9365e3b34aba1c0d4f1ffe9e5e5eebcce886a42e
[git/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 static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
13
14 int save_commit_buffer = 1;
15
16 const char *commit_type = "commit";
17 static int commit_count;
18
19 static struct commit *check_commit(struct object *obj,
20 const unsigned char *sha1,
21 int quiet)
22 {
23 if (obj->type != OBJ_COMMIT) {
24 if (!quiet)
25 error("Object %s is a %s, not a commit",
26 sha1_to_hex(sha1), typename(obj->type));
27 return NULL;
28 }
29 return (struct commit *) obj;
30 }
31
32 struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
33 int quiet)
34 {
35 struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
36
37 if (!obj)
38 return NULL;
39 return check_commit(obj, sha1, quiet);
40 }
41
42 struct commit *lookup_commit_reference(const unsigned char *sha1)
43 {
44 return lookup_commit_reference_gently(sha1, 0);
45 }
46
47 struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name)
48 {
49 struct commit *c = lookup_commit_reference(sha1);
50 if (!c)
51 die(_("could not parse %s"), ref_name);
52 if (hashcmp(sha1, c->object.sha1)) {
53 warning(_("%s %s is not a commit!"),
54 ref_name, sha1_to_hex(sha1));
55 }
56 return c;
57 }
58
59 struct commit *lookup_commit(const unsigned char *sha1)
60 {
61 struct object *obj = lookup_object(sha1);
62 if (!obj) {
63 struct commit *c = alloc_commit_node();
64 c->index = commit_count++;
65 return create_object(sha1, OBJ_COMMIT, c);
66 }
67 if (!obj->type)
68 obj->type = OBJ_COMMIT;
69 return check_commit(obj, sha1, 0);
70 }
71
72 struct commit *lookup_commit_reference_by_name(const char *name)
73 {
74 unsigned char sha1[20];
75 struct commit *commit;
76
77 if (get_sha1_committish(name, sha1))
78 return NULL;
79 commit = lookup_commit_reference(sha1);
80 if (!commit || parse_commit(commit))
81 return NULL;
82 return commit;
83 }
84
85 static unsigned long parse_commit_date(const char *buf, const char *tail)
86 {
87 const char *dateptr;
88
89 if (buf + 6 >= tail)
90 return 0;
91 if (memcmp(buf, "author", 6))
92 return 0;
93 while (buf < tail && *buf++ != '\n')
94 /* nada */;
95 if (buf + 9 >= tail)
96 return 0;
97 if (memcmp(buf, "committer", 9))
98 return 0;
99 while (buf < tail && *buf++ != '>')
100 /* nada */;
101 if (buf >= tail)
102 return 0;
103 dateptr = buf;
104 while (buf < tail && *buf++ != '\n')
105 /* nada */;
106 if (buf >= tail)
107 return 0;
108 /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
109 return strtoul(dateptr, NULL, 10);
110 }
111
112 static struct commit_graft **commit_graft;
113 static int commit_graft_alloc, commit_graft_nr;
114
115 static int commit_graft_pos(const unsigned char *sha1)
116 {
117 int lo, hi;
118 lo = 0;
119 hi = commit_graft_nr;
120 while (lo < hi) {
121 int mi = (lo + hi) / 2;
122 struct commit_graft *graft = commit_graft[mi];
123 int cmp = hashcmp(sha1, graft->sha1);
124 if (!cmp)
125 return mi;
126 if (cmp < 0)
127 hi = mi;
128 else
129 lo = mi + 1;
130 }
131 return -lo - 1;
132 }
133
134 int register_commit_graft(struct commit_graft *graft, int ignore_dups)
135 {
136 int pos = commit_graft_pos(graft->sha1);
137
138 if (0 <= pos) {
139 if (ignore_dups)
140 free(graft);
141 else {
142 free(commit_graft[pos]);
143 commit_graft[pos] = graft;
144 }
145 return 1;
146 }
147 pos = -pos - 1;
148 if (commit_graft_alloc <= ++commit_graft_nr) {
149 commit_graft_alloc = alloc_nr(commit_graft_alloc);
150 commit_graft = xrealloc(commit_graft,
151 sizeof(*commit_graft) *
152 commit_graft_alloc);
153 }
154 if (pos < commit_graft_nr)
155 memmove(commit_graft + pos + 1,
156 commit_graft + pos,
157 (commit_graft_nr - pos - 1) *
158 sizeof(*commit_graft));
159 commit_graft[pos] = graft;
160 return 0;
161 }
162
163 struct commit_graft *read_graft_line(char *buf, int len)
164 {
165 /* The format is just "Commit Parent1 Parent2 ...\n" */
166 int i;
167 struct commit_graft *graft = NULL;
168
169 while (len && isspace(buf[len-1]))
170 buf[--len] = '\0';
171 if (buf[0] == '#' || buf[0] == '\0')
172 return NULL;
173 if ((len + 1) % 41)
174 goto bad_graft_data;
175 i = (len + 1) / 41 - 1;
176 graft = xmalloc(sizeof(*graft) + 20 * i);
177 graft->nr_parent = i;
178 if (get_sha1_hex(buf, graft->sha1))
179 goto bad_graft_data;
180 for (i = 40; i < len; i += 41) {
181 if (buf[i] != ' ')
182 goto bad_graft_data;
183 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
184 goto bad_graft_data;
185 }
186 return graft;
187
188 bad_graft_data:
189 error("bad graft data: %s", buf);
190 free(graft);
191 return NULL;
192 }
193
194 static int read_graft_file(const char *graft_file)
195 {
196 FILE *fp = fopen(graft_file, "r");
197 char buf[1024];
198 if (!fp)
199 return -1;
200 while (fgets(buf, sizeof(buf), fp)) {
201 /* The format is just "Commit Parent1 Parent2 ...\n" */
202 int len = strlen(buf);
203 struct commit_graft *graft = read_graft_line(buf, len);
204 if (!graft)
205 continue;
206 if (register_commit_graft(graft, 1))
207 error("duplicate graft data: %s", buf);
208 }
209 fclose(fp);
210 return 0;
211 }
212
213 static void prepare_commit_graft(void)
214 {
215 static int commit_graft_prepared;
216 char *graft_file;
217
218 if (commit_graft_prepared)
219 return;
220 graft_file = get_graft_file();
221 read_graft_file(graft_file);
222 /* make sure shallows are read */
223 is_repository_shallow();
224 commit_graft_prepared = 1;
225 }
226
227 struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
228 {
229 int pos;
230 prepare_commit_graft();
231 pos = commit_graft_pos(sha1);
232 if (pos < 0)
233 return NULL;
234 return commit_graft[pos];
235 }
236
237 int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
238 {
239 int i, ret;
240 for (i = ret = 0; i < commit_graft_nr && !ret; i++)
241 ret = fn(commit_graft[i], cb_data);
242 return ret;
243 }
244
245 int unregister_shallow(const unsigned char *sha1)
246 {
247 int pos = commit_graft_pos(sha1);
248 if (pos < 0)
249 return -1;
250 if (pos + 1 < commit_graft_nr)
251 memmove(commit_graft + pos, commit_graft + pos + 1,
252 sizeof(struct commit_graft *)
253 * (commit_graft_nr - pos - 1));
254 commit_graft_nr--;
255 return 0;
256 }
257
258 int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
259 {
260 const char *tail = buffer;
261 const char *bufptr = buffer;
262 unsigned char parent[20];
263 struct commit_list **pptr;
264 struct commit_graft *graft;
265
266 if (item->object.parsed)
267 return 0;
268 item->object.parsed = 1;
269 tail += size;
270 if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
271 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
272 if (get_sha1_hex(bufptr + 5, parent) < 0)
273 return error("bad tree pointer in commit %s",
274 sha1_to_hex(item->object.sha1));
275 item->tree = lookup_tree(parent);
276 bufptr += 46; /* "tree " + "hex sha1" + "\n" */
277 pptr = &item->parents;
278
279 graft = lookup_commit_graft(item->object.sha1);
280 while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
281 struct commit *new_parent;
282
283 if (tail <= bufptr + 48 ||
284 get_sha1_hex(bufptr + 7, parent) ||
285 bufptr[47] != '\n')
286 return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
287 bufptr += 48;
288 /*
289 * The clone is shallow if nr_parent < 0, and we must
290 * not traverse its real parents even when we unhide them.
291 */
292 if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
293 continue;
294 new_parent = lookup_commit(parent);
295 if (new_parent)
296 pptr = &commit_list_insert(new_parent, pptr)->next;
297 }
298 if (graft) {
299 int i;
300 struct commit *new_parent;
301 for (i = 0; i < graft->nr_parent; i++) {
302 new_parent = lookup_commit(graft->parent[i]);
303 if (!new_parent)
304 continue;
305 pptr = &commit_list_insert(new_parent, pptr)->next;
306 }
307 }
308 item->date = parse_commit_date(bufptr, tail);
309
310 return 0;
311 }
312
313 int parse_commit(struct commit *item)
314 {
315 enum object_type type;
316 void *buffer;
317 unsigned long size;
318 int ret;
319
320 if (!item)
321 return -1;
322 if (item->object.parsed)
323 return 0;
324 buffer = read_sha1_file(item->object.sha1, &type, &size);
325 if (!buffer)
326 return error("Could not read %s",
327 sha1_to_hex(item->object.sha1));
328 if (type != OBJ_COMMIT) {
329 free(buffer);
330 return error("Object %s not a commit",
331 sha1_to_hex(item->object.sha1));
332 }
333 ret = parse_commit_buffer(item, buffer, size);
334 if (save_commit_buffer && !ret) {
335 item->buffer = buffer;
336 return 0;
337 }
338 free(buffer);
339 return ret;
340 }
341
342 int find_commit_subject(const char *commit_buffer, const char **subject)
343 {
344 const char *eol;
345 const char *p = commit_buffer;
346
347 while (*p && (*p != '\n' || p[1] != '\n'))
348 p++;
349 if (*p) {
350 p += 2;
351 for (eol = p; *eol && *eol != '\n'; eol++)
352 ; /* do nothing */
353 } else
354 eol = p;
355
356 *subject = p;
357
358 return eol - p;
359 }
360
361 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
362 {
363 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
364 new_list->item = item;
365 new_list->next = *list_p;
366 *list_p = new_list;
367 return new_list;
368 }
369
370 unsigned commit_list_count(const struct commit_list *l)
371 {
372 unsigned c = 0;
373 for (; l; l = l->next )
374 c++;
375 return c;
376 }
377
378 void free_commit_list(struct commit_list *list)
379 {
380 while (list) {
381 struct commit_list *temp = list;
382 list = temp->next;
383 free(temp);
384 }
385 }
386
387 struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
388 {
389 struct commit_list **pp = list;
390 struct commit_list *p;
391 while ((p = *pp) != NULL) {
392 if (p->item->date < item->date) {
393 break;
394 }
395 pp = &p->next;
396 }
397 return commit_list_insert(item, pp);
398 }
399
400 static int commit_list_compare_by_date(const void *a, const void *b)
401 {
402 unsigned long a_date = ((const struct commit_list *)a)->item->date;
403 unsigned long b_date = ((const struct commit_list *)b)->item->date;
404 if (a_date < b_date)
405 return 1;
406 if (a_date > b_date)
407 return -1;
408 return 0;
409 }
410
411 static void *commit_list_get_next(const void *a)
412 {
413 return ((const struct commit_list *)a)->next;
414 }
415
416 static void commit_list_set_next(void *a, void *next)
417 {
418 ((struct commit_list *)a)->next = next;
419 }
420
421 void commit_list_sort_by_date(struct commit_list **list)
422 {
423 *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
424 commit_list_compare_by_date);
425 }
426
427 struct commit *pop_most_recent_commit(struct commit_list **list,
428 unsigned int mark)
429 {
430 struct commit *ret = (*list)->item;
431 struct commit_list *parents = ret->parents;
432 struct commit_list *old = *list;
433
434 *list = (*list)->next;
435 free(old);
436
437 while (parents) {
438 struct commit *commit = parents->item;
439 if (!parse_commit(commit) && !(commit->object.flags & mark)) {
440 commit->object.flags |= mark;
441 commit_list_insert_by_date(commit, list);
442 }
443 parents = parents->next;
444 }
445 return ret;
446 }
447
448 static void clear_commit_marks_1(struct commit_list **plist,
449 struct commit *commit, unsigned int mark)
450 {
451 while (commit) {
452 struct commit_list *parents;
453
454 if (!(mark & commit->object.flags))
455 return;
456
457 commit->object.flags &= ~mark;
458
459 parents = commit->parents;
460 if (!parents)
461 return;
462
463 while ((parents = parents->next))
464 commit_list_insert(parents->item, plist);
465
466 commit = commit->parents->item;
467 }
468 }
469
470 void clear_commit_marks(struct commit *commit, unsigned int mark)
471 {
472 struct commit_list *list = NULL;
473 commit_list_insert(commit, &list);
474 while (list)
475 clear_commit_marks_1(&list, pop_commit(&list), mark);
476 }
477
478 void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
479 {
480 struct object *object;
481 struct commit *commit;
482 unsigned int i;
483
484 for (i = 0; i < a->nr; i++) {
485 object = a->objects[i].item;
486 commit = lookup_commit_reference_gently(object->sha1, 1);
487 if (commit)
488 clear_commit_marks(commit, mark);
489 }
490 }
491
492 struct commit *pop_commit(struct commit_list **stack)
493 {
494 struct commit_list *top = *stack;
495 struct commit *item = top ? top->item : NULL;
496
497 if (top) {
498 *stack = top->next;
499 free(top);
500 }
501 return item;
502 }
503
504 struct commit_slab {
505 int *buf;
506 int alloc;
507 };
508
509 static void slab_init(struct commit_slab *s)
510 {
511 memset(s, 0, sizeof(*s));
512 }
513
514 static void slab_clear(struct commit_slab *s)
515 {
516 free(s->buf);
517 slab_init(s);
518 }
519
520 static inline int *slab_at(struct commit_slab *s, const struct commit *c)
521 {
522 if (s->alloc <= c->index) {
523 int new_alloc = alloc_nr(s->alloc);
524 if (new_alloc <= c->index)
525 new_alloc = c->index + 1;
526
527 s->buf = xrealloc(s->buf, new_alloc * sizeof(*s->buf));
528 memset(s->buf + s->alloc, 0, new_alloc - s->alloc);
529 s->alloc = new_alloc;
530 }
531 return s->buf + c->index;
532 }
533
534 /*
535 * Performs an in-place topological sort on the list supplied.
536 */
537 void sort_in_topological_order(struct commit_list ** list, int lifo)
538 {
539 struct commit_list *next, *orig = *list;
540 struct commit_list *work, **insert;
541 struct commit_list **pptr;
542 struct commit_slab indegree;
543
544 if (!orig)
545 return;
546 *list = NULL;
547
548 slab_init(&indegree);
549
550 /* Mark them and clear the indegree */
551 for (next = orig; next; next = next->next) {
552 struct commit *commit = next->item;
553 *slab_at(&indegree, commit) = 1;
554 }
555
556 /* update the indegree */
557 for (next = orig; next; next = next->next) {
558 struct commit_list * parents = next->item->parents;
559 while (parents) {
560 struct commit *parent = parents->item;
561 int *pi = slab_at(&indegree, parent);
562
563 if (*pi)
564 (*pi)++;
565 parents = parents->next;
566 }
567 }
568
569 /*
570 * find the tips
571 *
572 * tips are nodes not reachable from any other node in the list
573 *
574 * the tips serve as a starting set for the work queue.
575 */
576 work = NULL;
577 insert = &work;
578 for (next = orig; next; next = next->next) {
579 struct commit *commit = next->item;
580
581 if (*slab_at(&indegree, commit) == 1)
582 insert = &commit_list_insert(commit, insert)->next;
583 }
584
585 /* process the list in topological order */
586 if (!lifo)
587 commit_list_sort_by_date(&work);
588
589 pptr = list;
590 *list = NULL;
591 while (work) {
592 struct commit *commit;
593 struct commit_list *parents, *work_item;
594
595 work_item = work;
596 work = work_item->next;
597 work_item->next = NULL;
598
599 commit = work_item->item;
600 for (parents = commit->parents; parents ; parents = parents->next) {
601 struct commit *parent = parents->item;
602 int *pi = slab_at(&indegree, parent);
603
604 if (!*pi)
605 continue;
606
607 /*
608 * parents are only enqueued for emission
609 * when all their children have been emitted thereby
610 * guaranteeing topological order.
611 */
612 if (--(*pi) == 1) {
613 if (!lifo)
614 commit_list_insert_by_date(parent, &work);
615 else
616 commit_list_insert(parent, &work);
617 }
618 }
619 /*
620 * work_item is a commit all of whose children
621 * have already been emitted. we can emit it now.
622 */
623 *slab_at(&indegree, commit) = 0;
624 *pptr = work_item;
625 pptr = &work_item->next;
626 }
627
628 slab_clear(&indegree);
629 }
630
631 /* merge-base stuff */
632
633 /* bits #0..15 in revision.h */
634 #define PARENT1 (1u<<16)
635 #define PARENT2 (1u<<17)
636 #define STALE (1u<<18)
637 #define RESULT (1u<<19)
638
639 static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
640
641 static struct commit *interesting(struct commit_list *list)
642 {
643 while (list) {
644 struct commit *commit = list->item;
645 list = list->next;
646 if (commit->object.flags & STALE)
647 continue;
648 return commit;
649 }
650 return NULL;
651 }
652
653 /* all input commits in one and twos[] must have been parsed! */
654 static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
655 {
656 struct commit_list *list = NULL;
657 struct commit_list *result = NULL;
658 int i;
659
660 one->object.flags |= PARENT1;
661 commit_list_insert_by_date(one, &list);
662 if (!n)
663 return list;
664 for (i = 0; i < n; i++) {
665 twos[i]->object.flags |= PARENT2;
666 commit_list_insert_by_date(twos[i], &list);
667 }
668
669 while (interesting(list)) {
670 struct commit *commit;
671 struct commit_list *parents;
672 struct commit_list *next;
673 int flags;
674
675 commit = list->item;
676 next = list->next;
677 free(list);
678 list = next;
679
680 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
681 if (flags == (PARENT1 | PARENT2)) {
682 if (!(commit->object.flags & RESULT)) {
683 commit->object.flags |= RESULT;
684 commit_list_insert_by_date(commit, &result);
685 }
686 /* Mark parents of a found merge stale */
687 flags |= STALE;
688 }
689 parents = commit->parents;
690 while (parents) {
691 struct commit *p = parents->item;
692 parents = parents->next;
693 if ((p->object.flags & flags) == flags)
694 continue;
695 if (parse_commit(p))
696 return NULL;
697 p->object.flags |= flags;
698 commit_list_insert_by_date(p, &list);
699 }
700 }
701
702 free_commit_list(list);
703 return result;
704 }
705
706 static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
707 {
708 struct commit_list *list = NULL;
709 struct commit_list *result = NULL;
710 int i;
711
712 for (i = 0; i < n; i++) {
713 if (one == twos[i])
714 /*
715 * We do not mark this even with RESULT so we do not
716 * have to clean it up.
717 */
718 return commit_list_insert(one, &result);
719 }
720
721 if (parse_commit(one))
722 return NULL;
723 for (i = 0; i < n; i++) {
724 if (parse_commit(twos[i]))
725 return NULL;
726 }
727
728 list = paint_down_to_common(one, n, twos);
729
730 while (list) {
731 struct commit_list *next = list->next;
732 if (!(list->item->object.flags & STALE))
733 commit_list_insert_by_date(list->item, &result);
734 free(list);
735 list = next;
736 }
737 return result;
738 }
739
740 struct commit_list *get_octopus_merge_bases(struct commit_list *in)
741 {
742 struct commit_list *i, *j, *k, *ret = NULL;
743 struct commit_list **pptr = &ret;
744
745 for (i = in; i; i = i->next) {
746 if (!ret)
747 pptr = &commit_list_insert(i->item, pptr)->next;
748 else {
749 struct commit_list *new = NULL, *end = NULL;
750
751 for (j = ret; j; j = j->next) {
752 struct commit_list *bases;
753 bases = get_merge_bases(i->item, j->item, 1);
754 if (!new)
755 new = bases;
756 else
757 end->next = bases;
758 for (k = bases; k; k = k->next)
759 end = k;
760 }
761 ret = new;
762 }
763 }
764 return ret;
765 }
766
767 static int remove_redundant(struct commit **array, int cnt)
768 {
769 /*
770 * Some commit in the array may be an ancestor of
771 * another commit. Move such commit to the end of
772 * the array, and return the number of commits that
773 * are independent from each other.
774 */
775 struct commit **work;
776 unsigned char *redundant;
777 int *filled_index;
778 int i, j, filled;
779
780 work = xcalloc(cnt, sizeof(*work));
781 redundant = xcalloc(cnt, 1);
782 filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
783
784 for (i = 0; i < cnt; i++)
785 parse_commit(array[i]);
786 for (i = 0; i < cnt; i++) {
787 struct commit_list *common;
788
789 if (redundant[i])
790 continue;
791 for (j = filled = 0; j < cnt; j++) {
792 if (i == j || redundant[j])
793 continue;
794 filled_index[filled] = j;
795 work[filled++] = array[j];
796 }
797 common = paint_down_to_common(array[i], filled, work);
798 if (array[i]->object.flags & PARENT2)
799 redundant[i] = 1;
800 for (j = 0; j < filled; j++)
801 if (work[j]->object.flags & PARENT1)
802 redundant[filled_index[j]] = 1;
803 clear_commit_marks(array[i], all_flags);
804 for (j = 0; j < filled; j++)
805 clear_commit_marks(work[j], all_flags);
806 free_commit_list(common);
807 }
808
809 /* Now collect the result */
810 memcpy(work, array, sizeof(*array) * cnt);
811 for (i = filled = 0; i < cnt; i++)
812 if (!redundant[i])
813 array[filled++] = work[i];
814 for (j = filled, i = 0; i < cnt; i++)
815 if (redundant[i])
816 array[j++] = work[i];
817 free(work);
818 free(redundant);
819 free(filled_index);
820 return filled;
821 }
822
823 struct commit_list *get_merge_bases_many(struct commit *one,
824 int n,
825 struct commit **twos,
826 int cleanup)
827 {
828 struct commit_list *list;
829 struct commit **rslt;
830 struct commit_list *result;
831 int cnt, i;
832
833 result = merge_bases_many(one, n, twos);
834 for (i = 0; i < n; i++) {
835 if (one == twos[i])
836 return result;
837 }
838 if (!result || !result->next) {
839 if (cleanup) {
840 clear_commit_marks(one, all_flags);
841 for (i = 0; i < n; i++)
842 clear_commit_marks(twos[i], all_flags);
843 }
844 return result;
845 }
846
847 /* There are more than one */
848 cnt = 0;
849 list = result;
850 while (list) {
851 list = list->next;
852 cnt++;
853 }
854 rslt = xcalloc(cnt, sizeof(*rslt));
855 for (list = result, i = 0; list; list = list->next)
856 rslt[i++] = list->item;
857 free_commit_list(result);
858
859 clear_commit_marks(one, all_flags);
860 for (i = 0; i < n; i++)
861 clear_commit_marks(twos[i], all_flags);
862
863 cnt = remove_redundant(rslt, cnt);
864 result = NULL;
865 for (i = 0; i < cnt; i++)
866 commit_list_insert_by_date(rslt[i], &result);
867 free(rslt);
868 return result;
869 }
870
871 struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
872 int cleanup)
873 {
874 return get_merge_bases_many(one, 1, &two, cleanup);
875 }
876
877 /*
878 * Is "commit" a descendant of one of the elements on the "with_commit" list?
879 */
880 int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
881 {
882 if (!with_commit)
883 return 1;
884 while (with_commit) {
885 struct commit *other;
886
887 other = with_commit->item;
888 with_commit = with_commit->next;
889 if (in_merge_bases(other, commit))
890 return 1;
891 }
892 return 0;
893 }
894
895 /*
896 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
897 */
898 int in_merge_bases(struct commit *commit, struct commit *reference)
899 {
900 struct commit_list *bases;
901 int ret = 0;
902
903 if (parse_commit(commit) || parse_commit(reference))
904 return ret;
905
906 bases = paint_down_to_common(commit, 1, &reference);
907 if (commit->object.flags & PARENT2)
908 ret = 1;
909 clear_commit_marks(commit, all_flags);
910 clear_commit_marks(reference, all_flags);
911 free_commit_list(bases);
912 return ret;
913 }
914
915 struct commit_list *reduce_heads(struct commit_list *heads)
916 {
917 struct commit_list *p;
918 struct commit_list *result = NULL, **tail = &result;
919 struct commit **array;
920 int num_head, i;
921
922 if (!heads)
923 return NULL;
924
925 /* Uniquify */
926 for (p = heads; p; p = p->next)
927 p->item->object.flags &= ~STALE;
928 for (p = heads, num_head = 0; p; p = p->next) {
929 if (p->item->object.flags & STALE)
930 continue;
931 p->item->object.flags |= STALE;
932 num_head++;
933 }
934 array = xcalloc(sizeof(*array), num_head);
935 for (p = heads, i = 0; p; p = p->next) {
936 if (p->item->object.flags & STALE) {
937 array[i++] = p->item;
938 p->item->object.flags &= ~STALE;
939 }
940 }
941 num_head = remove_redundant(array, num_head);
942 for (i = 0; i < num_head; i++)
943 tail = &commit_list_insert(array[i], tail)->next;
944 return result;
945 }
946
947 static const char gpg_sig_header[] = "gpgsig";
948 static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
949
950 static int do_sign_commit(struct strbuf *buf, const char *keyid)
951 {
952 struct strbuf sig = STRBUF_INIT;
953 int inspos, copypos;
954
955 /* find the end of the header */
956 inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
957
958 if (!keyid || !*keyid)
959 keyid = get_signing_key();
960 if (sign_buffer(buf, &sig, keyid)) {
961 strbuf_release(&sig);
962 return -1;
963 }
964
965 for (copypos = 0; sig.buf[copypos]; ) {
966 const char *bol = sig.buf + copypos;
967 const char *eol = strchrnul(bol, '\n');
968 int len = (eol - bol) + !!*eol;
969
970 if (!copypos) {
971 strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
972 inspos += gpg_sig_header_len;
973 }
974 strbuf_insert(buf, inspos++, " ", 1);
975 strbuf_insert(buf, inspos, bol, len);
976 inspos += len;
977 copypos += len;
978 }
979 strbuf_release(&sig);
980 return 0;
981 }
982
983 int parse_signed_commit(const unsigned char *sha1,
984 struct strbuf *payload, struct strbuf *signature)
985 {
986 unsigned long size;
987 enum object_type type;
988 char *buffer = read_sha1_file(sha1, &type, &size);
989 int in_signature, saw_signature = -1;
990 char *line, *tail;
991
992 if (!buffer || type != OBJ_COMMIT)
993 goto cleanup;
994
995 line = buffer;
996 tail = buffer + size;
997 in_signature = 0;
998 saw_signature = 0;
999 while (line < tail) {
1000 const char *sig = NULL;
1001 char *next = memchr(line, '\n', tail - line);
1002
1003 next = next ? next + 1 : tail;
1004 if (in_signature && line[0] == ' ')
1005 sig = line + 1;
1006 else if (!prefixcmp(line, gpg_sig_header) &&
1007 line[gpg_sig_header_len] == ' ')
1008 sig = line + gpg_sig_header_len + 1;
1009 if (sig) {
1010 strbuf_add(signature, sig, next - sig);
1011 saw_signature = 1;
1012 in_signature = 1;
1013 } else {
1014 if (*line == '\n')
1015 /* dump the whole remainder of the buffer */
1016 next = tail;
1017 strbuf_add(payload, line, next - line);
1018 in_signature = 0;
1019 }
1020 line = next;
1021 }
1022 cleanup:
1023 free(buffer);
1024 return saw_signature;
1025 }
1026
1027 static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1028 {
1029 struct merge_remote_desc *desc;
1030 struct commit_extra_header *mergetag;
1031 char *buf;
1032 unsigned long size, len;
1033 enum object_type type;
1034
1035 desc = merge_remote_util(parent);
1036 if (!desc || !desc->obj)
1037 return;
1038 buf = read_sha1_file(desc->obj->sha1, &type, &size);
1039 if (!buf || type != OBJ_TAG)
1040 goto free_return;
1041 len = parse_signature(buf, size);
1042 if (size == len)
1043 goto free_return;
1044 /*
1045 * We could verify this signature and either omit the tag when
1046 * it does not validate, but the integrator may not have the
1047 * public key of the signer of the tag he is merging, while a
1048 * later auditor may have it while auditing, so let's not run
1049 * verify-signed-buffer here for now...
1050 *
1051 * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1052 * warn("warning: signed tag unverified.");
1053 */
1054 mergetag = xcalloc(1, sizeof(*mergetag));
1055 mergetag->key = xstrdup("mergetag");
1056 mergetag->value = buf;
1057 mergetag->len = size;
1058
1059 **tail = mergetag;
1060 *tail = &mergetag->next;
1061 return;
1062
1063 free_return:
1064 free(buf);
1065 }
1066
1067 void append_merge_tag_headers(struct commit_list *parents,
1068 struct commit_extra_header ***tail)
1069 {
1070 while (parents) {
1071 struct commit *parent = parents->item;
1072 handle_signed_tag(parent, tail);
1073 parents = parents->next;
1074 }
1075 }
1076
1077 static void add_extra_header(struct strbuf *buffer,
1078 struct commit_extra_header *extra)
1079 {
1080 strbuf_addstr(buffer, extra->key);
1081 if (extra->len)
1082 strbuf_add_lines(buffer, " ", extra->value, extra->len);
1083 else
1084 strbuf_addch(buffer, '\n');
1085 }
1086
1087 struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1088 const char **exclude)
1089 {
1090 struct commit_extra_header *extra = NULL;
1091 unsigned long size;
1092 enum object_type type;
1093 char *buffer = read_sha1_file(commit->object.sha1, &type, &size);
1094 if (buffer && type == OBJ_COMMIT)
1095 extra = read_commit_extra_header_lines(buffer, size, exclude);
1096 free(buffer);
1097 return extra;
1098 }
1099
1100 static inline int standard_header_field(const char *field, size_t len)
1101 {
1102 return ((len == 4 && !memcmp(field, "tree ", 5)) ||
1103 (len == 6 && !memcmp(field, "parent ", 7)) ||
1104 (len == 6 && !memcmp(field, "author ", 7)) ||
1105 (len == 9 && !memcmp(field, "committer ", 10)) ||
1106 (len == 8 && !memcmp(field, "encoding ", 9)));
1107 }
1108
1109 static int excluded_header_field(const char *field, size_t len, const char **exclude)
1110 {
1111 if (!exclude)
1112 return 0;
1113
1114 while (*exclude) {
1115 size_t xlen = strlen(*exclude);
1116 if (len == xlen &&
1117 !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
1118 return 1;
1119 exclude++;
1120 }
1121 return 0;
1122 }
1123
1124 static struct commit_extra_header *read_commit_extra_header_lines(
1125 const char *buffer, size_t size,
1126 const char **exclude)
1127 {
1128 struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1129 const char *line, *next, *eof, *eob;
1130 struct strbuf buf = STRBUF_INIT;
1131
1132 for (line = buffer, eob = line + size;
1133 line < eob && *line != '\n';
1134 line = next) {
1135 next = memchr(line, '\n', eob - line);
1136 next = next ? next + 1 : eob;
1137 if (*line == ' ') {
1138 /* continuation */
1139 if (it)
1140 strbuf_add(&buf, line + 1, next - (line + 1));
1141 continue;
1142 }
1143 if (it)
1144 it->value = strbuf_detach(&buf, &it->len);
1145 strbuf_reset(&buf);
1146 it = NULL;
1147
1148 eof = strchr(line, ' ');
1149 if (next <= eof)
1150 eof = next;
1151
1152 if (standard_header_field(line, eof - line) ||
1153 excluded_header_field(line, eof - line, exclude))
1154 continue;
1155
1156 it = xcalloc(1, sizeof(*it));
1157 it->key = xmemdupz(line, eof-line);
1158 *tail = it;
1159 tail = &it->next;
1160 if (eof + 1 < next)
1161 strbuf_add(&buf, eof + 1, next - (eof + 1));
1162 }
1163 if (it)
1164 it->value = strbuf_detach(&buf, &it->len);
1165 return extra;
1166 }
1167
1168 void free_commit_extra_headers(struct commit_extra_header *extra)
1169 {
1170 while (extra) {
1171 struct commit_extra_header *next = extra->next;
1172 free(extra->key);
1173 free(extra->value);
1174 free(extra);
1175 extra = next;
1176 }
1177 }
1178
1179 int commit_tree(const struct strbuf *msg, unsigned char *tree,
1180 struct commit_list *parents, unsigned char *ret,
1181 const char *author, const char *sign_commit)
1182 {
1183 struct commit_extra_header *extra = NULL, **tail = &extra;
1184 int result;
1185
1186 append_merge_tag_headers(parents, &tail);
1187 result = commit_tree_extended(msg, tree, parents, ret,
1188 author, sign_commit, extra);
1189 free_commit_extra_headers(extra);
1190 return result;
1191 }
1192
1193 static int find_invalid_utf8(const char *buf, int len)
1194 {
1195 int offset = 0;
1196
1197 while (len) {
1198 unsigned char c = *buf++;
1199 int bytes, bad_offset;
1200
1201 len--;
1202 offset++;
1203
1204 /* Simple US-ASCII? No worries. */
1205 if (c < 0x80)
1206 continue;
1207
1208 bad_offset = offset-1;
1209
1210 /*
1211 * Count how many more high bits set: that's how
1212 * many more bytes this sequence should have.
1213 */
1214 bytes = 0;
1215 while (c & 0x40) {
1216 c <<= 1;
1217 bytes++;
1218 }
1219
1220 /* Must be between 1 and 5 more bytes */
1221 if (bytes < 1 || bytes > 5)
1222 return bad_offset;
1223
1224 /* Do we *have* that many bytes? */
1225 if (len < bytes)
1226 return bad_offset;
1227
1228 offset += bytes;
1229 len -= bytes;
1230
1231 /* And verify that they are good continuation bytes */
1232 do {
1233 if ((*buf++ & 0xc0) != 0x80)
1234 return bad_offset;
1235 } while (--bytes);
1236
1237 /* We could/should check the value and length here too */
1238 }
1239 return -1;
1240 }
1241
1242 /*
1243 * This verifies that the buffer is in proper utf8 format.
1244 *
1245 * If it isn't, it assumes any non-utf8 characters are Latin1,
1246 * and does the conversion.
1247 *
1248 * Fixme: we should probably also disallow overlong forms and
1249 * invalid characters. But we don't do that currently.
1250 */
1251 static int verify_utf8(struct strbuf *buf)
1252 {
1253 int ok = 1;
1254 long pos = 0;
1255
1256 for (;;) {
1257 int bad;
1258 unsigned char c;
1259 unsigned char replace[2];
1260
1261 bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1262 if (bad < 0)
1263 return ok;
1264 pos += bad;
1265 ok = 0;
1266 c = buf->buf[pos];
1267 strbuf_remove(buf, pos, 1);
1268
1269 /* We know 'c' must be in the range 128-255 */
1270 replace[0] = 0xc0 + (c >> 6);
1271 replace[1] = 0x80 + (c & 0x3f);
1272 strbuf_insert(buf, pos, replace, 2);
1273 pos += 2;
1274 }
1275 }
1276
1277 static const char commit_utf8_warn[] =
1278 "Warning: commit message did not conform to UTF-8.\n"
1279 "You may want to amend it after fixing the message, or set the config\n"
1280 "variable i18n.commitencoding to the encoding your project uses.\n";
1281
1282 int commit_tree_extended(const struct strbuf *msg, unsigned char *tree,
1283 struct commit_list *parents, unsigned char *ret,
1284 const char *author, const char *sign_commit,
1285 struct commit_extra_header *extra)
1286 {
1287 int result;
1288 int encoding_is_utf8;
1289 struct strbuf buffer;
1290
1291 assert_sha1_type(tree, OBJ_TREE);
1292
1293 if (memchr(msg->buf, '\0', msg->len))
1294 return error("a NUL byte in commit log message not allowed.");
1295
1296 /* Not having i18n.commitencoding is the same as having utf-8 */
1297 encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1298
1299 strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1300 strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1301
1302 /*
1303 * NOTE! This ordering means that the same exact tree merged with a
1304 * different order of parents will be a _different_ changeset even
1305 * if everything else stays the same.
1306 */
1307 while (parents) {
1308 struct commit_list *next = parents->next;
1309 struct commit *parent = parents->item;
1310
1311 strbuf_addf(&buffer, "parent %s\n",
1312 sha1_to_hex(parent->object.sha1));
1313 free(parents);
1314 parents = next;
1315 }
1316
1317 /* Person/date information */
1318 if (!author)
1319 author = git_author_info(IDENT_STRICT);
1320 strbuf_addf(&buffer, "author %s\n", author);
1321 strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1322 if (!encoding_is_utf8)
1323 strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1324
1325 while (extra) {
1326 add_extra_header(&buffer, extra);
1327 extra = extra->next;
1328 }
1329 strbuf_addch(&buffer, '\n');
1330
1331 /* And add the comment */
1332 strbuf_addbuf(&buffer, msg);
1333
1334 /* And check the encoding */
1335 if (encoding_is_utf8 && !verify_utf8(&buffer))
1336 fprintf(stderr, commit_utf8_warn);
1337
1338 if (sign_commit && do_sign_commit(&buffer, sign_commit))
1339 return -1;
1340
1341 result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1342 strbuf_release(&buffer);
1343 return result;
1344 }
1345
1346 struct commit *get_merge_parent(const char *name)
1347 {
1348 struct object *obj;
1349 struct commit *commit;
1350 unsigned char sha1[20];
1351 if (get_sha1(name, sha1))
1352 return NULL;
1353 obj = parse_object(sha1);
1354 commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1355 if (commit && !commit->util) {
1356 struct merge_remote_desc *desc;
1357 desc = xmalloc(sizeof(*desc));
1358 desc->obj = obj;
1359 desc->name = strdup(name);
1360 commit->util = desc;
1361 }
1362 return commit;
1363 }
1364
1365 /*
1366 * Append a commit to the end of the commit_list.
1367 *
1368 * next starts by pointing to the variable that holds the head of an
1369 * empty commit_list, and is updated to point to the "next" field of
1370 * the last item on the list as new commits are appended.
1371 *
1372 * Usage example:
1373 *
1374 * struct commit_list *list;
1375 * struct commit_list **next = &list;
1376 *
1377 * next = commit_list_append(c1, next);
1378 * next = commit_list_append(c2, next);
1379 * assert(commit_list_count(list) == 2);
1380 * return list;
1381 */
1382 struct commit_list **commit_list_append(struct commit *commit,
1383 struct commit_list **next)
1384 {
1385 struct commit_list *new = xmalloc(sizeof(struct commit_list));
1386 new->item = commit;
1387 *next = new;
1388 new->next = NULL;
1389 return &new->next;
1390 }
1391
1392 void print_commit_list(struct commit_list *list,
1393 const char *format_cur,
1394 const char *format_last)
1395 {
1396 for ( ; list; list = list->next) {
1397 const char *format = list->next ? format_cur : format_last;
1398 printf(format, sha1_to_hex(list->item->object.sha1));
1399 }
1400 }