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