allow deepening of a shallow repository
[git/git.git] / commit.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "commit.h"
4 #include "pkt-line.h"
5
6 int save_commit_buffer = 1;
7
8 struct sort_node
9 {
10 /*
11 * the number of children of the associated commit
12 * that also occur in the list being sorted.
13 */
14 unsigned int indegree;
15
16 /*
17 * reference to original list item that we will re-use
18 * on output.
19 */
20 struct commit_list * list_item;
21
22 };
23
24 const char *commit_type = "commit";
25
26 struct cmt_fmt_map {
27 const char *n;
28 size_t cmp_len;
29 enum cmit_fmt v;
30 } cmt_fmts[] = {
31 { "raw", 1, CMIT_FMT_RAW },
32 { "medium", 1, CMIT_FMT_MEDIUM },
33 { "short", 1, CMIT_FMT_SHORT },
34 { "email", 1, CMIT_FMT_EMAIL },
35 { "full", 5, CMIT_FMT_FULL },
36 { "fuller", 5, CMIT_FMT_FULLER },
37 { "oneline", 1, CMIT_FMT_ONELINE },
38 };
39
40 enum cmit_fmt get_commit_format(const char *arg)
41 {
42 int i;
43
44 if (!arg || !*arg)
45 return CMIT_FMT_DEFAULT;
46 if (*arg == '=')
47 arg++;
48 for (i = 0; i < ARRAY_SIZE(cmt_fmts); i++) {
49 if (!strncmp(arg, cmt_fmts[i].n, cmt_fmts[i].cmp_len))
50 return cmt_fmts[i].v;
51 }
52
53 die("invalid --pretty format: %s", arg);
54 }
55
56 static struct commit *check_commit(struct object *obj,
57 const unsigned char *sha1,
58 int quiet)
59 {
60 if (obj->type != OBJ_COMMIT) {
61 if (!quiet)
62 error("Object %s is a %s, not a commit",
63 sha1_to_hex(sha1), typename(obj->type));
64 return NULL;
65 }
66 return (struct commit *) obj;
67 }
68
69 struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
70 int quiet)
71 {
72 struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
73
74 if (!obj)
75 return NULL;
76 return check_commit(obj, sha1, quiet);
77 }
78
79 struct commit *lookup_commit_reference(const unsigned char *sha1)
80 {
81 return lookup_commit_reference_gently(sha1, 0);
82 }
83
84 struct commit *lookup_commit(const unsigned char *sha1)
85 {
86 struct object *obj = lookup_object(sha1);
87 if (!obj) {
88 struct commit *ret = alloc_commit_node();
89 created_object(sha1, &ret->object);
90 ret->object.type = OBJ_COMMIT;
91 return ret;
92 }
93 if (!obj->type)
94 obj->type = OBJ_COMMIT;
95 return check_commit(obj, sha1, 0);
96 }
97
98 static unsigned long parse_commit_date(const char *buf)
99 {
100 unsigned long date;
101
102 if (memcmp(buf, "author", 6))
103 return 0;
104 while (*buf++ != '\n')
105 /* nada */;
106 if (memcmp(buf, "committer", 9))
107 return 0;
108 while (*buf++ != '>')
109 /* nada */;
110 date = strtoul(buf, NULL, 10);
111 if (date == ULONG_MAX)
112 date = 0;
113 return date;
114 }
115
116 static struct commit_graft **commit_graft;
117 static int commit_graft_alloc, commit_graft_nr;
118
119 static int commit_graft_pos(const unsigned char *sha1)
120 {
121 int lo, hi;
122 lo = 0;
123 hi = commit_graft_nr;
124 while (lo < hi) {
125 int mi = (lo + hi) / 2;
126 struct commit_graft *graft = commit_graft[mi];
127 int cmp = hashcmp(sha1, graft->sha1);
128 if (!cmp)
129 return mi;
130 if (cmp < 0)
131 hi = mi;
132 else
133 lo = mi + 1;
134 }
135 return -lo - 1;
136 }
137
138 int register_commit_graft(struct commit_graft *graft, int ignore_dups)
139 {
140 int pos = commit_graft_pos(graft->sha1);
141
142 if (0 <= pos) {
143 if (ignore_dups)
144 free(graft);
145 else {
146 free(commit_graft[pos]);
147 commit_graft[pos] = graft;
148 }
149 return 1;
150 }
151 pos = -pos - 1;
152 if (commit_graft_alloc <= ++commit_graft_nr) {
153 commit_graft_alloc = alloc_nr(commit_graft_alloc);
154 commit_graft = xrealloc(commit_graft,
155 sizeof(*commit_graft) *
156 commit_graft_alloc);
157 }
158 if (pos < commit_graft_nr)
159 memmove(commit_graft + pos + 1,
160 commit_graft + pos,
161 (commit_graft_nr - pos - 1) *
162 sizeof(*commit_graft));
163 commit_graft[pos] = graft;
164 return 0;
165 }
166
167 struct commit_graft *read_graft_line(char *buf, int len)
168 {
169 /* The format is just "Commit Parent1 Parent2 ...\n" */
170 int i;
171 struct commit_graft *graft = NULL;
172
173 if (buf[len-1] == '\n')
174 buf[--len] = 0;
175 if (buf[0] == '#' || buf[0] == '\0')
176 return NULL;
177 if ((len + 1) % 41) {
178 bad_graft_data:
179 error("bad graft data: %s", buf);
180 free(graft);
181 return NULL;
182 }
183 i = (len + 1) / 41 - 1;
184 graft = xmalloc(sizeof(*graft) + 20 * i);
185 graft->nr_parent = i;
186 if (get_sha1_hex(buf, graft->sha1))
187 goto bad_graft_data;
188 for (i = 40; i < len; i += 41) {
189 if (buf[i] != ' ')
190 goto bad_graft_data;
191 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
192 goto bad_graft_data;
193 }
194 return graft;
195 }
196
197 int read_graft_file(const char *graft_file)
198 {
199 FILE *fp = fopen(graft_file, "r");
200 char buf[1024];
201 if (!fp)
202 return -1;
203 while (fgets(buf, sizeof(buf), fp)) {
204 /* The format is just "Commit Parent1 Parent2 ...\n" */
205 int len = strlen(buf);
206 struct commit_graft *graft = read_graft_line(buf, len);
207 if (!graft)
208 continue;
209 if (register_commit_graft(graft, 1))
210 error("duplicate graft data: %s", buf);
211 }
212 fclose(fp);
213 return 0;
214 }
215
216 static void prepare_commit_graft(void)
217 {
218 static int commit_graft_prepared;
219 char *graft_file;
220
221 if (commit_graft_prepared)
222 return;
223 graft_file = get_graft_file();
224 read_graft_file(graft_file);
225 /* make sure shallows are read */
226 is_repository_shallow();
227 commit_graft_prepared = 1;
228 }
229
230 static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
231 {
232 int pos;
233 prepare_commit_graft();
234 pos = commit_graft_pos(sha1);
235 if (pos < 0)
236 return NULL;
237 return commit_graft[pos];
238 }
239
240 int write_shallow_commits(int fd, int use_pack_protocol)
241 {
242 int i, count = 0;
243 for (i = 0; i < commit_graft_nr; i++)
244 if (commit_graft[i]->nr_parent < 0) {
245 const char *hex =
246 sha1_to_hex(commit_graft[i]->sha1);
247 count++;
248 if (use_pack_protocol)
249 packet_write(fd, "shallow %s", hex);
250 else {
251 write(fd, hex, 40);
252 write(fd, "\n", 1);
253 }
254 }
255 return count;
256 }
257
258 int unregister_shallow(const unsigned char *sha1)
259 {
260 int pos = commit_graft_pos(sha1);
261 if (pos < 0)
262 return -1;
263 if (pos + 1 < commit_graft_nr)
264 memcpy(commit_graft + pos, commit_graft + pos + 1,
265 sizeof(struct commit_graft *)
266 * (commit_graft_nr - pos - 1));
267 commit_graft_nr--;
268 return 0;
269 }
270
271 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
272 {
273 char *tail = buffer;
274 char *bufptr = buffer;
275 unsigned char parent[20];
276 struct commit_list **pptr;
277 struct commit_graft *graft;
278 unsigned n_refs = 0;
279
280 if (item->object.parsed)
281 return 0;
282 item->object.parsed = 1;
283 tail += size;
284 if (tail <= bufptr + 5 || memcmp(bufptr, "tree ", 5))
285 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
286 if (tail <= bufptr + 45 || get_sha1_hex(bufptr + 5, parent) < 0)
287 return error("bad tree pointer in commit %s",
288 sha1_to_hex(item->object.sha1));
289 item->tree = lookup_tree(parent);
290 if (item->tree)
291 n_refs++;
292 bufptr += 46; /* "tree " + "hex sha1" + "\n" */
293 pptr = &item->parents;
294
295 graft = lookup_commit_graft(item->object.sha1);
296 while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
297 struct commit *new_parent;
298
299 if (tail <= bufptr + 48 ||
300 get_sha1_hex(bufptr + 7, parent) ||
301 bufptr[47] != '\n')
302 return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
303 bufptr += 48;
304 if (graft)
305 continue;
306 new_parent = lookup_commit(parent);
307 if (new_parent) {
308 pptr = &commit_list_insert(new_parent, pptr)->next;
309 n_refs++;
310 }
311 }
312 if (graft) {
313 int i;
314 struct commit *new_parent;
315 for (i = 0; i < graft->nr_parent; i++) {
316 new_parent = lookup_commit(graft->parent[i]);
317 if (!new_parent)
318 continue;
319 pptr = &commit_list_insert(new_parent, pptr)->next;
320 n_refs++;
321 }
322 }
323 item->date = parse_commit_date(bufptr);
324
325 if (track_object_refs) {
326 unsigned i = 0;
327 struct commit_list *p;
328 struct object_refs *refs = alloc_object_refs(n_refs);
329 if (item->tree)
330 refs->ref[i++] = &item->tree->object;
331 for (p = item->parents; p; p = p->next)
332 refs->ref[i++] = &p->item->object;
333 set_object_refs(&item->object, refs);
334 }
335
336 return 0;
337 }
338
339 int parse_commit(struct commit *item)
340 {
341 char type[20];
342 void *buffer;
343 unsigned long size;
344 int ret;
345
346 if (item->object.parsed)
347 return 0;
348 buffer = read_sha1_file(item->object.sha1, type, &size);
349 if (!buffer)
350 return error("Could not read %s",
351 sha1_to_hex(item->object.sha1));
352 if (strcmp(type, commit_type)) {
353 free(buffer);
354 return error("Object %s not a commit",
355 sha1_to_hex(item->object.sha1));
356 }
357 ret = parse_commit_buffer(item, buffer, size);
358 if (save_commit_buffer && !ret) {
359 item->buffer = buffer;
360 return 0;
361 }
362 free(buffer);
363 return ret;
364 }
365
366 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
367 {
368 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
369 new_list->item = item;
370 new_list->next = *list_p;
371 *list_p = new_list;
372 return new_list;
373 }
374
375 void free_commit_list(struct commit_list *list)
376 {
377 while (list) {
378 struct commit_list *temp = list;
379 list = temp->next;
380 free(temp);
381 }
382 }
383
384 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
385 {
386 struct commit_list **pp = list;
387 struct commit_list *p;
388 while ((p = *pp) != NULL) {
389 if (p->item->date < item->date) {
390 break;
391 }
392 pp = &p->next;
393 }
394 return commit_list_insert(item, pp);
395 }
396
397
398 void sort_by_date(struct commit_list **list)
399 {
400 struct commit_list *ret = NULL;
401 while (*list) {
402 insert_by_date((*list)->item, &ret);
403 *list = (*list)->next;
404 }
405 *list = ret;
406 }
407
408 struct commit *pop_most_recent_commit(struct commit_list **list,
409 unsigned int mark)
410 {
411 struct commit *ret = (*list)->item;
412 struct commit_list *parents = ret->parents;
413 struct commit_list *old = *list;
414
415 *list = (*list)->next;
416 free(old);
417
418 while (parents) {
419 struct commit *commit = parents->item;
420 parse_commit(commit);
421 if (!(commit->object.flags & mark)) {
422 commit->object.flags |= mark;
423 insert_by_date(commit, list);
424 }
425 parents = parents->next;
426 }
427 return ret;
428 }
429
430 void clear_commit_marks(struct commit *commit, unsigned int mark)
431 {
432 struct commit_list *parents;
433
434 commit->object.flags &= ~mark;
435 parents = commit->parents;
436 while (parents) {
437 struct commit *parent = parents->item;
438
439 /* Have we already cleared this? */
440 if (mark & parent->object.flags)
441 clear_commit_marks(parent, mark);
442 parents = parents->next;
443 }
444 }
445
446 /*
447 * Generic support for pretty-printing the header
448 */
449 static int get_one_line(const char *msg, unsigned long len)
450 {
451 int ret = 0;
452
453 while (len--) {
454 char c = *msg++;
455 if (!c)
456 break;
457 ret++;
458 if (c == '\n')
459 break;
460 }
461 return ret;
462 }
463
464 static int is_rfc2047_special(char ch)
465 {
466 return ((ch & 0x80) || (ch == '=') || (ch == '?') || (ch == '_'));
467 }
468
469 static int add_rfc2047(char *buf, const char *line, int len)
470 {
471 char *bp = buf;
472 int i, needquote;
473 static const char q_utf8[] = "=?utf-8?q?";
474
475 for (i = needquote = 0; !needquote && i < len; i++) {
476 unsigned ch = line[i];
477 if (ch & 0x80)
478 needquote++;
479 if ((i + 1 < len) &&
480 (ch == '=' && line[i+1] == '?'))
481 needquote++;
482 }
483 if (!needquote)
484 return sprintf(buf, "%.*s", len, line);
485
486 memcpy(bp, q_utf8, sizeof(q_utf8)-1);
487 bp += sizeof(q_utf8)-1;
488 for (i = 0; i < len; i++) {
489 unsigned ch = line[i] & 0xFF;
490 if (is_rfc2047_special(ch)) {
491 sprintf(bp, "=%02X", ch);
492 bp += 3;
493 }
494 else if (ch == ' ')
495 *bp++ = '_';
496 else
497 *bp++ = ch;
498 }
499 memcpy(bp, "?=", 2);
500 bp += 2;
501 return bp - buf;
502 }
503
504 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf,
505 const char *line, int relative_date)
506 {
507 char *date;
508 int namelen;
509 unsigned long time;
510 int tz, ret;
511 const char *filler = " ";
512
513 if (fmt == CMIT_FMT_ONELINE)
514 return 0;
515 date = strchr(line, '>');
516 if (!date)
517 return 0;
518 namelen = ++date - line;
519 time = strtoul(date, &date, 10);
520 tz = strtol(date, NULL, 10);
521
522 if (fmt == CMIT_FMT_EMAIL) {
523 char *name_tail = strchr(line, '<');
524 int display_name_length;
525 if (!name_tail)
526 return 0;
527 while (line < name_tail && isspace(name_tail[-1]))
528 name_tail--;
529 display_name_length = name_tail - line;
530 filler = "";
531 strcpy(buf, "From: ");
532 ret = strlen(buf);
533 ret += add_rfc2047(buf + ret, line, display_name_length);
534 memcpy(buf + ret, name_tail, namelen - display_name_length);
535 ret += namelen - display_name_length;
536 buf[ret++] = '\n';
537 }
538 else {
539 ret = sprintf(buf, "%s: %.*s%.*s\n", what,
540 (fmt == CMIT_FMT_FULLER) ? 4 : 0,
541 filler, namelen, line);
542 }
543 switch (fmt) {
544 case CMIT_FMT_MEDIUM:
545 ret += sprintf(buf + ret, "Date: %s\n",
546 show_date(time, tz, relative_date));
547 break;
548 case CMIT_FMT_EMAIL:
549 ret += sprintf(buf + ret, "Date: %s\n",
550 show_rfc2822_date(time, tz));
551 break;
552 case CMIT_FMT_FULLER:
553 ret += sprintf(buf + ret, "%sDate: %s\n", what,
554 show_date(time, tz, relative_date));
555 break;
556 default:
557 /* notin' */
558 break;
559 }
560 return ret;
561 }
562
563 static int is_empty_line(const char *line, int *len_p)
564 {
565 int len = *len_p;
566 while (len && isspace(line[len-1]))
567 len--;
568 *len_p = len;
569 return !len;
570 }
571
572 static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
573 {
574 struct commit_list *parent = commit->parents;
575 int offset;
576
577 if ((fmt == CMIT_FMT_ONELINE) || (fmt == CMIT_FMT_EMAIL) ||
578 !parent || !parent->next)
579 return 0;
580
581 offset = sprintf(buf, "Merge:");
582
583 while (parent) {
584 struct commit *p = parent->item;
585 const char *hex = NULL;
586 const char *dots;
587 if (abbrev)
588 hex = find_unique_abbrev(p->object.sha1, abbrev);
589 if (!hex)
590 hex = sha1_to_hex(p->object.sha1);
591 dots = (abbrev && strlen(hex) != 40) ? "..." : "";
592 parent = parent->next;
593
594 offset += sprintf(buf + offset, " %s%s", hex, dots);
595 }
596 buf[offset++] = '\n';
597 return offset;
598 }
599
600 unsigned long pretty_print_commit(enum cmit_fmt fmt, const struct commit *commit,
601 unsigned long len, char *buf, unsigned long space,
602 int abbrev, const char *subject,
603 const char *after_subject, int relative_date)
604 {
605 int hdr = 1, body = 0;
606 unsigned long offset = 0;
607 int indent = 4;
608 int parents_shown = 0;
609 const char *msg = commit->buffer;
610 int plain_non_ascii = 0;
611
612 if (fmt == CMIT_FMT_ONELINE || fmt == CMIT_FMT_EMAIL)
613 indent = 0;
614
615 /* After-subject is used to pass in Content-Type: multipart
616 * MIME header; in that case we do not have to do the
617 * plaintext content type even if the commit message has
618 * non 7-bit ASCII character. Otherwise, check if we need
619 * to say this is not a 7-bit ASCII.
620 */
621 if (fmt == CMIT_FMT_EMAIL && !after_subject) {
622 int i, ch, in_body;
623
624 for (in_body = i = 0; (ch = msg[i]) && i < len; i++) {
625 if (!in_body) {
626 /* author could be non 7-bit ASCII but
627 * the log may so; skip over the
628 * header part first.
629 */
630 if (ch == '\n' &&
631 i + 1 < len && msg[i+1] == '\n')
632 in_body = 1;
633 }
634 else if (ch & 0x80) {
635 plain_non_ascii = 1;
636 break;
637 }
638 }
639 }
640
641 for (;;) {
642 const char *line = msg;
643 int linelen = get_one_line(msg, len);
644
645 if (!linelen)
646 break;
647
648 /*
649 * We want some slop for indentation and a possible
650 * final "...". Thus the "+ 20".
651 */
652 if (offset + linelen + 20 > space) {
653 memcpy(buf + offset, " ...\n", 8);
654 offset += 8;
655 break;
656 }
657
658 msg += linelen;
659 len -= linelen;
660 if (hdr) {
661 if (linelen == 1) {
662 hdr = 0;
663 if ((fmt != CMIT_FMT_ONELINE) && !subject)
664 buf[offset++] = '\n';
665 continue;
666 }
667 if (fmt == CMIT_FMT_RAW) {
668 memcpy(buf + offset, line, linelen);
669 offset += linelen;
670 continue;
671 }
672 if (!memcmp(line, "parent ", 7)) {
673 if (linelen != 48)
674 die("bad parent line in commit");
675 continue;
676 }
677
678 if (!parents_shown) {
679 offset += add_merge_info(fmt, buf + offset,
680 commit, abbrev);
681 parents_shown = 1;
682 continue;
683 }
684 /*
685 * MEDIUM == DEFAULT shows only author with dates.
686 * FULL shows both authors but not dates.
687 * FULLER shows both authors and dates.
688 */
689 if (!memcmp(line, "author ", 7))
690 offset += add_user_info("Author", fmt,
691 buf + offset,
692 line + 7,
693 relative_date);
694 if (!memcmp(line, "committer ", 10) &&
695 (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
696 offset += add_user_info("Commit", fmt,
697 buf + offset,
698 line + 10,
699 relative_date);
700 continue;
701 }
702
703 if (!subject)
704 body = 1;
705
706 if (is_empty_line(line, &linelen)) {
707 if (!body)
708 continue;
709 if (subject)
710 continue;
711 if (fmt == CMIT_FMT_SHORT)
712 break;
713 }
714
715 if (subject) {
716 int slen = strlen(subject);
717 memcpy(buf + offset, subject, slen);
718 offset += slen;
719 offset += add_rfc2047(buf + offset, line, linelen);
720 }
721 else {
722 memset(buf + offset, ' ', indent);
723 memcpy(buf + offset + indent, line, linelen);
724 offset += linelen + indent;
725 }
726 buf[offset++] = '\n';
727 if (fmt == CMIT_FMT_ONELINE)
728 break;
729 if (subject && plain_non_ascii) {
730 static const char header[] =
731 "Content-Type: text/plain; charset=UTF-8\n"
732 "Content-Transfer-Encoding: 8bit\n";
733 memcpy(buf + offset, header, sizeof(header)-1);
734 offset += sizeof(header)-1;
735 }
736 if (after_subject) {
737 int slen = strlen(after_subject);
738 if (slen > space - offset - 1)
739 slen = space - offset - 1;
740 memcpy(buf + offset, after_subject, slen);
741 offset += slen;
742 after_subject = NULL;
743 }
744 subject = NULL;
745 }
746 while (offset && isspace(buf[offset-1]))
747 offset--;
748 /* Make sure there is an EOLN for the non-oneline case */
749 if (fmt != CMIT_FMT_ONELINE)
750 buf[offset++] = '\n';
751 /*
752 * make sure there is another EOLN to separate the headers from whatever
753 * body the caller appends if we haven't already written a body
754 */
755 if (fmt == CMIT_FMT_EMAIL && !body)
756 buf[offset++] = '\n';
757 buf[offset] = '\0';
758 return offset;
759 }
760
761 struct commit *pop_commit(struct commit_list **stack)
762 {
763 struct commit_list *top = *stack;
764 struct commit *item = top ? top->item : NULL;
765
766 if (top) {
767 *stack = top->next;
768 free(top);
769 }
770 return item;
771 }
772
773 int count_parents(struct commit * commit)
774 {
775 int count;
776 struct commit_list * parents = commit->parents;
777 for (count = 0; parents; parents = parents->next,count++)
778 ;
779 return count;
780 }
781
782 void topo_sort_default_setter(struct commit *c, void *data)
783 {
784 c->util = data;
785 }
786
787 void *topo_sort_default_getter(struct commit *c)
788 {
789 return c->util;
790 }
791
792 /*
793 * Performs an in-place topological sort on the list supplied.
794 */
795 void sort_in_topological_order(struct commit_list ** list, int lifo)
796 {
797 sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
798 topo_sort_default_getter);
799 }
800
801 void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
802 topo_sort_set_fn_t setter,
803 topo_sort_get_fn_t getter)
804 {
805 struct commit_list * next = *list;
806 struct commit_list * work = NULL, **insert;
807 struct commit_list ** pptr = list;
808 struct sort_node * nodes;
809 struct sort_node * next_nodes;
810 int count = 0;
811
812 /* determine the size of the list */
813 while (next) {
814 next = next->next;
815 count++;
816 }
817
818 if (!count)
819 return;
820 /* allocate an array to help sort the list */
821 nodes = xcalloc(count, sizeof(*nodes));
822 /* link the list to the array */
823 next_nodes = nodes;
824 next=*list;
825 while (next) {
826 next_nodes->list_item = next;
827 setter(next->item, next_nodes);
828 next_nodes++;
829 next = next->next;
830 }
831 /* update the indegree */
832 next=*list;
833 while (next) {
834 struct commit_list * parents = next->item->parents;
835 while (parents) {
836 struct commit * parent=parents->item;
837 struct sort_node * pn = (struct sort_node *) getter(parent);
838
839 if (pn)
840 pn->indegree++;
841 parents=parents->next;
842 }
843 next=next->next;
844 }
845 /*
846 * find the tips
847 *
848 * tips are nodes not reachable from any other node in the list
849 *
850 * the tips serve as a starting set for the work queue.
851 */
852 next=*list;
853 insert = &work;
854 while (next) {
855 struct sort_node * node = (struct sort_node *) getter(next->item);
856
857 if (node->indegree == 0) {
858 insert = &commit_list_insert(next->item, insert)->next;
859 }
860 next=next->next;
861 }
862
863 /* process the list in topological order */
864 if (!lifo)
865 sort_by_date(&work);
866 while (work) {
867 struct commit * work_item = pop_commit(&work);
868 struct sort_node * work_node = (struct sort_node *) getter(work_item);
869 struct commit_list * parents = work_item->parents;
870
871 while (parents) {
872 struct commit * parent=parents->item;
873 struct sort_node * pn = (struct sort_node *) getter(parent);
874
875 if (pn) {
876 /*
877 * parents are only enqueued for emission
878 * when all their children have been emitted thereby
879 * guaranteeing topological order.
880 */
881 pn->indegree--;
882 if (!pn->indegree) {
883 if (!lifo)
884 insert_by_date(parent, &work);
885 else
886 commit_list_insert(parent, &work);
887 }
888 }
889 parents=parents->next;
890 }
891 /*
892 * work_item is a commit all of whose children
893 * have already been emitted. we can emit it now.
894 */
895 *pptr = work_node->list_item;
896 pptr = &(*pptr)->next;
897 *pptr = NULL;
898 setter(work_item, NULL);
899 }
900 free(nodes);
901 }
902
903 /* merge-rebase stuff */
904
905 /* bits #0..7 in revision.h */
906 #define PARENT1 (1u<< 8)
907 #define PARENT2 (1u<< 9)
908 #define STALE (1u<<10)
909 #define RESULT (1u<<11)
910
911 static struct commit *interesting(struct commit_list *list)
912 {
913 while (list) {
914 struct commit *commit = list->item;
915 list = list->next;
916 if (commit->object.flags & STALE)
917 continue;
918 return commit;
919 }
920 return NULL;
921 }
922
923 static struct commit_list *merge_bases(struct commit *one, struct commit *two)
924 {
925 struct commit_list *list = NULL;
926 struct commit_list *result = NULL;
927
928 if (one == two)
929 /* We do not mark this even with RESULT so we do not
930 * have to clean it up.
931 */
932 return commit_list_insert(one, &result);
933
934 parse_commit(one);
935 parse_commit(two);
936
937 one->object.flags |= PARENT1;
938 two->object.flags |= PARENT2;
939 insert_by_date(one, &list);
940 insert_by_date(two, &list);
941
942 while (interesting(list)) {
943 struct commit *commit;
944 struct commit_list *parents;
945 struct commit_list *n;
946 int flags;
947
948 commit = list->item;
949 n = list->next;
950 free(list);
951 list = n;
952
953 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
954 if (flags == (PARENT1 | PARENT2)) {
955 if (!(commit->object.flags & RESULT)) {
956 commit->object.flags |= RESULT;
957 insert_by_date(commit, &result);
958 }
959 /* Mark parents of a found merge stale */
960 flags |= STALE;
961 }
962 parents = commit->parents;
963 while (parents) {
964 struct commit *p = parents->item;
965 parents = parents->next;
966 if ((p->object.flags & flags) == flags)
967 continue;
968 parse_commit(p);
969 p->object.flags |= flags;
970 insert_by_date(p, &list);
971 }
972 }
973
974 /* Clean up the result to remove stale ones */
975 list = result; result = NULL;
976 while (list) {
977 struct commit_list *n = list->next;
978 if (!(list->item->object.flags & STALE))
979 insert_by_date(list->item, &result);
980 free(list);
981 list = n;
982 }
983 return result;
984 }
985
986 struct commit_list *get_merge_bases(struct commit *one,
987 struct commit *two,
988 int cleanup)
989 {
990 const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
991 struct commit_list *list;
992 struct commit **rslt;
993 struct commit_list *result;
994 int cnt, i, j;
995
996 result = merge_bases(one, two);
997 if (one == two)
998 return result;
999 if (!result || !result->next) {
1000 if (cleanup) {
1001 clear_commit_marks(one, all_flags);
1002 clear_commit_marks(two, all_flags);
1003 }
1004 return result;
1005 }
1006
1007 /* There are more than one */
1008 cnt = 0;
1009 list = result;
1010 while (list) {
1011 list = list->next;
1012 cnt++;
1013 }
1014 rslt = xcalloc(cnt, sizeof(*rslt));
1015 for (list = result, i = 0; list; list = list->next)
1016 rslt[i++] = list->item;
1017 free_commit_list(result);
1018
1019 clear_commit_marks(one, all_flags);
1020 clear_commit_marks(two, all_flags);
1021 for (i = 0; i < cnt - 1; i++) {
1022 for (j = i+1; j < cnt; j++) {
1023 if (!rslt[i] || !rslt[j])
1024 continue;
1025 result = merge_bases(rslt[i], rslt[j]);
1026 clear_commit_marks(rslt[i], all_flags);
1027 clear_commit_marks(rslt[j], all_flags);
1028 for (list = result; list; list = list->next) {
1029 if (rslt[i] == list->item)
1030 rslt[i] = NULL;
1031 if (rslt[j] == list->item)
1032 rslt[j] = NULL;
1033 }
1034 }
1035 }
1036
1037 /* Surviving ones in rslt[] are the independent results */
1038 result = NULL;
1039 for (i = 0; i < cnt; i++) {
1040 if (rslt[i])
1041 insert_by_date(rslt[i], &result);
1042 }
1043 free(rslt);
1044 return result;
1045 }