges) {
1022                 revs->ignore_merges = 0;
1023                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1024                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1025         }
1026         revs->diffopt.abbrev = revs->abbrev;
1027         if (diff_setup_done(&revs->diffopt) < 0)
1028                 die("diff_setup_done failed");
1029
1030         if (revs->header_filter)
1031                 compile_grep_patterns(revs->header_filter);
1032         if (revs->message_filter)
1033                 compile_grep_patterns(revs->message_filter);
1034
1035         return left;
1036 }
1037
1038 void prepare_revision_walk(struct rev_info *revs)
1039 {
1040         int nr = revs->pending.nr;
1041         struct object_array_entry *list = revs->pending.objects;
1042
1043         revs->pending.nr = 0;
1044         revs->pending.alloc = 0;
1045         revs->pending.objects = NULL;
1046         while (--nr >= 0) {
1047                 struct commit *commit = handle_commit(revs, list->item, list->name);
1048                 if (commit) {
1049                         if (!(commit->object.flags & SEEN)) {
1050                                 commit->object.flags |= SEEN;
1051                                 insert_by_date(commit, &revs->commits);
1052                         }
1053                 }
1054                 list++;
1055         }
1056
1057         if (revs->no_walk)
1058                 return;
1059         if (revs->limited)
1060                 limit_list(revs);
1061         if (revs->topo_order)
1062                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
1063                                              revs->topo_setter,
1064                                              revs->topo_getter);
1065 }
1066
1067 static int rewrite_one(struct rev_info *revs, struct commit **pp)
1068 {
1069         for (;;) {
1070                 struct commit *p = *pp;
1071                 if (!revs->limited)
1072                         add_parents_to_list(revs, p, &revs->commits);
1073                 if (p->parents && p->parents->next)
1074                         return 0;
1075                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
1076                         return 0;
1077                 if (!p->parents)
1078                         return -1;
1079                 *pp = p->parents->item;
1080         }
1081 }
1082
1083 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
1084 {
1085         struct commit_list **pp = &commit->parents;
1086         while (*pp) {
1087                 struct commit_list *parent = *pp;
1088                 if (rewrite_one(revs, &parent->item) < 0) {
1089                         *pp = parent->next;
1090                         continue;
1091                 }
1092                 pp = &parent->next;
1093         }
1094 }
1095
1096 static void mark_boundary_to_show(struct commit *commit)
1097 {
1098         struct commit_list *p = commit->parents;
1099         while (p) {
1100                 commit = p->item;
1101                 p = p->next;
1102                 if (commit->object.flags & BOUNDARY)
1103                         commit->object.flags |= BOUNDARY_SHOW;
1104         }
1105 }
1106
1107 static int commit_match(struct commit *commit, struct rev_info *opt)
1108 {
1109         char *header, *message;
1110         unsigned long header_len, message_len;
1111
1112         if (!opt->header_filter && !opt->message_filter)
1113                 return 1;
1114
1115         header = commit->buffer;
1116         message = strstr(header, "\n\n");
1117         if (message) {
1118                 message += 2;
1119                 header_len = message - header - 1;
1120                 message_len = strlen(message);
1121         }
1122         else {
1123                 header_len = strlen(header);
1124                 message = header;
1125                 message_len = 0;
1126         }
1127
1128         if (opt->header_filter &&
1129             !grep_buffer(opt->header_filter, NULL, header, header_len))
1130                 return 0;
1131
1132         if (opt->message_filter &&
1133             !grep_buffer(opt->message_filter, NULL, message, message_len))
1134                 return 0;
1135
1136         return 1;
1137 }
1138
1139 struct commit *get_revision(struct rev_info *revs)
1140 {
1141         struct commit_list *list = revs->commits;
1142
1143         if (!list)
1144                 return NULL;
1145
1146         /* Check the max_count ... */
1147         switch (revs->max_count) {
1148         case -1:
1149                 break;
1150         case 0:
1151                 return NULL;
1152         default:
1153                 revs->max_count--;
1154         }
1155
1156         do {
1157                 struct commit_list *entry = revs->commits;
1158                 struct commit *commit = entry->item;
1159
1160                 revs->commits = entry->next;
1161                 free(entry);
1162
1163                 /*
1164                  * If we haven't done the list limiting, we need to look at
1165                  * the parents here. We also need to do the date-based limiting
1166                  * that we'd otherwise have done in limit_list().
1167                  */
1168                 if (!revs->limited) {
1169                         if ((revs->unpacked &&
1170                              has_sha1_pack(commit->object.sha1,
1171                                            revs->ignore_packed)) ||
1172                             (revs->max_age != -1 &&
1173                              (commit->date < revs->max_age)))
1174                                 continue;
1175                         add_parents_to_list(revs, commit, &revs->commits);
1176                 }
1177                 if (commit->object.flags & SHOWN)
1178                         continue;
1179
1180                 /* We want to show boundary commits only when their
1181                  * children are shown.  When path-limiter is in effect,
1182                  * rewrite_parents() drops some commits from getting shown,
1183                  * and there is no point showing boundary parents that
1184                  * are not shown.  After rewrite_parents() rewrites the
1185                  * parents of a commit that is shown, we mark the boundary
1186                  * parents with BOUNDARY_SHOW.
1187                  */
1188                 if (commit->object.flags & BOUNDARY_SHOW) {
1189                         commit->object.flags |= SHOWN;
1190                         return commit;
1191                 }
1192                 if (commit->object.flags & UNINTERESTING)
1193                         continue;
1194                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1195                         continue;
1196                 if (revs->no_merges &&
1197                     commit->parents && commit->parents->next)
1198                         continue;
1199                 if (!commit_match(commit, revs))
1200                         continue;
1201                 if (revs->prune_fn && revs->dense) {
1202                         /* Commit without changes? */
1203                         if (!(commit->object.flags & TREECHANGE)) {
1204                                 /* drop merges unless we want parenthood */
1205                                 if (!revs->parents)
1206                                         continue;
1207                                 /* non-merge - always ignore it */
1208                                 if (!commit->parents || !commit->parents->next)
1209                                         continue;
1210                         }
1211                         if (revs->parents)
1212                                 rewrite_parents(revs, commit);
1213                 }
1214                 if (revs->boundary)
1215                         mark_boundary_to_show(commit);
1216                 commit->object.flags |= SHOWN;
1217                 return commit;
1218         } while (revs->commits);
1219         return NULL;
1220 }