commit: allow prepare_commit_graft to handle arbitrary repositories
[git/git.git] / commit.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "commit.h"
4 #include "repository.h"
5 #include "object-store.h"
6 #include "pkt-line.h"
7 #include "utf8.h"
8 #include "diff.h"
9 #include "revision.h"
10 #include "notes.h"
11 #include "alloc.h"
12 #include "gpg-interface.h"
13 #include "mergesort.h"
14 #include "commit-slab.h"
15 #include "prio-queue.h"
16 #include "sha1-lookup.h"
17 #include "wt-status.h"
18
19 static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
20
21 int save_commit_buffer = 1;
22
23 const char *commit_type = "commit";
24
25 struct commit *lookup_commit_reference_gently(const struct object_id *oid,
26 int quiet)
27 {
28 struct object *obj = deref_tag(parse_object(oid), NULL, 0);
29
30 if (!obj)
31 return NULL;
32 return object_as_type(obj, OBJ_COMMIT, quiet);
33 }
34
35 struct commit *lookup_commit_reference(const struct object_id *oid)
36 {
37 return lookup_commit_reference_gently(oid, 0);
38 }
39
40 struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name)
41 {
42 struct commit *c = lookup_commit_reference(oid);
43 if (!c)
44 die(_("could not parse %s"), ref_name);
45 if (oidcmp(oid, &c->object.oid)) {
46 warning(_("%s %s is not a commit!"),
47 ref_name, oid_to_hex(oid));
48 }
49 return c;
50 }
51
52 struct commit *lookup_commit(const struct object_id *oid)
53 {
54 struct object *obj = lookup_object(oid->hash);
55 if (!obj)
56 return create_object(the_repository, oid->hash,
57 alloc_commit_node(the_repository));
58 return object_as_type(obj, OBJ_COMMIT, 0);
59 }
60
61 struct commit *lookup_commit_reference_by_name(const char *name)
62 {
63 struct object_id oid;
64 struct commit *commit;
65
66 if (get_oid_committish(name, &oid))
67 return NULL;
68 commit = lookup_commit_reference(&oid);
69 if (parse_commit(commit))
70 return NULL;
71 return commit;
72 }
73
74 static timestamp_t parse_commit_date(const char *buf, const char *tail)
75 {
76 const char *dateptr;
77
78 if (buf + 6 >= tail)
79 return 0;
80 if (memcmp(buf, "author", 6))
81 return 0;
82 while (buf < tail && *buf++ != '\n')
83 /* nada */;
84 if (buf + 9 >= tail)
85 return 0;
86 if (memcmp(buf, "committer", 9))
87 return 0;
88 while (buf < tail && *buf++ != '>')
89 /* nada */;
90 if (buf >= tail)
91 return 0;
92 dateptr = buf;
93 while (buf < tail && *buf++ != '\n')
94 /* nada */;
95 if (buf >= tail)
96 return 0;
97 /* dateptr < buf && buf[-1] == '\n', so parsing will stop at buf-1 */
98 return parse_timestamp(dateptr, NULL, 10);
99 }
100
101 static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
102 {
103 struct commit_graft **commit_graft_table = table;
104 return commit_graft_table[index]->oid.hash;
105 }
106
107 static int commit_graft_pos(struct repository *r, const unsigned char *sha1)
108 {
109 return sha1_pos(sha1, r->parsed_objects->grafts,
110 r->parsed_objects->grafts_nr,
111 commit_graft_sha1_access);
112 }
113
114 int register_commit_graft(struct repository *r, struct commit_graft *graft,
115 int ignore_dups)
116 {
117 int pos = commit_graft_pos(r, graft->oid.hash);
118
119 if (0 <= pos) {
120 if (ignore_dups)
121 free(graft);
122 else {
123 free(r->parsed_objects->grafts[pos]);
124 r->parsed_objects->grafts[pos] = graft;
125 }
126 return 1;
127 }
128 pos = -pos - 1;
129 ALLOC_GROW(r->parsed_objects->grafts,
130 r->parsed_objects->grafts_nr + 1,
131 r->parsed_objects->grafts_alloc);
132 r->parsed_objects->grafts_nr++;
133 if (pos < r->parsed_objects->grafts_nr)
134 memmove(r->parsed_objects->grafts + pos + 1,
135 r->parsed_objects->grafts + pos,
136 (r->parsed_objects->grafts_nr - pos - 1) *
137 sizeof(*r->parsed_objects->grafts));
138 r->parsed_objects->grafts[pos] = graft;
139 return 0;
140 }
141
142 struct commit_graft *read_graft_line(struct strbuf *line)
143 {
144 /* The format is just "Commit Parent1 Parent2 ...\n" */
145 int i, phase;
146 const char *tail = NULL;
147 struct commit_graft *graft = NULL;
148 struct object_id dummy_oid, *oid;
149
150 strbuf_rtrim(line);
151 if (!line->len || line->buf[0] == '#')
152 return NULL;
153 /*
154 * phase 0 verifies line, counts hashes in line and allocates graft
155 * phase 1 fills graft
156 */
157 for (phase = 0; phase < 2; phase++) {
158 oid = graft ? &graft->oid : &dummy_oid;
159 if (parse_oid_hex(line->buf, oid, &tail))
160 goto bad_graft_data;
161 for (i = 0; *tail != '\0'; i++) {
162 oid = graft ? &graft->parent[i] : &dummy_oid;
163 if (!isspace(*tail++) || parse_oid_hex(tail, oid, &tail))
164 goto bad_graft_data;
165 }
166 if (!graft) {
167 graft = xmalloc(st_add(sizeof(*graft),
168 st_mult(sizeof(struct object_id), i)));
169 graft->nr_parent = i;
170 }
171 }
172 return graft;
173
174 bad_graft_data:
175 error("bad graft data: %s", line->buf);
176 assert(!graft);
177 return NULL;
178 }
179
180 static int read_graft_file(struct repository *r, const char *graft_file)
181 {
182 FILE *fp = fopen_or_warn(graft_file, "r");
183 struct strbuf buf = STRBUF_INIT;
184 if (!fp)
185 return -1;
186 while (!strbuf_getwholeline(&buf, fp, '\n')) {
187 /* The format is just "Commit Parent1 Parent2 ...\n" */
188 struct commit_graft *graft = read_graft_line(&buf);
189 if (!graft)
190 continue;
191 if (register_commit_graft(r, graft, 1))
192 error("duplicate graft data: %s", buf.buf);
193 }
194 fclose(fp);
195 strbuf_release(&buf);
196 return 0;
197 }
198
199 static void prepare_commit_graft(struct repository *r)
200 {
201 char *graft_file;
202
203 if (r->parsed_objects->commit_graft_prepared)
204 return;
205 graft_file = get_graft_file(r);
206 read_graft_file(r, graft_file);
207 /* make sure shallows are read */
208 is_repository_shallow(r);
209 r->parsed_objects->commit_graft_prepared = 1;
210 }
211
212 struct commit_graft *lookup_commit_graft_the_repository(const struct object_id *oid)
213 {
214 int pos;
215 prepare_commit_graft(the_repository);
216 pos = commit_graft_pos(the_repository, oid->hash);
217 if (pos < 0)
218 return NULL;
219 return the_repository->parsed_objects->grafts[pos];
220 }
221
222 int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
223 {
224 int i, ret;
225 for (i = ret = 0; i < the_repository->parsed_objects->grafts_nr && !ret; i++)
226 ret = fn(the_repository->parsed_objects->grafts[i], cb_data);
227 return ret;
228 }
229
230 int unregister_shallow(const struct object_id *oid)
231 {
232 int pos = commit_graft_pos(the_repository, oid->hash);
233 if (pos < 0)
234 return -1;
235 if (pos + 1 < the_repository->parsed_objects->grafts_nr)
236 MOVE_ARRAY(the_repository->parsed_objects->grafts + pos,
237 the_repository->parsed_objects->grafts + pos + 1,
238 the_repository->parsed_objects->grafts_nr - pos - 1);
239 the_repository->parsed_objects->grafts_nr--;
240 return 0;
241 }
242
243 struct commit_buffer {
244 void *buffer;
245 unsigned long size;
246 };
247 define_commit_slab(buffer_slab, struct commit_buffer);
248 static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
249
250 void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
251 {
252 struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
253 v->buffer = buffer;
254 v->size = size;
255 }
256
257 const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
258 {
259 struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
260 if (!v) {
261 if (sizep)
262 *sizep = 0;
263 return NULL;
264 }
265 if (sizep)
266 *sizep = v->size;
267 return v->buffer;
268 }
269
270 const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
271 {
272 const void *ret = get_cached_commit_buffer(commit, sizep);
273 if (!ret) {
274 enum object_type type;
275 unsigned long size;
276 ret = read_object_file(&commit->object.oid, &type, &size);
277 if (!ret)
278 die("cannot read commit object %s",
279 oid_to_hex(&commit->object.oid));
280 if (type != OBJ_COMMIT)
281 die("expected commit for %s, got %s",
282 oid_to_hex(&commit->object.oid), type_name(type));
283 if (sizep)
284 *sizep = size;
285 }
286 return ret;
287 }
288
289 void unuse_commit_buffer(const struct commit *commit, const void *buffer)
290 {
291 struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
292 if (!(v && v->buffer == buffer))
293 free((void *)buffer);
294 }
295
296 void free_commit_buffer(struct commit *commit)
297 {
298 struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
299 if (v) {
300 FREE_AND_NULL(v->buffer);
301 v->size = 0;
302 }
303 }
304
305 void release_commit_memory(struct commit *c)
306 {
307 c->tree = NULL;
308 c->index = 0;
309 free_commit_buffer(c);
310 free_commit_list(c->parents);
311 /* TODO: what about commit->util? */
312
313 c->object.parsed = 0;
314 }
315
316 const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
317 {
318 struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
319 void *ret;
320
321 if (!v) {
322 if (sizep)
323 *sizep = 0;
324 return NULL;
325 }
326 ret = v->buffer;
327 if (sizep)
328 *sizep = v->size;
329
330 v->buffer = NULL;
331 v->size = 0;
332 return ret;
333 }
334
335 int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
336 {
337 const char *tail = buffer;
338 const char *bufptr = buffer;
339 struct object_id parent;
340 struct commit_list **pptr;
341 struct commit_graft *graft;
342 const int tree_entry_len = GIT_SHA1_HEXSZ + 5;
343 const int parent_entry_len = GIT_SHA1_HEXSZ + 7;
344
345 if (item->object.parsed)
346 return 0;
347 item->object.parsed = 1;
348 tail += size;
349 if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
350 bufptr[tree_entry_len] != '\n')
351 return error("bogus commit object %s", oid_to_hex(&item->object.oid));
352 if (get_sha1_hex(bufptr + 5, parent.hash) < 0)
353 return error("bad tree pointer in commit %s",
354 oid_to_hex(&item->object.oid));
355 item->tree = lookup_tree(&parent);
356 bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
357 pptr = &item->parents;
358
359 graft = lookup_commit_graft(the_repository, &item->object.oid);
360 while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
361 struct commit *new_parent;
362
363 if (tail <= bufptr + parent_entry_len + 1 ||
364 get_sha1_hex(bufptr + 7, parent.hash) ||
365 bufptr[parent_entry_len] != '\n')
366 return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
367 bufptr += parent_entry_len + 1;
368 /*
369 * The clone is shallow if nr_parent < 0, and we must
370 * not traverse its real parents even when we unhide them.
371 */
372 if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
373 continue;
374 new_parent = lookup_commit(&parent);
375 if (new_parent)
376 pptr = &commit_list_insert(new_parent, pptr)->next;
377 }
378 if (graft) {
379 int i;
380 struct commit *new_parent;
381 for (i = 0; i < graft->nr_parent; i++) {
382 new_parent = lookup_commit(&graft->parent[i]);
383 if (!new_parent)
384 continue;
385 pptr = &commit_list_insert(new_parent, pptr)->next;
386 }
387 }
388 item->date = parse_commit_date(bufptr, tail);
389
390 return 0;
391 }
392
393 int parse_commit_gently(struct commit *item, int quiet_on_missing)
394 {
395 enum object_type type;
396 void *buffer;
397 unsigned long size;
398 int ret;
399
400 if (!item)
401 return -1;
402 if (item->object.parsed)
403 return 0;
404 buffer = read_object_file(&item->object.oid, &type, &size);
405 if (!buffer)
406 return quiet_on_missing ? -1 :
407 error("Could not read %s",
408 oid_to_hex(&item->object.oid));
409 if (type != OBJ_COMMIT) {
410 free(buffer);
411 return error("Object %s not a commit",
412 oid_to_hex(&item->object.oid));
413 }
414 ret = parse_commit_buffer(item, buffer, size);
415 if (save_commit_buffer && !ret) {
416 set_commit_buffer(item, buffer, size);
417 return 0;
418 }
419 free(buffer);
420 return ret;
421 }
422
423 void parse_commit_or_die(struct commit *item)
424 {
425 if (parse_commit(item))
426 die("unable to parse commit %s",
427 item ? oid_to_hex(&item->object.oid) : "(null)");
428 }
429
430 int find_commit_subject(const char *commit_buffer, const char **subject)
431 {
432 const char *eol;
433 const char *p = commit_buffer;
434
435 while (*p && (*p != '\n' || p[1] != '\n'))
436 p++;
437 if (*p) {
438 p = skip_blank_lines(p + 2);
439 eol = strchrnul(p, '\n');
440 } else
441 eol = p;
442
443 *subject = p;
444
445 return eol - p;
446 }
447
448 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
449 {
450 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
451 new_list->item = item;
452 new_list->next = *list_p;
453 *list_p = new_list;
454 return new_list;
455 }
456
457 unsigned commit_list_count(const struct commit_list *l)
458 {
459 unsigned c = 0;
460 for (; l; l = l->next )
461 c++;
462 return c;
463 }
464
465 struct commit_list *copy_commit_list(struct commit_list *list)
466 {
467 struct commit_list *head = NULL;
468 struct commit_list **pp = &head;
469 while (list) {
470 pp = commit_list_append(list->item, pp);
471 list = list->next;
472 }
473 return head;
474 }
475
476 void free_commit_list(struct commit_list *list)
477 {
478 while (list)
479 pop_commit(&list);
480 }
481
482 struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
483 {
484 struct commit_list **pp = list;
485 struct commit_list *p;
486 while ((p = *pp) != NULL) {
487 if (p->item->date < item->date) {
488 break;
489 }
490 pp = &p->next;
491 }
492 return commit_list_insert(item, pp);
493 }
494
495 static int commit_list_compare_by_date(const void *a, const void *b)
496 {
497 timestamp_t a_date = ((const struct commit_list *)a)->item->date;
498 timestamp_t b_date = ((const struct commit_list *)b)->item->date;
499 if (a_date < b_date)
500 return 1;
501 if (a_date > b_date)
502 return -1;
503 return 0;
504 }
505
506 static void *commit_list_get_next(const void *a)
507 {
508 return ((const struct commit_list *)a)->next;
509 }
510
511 static void commit_list_set_next(void *a, void *next)
512 {
513 ((struct commit_list *)a)->next = next;
514 }
515
516 void commit_list_sort_by_date(struct commit_list **list)
517 {
518 *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
519 commit_list_compare_by_date);
520 }
521
522 struct commit *pop_most_recent_commit(struct commit_list **list,
523 unsigned int mark)
524 {
525 struct commit *ret = pop_commit(list);
526 struct commit_list *parents = ret->parents;
527
528 while (parents) {
529 struct commit *commit = parents->item;
530 if (!parse_commit(commit) && !(commit->object.flags & mark)) {
531 commit->object.flags |= mark;
532 commit_list_insert_by_date(commit, list);
533 }
534 parents = parents->next;
535 }
536 return ret;
537 }
538
539 static void clear_commit_marks_1(struct commit_list **plist,
540 struct commit *commit, unsigned int mark)
541 {
542 while (commit) {
543 struct commit_list *parents;
544
545 if (!(mark & commit->object.flags))
546 return;
547
548 commit->object.flags &= ~mark;
549
550 parents = commit->parents;
551 if (!parents)
552 return;
553
554 while ((parents = parents->next))
555 commit_list_insert(parents->item, plist);
556
557 commit = commit->parents->item;
558 }
559 }
560
561 void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
562 {
563 struct commit_list *list = NULL;
564
565 while (nr--) {
566 clear_commit_marks_1(&list, *commit, mark);
567 commit++;
568 }
569 while (list)
570 clear_commit_marks_1(&list, pop_commit(&list), mark);
571 }
572
573 void clear_commit_marks(struct commit *commit, unsigned int mark)
574 {
575 clear_commit_marks_many(1, &commit, mark);
576 }
577
578 struct commit *pop_commit(struct commit_list **stack)
579 {
580 struct commit_list *top = *stack;
581 struct commit *item = top ? top->item : NULL;
582
583 if (top) {
584 *stack = top->next;
585 free(top);
586 }
587 return item;
588 }
589
590 /*
591 * Topological sort support
592 */
593
594 /* count number of children that have not been emitted */
595 define_commit_slab(indegree_slab, int);
596
597 /* record author-date for each commit object */
598 define_commit_slab(author_date_slab, unsigned long);
599
600 static void record_author_date(struct author_date_slab *author_date,
601 struct commit *commit)
602 {
603 const char *buffer = get_commit_buffer(commit, NULL);
604 struct ident_split ident;
605 const char *ident_line;
606 size_t ident_len;
607 char *date_end;
608 timestamp_t date;
609
610 ident_line = find_commit_header(buffer, "author", &ident_len);
611 if (!ident_line)
612 goto fail_exit; /* no author line */
613 if (split_ident_line(&ident, ident_line, ident_len) ||
614 !ident.date_begin || !ident.date_end)
615 goto fail_exit; /* malformed "author" line */
616
617 date = parse_timestamp(ident.date_begin, &date_end, 10);
618 if (date_end != ident.date_end)
619 goto fail_exit; /* malformed date */
620 *(author_date_slab_at(author_date, commit)) = date;
621
622 fail_exit:
623 unuse_commit_buffer(commit, buffer);
624 }
625
626 static int compare_commits_by_author_date(const void *a_, const void *b_,
627 void *cb_data)
628 {
629 const struct commit *a = a_, *b = b_;
630 struct author_date_slab *author_date = cb_data;
631 timestamp_t a_date = *(author_date_slab_at(author_date, a));
632 timestamp_t b_date = *(author_date_slab_at(author_date, b));
633
634 /* newer commits with larger date first */
635 if (a_date < b_date)
636 return 1;
637 else if (a_date > b_date)
638 return -1;
639 return 0;
640 }
641
642 int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
643 {
644 const struct commit *a = a_, *b = b_;
645 /* newer commits with larger date first */
646 if (a->date < b->date)
647 return 1;
648 else if (a->date > b->date)
649 return -1;
650 return 0;
651 }
652
653 /*
654 * Performs an in-place topological sort on the list supplied.
655 */
656 void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
657 {
658 struct commit_list *next, *orig = *list;
659 struct commit_list **pptr;
660 struct indegree_slab indegree;
661 struct prio_queue queue;
662 struct commit *commit;
663 struct author_date_slab author_date;
664
665 if (!orig)
666 return;
667 *list = NULL;
668
669 init_indegree_slab(&indegree);
670 memset(&queue, '\0', sizeof(queue));
671
672 switch (sort_order) {
673 default: /* REV_SORT_IN_GRAPH_ORDER */
674 queue.compare = NULL;
675 break;
676 case REV_SORT_BY_COMMIT_DATE:
677 queue.compare = compare_commits_by_commit_date;
678 break;
679 case REV_SORT_BY_AUTHOR_DATE:
680 init_author_date_slab(&author_date);
681 queue.compare = compare_commits_by_author_date;
682 queue.cb_data = &author_date;
683 break;
684 }
685
686 /* Mark them and clear the indegree */
687 for (next = orig; next; next = next->next) {
688 struct commit *commit = next->item;
689 *(indegree_slab_at(&indegree, commit)) = 1;
690 /* also record the author dates, if needed */
691 if (sort_order == REV_SORT_BY_AUTHOR_DATE)
692 record_author_date(&author_date, commit);
693 }
694
695 /* update the indegree */
696 for (next = orig; next; next = next->next) {
697 struct commit_list *parents = next->item->parents;
698 while (parents) {
699 struct commit *parent = parents->item;
700 int *pi = indegree_slab_at(&indegree, parent);
701
702 if (*pi)
703 (*pi)++;
704 parents = parents->next;
705 }
706 }
707
708 /*
709 * find the tips
710 *
711 * tips are nodes not reachable from any other node in the list
712 *
713 * the tips serve as a starting set for the work queue.
714 */
715 for (next = orig; next; next = next->next) {
716 struct commit *commit = next->item;
717
718 if (*(indegree_slab_at(&indegree, commit)) == 1)
719 prio_queue_put(&queue, commit);
720 }
721
722 /*
723 * This is unfortunate; the initial tips need to be shown
724 * in the order given from the revision traversal machinery.
725 */
726 if (sort_order == REV_SORT_IN_GRAPH_ORDER)
727 prio_queue_reverse(&queue);
728
729 /* We no longer need the commit list */
730 free_commit_list(orig);
731
732 pptr = list;
733 *list = NULL;
734 while ((commit = prio_queue_get(&queue)) != NULL) {
735 struct commit_list *parents;
736
737 for (parents = commit->parents; parents ; parents = parents->next) {
738 struct commit *parent = parents->item;
739 int *pi = indegree_slab_at(&indegree, parent);
740
741 if (!*pi)
742 continue;
743
744 /*
745 * parents are only enqueued for emission
746 * when all their children have been emitted thereby
747 * guaranteeing topological order.
748 */
749 if (--(*pi) == 1)
750 prio_queue_put(&queue, parent);
751 }
752 /*
753 * all children of commit have already been
754 * emitted. we can emit it now.
755 */
756 *(indegree_slab_at(&indegree, commit)) = 0;
757
758 pptr = &commit_list_insert(commit, pptr)->next;
759 }
760
761 clear_indegree_slab(&indegree);
762 clear_prio_queue(&queue);
763 if (sort_order == REV_SORT_BY_AUTHOR_DATE)
764 clear_author_date_slab(&author_date);
765 }
766
767 /* merge-base stuff */
768
769 /* Remember to update object flag allocation in object.h */
770 #define PARENT1 (1u<<16)
771 #define PARENT2 (1u<<17)
772 #define STALE (1u<<18)
773 #define RESULT (1u<<19)
774
775 static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
776
777 static int queue_has_nonstale(struct prio_queue *queue)
778 {
779 int i;
780 for (i = 0; i < queue->nr; i++) {
781 struct commit *commit = queue->array[i].data;
782 if (!(commit->object.flags & STALE))
783 return 1;
784 }
785 return 0;
786 }
787
788 /* all input commits in one and twos[] must have been parsed! */
789 static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
790 {
791 struct prio_queue queue = { compare_commits_by_commit_date };
792 struct commit_list *result = NULL;
793 int i;
794
795 one->object.flags |= PARENT1;
796 if (!n) {
797 commit_list_append(one, &result);
798 return result;
799 }
800 prio_queue_put(&queue, one);
801
802 for (i = 0; i < n; i++) {
803 twos[i]->object.flags |= PARENT2;
804 prio_queue_put(&queue, twos[i]);
805 }
806
807 while (queue_has_nonstale(&queue)) {
808 struct commit *commit = prio_queue_get(&queue);
809 struct commit_list *parents;
810 int flags;
811
812 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
813 if (flags == (PARENT1 | PARENT2)) {
814 if (!(commit->object.flags & RESULT)) {
815 commit->object.flags |= RESULT;
816 commit_list_insert_by_date(commit, &result);
817 }
818 /* Mark parents of a found merge stale */
819 flags |= STALE;
820 }
821 parents = commit->parents;
822 while (parents) {
823 struct commit *p = parents->item;
824 parents = parents->next;
825 if ((p->object.flags & flags) == flags)
826 continue;
827 if (parse_commit(p))
828 return NULL;
829 p->object.flags |= flags;
830 prio_queue_put(&queue, p);
831 }
832 }
833
834 clear_prio_queue(&queue);
835 return result;
836 }
837
838 static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
839 {
840 struct commit_list *list = NULL;
841 struct commit_list *result = NULL;
842 int i;
843
844 for (i = 0; i < n; i++) {
845 if (one == twos[i])
846 /*
847 * We do not mark this even with RESULT so we do not
848 * have to clean it up.
849 */
850 return commit_list_insert(one, &result);
851 }
852
853 if (parse_commit(one))
854 return NULL;
855 for (i = 0; i < n; i++) {
856 if (parse_commit(twos[i]))
857 return NULL;
858 }
859
860 list = paint_down_to_common(one, n, twos);
861
862 while (list) {
863 struct commit *commit = pop_commit(&list);
864 if (!(commit->object.flags & STALE))
865 commit_list_insert_by_date(commit, &result);
866 }
867 return result;
868 }
869
870 struct commit_list *get_octopus_merge_bases(struct commit_list *in)
871 {
872 struct commit_list *i, *j, *k, *ret = NULL;
873
874 if (!in)
875 return ret;
876
877 commit_list_insert(in->item, &ret);
878
879 for (i = in->next; i; i = i->next) {
880 struct commit_list *new_commits = NULL, *end = NULL;
881
882 for (j = ret; j; j = j->next) {
883 struct commit_list *bases;
884 bases = get_merge_bases(i->item, j->item);
885 if (!new_commits)
886 new_commits = bases;
887 else
888 end->next = bases;
889 for (k = bases; k; k = k->next)
890 end = k;
891 }
892 ret = new_commits;
893 }
894 return ret;
895 }
896
897 static int remove_redundant(struct commit **array, int cnt)
898 {
899 /*
900 * Some commit in the array may be an ancestor of
901 * another commit. Move such commit to the end of
902 * the array, and return the number of commits that
903 * are independent from each other.
904 */
905 struct commit **work;
906 unsigned char *redundant;
907 int *filled_index;
908 int i, j, filled;
909
910 work = xcalloc(cnt, sizeof(*work));
911 redundant = xcalloc(cnt, 1);
912 ALLOC_ARRAY(filled_index, cnt - 1);
913
914 for (i = 0; i < cnt; i++)
915 parse_commit(array[i]);
916 for (i = 0; i < cnt; i++) {
917 struct commit_list *common;
918
919 if (redundant[i])
920 continue;
921 for (j = filled = 0; j < cnt; j++) {
922 if (i == j || redundant[j])
923 continue;
924 filled_index[filled] = j;
925 work[filled++] = array[j];
926 }
927 common = paint_down_to_common(array[i], filled, work);
928 if (array[i]->object.flags & PARENT2)
929 redundant[i] = 1;
930 for (j = 0; j < filled; j++)
931 if (work[j]->object.flags & PARENT1)
932 redundant[filled_index[j]] = 1;
933 clear_commit_marks(array[i], all_flags);
934 clear_commit_marks_many(filled, work, all_flags);
935 free_commit_list(common);
936 }
937
938 /* Now collect the result */
939 COPY_ARRAY(work, array, cnt);
940 for (i = filled = 0; i < cnt; i++)
941 if (!redundant[i])
942 array[filled++] = work[i];
943 for (j = filled, i = 0; i < cnt; i++)
944 if (redundant[i])
945 array[j++] = work[i];
946 free(work);
947 free(redundant);
948 free(filled_index);
949 return filled;
950 }
951
952 static struct commit_list *get_merge_bases_many_0(struct commit *one,
953 int n,
954 struct commit **twos,
955 int cleanup)
956 {
957 struct commit_list *list;
958 struct commit **rslt;
959 struct commit_list *result;
960 int cnt, i;
961
962 result = merge_bases_many(one, n, twos);
963 for (i = 0; i < n; i++) {
964 if (one == twos[i])
965 return result;
966 }
967 if (!result || !result->next) {
968 if (cleanup) {
969 clear_commit_marks(one, all_flags);
970 clear_commit_marks_many(n, twos, all_flags);
971 }
972 return result;
973 }
974
975 /* There are more than one */
976 cnt = commit_list_count(result);
977 rslt = xcalloc(cnt, sizeof(*rslt));
978 for (list = result, i = 0; list; list = list->next)
979 rslt[i++] = list->item;
980 free_commit_list(result);
981
982 clear_commit_marks(one, all_flags);
983 clear_commit_marks_many(n, twos, all_flags);
984
985 cnt = remove_redundant(rslt, cnt);
986 result = NULL;
987 for (i = 0; i < cnt; i++)
988 commit_list_insert_by_date(rslt[i], &result);
989 free(rslt);
990 return result;
991 }
992
993 struct commit_list *get_merge_bases_many(struct commit *one,
994 int n,
995 struct commit **twos)
996 {
997 return get_merge_bases_many_0(one, n, twos, 1);
998 }
999
1000 struct commit_list *get_merge_bases_many_dirty(struct commit *one,
1001 int n,
1002 struct commit **twos)
1003 {
1004 return get_merge_bases_many_0(one, n, twos, 0);
1005 }
1006
1007 struct commit_list *get_merge_bases(struct commit *one, struct commit *two)
1008 {
1009 return get_merge_bases_many_0(one, 1, &two, 1);
1010 }
1011
1012 /*
1013 * Is "commit" a descendant of one of the elements on the "with_commit" list?
1014 */
1015 int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
1016 {
1017 if (!with_commit)
1018 return 1;
1019 while (with_commit) {
1020 struct commit *other;
1021
1022 other = with_commit->item;
1023 with_commit = with_commit->next;
1024 if (in_merge_bases(other, commit))
1025 return 1;
1026 }
1027 return 0;
1028 }
1029
1030 /*
1031 * Is "commit" an ancestor of one of the "references"?
1032 */
1033 int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1034 {
1035 struct commit_list *bases;
1036 int ret = 0, i;
1037
1038 if (parse_commit(commit))
1039 return ret;
1040 for (i = 0; i < nr_reference; i++)
1041 if (parse_commit(reference[i]))
1042 return ret;
1043
1044 bases = paint_down_to_common(commit, nr_reference, reference);
1045 if (commit->object.flags & PARENT2)
1046 ret = 1;
1047 clear_commit_marks(commit, all_flags);
1048 clear_commit_marks_many(nr_reference, reference, all_flags);
1049 free_commit_list(bases);
1050 return ret;
1051 }
1052
1053 /*
1054 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1055 */
1056 int in_merge_bases(struct commit *commit, struct commit *reference)
1057 {
1058 return in_merge_bases_many(commit, 1, &reference);
1059 }
1060
1061 struct commit_list *reduce_heads(struct commit_list *heads)
1062 {
1063 struct commit_list *p;
1064 struct commit_list *result = NULL, **tail = &result;
1065 struct commit **array;
1066 int num_head, i;
1067
1068 if (!heads)
1069 return NULL;
1070
1071 /* Uniquify */
1072 for (p = heads; p; p = p->next)
1073 p->item->object.flags &= ~STALE;
1074 for (p = heads, num_head = 0; p; p = p->next) {
1075 if (p->item->object.flags & STALE)
1076 continue;
1077 p->item->object.flags |= STALE;
1078 num_head++;
1079 }
1080 array = xcalloc(num_head, sizeof(*array));
1081 for (p = heads, i = 0; p; p = p->next) {
1082 if (p->item->object.flags & STALE) {
1083 array[i++] = p->item;
1084 p->item->object.flags &= ~STALE;
1085 }
1086 }
1087 num_head = remove_redundant(array, num_head);
1088 for (i = 0; i < num_head; i++)
1089 tail = &commit_list_insert(array[i], tail)->next;
1090 free(array);
1091 return result;
1092 }
1093
1094 void reduce_heads_replace(struct commit_list **heads)
1095 {
1096 struct commit_list *result = reduce_heads(*heads);
1097 free_commit_list(*heads);
1098 *heads = result;
1099 }
1100
1101 static const char gpg_sig_header[] = "gpgsig";
1102 static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1103
1104 static int do_sign_commit(struct strbuf *buf, const char *keyid)
1105 {
1106 struct strbuf sig = STRBUF_INIT;
1107 int inspos, copypos;
1108 const char *eoh;
1109
1110 /* find the end of the header */
1111 eoh = strstr(buf->buf, "\n\n");
1112 if (!eoh)
1113 inspos = buf->len;
1114 else
1115 inspos = eoh - buf->buf + 1;
1116
1117 if (!keyid || !*keyid)
1118 keyid = get_signing_key();
1119 if (sign_buffer(buf, &sig, keyid)) {
1120 strbuf_release(&sig);
1121 return -1;
1122 }
1123
1124 for (copypos = 0; sig.buf[copypos]; ) {
1125 const char *bol = sig.buf + copypos;
1126 const char *eol = strchrnul(bol, '\n');
1127 int len = (eol - bol) + !!*eol;
1128
1129 if (!copypos) {
1130 strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1131 inspos += gpg_sig_header_len;
1132 }
1133 strbuf_insert(buf, inspos++, " ", 1);
1134 strbuf_insert(buf, inspos, bol, len);
1135 inspos += len;
1136 copypos += len;
1137 }
1138 strbuf_release(&sig);
1139 return 0;
1140 }
1141
1142 int parse_signed_commit(const struct commit *commit,
1143 struct strbuf *payload, struct strbuf *signature)
1144 {
1145
1146 unsigned long size;
1147 const char *buffer = get_commit_buffer(commit, &size);
1148 int in_signature, saw_signature = -1;
1149 const char *line, *tail;
1150
1151 line = buffer;
1152 tail = buffer + size;
1153 in_signature = 0;
1154 saw_signature = 0;
1155 while (line < tail) {
1156 const char *sig = NULL;
1157 const char *next = memchr(line, '\n', tail - line);
1158
1159 next = next ? next + 1 : tail;
1160 if (in_signature && line[0] == ' ')
1161 sig = line + 1;
1162 else if (starts_with(line, gpg_sig_header) &&
1163 line[gpg_sig_header_len] == ' ')
1164 sig = line + gpg_sig_header_len + 1;
1165 if (sig) {
1166 strbuf_add(signature, sig, next - sig);
1167 saw_signature = 1;
1168 in_signature = 1;
1169 } else {
1170 if (*line == '\n')
1171 /* dump the whole remainder of the buffer */
1172 next = tail;
1173 strbuf_add(payload, line, next - line);
1174 in_signature = 0;
1175 }
1176 line = next;
1177 }
1178 unuse_commit_buffer(commit, buffer);
1179 return saw_signature;
1180 }
1181
1182 int remove_signature(struct strbuf *buf)
1183 {
1184 const char *line = buf->buf;
1185 const char *tail = buf->buf + buf->len;
1186 int in_signature = 0;
1187 const char *sig_start = NULL;
1188 const char *sig_end = NULL;
1189
1190 while (line < tail) {
1191 const char *next = memchr(line, '\n', tail - line);
1192 next = next ? next + 1 : tail;
1193
1194 if (in_signature && line[0] == ' ')
1195 sig_end = next;
1196 else if (starts_with(line, gpg_sig_header) &&
1197 line[gpg_sig_header_len] == ' ') {
1198 sig_start = line;
1199 sig_end = next;
1200 in_signature = 1;
1201 } else {
1202 if (*line == '\n')
1203 /* dump the whole remainder of the buffer */
1204 next = tail;
1205 in_signature = 0;
1206 }
1207 line = next;
1208 }
1209
1210 if (sig_start)
1211 strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1212
1213 return sig_start != NULL;
1214 }
1215
1216 static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1217 {
1218 struct merge_remote_desc *desc;
1219 struct commit_extra_header *mergetag;
1220 char *buf;
1221 unsigned long size, len;
1222 enum object_type type;
1223
1224 desc = merge_remote_util(parent);
1225 if (!desc || !desc->obj)
1226 return;
1227 buf = read_object_file(&desc->obj->oid, &type, &size);
1228 if (!buf || type != OBJ_TAG)
1229 goto free_return;
1230 len = parse_signature(buf, size);
1231 if (size == len)
1232 goto free_return;
1233 /*
1234 * We could verify this signature and either omit the tag when
1235 * it does not validate, but the integrator may not have the
1236 * public key of the signer of the tag he is merging, while a
1237 * later auditor may have it while auditing, so let's not run
1238 * verify-signed-buffer here for now...
1239 *
1240 * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1241 * warn("warning: signed tag unverified.");
1242 */
1243 mergetag = xcalloc(1, sizeof(*mergetag));
1244 mergetag->key = xstrdup("mergetag");
1245 mergetag->value = buf;
1246 mergetag->len = size;
1247
1248 **tail = mergetag;
1249 *tail = &mergetag->next;
1250 return;
1251
1252 free_return:
1253 free(buf);
1254 }
1255
1256 int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1257 {
1258 struct strbuf payload = STRBUF_INIT;
1259 struct strbuf signature = STRBUF_INIT;
1260 int ret = 1;
1261
1262 sigc->result = 'N';
1263
1264 if (parse_signed_commit(commit, &payload, &signature) <= 0)
1265 goto out;
1266 ret = check_signature(payload.buf, payload.len, signature.buf,
1267 signature.len, sigc);
1268
1269 out:
1270 strbuf_release(&payload);
1271 strbuf_release(&signature);
1272
1273 return ret;
1274 }
1275
1276
1277
1278 void append_merge_tag_headers(struct commit_list *parents,
1279 struct commit_extra_header ***tail)
1280 {
1281 while (parents) {
1282 struct commit *parent = parents->item;
1283 handle_signed_tag(parent, tail);
1284 parents = parents->next;
1285 }
1286 }
1287
1288 static void add_extra_header(struct strbuf *buffer,
1289 struct commit_extra_header *extra)
1290 {
1291 strbuf_addstr(buffer, extra->key);
1292 if (extra->len)
1293 strbuf_add_lines(buffer, " ", extra->value, extra->len);
1294 else
1295 strbuf_addch(buffer, '\n');
1296 }
1297
1298 struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1299 const char **exclude)
1300 {
1301 struct commit_extra_header *extra = NULL;
1302 unsigned long size;
1303 const char *buffer = get_commit_buffer(commit, &size);
1304 extra = read_commit_extra_header_lines(buffer, size, exclude);
1305 unuse_commit_buffer(commit, buffer);
1306 return extra;
1307 }
1308
1309 void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1310 {
1311 struct commit_extra_header *extra, *to_free;
1312
1313 to_free = read_commit_extra_headers(commit, NULL);
1314 for (extra = to_free; extra; extra = extra->next) {
1315 if (strcmp(extra->key, "mergetag"))
1316 continue; /* not a merge tag */
1317 fn(commit, extra, data);
1318 }
1319 free_commit_extra_headers(to_free);
1320 }
1321
1322 static inline int standard_header_field(const char *field, size_t len)
1323 {
1324 return ((len == 4 && !memcmp(field, "tree", 4)) ||
1325 (len == 6 && !memcmp(field, "parent", 6)) ||
1326 (len == 6 && !memcmp(field, "author", 6)) ||
1327 (len == 9 && !memcmp(field, "committer", 9)) ||
1328 (len == 8 && !memcmp(field, "encoding", 8)));
1329 }
1330
1331 static int excluded_header_field(const char *field, size_t len, const char **exclude)
1332 {
1333 if (!exclude)
1334 return 0;
1335
1336 while (*exclude) {
1337 size_t xlen = strlen(*exclude);
1338 if (len == xlen && !memcmp(field, *exclude, xlen))
1339 return 1;
1340 exclude++;
1341 }
1342 return 0;
1343 }
1344
1345 static struct commit_extra_header *read_commit_extra_header_lines(
1346 const char *buffer, size_t size,
1347 const char **exclude)
1348 {
1349 struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1350 const char *line, *next, *eof, *eob;
1351 struct strbuf buf = STRBUF_INIT;
1352
1353 for (line = buffer, eob = line + size;
1354 line < eob && *line != '\n';
1355 line = next) {
1356 next = memchr(line, '\n', eob - line);
1357 next = next ? next + 1 : eob;
1358 if (*line == ' ') {
1359 /* continuation */
1360 if (it)
1361 strbuf_add(&buf, line + 1, next - (line + 1));
1362 continue;
1363 }
1364 if (it)
1365 it->value = strbuf_detach(&buf, &it->len);
1366 strbuf_reset(&buf);
1367 it = NULL;
1368
1369 eof = memchr(line, ' ', next - line);
1370 if (!eof)
1371 eof = next;
1372 else if (standard_header_field(line, eof - line) ||
1373 excluded_header_field(line, eof - line, exclude))
1374 continue;
1375
1376 it = xcalloc(1, sizeof(*it));
1377 it->key = xmemdupz(line, eof-line);
1378 *tail = it;
1379 tail = &it->next;
1380 if (eof + 1 < next)
1381 strbuf_add(&buf, eof + 1, next - (eof + 1));
1382 }
1383 if (it)
1384 it->value = strbuf_detach(&buf, &it->len);
1385 return extra;
1386 }
1387
1388 void free_commit_extra_headers(struct commit_extra_header *extra)
1389 {
1390 while (extra) {
1391 struct commit_extra_header *next = extra->next;
1392 free(extra->key);
1393 free(extra->value);
1394 free(extra);
1395 extra = next;
1396 }
1397 }
1398
1399 int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
1400 struct commit_list *parents, struct object_id *ret,
1401 const char *author, const char *sign_commit)
1402 {
1403 struct commit_extra_header *extra = NULL, **tail = &extra;
1404 int result;
1405
1406 append_merge_tag_headers(parents, &tail);
1407 result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1408 author, sign_commit, extra);
1409 free_commit_extra_headers(extra);
1410 return result;
1411 }
1412
1413 static int find_invalid_utf8(const char *buf, int len)
1414 {
1415 int offset = 0;
1416 static const unsigned int max_codepoint[] = {
1417 0x7f, 0x7ff, 0xffff, 0x10ffff
1418 };
1419
1420 while (len) {
1421 unsigned char c = *buf++;
1422 int bytes, bad_offset;
1423 unsigned int codepoint;
1424 unsigned int min_val, max_val;
1425
1426 len--;
1427 offset++;
1428
1429 /* Simple US-ASCII? No worries. */
1430 if (c < 0x80)
1431 continue;
1432
1433 bad_offset = offset-1;
1434
1435 /*
1436 * Count how many more high bits set: that's how
1437 * many more bytes this sequence should have.
1438 */
1439 bytes = 0;
1440 while (c & 0x40) {
1441 c <<= 1;
1442 bytes++;
1443 }
1444
1445 /*
1446 * Must be between 1 and 3 more bytes. Longer sequences result in
1447 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1448 */
1449 if (bytes < 1 || 3 < bytes)
1450 return bad_offset;
1451
1452 /* Do we *have* that many bytes? */
1453 if (len < bytes)
1454 return bad_offset;
1455
1456 /*
1457 * Place the encoded bits at the bottom of the value and compute the
1458 * valid range.
1459 */
1460 codepoint = (c & 0x7f) >> bytes;
1461 min_val = max_codepoint[bytes-1] + 1;
1462 max_val = max_codepoint[bytes];
1463
1464 offset += bytes;
1465 len -= bytes;
1466
1467 /* And verify that they are good continuation bytes */
1468 do {
1469 codepoint <<= 6;
1470 codepoint |= *buf & 0x3f;
1471 if ((*buf++ & 0xc0) != 0x80)
1472 return bad_offset;
1473 } while (--bytes);
1474
1475 /* Reject codepoints that are out of range for the sequence length. */
1476 if (codepoint < min_val || codepoint > max_val)
1477 return bad_offset;
1478 /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1479 if ((codepoint & 0x1ff800) == 0xd800)
1480 return bad_offset;
1481 /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1482 if ((codepoint & 0xfffe) == 0xfffe)
1483 return bad_offset;
1484 /* So are anything in the range U+FDD0..U+FDEF. */
1485 if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1486 return bad_offset;
1487 }
1488 return -1;
1489 }
1490
1491 /*
1492 * This verifies that the buffer is in proper utf8 format.
1493 *
1494 * If it isn't, it assumes any non-utf8 characters are Latin1,
1495 * and does the conversion.
1496 */
1497 static int verify_utf8(struct strbuf *buf)
1498 {
1499 int ok = 1;
1500 long pos = 0;
1501
1502 for (;;) {
1503 int bad;
1504 unsigned char c;
1505 unsigned char replace[2];
1506
1507 bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1508 if (bad < 0)
1509 return ok;
1510 pos += bad;
1511 ok = 0;
1512 c = buf->buf[pos];
1513 strbuf_remove(buf, pos, 1);
1514
1515 /* We know 'c' must be in the range 128-255 */
1516 replace[0] = 0xc0 + (c >> 6);
1517 replace[1] = 0x80 + (c & 0x3f);
1518 strbuf_insert(buf, pos, replace, 2);
1519 pos += 2;
1520 }
1521 }
1522
1523 static const char commit_utf8_warn[] =
1524 N_("Warning: commit message did not conform to UTF-8.\n"
1525 "You may want to amend it after fixing the message, or set the config\n"
1526 "variable i18n.commitencoding to the encoding your project uses.\n");
1527
1528 int commit_tree_extended(const char *msg, size_t msg_len,
1529 const struct object_id *tree,
1530 struct commit_list *parents, struct object_id *ret,
1531 const char *author, const char *sign_commit,
1532 struct commit_extra_header *extra)
1533 {
1534 int result;
1535 int encoding_is_utf8;
1536 struct strbuf buffer;
1537
1538 assert_oid_type(tree, OBJ_TREE);
1539
1540 if (memchr(msg, '\0', msg_len))
1541 return error("a NUL byte in commit log message not allowed.");
1542
1543 /* Not having i18n.commitencoding is the same as having utf-8 */
1544 encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1545
1546 strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1547 strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
1548
1549 /*
1550 * NOTE! This ordering means that the same exact tree merged with a
1551 * different order of parents will be a _different_ changeset even
1552 * if everything else stays the same.
1553 */
1554 while (parents) {
1555 struct commit *parent = pop_commit(&parents);
1556 strbuf_addf(&buffer, "parent %s\n",
1557 oid_to_hex(&parent->object.oid));
1558 }
1559
1560 /* Person/date information */
1561 if (!author)
1562 author = git_author_info(IDENT_STRICT);
1563 strbuf_addf(&buffer, "author %s\n", author);
1564 strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1565 if (!encoding_is_utf8)
1566 strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1567
1568 while (extra) {
1569 add_extra_header(&buffer, extra);
1570 extra = extra->next;
1571 }
1572 strbuf_addch(&buffer, '\n');
1573
1574 /* And add the comment */
1575 strbuf_add(&buffer, msg, msg_len);
1576
1577 /* And check the encoding */
1578 if (encoding_is_utf8 && !verify_utf8(&buffer))
1579 fprintf(stderr, _(commit_utf8_warn));
1580
1581 if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
1582 result = -1;
1583 goto out;
1584 }
1585
1586 result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
1587 out:
1588 strbuf_release(&buffer);
1589 return result;
1590 }
1591
1592 void set_merge_remote_desc(struct commit *commit,
1593 const char *name, struct object *obj)
1594 {
1595 struct merge_remote_desc *desc;
1596 FLEX_ALLOC_STR(desc, name, name);
1597 desc->obj = obj;
1598 commit->util = desc;
1599 }
1600
1601 struct commit *get_merge_parent(const char *name)
1602 {
1603 struct object *obj;
1604 struct commit *commit;
1605 struct object_id oid;
1606 if (get_oid(name, &oid))
1607 return NULL;
1608 obj = parse_object(&oid);
1609 commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1610 if (commit && !commit->util)
1611 set_merge_remote_desc(commit, name, obj);
1612 return commit;
1613 }
1614
1615 /*
1616 * Append a commit to the end of the commit_list.
1617 *
1618 * next starts by pointing to the variable that holds the head of an
1619 * empty commit_list, and is updated to point to the "next" field of
1620 * the last item on the list as new commits are appended.
1621 *
1622 * Usage example:
1623 *
1624 * struct commit_list *list;
1625 * struct commit_list **next = &list;
1626 *
1627 * next = commit_list_append(c1, next);
1628 * next = commit_list_append(c2, next);
1629 * assert(commit_list_count(list) == 2);
1630 * return list;
1631 */
1632 struct commit_list **commit_list_append(struct commit *commit,
1633 struct commit_list **next)
1634 {
1635 struct commit_list *new_commit = xmalloc(sizeof(struct commit_list));
1636 new_commit->item = commit;
1637 *next = new_commit;
1638 new_commit->next = NULL;
1639 return &new_commit->next;
1640 }
1641
1642 const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1643 {
1644 int key_len = strlen(key);
1645 const char *line = msg;
1646
1647 while (line) {
1648 const char *eol = strchrnul(line, '\n');
1649
1650 if (line == eol)
1651 return NULL;
1652
1653 if (eol - line > key_len &&
1654 !strncmp(line, key, key_len) &&
1655 line[key_len] == ' ') {
1656 *out_len = eol - line - key_len - 1;
1657 return line + key_len + 1;
1658 }
1659 line = *eol ? eol + 1 : NULL;
1660 }
1661 return NULL;
1662 }
1663
1664 /*
1665 * Inspect the given string and determine the true "end" of the log message, in
1666 * order to find where to put a new Signed-off-by: line. Ignored are
1667 * trailing comment lines and blank lines. To support "git commit -s
1668 * --amend" on an existing commit, we also ignore "Conflicts:". To
1669 * support "git commit -v", we truncate at cut lines.
1670 *
1671 * Returns the number of bytes from the tail to ignore, to be fed as
1672 * the second parameter to append_signoff().
1673 */
1674 int ignore_non_trailer(const char *buf, size_t len)
1675 {
1676 int boc = 0;
1677 int bol = 0;
1678 int in_old_conflicts_block = 0;
1679 size_t cutoff = wt_status_locate_end(buf, len);
1680
1681 while (bol < cutoff) {
1682 const char *next_line = memchr(buf + bol, '\n', len - bol);
1683
1684 if (!next_line)
1685 next_line = buf + len;
1686 else
1687 next_line++;
1688
1689 if (buf[bol] == comment_line_char || buf[bol] == '\n') {
1690 /* is this the first of the run of comments? */
1691 if (!boc)
1692 boc = bol;
1693 /* otherwise, it is just continuing */
1694 } else if (starts_with(buf + bol, "Conflicts:\n")) {
1695 in_old_conflicts_block = 1;
1696 if (!boc)
1697 boc = bol;
1698 } else if (in_old_conflicts_block && buf[bol] == '\t') {
1699 ; /* a pathname in the conflicts block */
1700 } else if (boc) {
1701 /* the previous was not trailing comment */
1702 boc = 0;
1703 in_old_conflicts_block = 0;
1704 }
1705 bol = next_line - buf;
1706 }
1707 return boc ? len - boc : len - cutoff;
1708 }