git-apply: Documentation typo fix
[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                 add_parents_to_list(revs, commit, &list);
422                 if (obj->flags & UNINTERESTING) {
423                         mark_parents_uninteresting(commit);
424                         if (everybody_uninteresting(list))
425                                 break;
426                         continue;
427                 }
428                 if (revs->min_age != -1 && (commit->date > revs->min_age))
429                         continue;
430                 p = &commit_list_insert(commit, p)->next;
431         }
432         if (revs->boundary) {
433                 /* mark the ones that are on the result list first */
434                 for (list = newlist; list; list = list->next) {
435                         struct commit *commit = list->item;
436                         commit->object.flags |= TMP_MARK;
437                 }
438                 for (list = newlist; list; list = list->next) {
439                         struct commit *commit = list->item;
440                         struct object *obj = &commit->object;
441                         struct commit_list *parent;
442                         if (obj->flags & UNINTERESTING)
443                                 continue;
444                         for (parent = commit->parents;
445                              parent;
446                              parent = parent->next) {
447                                 struct commit *pcommit = parent->item;
448                                 if (!(pcommit->object.flags & UNINTERESTING))
449                                         continue;
450                                 pcommit->object.flags |= BOUNDARY;
451                                 if (pcommit->object.flags & TMP_MARK)
452                                         continue;
453                                 pcommit->object.flags |= TMP_MARK;
454                                 p = &commit_list_insert(pcommit, p)->next;
455                         }
456                 }
457                 for (list = newlist; list; list = list->next) {
458                         struct commit *commit = list->item;
459                         commit->object.flags &= ~TMP_MARK;
460                 }
461         }
462         revs->commits = newlist;
463 }
464
465 static int all_flags;
466 static struct rev_info *all_revs;
467
468 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
469 {
470         struct object *object = get_reference(all_revs, path, sha1, all_flags);
471         add_pending_object(all_revs, object, "");
472         return 0;
473 }
474
475 static void handle_all(struct rev_info *revs, unsigned flags)
476 {
477         all_revs = revs;
478         all_flags = flags;
479         for_each_ref(handle_one_ref, NULL);
480 }
481
482 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
483 {
484         unsigned char sha1[20];
485         struct object *it;
486         struct commit *commit;
487         struct commit_list *parents;
488
489         if (*arg == '^') {
490                 flags ^= UNINTERESTING;
491                 arg++;
492         }
493         if (get_sha1(arg, sha1))
494                 return 0;
495         while (1) {
496                 it = get_reference(revs, arg, sha1, 0);
497                 if (it->type != OBJ_TAG)
498                         break;
499                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
500         }
501         if (it->type != OBJ_COMMIT)
502                 return 0;
503         commit = (struct commit *)it;
504         for (parents = commit->parents; parents; parents = parents->next) {
505                 it = &parents->item->object;
506                 it->flags |= flags;
507                 add_pending_object(revs, it, arg);
508         }
509         return 1;
510 }
511
512 void init_revisions(struct rev_info *revs, const char *prefix)
513 {
514         memset(revs, 0, sizeof(*revs));
515
516         revs->abbrev = DEFAULT_ABBREV;
517         revs->ignore_merges = 1;
518         revs->simplify_history = 1;
519         revs->pruning.recursive = 1;
520         revs->pruning.add_remove = file_add_remove;
521         revs->pruning.change = file_change;
522         revs->lifo = 1;
523         revs->dense = 1;
524         revs->prefix = prefix;
525         revs->max_age = -1;
526         revs->min_age = -1;
527         revs->max_count = -1;
528
529         revs->prune_fn = NULL;
530         revs->prune_data = NULL;
531
532         revs->topo_setter = topo_sort_default_setter;
533         revs->topo_getter = topo_sort_default_getter;
534
535         revs->commit_format = CMIT_FMT_DEFAULT;
536
537         diff_setup(&revs->diffopt);
538 }
539
540 static void add_pending_commit_list(struct rev_info *revs,
541                                     struct commit_list *commit_list,
542                                     unsigned int flags)
543 {
544         while (commit_list) {
545                 struct object *object = &commit_list->item->object;
546                 object->flags |= flags;
547                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
548                 commit_list = commit_list->next;
549         }
550 }
551
552 static void prepare_show_merge(struct rev_info *revs)
553 {
554         struct commit_list *bases;
555         struct commit *head, *other;
556         unsigned char sha1[20];
557         const char **prune = NULL;
558         int i, prune_num = 1; /* counting terminating NULL */
559
560         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
561                 die("--merge without HEAD?");
562         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
563                 die("--merge without MERGE_HEAD?");
564         add_pending_object(revs, &head->object, "HEAD");
565         add_pending_object(revs, &other->object, "MERGE_HEAD");
566         bases = get_merge_bases(head, other, 1);
567         while (bases) {
568                 struct commit *it = bases->item;
569                 struct commit_list *n = bases->next;
570                 free(bases);
571                 bases = n;
572                 it->object.flags |= UNINTERESTING;
573                 add_pending_object(revs, &it->object, "(merge-base)");
574         }
575
576         if (!active_nr)
577                 read_cache();
578         for (i = 0; i < active_nr; i++) {
579                 struct cache_entry *ce = active_cache[i];
580                 if (!ce_stage(ce))
581                         continue;
582                 if (ce_path_match(ce, revs->prune_data)) {
583                         prune_num++;
584                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
585                         prune[prune_num-2] = ce->name;
586                         prune[prune_num-1] = NULL;
587                 }
588                 while ((i+1 < active_nr) &&
589                        ce_same_name(ce, active_cache[i+1]))
590                         i++;
591         }
592         revs->prune_data = prune;
593 }
594
595 int handle_revision_arg(const char *arg, struct rev_info *revs,
596                         int flags,
597                         int cant_be_filename)
598 {
599         char *dotdot;
600         struct object *object;
601         unsigned char sha1[20];
602         int local_flags;
603
604         dotdot = strstr(arg, "..");
605         if (dotdot) {
606                 unsigned char from_sha1[20];
607                 const char *next = dotdot + 2;
608                 const char *this = arg;
609                 int symmetric = *next == '.';
610                 unsigned int flags_exclude = flags ^ UNINTERESTING;
611
612                 *dotdot = 0;
613                 next += symmetric;
614
615                 if (!*next)
616                         next = "HEAD";
617                 if (dotdot == arg)
618                         this = "HEAD";
619                 if (!get_sha1(this, from_sha1) &&
620                     !get_sha1(next, sha1)) {
621                         struct commit *a, *b;
622                         struct commit_list *exclude;
623
624                         a = lookup_commit_reference(from_sha1);
625                         b = lookup_commit_reference(sha1);
626                         if (!a || !b) {
627                                 die(symmetric ?
628                                     "Invalid symmetric difference expression %s...%s" :
629                                     "Invalid revision range %s..%s",
630                                     arg, next);
631                         }
632
633                         if (!cant_be_filename) {
634                                 *dotdot = '.';
635                                 verify_non_filename(revs->prefix, arg);
636                         }
637
638                         if (symmetric) {
639                                 exclude = get_merge_bases(a, b, 1);
640                                 add_pending_commit_list(revs, exclude,
641                                                         flags_exclude);
642                                 free_commit_list(exclude);
643                                 a->object.flags |= flags;
644                         } else
645                                 a->object.flags |= flags_exclude;
646                         b->object.flags |= flags;
647                         add_pending_object(revs, &a->object, this);
648                         add_pending_object(revs, &b->object, next);
649                         return 0;
650                 }
651                 *dotdot = '.';
652         }
653         dotdot = strstr(arg, "^@");
654         if (dotdot && !dotdot[2]) {
655                 *dotdot = 0;
656                 if (add_parents_only(revs, arg, flags))
657                         return 0;
658                 *dotdot = '^';
659         }
660         dotdot = strstr(arg, "^!");
661         if (dotdot && !dotdot[2]) {
662                 *dotdot = 0;
663                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
664                         *dotdot = '^';
665         }
666
667         local_flags = 0;
668         if (*arg == '^') {
669                 local_flags = UNINTERESTING;
670                 arg++;
671         }
672         if (get_sha1(arg, sha1))
673                 return -1;
674         if (!cant_be_filename)
675                 verify_non_filename(revs->prefix, arg);
676         object = get_reference(revs, arg, sha1, flags ^ local_flags);
677         add_pending_object(revs, object, arg);
678         return 0;
679 }
680
681 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
682 {
683         if (!revs->grep_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->grep_filter = opt;
689         }
690         append_grep_pattern(revs->grep_filter, ptn,
691                             "command line", 0, what);
692 }
693
694 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
695 {
696         char *pat;
697         const char *prefix;
698         int patlen, fldlen;
699
700         fldlen = strlen(field);
701         patlen = strlen(pattern);
702         pat = xmalloc(patlen + fldlen + 10);
703         prefix = ".*";
704         if (*pattern == '^') {
705                 prefix = "";
706                 pattern++;
707         }
708         sprintf(pat, "^%s %s%s", field, prefix, pattern);
709         add_grep(revs, pat, GREP_PATTERN_HEAD);
710 }
711
712 static void add_message_grep(struct rev_info *revs, const char *pattern)
713 {
714         add_grep(revs, pattern, GREP_PATTERN_BODY);
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         int all_match = 0;
740
741         /* First, search for "--" */
742         seen_dashdash = 0;
743         for (i = 1; i < argc; i++) {
744                 const char *arg = argv[i];
745                 if (strcmp(arg, "--"))
746                         continue;
747                 argv[i] = NULL;
748                 argc = i;
749                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
750                 seen_dashdash = 1;
751                 break;
752         }
753
754         flags = show_merge = 0;
755         for (i = 1; i < argc; i++) {
756                 const char *arg = argv[i];
757                 if (*arg == '-') {
758                         int opts;
759                         if (!strncmp(arg, "--max-count=", 12)) {
760                                 revs->max_count = atoi(arg + 12);
761                                 continue;
762                         }
763                         /* accept -<digit>, like traditional "head" */
764                         if ((*arg == '-') && isdigit(arg[1])) {
765                                 revs->max_count = atoi(arg + 1);
766                                 continue;
767                         }
768                         if (!strcmp(arg, "-n")) {
769                                 if (argc <= i + 1)
770                                         die("-n requires an argument");
771                                 revs->max_count = atoi(argv[++i]);
772                                 continue;
773                         }
774                         if (!strncmp(arg,"-n",2)) {
775                                 revs->max_count = atoi(arg + 2);
776                                 continue;
777                         }
778                         if (!strncmp(arg, "--max-age=", 10)) {
779                                 revs->max_age = atoi(arg + 10);
780                                 continue;
781                         }
782                         if (!strncmp(arg, "--since=", 8)) {
783                                 revs->max_age = approxidate(arg + 8);
784                                 continue;
785                         }
786                         if (!strncmp(arg, "--after=", 8)) {
787                                 revs->max_age = approxidate(arg + 8);
788                                 continue;
789                         }
790                         if (!strncmp(arg, "--min-age=", 10)) {
791                                 revs->min_age = atoi(arg + 10);
792                                 continue;
793                         }
794                         if (!strncmp(arg, "--before=", 9)) {
795                                 revs->min_age = approxidate(arg + 9);
796                                 continue;
797                         }
798                         if (!strncmp(arg, "--until=", 8)) {
799                                 revs->min_age = approxidate(arg + 8);
800                                 continue;
801                         }
802                         if (!strcmp(arg, "--all")) {
803                                 handle_all(revs, flags);
804                                 continue;
805                         }
806                         if (!strcmp(arg, "--not")) {
807                                 flags ^= UNINTERESTING;
808                                 continue;
809                         }
810                         if (!strcmp(arg, "--default")) {
811                                 if (++i >= argc)
812                                         die("bad --default argument");
813                                 def = argv[i];
814                                 continue;
815                         }
816                         if (!strcmp(arg, "--merge")) {
817                                 show_merge = 1;
818                                 continue;
819                         }
820                         if (!strcmp(arg, "--topo-order")) {
821                                 revs->topo_order = 1;
822                                 continue;
823                         }
824                         if (!strcmp(arg, "--date-order")) {
825                                 revs->lifo = 0;
826                                 revs->topo_order = 1;
827                                 continue;
828                         }
829                         if (!strcmp(arg, "--parents")) {
830                                 revs->parents = 1;
831                                 continue;
832                         }
833                         if (!strcmp(arg, "--dense")) {
834                                 revs->dense = 1;
835                                 continue;
836                         }
837                         if (!strcmp(arg, "--sparse")) {
838                                 revs->dense = 0;
839                                 continue;
840                         }
841                         if (!strcmp(arg, "--remove-empty")) {
842                                 revs->remove_empty_trees = 1;
843                                 continue;
844                         }
845                         if (!strcmp(arg, "--no-merges")) {
846                                 revs->no_merges = 1;
847                                 continue;
848                         }
849                         if (!strcmp(arg, "--boundary")) {
850                                 revs->boundary = 1;
851                                 continue;
852                         }
853                         if (!strcmp(arg, "--objects")) {
854                                 revs->tag_objects = 1;
855                                 revs->tree_objects = 1;
856                                 revs->blob_objects = 1;
857                                 continue;
858                         }
859                         if (!strcmp(arg, "--objects-edge")) {
860                                 revs->tag_objects = 1;
861                                 revs->tree_objects = 1;
862                                 revs->blob_objects = 1;
863                                 revs->edge_hint = 1;
864                                 continue;
865                         }
866                         if (!strcmp(arg, "--unpacked")) {
867                                 revs->unpacked = 1;
868                                 free(revs->ignore_packed);
869                                 revs->ignore_packed = NULL;
870                                 revs->num_ignore_packed = 0;
871                                 continue;
872                         }
873                         if (!strncmp(arg, "--unpacked=", 11)) {
874                                 revs->unpacked = 1;
875                                 add_ignore_packed(revs, arg+11);
876                                 continue;
877                         }
878                         if (!strcmp(arg, "-r")) {
879                                 revs->diff = 1;
880                                 revs->diffopt.recursive = 1;
881                                 continue;
882                         }
883                         if (!strcmp(arg, "-t")) {
884                                 revs->diff = 1;
885                                 revs->diffopt.recursive = 1;
886                                 revs->diffopt.tree_in_recursive = 1;
887                                 continue;
888                         }
889                         if (!strcmp(arg, "-m")) {
890                                 revs->ignore_merges = 0;
891                                 continue;
892                         }
893                         if (!strcmp(arg, "-c")) {
894                                 revs->diff = 1;
895                                 revs->dense_combined_merges = 0;
896                                 revs->combine_merges = 1;
897                                 continue;
898                         }
899                         if (!strcmp(arg, "--cc")) {
900                                 revs->diff = 1;
901                                 revs->dense_combined_merges = 1;
902                                 revs->combine_merges = 1;
903                                 continue;
904                         }
905                         if (!strcmp(arg, "-v")) {
906                                 revs->verbose_header = 1;
907                                 continue;
908                         }
909                         if (!strncmp(arg, "--pretty", 8)) {
910                                 revs->verbose_header = 1;
911                                 revs->commit_format = get_commit_format(arg+8);
912                                 continue;
913                         }
914                         if (!strcmp(arg, "--root")) {
915                                 revs->show_root_diff = 1;
916                                 continue;
917                         }
918                         if (!strcmp(arg, "--no-commit-id")) {
919                                 revs->no_commit_id = 1;
920                                 continue;
921                         }
922                         if (!strcmp(arg, "--always")) {
923                                 revs->always_show_header = 1;
924                                 continue;
925                         }
926                         if (!strcmp(arg, "--no-abbrev")) {
927                                 revs->abbrev = 0;
928                                 continue;
929                         }
930                         if (!strcmp(arg, "--abbrev")) {
931                                 revs->abbrev = DEFAULT_ABBREV;
932                                 continue;
933                         }
934                         if (!strncmp(arg, "--abbrev=", 9)) {
935                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
936                                 if (revs->abbrev < MINIMUM_ABBREV)
937                                         revs->abbrev = MINIMUM_ABBREV;
938                                 else if (revs->abbrev > 40)
939                                         revs->abbrev = 40;
940                                 continue;
941                         }
942                         if (!strcmp(arg, "--abbrev-commit")) {
943                                 revs->abbrev_commit = 1;
944                                 continue;
945                         }
946                         if (!strcmp(arg, "--full-diff")) {
947                                 revs->diff = 1;
948                                 revs->full_diff = 1;
949                                 continue;
950                         }
951                         if (!strcmp(arg, "--full-history")) {
952                                 revs->simplify_history = 0;
953                                 continue;
954                         }
955                         if (!strcmp(arg, "--relative-date")) {
956                                 revs->relative_date = 1;
957                                 continue;
958                         }
959
960                         /*
961                          * Grepping the commit log
962                          */
963                         if (!strncmp(arg, "--author=", 9)) {
964                                 add_header_grep(revs, "author", arg+9);
965                                 continue;
966                         }
967                         if (!strncmp(arg, "--committer=", 12)) {
968                                 add_header_grep(revs, "committer", arg+12);
969                                 continue;
970                         }
971                         if (!strncmp(arg, "--grep=", 7)) {
972                                 add_message_grep(revs, arg+7);
973                                 continue;
974                         }
975                         if (!strcmp(arg, "--all-match")) {
976                                 all_match = 1;
977                                 continue;
978                         }
979
980                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
981                         if (opts > 0) {
982                                 revs->diff = 1;
983                                 i += opts - 1;
984                                 continue;
985                         }
986                         *unrecognized++ = arg;
987                         left++;
988                         continue;
989                 }
990
991                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
992                         int j;
993                         if (seen_dashdash || *arg == '^')
994                                 die("bad revision '%s'", arg);
995
996                         /* If we didn't have a "--":
997                          * (1) all filenames must exist;
998                          * (2) all rev-args must not be interpretable
999                          *     as a valid filename.
1000                          * but the latter we have checked in the main loop.
1001                          */
1002                         for (j = i; j < argc; j++)
1003                                 verify_filename(revs->prefix, argv[j]);
1004
1005                         revs->prune_data = get_pathspec(revs->prefix,
1006                                                         argv + i);
1007                         break;
1008                 }
1009         }
1010
1011         if (show_merge)
1012                 prepare_show_merge(revs);
1013         if (def && !revs->pending.nr) {
1014                 unsigned char sha1[20];
1015                 struct object *object;
1016                 if (get_sha1(def, sha1))
1017                         die("bad default revision '%s'", def);
1018                 object = get_reference(revs, def, sha1, 0);
1019                 add_pending_object(revs, object, def);
1020         }
1021
1022         if (revs->topo_order)
1023                 revs->limited = 1;
1024
1025         if (revs->prune_data) {
1026                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1027                 revs->prune_fn = try_to_simplify_commit;
1028                 if (!revs->full_diff)
1029                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1030         }
1031         if (revs->combine_merges) {
1032                 revs->ignore_merges = 0;
1033                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1034                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1035         }
1036         revs->diffopt.abbrev = revs->abbrev;
1037         if (diff_setup_done(&revs->diffopt) < 0)
1038                 die("diff_setup_done failed");
1039
1040         if (revs->grep_filter) {
1041                 revs->grep_filter->all_match = all_match;
1042                 compile_grep_patterns(revs->grep_filter);
1043         }
1044
1045         return left;
1046 }
1047
1048 void prepare_revision_walk(struct rev_info *revs)
1049 {
1050         int nr = revs->pending.nr;
1051         struct object_array_entry *list = revs->pending.objects;
1052
1053         revs->pending.nr = 0;
1054         revs->pending.alloc = 0;
1055         revs->pending.objects = NULL;
1056         while (--nr >= 0) {
1057                 struct commit *commit = handle_commit(revs, list->item, list->name);
1058                 if (commit) {
1059                         if (!(commit->object.flags & SEEN)) {
1060                                 commit->object.flags |= SEEN;
1061                                 insert_by_date(commit, &revs->commits);
1062                         }
1063                 }
1064                 list++;
1065         }
1066
1067         if (revs->no_walk)
1068                 return;
1069         if (revs->limited)
1070                 limit_list(revs);
1071         if (revs->topo_order)
1072                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
1073                                              revs->topo_setter,
1074                                              revs->topo_getter);
1075 }
1076
1077 static int rewrite_one(struct rev_info *revs, struct commit **pp)
1078 {
1079         for (;;) {
1080                 struct commit *p = *pp;
1081                 if (!revs->limited)
1082                         add_parents_to_list(revs, p, &revs->commits);
1083                 if (p->parents && p->parents->next)
1084                         return 0;
1085                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
1086                         return 0;
1087                 if (!p->parents)
1088                         return -1;
1089                 *pp = p->parents->item;
1090         }
1091 }
1092
1093 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
1094 {
1095         struct commit_list **pp = &commit->parents;
1096         while (*pp) {
1097                 struct commit_list *parent = *pp;
1098                 if (rewrite_one(revs, &parent->item) < 0) {
1099                         *pp = parent->next;
1100                         continue;
1101                 }
1102                 pp = &parent->next;
1103         }
1104 }
1105
1106 static void mark_boundary_to_show(struct commit *commit)
1107 {
1108         struct commit_list *p = commit->parents;
1109         while (p) {
1110                 commit = p->item;
1111                 p = p->next;
1112                 if (commit->object.flags & BOUNDARY)
1113                         commit->object.flags |= BOUNDARY_SHOW;
1114         }
1115 }
1116
1117 static int commit_match(struct commit *commit, struct rev_info *opt)
1118 {
1119         if (!opt->grep_filter)
1120                 return 1;
1121         return grep_buffer(opt->grep_filter,
1122                            NULL, /* we say nothing, not even filename */
1123                            commit->buffer, strlen(commit->buffer));
1124 }
1125
1126 struct commit *get_revision(struct rev_info *revs)
1127 {
1128         struct commit_list *list = revs->commits;
1129
1130         if (!list)
1131                 return NULL;
1132
1133         /* Check the max_count ... */
1134         switch (revs->max_count) {
1135         case -1:
1136                 break;
1137         case 0:
1138                 return NULL;
1139         default:
1140                 revs->max_count--;
1141         }
1142
1143         do {
1144                 struct commit_list *entry = revs->commits;
1145                 struct commit *commit = entry->item;
1146
1147                 revs->commits = entry->next;
1148                 free(entry);
1149
1150                 /*
1151                  * If we haven't done the list limiting, we need to look at
1152                  * the parents here. We also need to do the date-based limiting
1153                  * that we'd otherwise have done in limit_list().
1154                  */
1155                 if (!revs->limited) {
1156                         if (revs->max_age != -1 &&
1157                             (commit->date < revs->max_age))
1158                                 continue;
1159                         add_parents_to_list(revs, commit, &revs->commits);
1160                 }
1161                 if (commit->object.flags & SHOWN)
1162                         continue;
1163
1164                 if (revs->unpacked && has_sha1_pack(commit->object.sha1,
1165                                                     revs->ignore_packed))
1166                     continue;
1167
1168                 /* We want to show boundary commits only when their
1169                  * children are shown.  When path-limiter is in effect,
1170                  * rewrite_parents() drops some commits from getting shown,
1171                  * and there is no point showing boundary parents that
1172                  * are not shown.  After rewrite_parents() rewrites the
1173                  * parents of a commit that is shown, we mark the boundary
1174                  * parents with BOUNDARY_SHOW.
1175                  */
1176                 if (commit->object.flags & BOUNDARY_SHOW) {
1177                         commit->object.flags |= SHOWN;
1178                         return commit;
1179                 }
1180                 if (commit->object.flags & UNINTERESTING)
1181                         continue;
1182                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1183                         continue;
1184                 if (revs->no_merges &&
1185                     commit->parents && commit->parents->next)
1186                         continue;
1187                 if (!commit_match(commit, revs))
1188                         continue;
1189                 if (revs->prune_fn && revs->dense) {
1190                         /* Commit without changes? */
1191                         if (!(commit->object.flags & TREECHANGE)) {
1192                                 /* drop merges unless we want parenthood */
1193                                 if (!revs->parents)
1194                                         continue;
1195                                 /* non-merge - always ignore it */
1196                                 if (!commit->parents || !commit->parents->next)
1197                                         continue;
1198                         }
1199                         if (revs->parents)
1200                                 rewrite_parents(revs, commit);
1201                 }
1202                 if (revs->boundary)
1203                         mark_boundary_to_show(commit);
1204                 commit->object.flags |= SHOWN;
1205                 return commit;
1206         } while (revs->commits);
1207         return NULL;
1208 }