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