]> git.ipfire.org Git - thirdparty/git.git/blob - commit.c
Merge branch 'jc/tag-doc' into maint-1.7.11
[thirdparty/git.git] / commit.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "commit.h"
4 #include "pkt-line.h"
5 #include "utf8.h"
6 #include "diff.h"
7 #include "revision.h"
8 #include "notes.h"
9 #include "gpg-interface.h"
10 #include "mergesort.h"
11
12 int save_commit_buffer = 1;
13
14 const char *commit_type = "commit";
15
16 static struct commit *check_commit(struct object *obj,
17 const unsigned char *sha1,
18 int quiet)
19 {
20 if (obj->type != OBJ_COMMIT) {
21 if (!quiet)
22 error("Object %s is a %s, not a commit",
23 sha1_to_hex(sha1), typename(obj->type));
24 return NULL;
25 }
26 return (struct commit *) obj;
27 }
28
29 struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
30 int quiet)
31 {
32 struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
33
34 if (!obj)
35 return NULL;
36 return check_commit(obj, sha1, quiet);
37 }
38
39 struct commit *lookup_commit_reference(const unsigned char *sha1)
40 {
41 return lookup_commit_reference_gently(sha1, 0);
42 }
43
44 struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name)
45 {
46 struct commit *c = lookup_commit_reference(sha1);
47 if (!c)
48 die(_("could not parse %s"), ref_name);
49 if (hashcmp(sha1, c->object.sha1)) {
50 warning(_("%s %s is not a commit!"),
51 ref_name, sha1_to_hex(sha1));
52 }
53 return c;
54 }
55
56 struct commit *lookup_commit(const unsigned char *sha1)
57 {
58 struct object *obj = lookup_object(sha1);
59 if (!obj)
60 return create_object(sha1, OBJ_COMMIT, alloc_commit_node());
61 if (!obj->type)
62 obj->type = OBJ_COMMIT;
63 return check_commit(obj, sha1, 0);
64 }
65
66 struct commit *lookup_commit_reference_by_name(const char *name)
67 {
68 unsigned char sha1[20];
69 struct commit *commit;
70
71 if (get_sha1(name, sha1))
72 return NULL;
73 commit = lookup_commit_reference(sha1);
74 if (!commit || parse_commit(commit))
75 return NULL;
76 return commit;
77 }
78
79 static unsigned long parse_commit_date(const char *buf, const char *tail)
80 {
81 const char *dateptr;
82
83 if (buf + 6 >= tail)
84 return 0;
85 if (memcmp(buf, "author", 6))
86 return 0;
87 while (buf < tail && *buf++ != '\n')
88 /* nada */;
89 if (buf + 9 >= tail)
90 return 0;
91 if (memcmp(buf, "committer", 9))
92 return 0;
93 while (buf < tail && *buf++ != '>')
94 /* nada */;
95 if (buf >= tail)
96 return 0;
97 dateptr = buf;
98 while (buf < tail && *buf++ != '\n')
99 /* nada */;
100 if (buf >= tail)
101 return 0;
102 /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
103 return strtoul(dateptr, NULL, 10);
104 }
105
106 static struct commit_graft **commit_graft;
107 static int commit_graft_alloc, commit_graft_nr;
108
109 static int commit_graft_pos(const unsigned char *sha1)
110 {
111 int lo, hi;
112 lo = 0;
113 hi = commit_graft_nr;
114 while (lo < hi) {
115 int mi = (lo + hi) / 2;
116 struct commit_graft *graft = commit_graft[mi];
117 int cmp = hashcmp(sha1, graft->sha1);
118 if (!cmp)
119 return mi;
120 if (cmp < 0)
121 hi = mi;
122 else
123 lo = mi + 1;
124 }
125 return -lo - 1;
126 }
127
128 int register_commit_graft(struct commit_graft *graft, int ignore_dups)
129 {
130 int pos = commit_graft_pos(graft->sha1);
131
132 if (0 <= pos) {
133 if (ignore_dups)
134 free(graft);
135 else {
136 free(commit_graft[pos]);
137 commit_graft[pos] = graft;
138 }
139 return 1;
140 }
141 pos = -pos - 1;
142 if (commit_graft_alloc <= ++commit_graft_nr) {
143 commit_graft_alloc = alloc_nr(commit_graft_alloc);
144 commit_graft = xrealloc(commit_graft,
145 sizeof(*commit_graft) *
146 commit_graft_alloc);
147 }
148 if (pos < commit_graft_nr)
149 memmove(commit_graft + pos + 1,
150 commit_graft + pos,
151 (commit_graft_nr - pos - 1) *
152 sizeof(*commit_graft));
153 commit_graft[pos] = graft;
154 return 0;
155 }
156
157 struct commit_graft *read_graft_line(char *buf, int len)
158 {
159 /* The format is just "Commit Parent1 Parent2 ...\n" */
160 int i;
161 struct commit_graft *graft = NULL;
162
163 while (len && isspace(buf[len-1]))
164 buf[--len] = '\0';
165 if (buf[0] == '#' || buf[0] == '\0')
166 return NULL;
167 if ((len + 1) % 41)
168 goto bad_graft_data;
169 i = (len + 1) / 41 - 1;
170 graft = xmalloc(sizeof(*graft) + 20 * i);
171 graft->nr_parent = i;
172 if (get_sha1_hex(buf, graft->sha1))
173 goto bad_graft_data;
174 for (i = 40; i < len; i += 41) {
175 if (buf[i] != ' ')
176 goto bad_graft_data;
177 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
178 goto bad_graft_data;
179 }
180 return graft;
181
182 bad_graft_data:
183 error("bad graft data: %s", buf);
184 free(graft);
185 return NULL;
186 }
187
188 static int read_graft_file(const char *graft_file)
189 {
190 FILE *fp = fopen(graft_file, "r");
191 char buf[1024];
192 if (!fp)
193 return -1;
194 while (fgets(buf, sizeof(buf), fp)) {
195 /* The format is just "Commit Parent1 Parent2 ...\n" */
196 int len = strlen(buf);
197 struct commit_graft *graft = read_graft_line(buf, len);
198 if (!graft)
199 continue;
200 if (register_commit_graft(graft, 1))
201 error("duplicate graft data: %s", buf);
202 }
203 fclose(fp);
204 return 0;
205 }
206
207 static void prepare_commit_graft(void)
208 {
209 static int commit_graft_prepared;
210 char *graft_file;
211
212 if (commit_graft_prepared)
213 return;
214 graft_file = get_graft_file();
215 read_graft_file(graft_file);
216 /* make sure shallows are read */
217 is_repository_shallow();
218 commit_graft_prepared = 1;
219 }
220
221 struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
222 {
223 int pos;
224 prepare_commit_graft();
225 pos = commit_graft_pos(sha1);
226 if (pos < 0)
227 return NULL;
228 return commit_graft[pos];
229 }
230
231 int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
232 {
233 int i, ret;
234 for (i = ret = 0; i < commit_graft_nr && !ret; i++)
235 ret = fn(commit_graft[i], cb_data);
236 return ret;
237 }
238
239 int unregister_shallow(const unsigned char *sha1)
240 {
241 int pos = commit_graft_pos(sha1);
242 if (pos < 0)
243 return -1;
244 if (pos + 1 < commit_graft_nr)
245 memmove(commit_graft + pos, commit_graft + pos + 1,
246 sizeof(struct commit_graft *)
247 * (commit_graft_nr - pos - 1));
248 commit_graft_nr--;
249 return 0;
250 }
251
252 int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
253 {
254 const char *tail = buffer;
255 const char *bufptr = buffer;
256 unsigned char parent[20];
257 struct commit_list **pptr;
258 struct commit_graft *graft;
259
260 if (item->object.parsed)
261 return 0;
262 item->object.parsed = 1;
263 tail += size;
264 if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
265 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
266 if (get_sha1_hex(bufptr + 5, parent) < 0)
267 return error("bad tree pointer in commit %s",
268 sha1_to_hex(item->object.sha1));
269 item->tree = lookup_tree(parent);
270 bufptr += 46; /* "tree " + "hex sha1" + "\n" */
271 pptr = &item->parents;
272
273 graft = lookup_commit_graft(item->object.sha1);
274 while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
275 struct commit *new_parent;
276
277 if (tail <= bufptr + 48 ||
278 get_sha1_hex(bufptr + 7, parent) ||
279 bufptr[47] != '\n')
280 return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
281 bufptr += 48;
282 /*
283 * The clone is shallow if nr_parent < 0, and we must
284 * not traverse its real parents even when we unhide them.
285 */
286 if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
287 continue;
288 new_parent = lookup_commit(parent);
289 if (new_parent)
290 pptr = &commit_list_insert(new_parent, pptr)->next;
291 }
292 if (graft) {
293 int i;
294 struct commit *new_parent;
295 for (i = 0; i < graft->nr_parent; i++) {
296 new_parent = lookup_commit(graft->parent[i]);
297 if (!new_parent)
298 continue;
299 pptr = &commit_list_insert(new_parent, pptr)->next;
300 }
301 }
302 item->date = parse_commit_date(bufptr, tail);
303
304 return 0;
305 }
306
307 int parse_commit(struct commit *item)
308 {
309 enum object_type type;
310 void *buffer;
311 unsigned long size;
312 int ret;
313
314 if (!item)
315 return -1;
316 if (item->object.parsed)
317 return 0;
318 buffer = read_sha1_file(item->object.sha1, &type, &size);
319 if (!buffer)
320 return error("Could not read %s",
321 sha1_to_hex(item->object.sha1));
322 if (type != OBJ_COMMIT) {
323 free(buffer);
324 return error("Object %s not a commit",
325 sha1_to_hex(item->object.sha1));
326 }
327 ret = parse_commit_buffer(item, buffer, size);
328 if (save_commit_buffer && !ret) {
329 item->buffer = buffer;
330 return 0;
331 }
332 free(buffer);
333 return ret;
334 }
335
336 int find_commit_subject(const char *commit_buffer, const char **subject)
337 {
338 const char *eol;
339 const char *p = commit_buffer;
340
341 while (*p && (*p != '\n' || p[1] != '\n'))
342 p++;
343 if (*p) {
344 p += 2;
345 for (eol = p; *eol && *eol != '\n'; eol++)
346 ; /* do nothing */
347 } else
348 eol = p;
349
350 *subject = p;
351
352 return eol - p;
353 }
354
355 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
356 {
357 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
358 new_list->item = item;
359 new_list->next = *list_p;
360 *list_p = new_list;
361 return new_list;
362 }
363
364 unsigned commit_list_count(const struct commit_list *l)
365 {
366 unsigned c = 0;
367 for (; l; l = l->next )
368 c++;
369 return c;
370 }
371
372 void free_commit_list(struct commit_list *list)
373 {
374 while (list) {
375 struct commit_list *temp = list;
376 list = temp->next;
377 free(temp);
378 }
379 }
380
381 struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
382 {
383 struct commit_list **pp = list;
384 struct commit_list *p;
385 while ((p = *pp) != NULL) {
386 if (p->item->date < item->date) {
387 break;
388 }
389 pp = &p->next;
390 }
391 return commit_list_insert(item, pp);
392 }
393
394 static int commit_list_compare_by_date(const void *a, const void *b)
395 {
396 unsigned long a_date = ((const struct commit_list *)a)->item->date;
397 unsigned long b_date = ((const struct commit_list *)b)->item->date;
398 if (a_date < b_date)
399 return 1;
400 if (a_date > b_date)
401 return -1;
402 return 0;
403 }
404
405 static void *commit_list_get_next(const void *a)
406 {
407 return ((const struct commit_list *)a)->next;
408 }
409
410 static void commit_list_set_next(void *a, void *next)
411 {
412 ((struct commit_list *)a)->next = next;
413 }
414
415 void commit_list_sort_by_date(struct commit_list **list)
416 {
417 *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
418 commit_list_compare_by_date);
419 }
420
421 struct commit *pop_most_recent_commit(struct commit_list **list,
422 unsigned int mark)
423 {
424 struct commit *ret = (*list)->item;
425 struct commit_list *parents = ret->parents;
426 struct commit_list *old = *list;
427
428 *list = (*list)->next;
429 free(old);
430
431 while (parents) {
432 struct commit *commit = parents->item;
433 if (!parse_commit(commit) && !(commit->object.flags & mark)) {
434 commit->object.flags |= mark;
435 commit_list_insert_by_date(commit, list);
436 }
437 parents = parents->next;
438 }
439 return ret;
440 }
441
442 static void clear_commit_marks_1(struct commit_list **plist,
443 struct commit *commit, unsigned int mark)
444 {
445 while (commit) {
446 struct commit_list *parents;
447
448 if (!(mark & commit->object.flags))
449 return;
450
451 commit->object.flags &= ~mark;
452
453 parents = commit->parents;
454 if (!parents)
455 return;
456
457 while ((parents = parents->next))
458 commit_list_insert(parents->item, plist);
459
460 commit = commit->parents->item;
461 }
462 }
463
464 void clear_commit_marks(struct commit *commit, unsigned int mark)
465 {
466 struct commit_list *list = NULL;
467 commit_list_insert(commit, &list);
468 while (list)
469 clear_commit_marks_1(&list, pop_commit(&list), mark);
470 }
471
472 void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
473 {
474 struct object *object;
475 struct commit *commit;
476 unsigned int i;
477
478 for (i = 0; i < a->nr; i++) {
479 object = a->objects[i].item;
480 commit = lookup_commit_reference_gently(object->sha1, 1);
481 if (commit)
482 clear_commit_marks(commit, mark);
483 }
484 }
485
486 struct commit *pop_commit(struct commit_list **stack)
487 {
488 struct commit_list *top = *stack;
489 struct commit *item = top ? top->item : NULL;
490
491 if (top) {
492 *stack = top->next;
493 free(top);
494 }
495 return item;
496 }
497
498 /*
499 * Performs an in-place topological sort on the list supplied.
500 */
501 void sort_in_topological_order(struct commit_list ** list, int lifo)
502 {
503 struct commit_list *next, *orig = *list;
504 struct commit_list *work, **insert;
505 struct commit_list **pptr;
506
507 if (!orig)
508 return;
509 *list = NULL;
510
511 /* Mark them and clear the indegree */
512 for (next = orig; next; next = next->next) {
513 struct commit *commit = next->item;
514 commit->indegree = 1;
515 }
516
517 /* update the indegree */
518 for (next = orig; next; next = next->next) {
519 struct commit_list * parents = next->item->parents;
520 while (parents) {
521 struct commit *parent = parents->item;
522
523 if (parent->indegree)
524 parent->indegree++;
525 parents = parents->next;
526 }
527 }
528
529 /*
530 * find the tips
531 *
532 * tips are nodes not reachable from any other node in the list
533 *
534 * the tips serve as a starting set for the work queue.
535 */
536 work = NULL;
537 insert = &work;
538 for (next = orig; next; next = next->next) {
539 struct commit *commit = next->item;
540
541 if (commit->indegree == 1)
542 insert = &commit_list_insert(commit, insert)->next;
543 }
544
545 /* process the list in topological order */
546 if (!lifo)
547 commit_list_sort_by_date(&work);
548
549 pptr = list;
550 *list = NULL;
551 while (work) {
552 struct commit *commit;
553 struct commit_list *parents, *work_item;
554
555 work_item = work;
556 work = work_item->next;
557 work_item->next = NULL;
558
559 commit = work_item->item;
560 for (parents = commit->parents; parents ; parents = parents->next) {
561 struct commit *parent = parents->item;
562
563 if (!parent->indegree)
564 continue;
565
566 /*
567 * parents are only enqueued for emission
568 * when all their children have been emitted thereby
569 * guaranteeing topological order.
570 */
571 if (--parent->indegree == 1) {
572 if (!lifo)
573 commit_list_insert_by_date(parent, &work);
574 else
575 commit_list_insert(parent, &work);
576 }
577 }
578 /*
579 * work_item is a commit all of whose children
580 * have already been emitted. we can emit it now.
581 */
582 commit->indegree = 0;
583 *pptr = work_item;
584 pptr = &work_item->next;
585 }
586 }
587
588 /* merge-base stuff */
589
590 /* bits #0..15 in revision.h */
591 #define PARENT1 (1u<<16)
592 #define PARENT2 (1u<<17)
593 #define STALE (1u<<18)
594 #define RESULT (1u<<19)
595
596 static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
597
598 static struct commit *interesting(struct commit_list *list)
599 {
600 while (list) {
601 struct commit *commit = list->item;
602 list = list->next;
603 if (commit->object.flags & STALE)
604 continue;
605 return commit;
606 }
607 return NULL;
608 }
609
610 static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
611 {
612 struct commit_list *list = NULL;
613 struct commit_list *result = NULL;
614 int i;
615
616 for (i = 0; i < n; i++) {
617 if (one == twos[i])
618 /*
619 * We do not mark this even with RESULT so we do not
620 * have to clean it up.
621 */
622 return commit_list_insert(one, &result);
623 }
624
625 if (parse_commit(one))
626 return NULL;
627 for (i = 0; i < n; i++) {
628 if (parse_commit(twos[i]))
629 return NULL;
630 }
631
632 one->object.flags |= PARENT1;
633 commit_list_insert_by_date(one, &list);
634 for (i = 0; i < n; i++) {
635 twos[i]->object.flags |= PARENT2;
636 commit_list_insert_by_date(twos[i], &list);
637 }
638
639 while (interesting(list)) {
640 struct commit *commit;
641 struct commit_list *parents;
642 struct commit_list *next;
643 int flags;
644
645 commit = list->item;
646 next = list->next;
647 free(list);
648 list = next;
649
650 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
651 if (flags == (PARENT1 | PARENT2)) {
652 if (!(commit->object.flags & RESULT)) {
653 commit->object.flags |= RESULT;
654 commit_list_insert_by_date(commit, &result);
655 }
656 /* Mark parents of a found merge stale */
657 flags |= STALE;
658 }
659 parents = commit->parents;
660 while (parents) {
661 struct commit *p = parents->item;
662 parents = parents->next;
663 if ((p->object.flags & flags) == flags)
664 continue;
665 if (parse_commit(p))
666 return NULL;
667 p->object.flags |= flags;
668 commit_list_insert_by_date(p, &list);
669 }
670 }
671
672 /* Clean up the result to remove stale ones */
673 free_commit_list(list);
674 list = result; result = NULL;
675 while (list) {
676 struct commit_list *next = list->next;
677 if (!(list->item->object.flags & STALE))
678 commit_list_insert_by_date(list->item, &result);
679 free(list);
680 list = next;
681 }
682 return result;
683 }
684
685 struct commit_list *get_octopus_merge_bases(struct commit_list *in)
686 {
687 struct commit_list *i, *j, *k, *ret = NULL;
688 struct commit_list **pptr = &ret;
689
690 for (i = in; i; i = i->next) {
691 if (!ret)
692 pptr = &commit_list_insert(i->item, pptr)->next;
693 else {
694 struct commit_list *new = NULL, *end = NULL;
695
696 for (j = ret; j; j = j->next) {
697 struct commit_list *bases;
698 bases = get_merge_bases(i->item, j->item, 1);
699 if (!new)
700 new = bases;
701 else
702 end->next = bases;
703 for (k = bases; k; k = k->next)
704 end = k;
705 }
706 ret = new;
707 }
708 }
709 return ret;
710 }
711
712 struct commit_list *get_merge_bases_many(struct commit *one,
713 int n,
714 struct commit **twos,
715 int cleanup)
716 {
717 struct commit_list *list;
718 struct commit **rslt;
719 struct commit_list *result;
720 int cnt, i, j;
721
722 result = merge_bases_many(one, n, twos);
723 for (i = 0; i < n; i++) {
724 if (one == twos[i])
725 return result;
726 }
727 if (!result || !result->next) {
728 if (cleanup) {
729 clear_commit_marks(one, all_flags);
730 for (i = 0; i < n; i++)
731 clear_commit_marks(twos[i], all_flags);
732 }
733 return result;
734 }
735
736 /* There are more than one */
737 cnt = 0;
738 list = result;
739 while (list) {
740 list = list->next;
741 cnt++;
742 }
743 rslt = xcalloc(cnt, sizeof(*rslt));
744 for (list = result, i = 0; list; list = list->next)
745 rslt[i++] = list->item;
746 free_commit_list(result);
747
748 clear_commit_marks(one, all_flags);
749 for (i = 0; i < n; i++)
750 clear_commit_marks(twos[i], all_flags);
751 for (i = 0; i < cnt - 1; i++) {
752 for (j = i+1; j < cnt; j++) {
753 if (!rslt[i] || !rslt[j])
754 continue;
755 result = merge_bases_many(rslt[i], 1, &rslt[j]);
756 clear_commit_marks(rslt[i], all_flags);
757 clear_commit_marks(rslt[j], all_flags);
758 for (list = result; list; list = list->next) {
759 if (rslt[i] == list->item)
760 rslt[i] = NULL;
761 if (rslt[j] == list->item)
762 rslt[j] = NULL;
763 }
764 }
765 }
766
767 /* Surviving ones in rslt[] are the independent results */
768 result = NULL;
769 for (i = 0; i < cnt; i++) {
770 if (rslt[i])
771 commit_list_insert_by_date(rslt[i], &result);
772 }
773 free(rslt);
774 return result;
775 }
776
777 struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
778 int cleanup)
779 {
780 return get_merge_bases_many(one, 1, &two, cleanup);
781 }
782
783 int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
784 {
785 if (!with_commit)
786 return 1;
787 while (with_commit) {
788 struct commit *other;
789
790 other = with_commit->item;
791 with_commit = with_commit->next;
792 if (in_merge_bases(other, &commit, 1))
793 return 1;
794 }
795 return 0;
796 }
797
798 int in_merge_bases(struct commit *commit, struct commit **reference, int num)
799 {
800 struct commit_list *bases, *b;
801 int ret = 0;
802
803 if (num == 1)
804 bases = get_merge_bases(commit, *reference, 1);
805 else
806 die("not yet");
807 for (b = bases; b; b = b->next) {
808 if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
809 ret = 1;
810 break;
811 }
812 }
813
814 free_commit_list(bases);
815 return ret;
816 }
817
818 struct commit_list *reduce_heads(struct commit_list *heads)
819 {
820 struct commit_list *p;
821 struct commit_list *result = NULL, **tail = &result;
822 struct commit **other;
823 size_t num_head, num_other;
824
825 if (!heads)
826 return NULL;
827
828 /* Avoid unnecessary reallocations */
829 for (p = heads, num_head = 0; p; p = p->next)
830 num_head++;
831 other = xcalloc(sizeof(*other), num_head);
832
833 /* For each commit, see if it can be reached by others */
834 for (p = heads; p; p = p->next) {
835 struct commit_list *q, *base;
836
837 /* Do we already have this in the result? */
838 for (q = result; q; q = q->next)
839 if (p->item == q->item)
840 break;
841 if (q)
842 continue;
843
844 num_other = 0;
845 for (q = heads; q; q = q->next) {
846 if (p->item == q->item)
847 continue;
848 other[num_other++] = q->item;
849 }
850 if (num_other)
851 base = get_merge_bases_many(p->item, num_other, other, 1);
852 else
853 base = NULL;
854 /*
855 * If p->item does not have anything common with other
856 * commits, there won't be any merge base. If it is
857 * reachable from some of the others, p->item will be
858 * the merge base. If its history is connected with
859 * others, but p->item is not reachable by others, we
860 * will get something other than p->item back.
861 */
862 if (!base || (base->item != p->item))
863 tail = &(commit_list_insert(p->item, tail)->next);
864 free_commit_list(base);
865 }
866 free(other);
867 return result;
868 }
869
870 static const char gpg_sig_header[] = "gpgsig";
871 static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
872
873 static int do_sign_commit(struct strbuf *buf, const char *keyid)
874 {
875 struct strbuf sig = STRBUF_INIT;
876 int inspos, copypos;
877
878 /* find the end of the header */
879 inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
880
881 if (!keyid || !*keyid)
882 keyid = get_signing_key();
883 if (sign_buffer(buf, &sig, keyid)) {
884 strbuf_release(&sig);
885 return -1;
886 }
887
888 for (copypos = 0; sig.buf[copypos]; ) {
889 const char *bol = sig.buf + copypos;
890 const char *eol = strchrnul(bol, '\n');
891 int len = (eol - bol) + !!*eol;
892
893 if (!copypos) {
894 strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
895 inspos += gpg_sig_header_len;
896 }
897 strbuf_insert(buf, inspos++, " ", 1);
898 strbuf_insert(buf, inspos, bol, len);
899 inspos += len;
900 copypos += len;
901 }
902 strbuf_release(&sig);
903 return 0;
904 }
905
906 int parse_signed_commit(const unsigned char *sha1,
907 struct strbuf *payload, struct strbuf *signature)
908 {
909 unsigned long size;
910 enum object_type type;
911 char *buffer = read_sha1_file(sha1, &type, &size);
912 int in_signature, saw_signature = -1;
913 char *line, *tail;
914
915 if (!buffer || type != OBJ_COMMIT)
916 goto cleanup;
917
918 line = buffer;
919 tail = buffer + size;
920 in_signature = 0;
921 saw_signature = 0;
922 while (line < tail) {
923 const char *sig = NULL;
924 char *next = memchr(line, '\n', tail - line);
925
926 next = next ? next + 1 : tail;
927 if (in_signature && line[0] == ' ')
928 sig = line + 1;
929 else if (!prefixcmp(line, gpg_sig_header) &&
930 line[gpg_sig_header_len] == ' ')
931 sig = line + gpg_sig_header_len + 1;
932 if (sig) {
933 strbuf_add(signature, sig, next - sig);
934 saw_signature = 1;
935 in_signature = 1;
936 } else {
937 if (*line == '\n')
938 /* dump the whole remainder of the buffer */
939 next = tail;
940 strbuf_add(payload, line, next - line);
941 in_signature = 0;
942 }
943 line = next;
944 }
945 cleanup:
946 free(buffer);
947 return saw_signature;
948 }
949
950 static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
951 {
952 struct merge_remote_desc *desc;
953 struct commit_extra_header *mergetag;
954 char *buf;
955 unsigned long size, len;
956 enum object_type type;
957
958 desc = merge_remote_util(parent);
959 if (!desc || !desc->obj)
960 return;
961 buf = read_sha1_file(desc->obj->sha1, &type, &size);
962 if (!buf || type != OBJ_TAG)
963 goto free_return;
964 len = parse_signature(buf, size);
965 if (size == len)
966 goto free_return;
967 /*
968 * We could verify this signature and either omit the tag when
969 * it does not validate, but the integrator may not have the
970 * public key of the signer of the tag he is merging, while a
971 * later auditor may have it while auditing, so let's not run
972 * verify-signed-buffer here for now...
973 *
974 * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
975 * warn("warning: signed tag unverified.");
976 */
977 mergetag = xcalloc(1, sizeof(*mergetag));
978 mergetag->key = xstrdup("mergetag");
979 mergetag->value = buf;
980 mergetag->len = size;
981
982 **tail = mergetag;
983 *tail = &mergetag->next;
984 return;
985
986 free_return:
987 free(buf);
988 }
989
990 void append_merge_tag_headers(struct commit_list *parents,
991 struct commit_extra_header ***tail)
992 {
993 while (parents) {
994 struct commit *parent = parents->item;
995 handle_signed_tag(parent, tail);
996 parents = parents->next;
997 }
998 }
999
1000 static void add_extra_header(struct strbuf *buffer,
1001 struct commit_extra_header *extra)
1002 {
1003 strbuf_addstr(buffer, extra->key);
1004 if (extra->len)
1005 strbuf_add_lines(buffer, " ", extra->value, extra->len);
1006 else
1007 strbuf_addch(buffer, '\n');
1008 }
1009
1010 struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1011 const char **exclude)
1012 {
1013 struct commit_extra_header *extra = NULL;
1014 unsigned long size;
1015 enum object_type type;
1016 char *buffer = read_sha1_file(commit->object.sha1, &type, &size);
1017 if (buffer && type == OBJ_COMMIT)
1018 extra = read_commit_extra_header_lines(buffer, size, exclude);
1019 free(buffer);
1020 return extra;
1021 }
1022
1023 static inline int standard_header_field(const char *field, size_t len)
1024 {
1025 return ((len == 4 && !memcmp(field, "tree ", 5)) ||
1026 (len == 6 && !memcmp(field, "parent ", 7)) ||
1027 (len == 6 && !memcmp(field, "author ", 7)) ||
1028 (len == 9 && !memcmp(field, "committer ", 10)) ||
1029 (len == 8 && !memcmp(field, "encoding ", 9)));
1030 }
1031
1032 static int excluded_header_field(const char *field, size_t len, const char **exclude)
1033 {
1034 if (!exclude)
1035 return 0;
1036
1037 while (*exclude) {
1038 size_t xlen = strlen(*exclude);
1039 if (len == xlen &&
1040 !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
1041 return 1;
1042 exclude++;
1043 }
1044 return 0;
1045 }
1046
1047 struct commit_extra_header *read_commit_extra_header_lines(const char *buffer, size_t size,
1048 const char **exclude)
1049 {
1050 struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1051 const char *line, *next, *eof, *eob;
1052 struct strbuf buf = STRBUF_INIT;
1053
1054 for (line = buffer, eob = line + size;
1055 line < eob && *line != '\n';
1056 line = next) {
1057 next = memchr(line, '\n', eob - line);
1058 next = next ? next + 1 : eob;
1059 if (*line == ' ') {
1060 /* continuation */
1061 if (it)
1062 strbuf_add(&buf, line + 1, next - (line + 1));
1063 continue;
1064 }
1065 if (it)
1066 it->value = strbuf_detach(&buf, &it->len);
1067 strbuf_reset(&buf);
1068 it = NULL;
1069
1070 eof = strchr(line, ' ');
1071 if (next <= eof)
1072 eof = next;
1073
1074 if (standard_header_field(line, eof - line) ||
1075 excluded_header_field(line, eof - line, exclude))
1076 continue;
1077
1078 it = xcalloc(1, sizeof(*it));
1079 it->key = xmemdupz(line, eof-line);
1080 *tail = it;
1081 tail = &it->next;
1082 if (eof + 1 < next)
1083 strbuf_add(&buf, eof + 1, next - (eof + 1));
1084 }
1085 if (it)
1086 it->value = strbuf_detach(&buf, &it->len);
1087 return extra;
1088 }
1089
1090 void free_commit_extra_headers(struct commit_extra_header *extra)
1091 {
1092 while (extra) {
1093 struct commit_extra_header *next = extra->next;
1094 free(extra->key);
1095 free(extra->value);
1096 free(extra);
1097 extra = next;
1098 }
1099 }
1100
1101 int commit_tree(const struct strbuf *msg, unsigned char *tree,
1102 struct commit_list *parents, unsigned char *ret,
1103 const char *author, const char *sign_commit)
1104 {
1105 struct commit_extra_header *extra = NULL, **tail = &extra;
1106 int result;
1107
1108 append_merge_tag_headers(parents, &tail);
1109 result = commit_tree_extended(msg, tree, parents, ret,
1110 author, sign_commit, extra);
1111 free_commit_extra_headers(extra);
1112 return result;
1113 }
1114
1115 static const char commit_utf8_warn[] =
1116 "Warning: commit message does not conform to UTF-8.\n"
1117 "You may want to amend it after fixing the message, or set the config\n"
1118 "variable i18n.commitencoding to the encoding your project uses.\n";
1119
1120 int commit_tree_extended(const struct strbuf *msg, unsigned char *tree,
1121 struct commit_list *parents, unsigned char *ret,
1122 const char *author, const char *sign_commit,
1123 struct commit_extra_header *extra)
1124 {
1125 int result;
1126 int encoding_is_utf8;
1127 struct strbuf buffer;
1128
1129 assert_sha1_type(tree, OBJ_TREE);
1130
1131 if (memchr(msg->buf, '\0', msg->len))
1132 return error("a NUL byte in commit log message not allowed.");
1133
1134 /* Not having i18n.commitencoding is the same as having utf-8 */
1135 encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1136
1137 strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1138 strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1139
1140 /*
1141 * NOTE! This ordering means that the same exact tree merged with a
1142 * different order of parents will be a _different_ changeset even
1143 * if everything else stays the same.
1144 */
1145 while (parents) {
1146 struct commit_list *next = parents->next;
1147 struct commit *parent = parents->item;
1148
1149 strbuf_addf(&buffer, "parent %s\n",
1150 sha1_to_hex(parent->object.sha1));
1151 free(parents);
1152 parents = next;
1153 }
1154
1155 /* Person/date information */
1156 if (!author)
1157 author = git_author_info(IDENT_STRICT);
1158 strbuf_addf(&buffer, "author %s\n", author);
1159 strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1160 if (!encoding_is_utf8)
1161 strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1162
1163 while (extra) {
1164 add_extra_header(&buffer, extra);
1165 extra = extra->next;
1166 }
1167 strbuf_addch(&buffer, '\n');
1168
1169 /* And add the comment */
1170 strbuf_addbuf(&buffer, msg);
1171
1172 /* And check the encoding */
1173 if (encoding_is_utf8 && !is_utf8(buffer.buf))
1174 fprintf(stderr, commit_utf8_warn);
1175
1176 if (sign_commit && do_sign_commit(&buffer, sign_commit))
1177 return -1;
1178
1179 result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1180 strbuf_release(&buffer);
1181 return result;
1182 }
1183
1184 struct commit *get_merge_parent(const char *name)
1185 {
1186 struct object *obj;
1187 struct commit *commit;
1188 unsigned char sha1[20];
1189 if (get_sha1(name, sha1))
1190 return NULL;
1191 obj = parse_object(sha1);
1192 commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1193 if (commit && !commit->util) {
1194 struct merge_remote_desc *desc;
1195 desc = xmalloc(sizeof(*desc));
1196 desc->obj = obj;
1197 desc->name = strdup(name);
1198 commit->util = desc;
1199 }
1200 return commit;
1201 }
1202
1203 /*
1204 * Append a commit to the end of the commit_list.
1205 *
1206 * next starts by pointing to the variable that holds the head of an
1207 * empty commit_list, and is updated to point to the "next" field of
1208 * the last item on the list as new commits are appended.
1209 *
1210 * Usage example:
1211 *
1212 * struct commit_list *list;
1213 * struct commit_list **next = &list;
1214 *
1215 * next = commit_list_append(c1, next);
1216 * next = commit_list_append(c2, next);
1217 * assert(commit_list_count(list) == 2);
1218 * return list;
1219 */
1220 struct commit_list **commit_list_append(struct commit *commit,
1221 struct commit_list **next)
1222 {
1223 struct commit_list *new = xmalloc(sizeof(struct commit_list));
1224 new->item = commit;
1225 *next = new;
1226 new->next = NULL;
1227 return &new->next;
1228 }