Merge branch 'js/branch-track'
[git/git.git] / refs.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
6
7 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8 #define REF_KNOWS_PEELED 04
9
10 struct ref_list {
11 struct ref_list *next;
12 unsigned char flag; /* ISSYMREF? ISPACKED? */
13 unsigned char sha1[20];
14 unsigned char peeled[20];
15 char name[FLEX_ARRAY];
16 };
17
18 static const char *parse_ref_line(char *line, unsigned char *sha1)
19 {
20 /*
21 * 42: the answer to everything.
22 *
23 * In this case, it happens to be the answer to
24 * 40 (length of sha1 hex representation)
25 * +1 (space in between hex and name)
26 * +1 (newline at the end of the line)
27 */
28 int len = strlen(line) - 42;
29
30 if (len <= 0)
31 return NULL;
32 if (get_sha1_hex(line, sha1) < 0)
33 return NULL;
34 if (!isspace(line[40]))
35 return NULL;
36 line += 41;
37 if (isspace(*line))
38 return NULL;
39 if (line[len] != '\n')
40 return NULL;
41 line[len] = 0;
42
43 return line;
44 }
45
46 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
47 int flag, struct ref_list *list,
48 struct ref_list **new_entry)
49 {
50 int len;
51 struct ref_list *entry;
52
53 /* Allocate it and add it in.. */
54 len = strlen(name) + 1;
55 entry = xmalloc(sizeof(struct ref_list) + len);
56 hashcpy(entry->sha1, sha1);
57 hashclr(entry->peeled);
58 memcpy(entry->name, name, len);
59 entry->flag = flag;
60 entry->next = list;
61 if (new_entry)
62 *new_entry = entry;
63 return entry;
64 }
65
66 /* merge sort the ref list */
67 static struct ref_list *sort_ref_list(struct ref_list *list)
68 {
69 int psize, qsize, last_merge_count, cmp;
70 struct ref_list *p, *q, *l, *e;
71 struct ref_list *new_list = list;
72 int k = 1;
73 int merge_count = 0;
74
75 if (!list)
76 return list;
77
78 do {
79 last_merge_count = merge_count;
80 merge_count = 0;
81
82 psize = 0;
83
84 p = new_list;
85 q = new_list;
86 new_list = NULL;
87 l = NULL;
88
89 while (p) {
90 merge_count++;
91
92 while (psize < k && q->next) {
93 q = q->next;
94 psize++;
95 }
96 qsize = k;
97
98 while ((psize > 0) || (qsize > 0 && q)) {
99 if (qsize == 0 || !q) {
100 e = p;
101 p = p->next;
102 psize--;
103 } else if (psize == 0) {
104 e = q;
105 q = q->next;
106 qsize--;
107 } else {
108 cmp = strcmp(q->name, p->name);
109 if (cmp < 0) {
110 e = q;
111 q = q->next;
112 qsize--;
113 } else if (cmp > 0) {
114 e = p;
115 p = p->next;
116 psize--;
117 } else {
118 if (hashcmp(q->sha1, p->sha1))
119 die("Duplicated ref, and SHA1s don't match: %s",
120 q->name);
121 warning("Duplicated ref: %s", q->name);
122 e = q;
123 q = q->next;
124 qsize--;
125 free(e);
126 e = p;
127 p = p->next;
128 psize--;
129 }
130 }
131
132 e->next = NULL;
133
134 if (l)
135 l->next = e;
136 if (!new_list)
137 new_list = e;
138 l = e;
139 }
140
141 p = q;
142 };
143
144 k = k * 2;
145 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
146
147 return new_list;
148 }
149
150 /*
151 * Future: need to be in "struct repository"
152 * when doing a full libification.
153 */
154 static struct cached_refs {
155 char did_loose;
156 char did_packed;
157 struct ref_list *loose;
158 struct ref_list *packed;
159 } cached_refs;
160 static struct ref_list *current_ref;
161
162 static void free_ref_list(struct ref_list *list)
163 {
164 struct ref_list *next;
165 for ( ; list; list = next) {
166 next = list->next;
167 free(list);
168 }
169 }
170
171 static void invalidate_cached_refs(void)
172 {
173 struct cached_refs *ca = &cached_refs;
174
175 if (ca->did_loose && ca->loose)
176 free_ref_list(ca->loose);
177 if (ca->did_packed && ca->packed)
178 free_ref_list(ca->packed);
179 ca->loose = ca->packed = NULL;
180 ca->did_loose = ca->did_packed = 0;
181 }
182
183 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
184 {
185 struct ref_list *list = NULL;
186 struct ref_list *last = NULL;
187 char refline[PATH_MAX];
188 int flag = REF_ISPACKED;
189
190 while (fgets(refline, sizeof(refline), f)) {
191 unsigned char sha1[20];
192 const char *name;
193 static const char header[] = "# pack-refs with:";
194
195 if (!strncmp(refline, header, sizeof(header)-1)) {
196 const char *traits = refline + sizeof(header) - 1;
197 if (strstr(traits, " peeled "))
198 flag |= REF_KNOWS_PEELED;
199 /* perhaps other traits later as well */
200 continue;
201 }
202
203 name = parse_ref_line(refline, sha1);
204 if (name) {
205 list = add_ref(name, sha1, flag, list, &last);
206 continue;
207 }
208 if (last &&
209 refline[0] == '^' &&
210 strlen(refline) == 42 &&
211 refline[41] == '\n' &&
212 !get_sha1_hex(refline + 1, sha1))
213 hashcpy(last->peeled, sha1);
214 }
215 cached_refs->packed = sort_ref_list(list);
216 }
217
218 static struct ref_list *get_packed_refs(void)
219 {
220 if (!cached_refs.did_packed) {
221 FILE *f = fopen(git_path("packed-refs"), "r");
222 cached_refs.packed = NULL;
223 if (f) {
224 read_packed_refs(f, &cached_refs);
225 fclose(f);
226 }
227 cached_refs.did_packed = 1;
228 }
229 return cached_refs.packed;
230 }
231
232 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
233 {
234 DIR *dir = opendir(git_path("%s", base));
235
236 if (dir) {
237 struct dirent *de;
238 int baselen = strlen(base);
239 char *ref = xmalloc(baselen + 257);
240
241 memcpy(ref, base, baselen);
242 if (baselen && base[baselen-1] != '/')
243 ref[baselen++] = '/';
244
245 while ((de = readdir(dir)) != NULL) {
246 unsigned char sha1[20];
247 struct stat st;
248 int flag;
249 int namelen;
250
251 if (de->d_name[0] == '.')
252 continue;
253 namelen = strlen(de->d_name);
254 if (namelen > 255)
255 continue;
256 if (has_extension(de->d_name, ".lock"))
257 continue;
258 memcpy(ref + baselen, de->d_name, namelen+1);
259 if (stat(git_path("%s", ref), &st) < 0)
260 continue;
261 if (S_ISDIR(st.st_mode)) {
262 list = get_ref_dir(ref, list);
263 continue;
264 }
265 if (!resolve_ref(ref, sha1, 1, &flag)) {
266 error("%s points nowhere!", ref);
267 continue;
268 }
269 list = add_ref(ref, sha1, flag, list, NULL);
270 }
271 free(ref);
272 closedir(dir);
273 }
274 return sort_ref_list(list);
275 }
276
277 static struct ref_list *get_loose_refs(void)
278 {
279 if (!cached_refs.did_loose) {
280 cached_refs.loose = get_ref_dir("refs", NULL);
281 cached_refs.did_loose = 1;
282 }
283 return cached_refs.loose;
284 }
285
286 /* We allow "recursive" symbolic refs. Only within reason, though */
287 #define MAXDEPTH 5
288 #define MAXREFLEN (1024)
289
290 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
291 {
292 FILE *f;
293 struct cached_refs refs;
294 struct ref_list *ref;
295 int retval;
296
297 strcpy(name + pathlen, "packed-refs");
298 f = fopen(name, "r");
299 if (!f)
300 return -1;
301 read_packed_refs(f, &refs);
302 fclose(f);
303 ref = refs.packed;
304 retval = -1;
305 while (ref) {
306 if (!strcmp(ref->name, refname)) {
307 retval = 0;
308 memcpy(result, ref->sha1, 20);
309 break;
310 }
311 ref = ref->next;
312 }
313 free_ref_list(refs.packed);
314 return retval;
315 }
316
317 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
318 {
319 int fd, len = strlen(refname);
320 char buffer[128], *p;
321
322 if (recursion > MAXDEPTH || len > MAXREFLEN)
323 return -1;
324 memcpy(name + pathlen, refname, len+1);
325 fd = open(name, O_RDONLY);
326 if (fd < 0)
327 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
328
329 len = read(fd, buffer, sizeof(buffer)-1);
330 close(fd);
331 if (len < 0)
332 return -1;
333 while (len && isspace(buffer[len-1]))
334 len--;
335 buffer[len] = 0;
336
337 /* Was it a detached head or an old-fashioned symlink? */
338 if (!get_sha1_hex(buffer, result))
339 return 0;
340
341 /* Symref? */
342 if (strncmp(buffer, "ref:", 4))
343 return -1;
344 p = buffer + 4;
345 while (isspace(*p))
346 p++;
347
348 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
349 }
350
351 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
352 {
353 int len = strlen(path), retval;
354 char *gitdir;
355
356 while (len && path[len-1] == '/')
357 len--;
358 if (!len)
359 return -1;
360 gitdir = xmalloc(len + MAXREFLEN + 8);
361 memcpy(gitdir, path, len);
362 memcpy(gitdir + len, "/.git/", 7);
363
364 retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
365 free(gitdir);
366 return retval;
367 }
368
369 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
370 {
371 int depth = MAXDEPTH, len;
372 char buffer[256];
373 static char ref_buffer[256];
374
375 if (flag)
376 *flag = 0;
377
378 for (;;) {
379 const char *path = git_path("%s", ref);
380 struct stat st;
381 char *buf;
382 int fd;
383
384 if (--depth < 0)
385 return NULL;
386
387 /* Special case: non-existing file.
388 * Not having the refs/heads/new-branch is OK
389 * if we are writing into it, so is .git/HEAD
390 * that points at refs/heads/master still to be
391 * born. It is NOT OK if we are resolving for
392 * reading.
393 */
394 if (lstat(path, &st) < 0) {
395 struct ref_list *list = get_packed_refs();
396 while (list) {
397 if (!strcmp(ref, list->name)) {
398 hashcpy(sha1, list->sha1);
399 if (flag)
400 *flag |= REF_ISPACKED;
401 return ref;
402 }
403 list = list->next;
404 }
405 if (reading || errno != ENOENT)
406 return NULL;
407 hashclr(sha1);
408 return ref;
409 }
410
411 /* Follow "normalized" - ie "refs/.." symlinks by hand */
412 if (S_ISLNK(st.st_mode)) {
413 len = readlink(path, buffer, sizeof(buffer)-1);
414 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
415 buffer[len] = 0;
416 strcpy(ref_buffer, buffer);
417 ref = ref_buffer;
418 if (flag)
419 *flag |= REF_ISSYMREF;
420 continue;
421 }
422 }
423
424 /* Is it a directory? */
425 if (S_ISDIR(st.st_mode)) {
426 errno = EISDIR;
427 return NULL;
428 }
429
430 /*
431 * Anything else, just open it and try to use it as
432 * a ref
433 */
434 fd = open(path, O_RDONLY);
435 if (fd < 0)
436 return NULL;
437 len = read_in_full(fd, buffer, sizeof(buffer)-1);
438 close(fd);
439
440 /*
441 * Is it a symbolic ref?
442 */
443 if (len < 4 || memcmp("ref:", buffer, 4))
444 break;
445 buf = buffer + 4;
446 len -= 4;
447 while (len && isspace(*buf))
448 buf++, len--;
449 while (len && isspace(buf[len-1]))
450 len--;
451 buf[len] = 0;
452 memcpy(ref_buffer, buf, len + 1);
453 ref = ref_buffer;
454 if (flag)
455 *flag |= REF_ISSYMREF;
456 }
457 if (len < 40 || get_sha1_hex(buffer, sha1))
458 return NULL;
459 return ref;
460 }
461
462 int read_ref(const char *ref, unsigned char *sha1)
463 {
464 if (resolve_ref(ref, sha1, 1, NULL))
465 return 0;
466 return -1;
467 }
468
469 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
470 void *cb_data, struct ref_list *entry)
471 {
472 if (strncmp(base, entry->name, trim))
473 return 0;
474 if (is_null_sha1(entry->sha1))
475 return 0;
476 if (!has_sha1_file(entry->sha1)) {
477 error("%s does not point to a valid object!", entry->name);
478 return 0;
479 }
480 current_ref = entry;
481 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
482 }
483
484 int peel_ref(const char *ref, unsigned char *sha1)
485 {
486 int flag;
487 unsigned char base[20];
488 struct object *o;
489
490 if (current_ref && (current_ref->name == ref
491 || !strcmp(current_ref->name, ref))) {
492 if (current_ref->flag & REF_KNOWS_PEELED) {
493 hashcpy(sha1, current_ref->peeled);
494 return 0;
495 }
496 hashcpy(base, current_ref->sha1);
497 goto fallback;
498 }
499
500 if (!resolve_ref(ref, base, 1, &flag))
501 return -1;
502
503 if ((flag & REF_ISPACKED)) {
504 struct ref_list *list = get_packed_refs();
505
506 while (list) {
507 if (!strcmp(list->name, ref)) {
508 if (list->flag & REF_KNOWS_PEELED) {
509 hashcpy(sha1, list->peeled);
510 return 0;
511 }
512 /* older pack-refs did not leave peeled ones */
513 break;
514 }
515 list = list->next;
516 }
517 }
518
519 fallback:
520 o = parse_object(base);
521 if (o && o->type == OBJ_TAG) {
522 o = deref_tag(o, ref, 0);
523 if (o) {
524 hashcpy(sha1, o->sha1);
525 return 0;
526 }
527 }
528 return -1;
529 }
530
531 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
532 void *cb_data)
533 {
534 int retval = 0;
535 struct ref_list *packed = get_packed_refs();
536 struct ref_list *loose = get_loose_refs();
537
538 while (packed && loose) {
539 struct ref_list *entry;
540 int cmp = strcmp(packed->name, loose->name);
541 if (!cmp) {
542 packed = packed->next;
543 continue;
544 }
545 if (cmp > 0) {
546 entry = loose;
547 loose = loose->next;
548 } else {
549 entry = packed;
550 packed = packed->next;
551 }
552 retval = do_one_ref(base, fn, trim, cb_data, entry);
553 if (retval)
554 goto end_each;
555 }
556
557 for (packed = packed ? packed : loose; packed; packed = packed->next) {
558 retval = do_one_ref(base, fn, trim, cb_data, packed);
559 if (retval)
560 goto end_each;
561 }
562
563 end_each:
564 current_ref = NULL;
565 return retval;
566 }
567
568 int head_ref(each_ref_fn fn, void *cb_data)
569 {
570 unsigned char sha1[20];
571 int flag;
572
573 if (resolve_ref("HEAD", sha1, 1, &flag))
574 return fn("HEAD", sha1, flag, cb_data);
575 return 0;
576 }
577
578 int for_each_ref(each_ref_fn fn, void *cb_data)
579 {
580 return do_for_each_ref("refs/", fn, 0, cb_data);
581 }
582
583 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
584 {
585 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
586 }
587
588 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
589 {
590 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
591 }
592
593 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
594 {
595 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
596 }
597
598 /*
599 * Make sure "ref" is something reasonable to have under ".git/refs/";
600 * We do not like it if:
601 *
602 * - any path component of it begins with ".", or
603 * - it has double dots "..", or
604 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
605 * - it ends with a "/".
606 */
607
608 static inline int bad_ref_char(int ch)
609 {
610 if (((unsigned) ch) <= ' ' ||
611 ch == '~' || ch == '^' || ch == ':')
612 return 1;
613 /* 2.13 Pattern Matching Notation */
614 if (ch == '?' || ch == '[') /* Unsupported */
615 return 1;
616 if (ch == '*') /* Supported at the end */
617 return 2;
618 return 0;
619 }
620
621 int check_ref_format(const char *ref)
622 {
623 int ch, level, bad_type;
624 const char *cp = ref;
625
626 level = 0;
627 while (1) {
628 while ((ch = *cp++) == '/')
629 ; /* tolerate duplicated slashes */
630 if (!ch)
631 /* should not end with slashes */
632 return CHECK_REF_FORMAT_ERROR;
633
634 /* we are at the beginning of the path component */
635 if (ch == '.')
636 return CHECK_REF_FORMAT_ERROR;
637 bad_type = bad_ref_char(ch);
638 if (bad_type) {
639 return (bad_type == 2 && !*cp)
640 ? CHECK_REF_FORMAT_WILDCARD
641 : CHECK_REF_FORMAT_ERROR;
642 }
643
644 /* scan the rest of the path component */
645 while ((ch = *cp++) != 0) {
646 bad_type = bad_ref_char(ch);
647 if (bad_type) {
648 return (bad_type == 2 && !*cp)
649 ? CHECK_REF_FORMAT_WILDCARD
650 : CHECK_REF_FORMAT_ERROR;
651 }
652 if (ch == '/')
653 break;
654 if (ch == '.' && *cp == '.')
655 return CHECK_REF_FORMAT_ERROR;
656 }
657 level++;
658 if (!ch) {
659 if (level < 2)
660 return CHECK_REF_FORMAT_ONELEVEL;
661 return CHECK_REF_FORMAT_OK;
662 }
663 }
664 }
665
666 const char *ref_rev_parse_rules[] = {
667 "%.*s",
668 "refs/%.*s",
669 "refs/tags/%.*s",
670 "refs/heads/%.*s",
671 "refs/remotes/%.*s",
672 "refs/remotes/%.*s/HEAD",
673 NULL
674 };
675
676 const char *ref_fetch_rules[] = {
677 "%.*s",
678 "refs/%.*s",
679 "refs/heads/%.*s",
680 NULL
681 };
682
683 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
684 {
685 const char **p;
686 const int abbrev_name_len = strlen(abbrev_name);
687
688 for (p = rules; *p; p++) {
689 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
690 return 1;
691 }
692 }
693
694 return 0;
695 }
696
697 static struct ref_lock *verify_lock(struct ref_lock *lock,
698 const unsigned char *old_sha1, int mustexist)
699 {
700 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
701 error("Can't verify ref %s", lock->ref_name);
702 unlock_ref(lock);
703 return NULL;
704 }
705 if (hashcmp(lock->old_sha1, old_sha1)) {
706 error("Ref %s is at %s but expected %s", lock->ref_name,
707 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
708 unlock_ref(lock);
709 return NULL;
710 }
711 return lock;
712 }
713
714 static int remove_empty_directories(const char *file)
715 {
716 /* we want to create a file but there is a directory there;
717 * if that is an empty directory (or a directory that contains
718 * only empty directories), remove them.
719 */
720 struct strbuf path;
721 int result;
722
723 strbuf_init(&path, 20);
724 strbuf_addstr(&path, file);
725
726 result = remove_dir_recursively(&path, 1);
727
728 strbuf_release(&path);
729
730 return result;
731 }
732
733 static int is_refname_available(const char *ref, const char *oldref,
734 struct ref_list *list, int quiet)
735 {
736 int namlen = strlen(ref); /* e.g. 'foo/bar' */
737 while (list) {
738 /* list->name could be 'foo' or 'foo/bar/baz' */
739 if (!oldref || strcmp(oldref, list->name)) {
740 int len = strlen(list->name);
741 int cmplen = (namlen < len) ? namlen : len;
742 const char *lead = (namlen < len) ? list->name : ref;
743 if (!strncmp(ref, list->name, cmplen) &&
744 lead[cmplen] == '/') {
745 if (!quiet)
746 error("'%s' exists; cannot create '%s'",
747 list->name, ref);
748 return 0;
749 }
750 }
751 list = list->next;
752 }
753 return 1;
754 }
755
756 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
757 {
758 char *ref_file;
759 const char *orig_ref = ref;
760 struct ref_lock *lock;
761 struct stat st;
762 int last_errno = 0;
763 int type;
764 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
765
766 lock = xcalloc(1, sizeof(struct ref_lock));
767 lock->lock_fd = -1;
768
769 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
770 if (!ref && errno == EISDIR) {
771 /* we are trying to lock foo but we used to
772 * have foo/bar which now does not exist;
773 * it is normal for the empty directory 'foo'
774 * to remain.
775 */
776 ref_file = git_path("%s", orig_ref);
777 if (remove_empty_directories(ref_file)) {
778 last_errno = errno;
779 error("there are still refs under '%s'", orig_ref);
780 goto error_return;
781 }
782 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
783 }
784 if (type_p)
785 *type_p = type;
786 if (!ref) {
787 last_errno = errno;
788 error("unable to resolve reference %s: %s",
789 orig_ref, strerror(errno));
790 goto error_return;
791 }
792 /* When the ref did not exist and we are creating it,
793 * make sure there is no existing ref that is packed
794 * whose name begins with our refname, nor a ref whose
795 * name is a proper prefix of our refname.
796 */
797 if (is_null_sha1(lock->old_sha1) &&
798 !is_refname_available(ref, NULL, get_packed_refs(), 0))
799 goto error_return;
800
801 lock->lk = xcalloc(1, sizeof(struct lock_file));
802
803 if (flags & REF_NODEREF)
804 ref = orig_ref;
805 lock->ref_name = xstrdup(ref);
806 lock->orig_ref_name = xstrdup(orig_ref);
807 ref_file = git_path("%s", ref);
808 if (lstat(ref_file, &st) && errno == ENOENT)
809 lock->force_write = 1;
810 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
811 lock->force_write = 1;
812
813 if (safe_create_leading_directories(ref_file)) {
814 last_errno = errno;
815 error("unable to create directory for %s", ref_file);
816 goto error_return;
817 }
818 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
819
820 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
821
822 error_return:
823 unlock_ref(lock);
824 errno = last_errno;
825 return NULL;
826 }
827
828 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
829 {
830 char refpath[PATH_MAX];
831 if (check_ref_format(ref))
832 return NULL;
833 strcpy(refpath, mkpath("refs/%s", ref));
834 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
835 }
836
837 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
838 {
839 switch (check_ref_format(ref)) {
840 default:
841 return NULL;
842 case 0:
843 case CHECK_REF_FORMAT_ONELEVEL:
844 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
845 }
846 }
847
848 static struct lock_file packlock;
849
850 static int repack_without_ref(const char *refname)
851 {
852 struct ref_list *list, *packed_ref_list;
853 int fd;
854 int found = 0;
855
856 packed_ref_list = get_packed_refs();
857 for (list = packed_ref_list; list; list = list->next) {
858 if (!strcmp(refname, list->name)) {
859 found = 1;
860 break;
861 }
862 }
863 if (!found)
864 return 0;
865 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
866 if (fd < 0)
867 return error("cannot delete '%s' from packed refs", refname);
868
869 for (list = packed_ref_list; list; list = list->next) {
870 char line[PATH_MAX + 100];
871 int len;
872
873 if (!strcmp(refname, list->name))
874 continue;
875 len = snprintf(line, sizeof(line), "%s %s\n",
876 sha1_to_hex(list->sha1), list->name);
877 /* this should not happen but just being defensive */
878 if (len > sizeof(line))
879 die("too long a refname '%s'", list->name);
880 write_or_die(fd, line, len);
881 }
882 return commit_lock_file(&packlock);
883 }
884
885 int delete_ref(const char *refname, const unsigned char *sha1)
886 {
887 struct ref_lock *lock;
888 int err, i, ret = 0, flag = 0;
889
890 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
891 if (!lock)
892 return 1;
893 if (!(flag & REF_ISPACKED)) {
894 /* loose */
895 i = strlen(lock->lk->filename) - 5; /* .lock */
896 lock->lk->filename[i] = 0;
897 err = unlink(lock->lk->filename);
898 if (err) {
899 ret = 1;
900 error("unlink(%s) failed: %s",
901 lock->lk->filename, strerror(errno));
902 }
903 lock->lk->filename[i] = '.';
904 }
905 /* removing the loose one could have resurrected an earlier
906 * packed one. Also, if it was not loose we need to repack
907 * without it.
908 */
909 ret |= repack_without_ref(refname);
910
911 err = unlink(git_path("logs/%s", lock->ref_name));
912 if (err && errno != ENOENT)
913 fprintf(stderr, "warning: unlink(%s) failed: %s",
914 git_path("logs/%s", lock->ref_name), strerror(errno));
915 invalidate_cached_refs();
916 unlock_ref(lock);
917 return ret;
918 }
919
920 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
921 {
922 static const char renamed_ref[] = "RENAMED-REF";
923 unsigned char sha1[20], orig_sha1[20];
924 int flag = 0, logmoved = 0;
925 struct ref_lock *lock;
926 struct stat loginfo;
927 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
928
929 if (S_ISLNK(loginfo.st_mode))
930 return error("reflog for %s is a symlink", oldref);
931
932 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
933 return error("refname %s not found", oldref);
934
935 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
936 return 1;
937
938 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
939 return 1;
940
941 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
942 if (!lock)
943 return error("unable to lock %s", renamed_ref);
944 lock->force_write = 1;
945 if (write_ref_sha1(lock, orig_sha1, logmsg))
946 return error("unable to save current sha1 in %s", renamed_ref);
947
948 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
949 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
950 oldref, strerror(errno));
951
952 if (delete_ref(oldref, orig_sha1)) {
953 error("unable to delete old %s", oldref);
954 goto rollback;
955 }
956
957 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
958 if (errno==EISDIR) {
959 if (remove_empty_directories(git_path("%s", newref))) {
960 error("Directory not empty: %s", newref);
961 goto rollback;
962 }
963 } else {
964 error("unable to delete existing %s", newref);
965 goto rollback;
966 }
967 }
968
969 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
970 error("unable to create directory for %s", newref);
971 goto rollback;
972 }
973
974 retry:
975 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
976 if (errno==EISDIR || errno==ENOTDIR) {
977 /*
978 * rename(a, b) when b is an existing
979 * directory ought to result in ISDIR, but
980 * Solaris 5.8 gives ENOTDIR. Sheesh.
981 */
982 if (remove_empty_directories(git_path("logs/%s", newref))) {
983 error("Directory not empty: logs/%s", newref);
984 goto rollback;
985 }
986 goto retry;
987 } else {
988 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
989 newref, strerror(errno));
990 goto rollback;
991 }
992 }
993 logmoved = log;
994
995 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
996 if (!lock) {
997 error("unable to lock %s for update", newref);
998 goto rollback;
999 }
1000
1001 lock->force_write = 1;
1002 hashcpy(lock->old_sha1, orig_sha1);
1003 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1004 error("unable to write current sha1 into %s", newref);
1005 goto rollback;
1006 }
1007
1008 return 0;
1009
1010 rollback:
1011 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1012 if (!lock) {
1013 error("unable to lock %s for rollback", oldref);
1014 goto rollbacklog;
1015 }
1016
1017 lock->force_write = 1;
1018 flag = log_all_ref_updates;
1019 log_all_ref_updates = 0;
1020 if (write_ref_sha1(lock, orig_sha1, NULL))
1021 error("unable to write current sha1 into %s", oldref);
1022 log_all_ref_updates = flag;
1023
1024 rollbacklog:
1025 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1026 error("unable to restore logfile %s from %s: %s",
1027 oldref, newref, strerror(errno));
1028 if (!logmoved && log &&
1029 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1030 error("unable to restore logfile %s from tmp-renamed-log: %s",
1031 oldref, strerror(errno));
1032
1033 return 1;
1034 }
1035
1036 static int close_ref(struct ref_lock *lock)
1037 {
1038 if (close_lock_file(lock->lk))
1039 return -1;
1040 lock->lock_fd = -1;
1041 return 0;
1042 }
1043
1044 static int commit_ref(struct ref_lock *lock)
1045 {
1046 if (commit_lock_file(lock->lk))
1047 return -1;
1048 lock->lock_fd = -1;
1049 return 0;
1050 }
1051
1052 void unlock_ref(struct ref_lock *lock)
1053 {
1054 /* Do not free lock->lk -- atexit() still looks at them */
1055 if (lock->lk)
1056 rollback_lock_file(lock->lk);
1057 free(lock->ref_name);
1058 free(lock->orig_ref_name);
1059 free(lock);
1060 }
1061
1062 /*
1063 * copy the reflog message msg to buf, which has been allocated sufficiently
1064 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1065 * because reflog file is one line per entry.
1066 */
1067 static int copy_msg(char *buf, const char *msg)
1068 {
1069 char *cp = buf;
1070 char c;
1071 int wasspace = 1;
1072
1073 *cp++ = '\t';
1074 while ((c = *msg++)) {
1075 if (wasspace && isspace(c))
1076 continue;
1077 wasspace = isspace(c);
1078 if (wasspace)
1079 c = ' ';
1080 *cp++ = c;
1081 }
1082 while (buf < cp && isspace(cp[-1]))
1083 cp--;
1084 *cp++ = '\n';
1085 return cp - buf;
1086 }
1087
1088 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1089 const unsigned char *new_sha1, const char *msg)
1090 {
1091 int logfd, written, oflags = O_APPEND | O_WRONLY;
1092 unsigned maxlen, len;
1093 int msglen;
1094 char *log_file, *logrec;
1095 const char *committer;
1096
1097 if (log_all_ref_updates < 0)
1098 log_all_ref_updates = !is_bare_repository();
1099
1100 log_file = git_path("logs/%s", ref_name);
1101
1102 if (log_all_ref_updates &&
1103 (!prefixcmp(ref_name, "refs/heads/") ||
1104 !prefixcmp(ref_name, "refs/remotes/") ||
1105 !strcmp(ref_name, "HEAD"))) {
1106 if (safe_create_leading_directories(log_file) < 0)
1107 return error("unable to create directory for %s",
1108 log_file);
1109 oflags |= O_CREAT;
1110 }
1111
1112 logfd = open(log_file, oflags, 0666);
1113 if (logfd < 0) {
1114 if (!(oflags & O_CREAT) && errno == ENOENT)
1115 return 0;
1116
1117 if ((oflags & O_CREAT) && errno == EISDIR) {
1118 if (remove_empty_directories(log_file)) {
1119 return error("There are still logs under '%s'",
1120 log_file);
1121 }
1122 logfd = open(log_file, oflags, 0666);
1123 }
1124
1125 if (logfd < 0)
1126 return error("Unable to append to %s: %s",
1127 log_file, strerror(errno));
1128 }
1129
1130 adjust_shared_perm(log_file);
1131
1132 msglen = msg ? strlen(msg) : 0;
1133 committer = git_committer_info(0);
1134 maxlen = strlen(committer) + msglen + 100;
1135 logrec = xmalloc(maxlen);
1136 len = sprintf(logrec, "%s %s %s\n",
1137 sha1_to_hex(old_sha1),
1138 sha1_to_hex(new_sha1),
1139 committer);
1140 if (msglen)
1141 len += copy_msg(logrec + len - 1, msg) - 1;
1142 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1143 free(logrec);
1144 if (close(logfd) != 0 || written != len)
1145 return error("Unable to append to %s", log_file);
1146 return 0;
1147 }
1148
1149 static int is_branch(const char *refname)
1150 {
1151 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1152 }
1153
1154 int write_ref_sha1(struct ref_lock *lock,
1155 const unsigned char *sha1, const char *logmsg)
1156 {
1157 static char term = '\n';
1158 struct object *o;
1159
1160 if (!lock)
1161 return -1;
1162 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1163 unlock_ref(lock);
1164 return 0;
1165 }
1166 o = parse_object(sha1);
1167 if (!o) {
1168 error("Trying to write ref %s with nonexistant object %s",
1169 lock->ref_name, sha1_to_hex(sha1));
1170 unlock_ref(lock);
1171 return -1;
1172 }
1173 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1174 error("Trying to write non-commit object %s to branch %s",
1175 sha1_to_hex(sha1), lock->ref_name);
1176 unlock_ref(lock);
1177 return -1;
1178 }
1179 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1180 write_in_full(lock->lock_fd, &term, 1) != 1
1181 || close_ref(lock) < 0) {
1182 error("Couldn't write %s", lock->lk->filename);
1183 unlock_ref(lock);
1184 return -1;
1185 }
1186 invalidate_cached_refs();
1187 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1188 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1189 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1190 unlock_ref(lock);
1191 return -1;
1192 }
1193 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1194 /*
1195 * Special hack: If a branch is updated directly and HEAD
1196 * points to it (may happen on the remote side of a push
1197 * for example) then logically the HEAD reflog should be
1198 * updated too.
1199 * A generic solution implies reverse symref information,
1200 * but finding all symrefs pointing to the given branch
1201 * would be rather costly for this rare event (the direct
1202 * update of a branch) to be worth it. So let's cheat and
1203 * check with HEAD only which should cover 99% of all usage
1204 * scenarios (even 100% of the default ones).
1205 */
1206 unsigned char head_sha1[20];
1207 int head_flag;
1208 const char *head_ref;
1209 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1210 if (head_ref && (head_flag & REF_ISSYMREF) &&
1211 !strcmp(head_ref, lock->ref_name))
1212 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1213 }
1214 if (commit_ref(lock)) {
1215 error("Couldn't set %s", lock->ref_name);
1216 unlock_ref(lock);
1217 return -1;
1218 }
1219 unlock_ref(lock);
1220 return 0;
1221 }
1222
1223 int create_symref(const char *ref_target, const char *refs_heads_master,
1224 const char *logmsg)
1225 {
1226 const char *lockpath;
1227 char ref[1000];
1228 int fd, len, written;
1229 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1230 unsigned char old_sha1[20], new_sha1[20];
1231
1232 if (logmsg && read_ref(ref_target, old_sha1))
1233 hashclr(old_sha1);
1234
1235 if (safe_create_leading_directories(git_HEAD) < 0)
1236 return error("unable to create directory for %s", git_HEAD);
1237
1238 #ifndef NO_SYMLINK_HEAD
1239 if (prefer_symlink_refs) {
1240 unlink(git_HEAD);
1241 if (!symlink(refs_heads_master, git_HEAD))
1242 goto done;
1243 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1244 }
1245 #endif
1246
1247 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1248 if (sizeof(ref) <= len) {
1249 error("refname too long: %s", refs_heads_master);
1250 goto error_free_return;
1251 }
1252 lockpath = mkpath("%s.lock", git_HEAD);
1253 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1254 if (fd < 0) {
1255 error("Unable to open %s for writing", lockpath);
1256 goto error_free_return;
1257 }
1258 written = write_in_full(fd, ref, len);
1259 if (close(fd) != 0 || written != len) {
1260 error("Unable to write to %s", lockpath);
1261 goto error_unlink_return;
1262 }
1263 if (rename(lockpath, git_HEAD) < 0) {
1264 error("Unable to create %s", git_HEAD);
1265 goto error_unlink_return;
1266 }
1267 if (adjust_shared_perm(git_HEAD)) {
1268 error("Unable to fix permissions on %s", lockpath);
1269 error_unlink_return:
1270 unlink(lockpath);
1271 error_free_return:
1272 free(git_HEAD);
1273 return -1;
1274 }
1275
1276 #ifndef NO_SYMLINK_HEAD
1277 done:
1278 #endif
1279 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1280 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1281
1282 free(git_HEAD);
1283 return 0;
1284 }
1285
1286 static char *ref_msg(const char *line, const char *endp)
1287 {
1288 const char *ep;
1289 line += 82;
1290 ep = memchr(line, '\n', endp - line);
1291 if (!ep)
1292 ep = endp;
1293 return xmemdupz(line, ep - line);
1294 }
1295
1296 int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
1297 {
1298 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1299 char *tz_c;
1300 int logfd, tz, reccnt = 0;
1301 struct stat st;
1302 unsigned long date;
1303 unsigned char logged_sha1[20];
1304 void *log_mapped;
1305 size_t mapsz;
1306
1307 logfile = git_path("logs/%s", ref);
1308 logfd = open(logfile, O_RDONLY, 0);
1309 if (logfd < 0)
1310 die("Unable to read log %s: %s", logfile, strerror(errno));
1311 fstat(logfd, &st);
1312 if (!st.st_size)
1313 die("Log %s is empty.", logfile);
1314 mapsz = xsize_t(st.st_size);
1315 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1316 logdata = log_mapped;
1317 close(logfd);
1318
1319 lastrec = NULL;
1320 rec = logend = logdata + st.st_size;
1321 while (logdata < rec) {
1322 reccnt++;
1323 if (logdata < rec && *(rec-1) == '\n')
1324 rec--;
1325 lastgt = NULL;
1326 while (logdata < rec && *(rec-1) != '\n') {
1327 rec--;
1328 if (*rec == '>')
1329 lastgt = rec;
1330 }
1331 if (!lastgt)
1332 die("Log %s is corrupt.", logfile);
1333 date = strtoul(lastgt + 1, &tz_c, 10);
1334 if (date <= at_time || cnt == 0) {
1335 tz = strtoul(tz_c, NULL, 10);
1336 if (msg)
1337 *msg = ref_msg(rec, logend);
1338 if (cutoff_time)
1339 *cutoff_time = date;
1340 if (cutoff_tz)
1341 *cutoff_tz = tz;
1342 if (cutoff_cnt)
1343 *cutoff_cnt = reccnt - 1;
1344 if (lastrec) {
1345 if (get_sha1_hex(lastrec, logged_sha1))
1346 die("Log %s is corrupt.", logfile);
1347 if (get_sha1_hex(rec + 41, sha1))
1348 die("Log %s is corrupt.", logfile);
1349 if (hashcmp(logged_sha1, sha1)) {
1350 fprintf(stderr,
1351 "warning: Log %s has gap after %s.\n",
1352 logfile, show_date(date, tz, DATE_RFC2822));
1353 }
1354 }
1355 else if (date == at_time) {
1356 if (get_sha1_hex(rec + 41, sha1))
1357 die("Log %s is corrupt.", logfile);
1358 }
1359 else {
1360 if (get_sha1_hex(rec + 41, logged_sha1))
1361 die("Log %s is corrupt.", logfile);
1362 if (hashcmp(logged_sha1, sha1)) {
1363 fprintf(stderr,
1364 "warning: Log %s unexpectedly ended on %s.\n",
1365 logfile, show_date(date, tz, DATE_RFC2822));
1366 }
1367 }
1368 munmap(log_mapped, mapsz);
1369 return 0;
1370 }
1371 lastrec = rec;
1372 if (cnt > 0)
1373 cnt--;
1374 }
1375
1376 rec = logdata;
1377 while (rec < logend && *rec != '>' && *rec != '\n')
1378 rec++;
1379 if (rec == logend || *rec == '\n')
1380 die("Log %s is corrupt.", logfile);
1381 date = strtoul(rec + 1, &tz_c, 10);
1382 tz = strtoul(tz_c, NULL, 10);
1383 if (get_sha1_hex(logdata, sha1))
1384 die("Log %s is corrupt.", logfile);
1385 if (msg)
1386 *msg = ref_msg(logdata, logend);
1387 munmap(log_mapped, mapsz);
1388
1389 if (cutoff_time)
1390 *cutoff_time = date;
1391 if (cutoff_tz)
1392 *cutoff_tz = tz;
1393 if (cutoff_cnt)
1394 *cutoff_cnt = reccnt;
1395 return 1;
1396 }
1397
1398 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1399 {
1400 const char *logfile;
1401 FILE *logfp;
1402 char buf[1024];
1403 int ret = 0;
1404
1405 logfile = git_path("logs/%s", ref);
1406 logfp = fopen(logfile, "r");
1407 if (!logfp)
1408 return -1;
1409 while (fgets(buf, sizeof(buf), logfp)) {
1410 unsigned char osha1[20], nsha1[20];
1411 char *email_end, *message;
1412 unsigned long timestamp;
1413 int len, tz;
1414
1415 /* old SP new SP name <email> SP time TAB msg LF */
1416 len = strlen(buf);
1417 if (len < 83 || buf[len-1] != '\n' ||
1418 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1419 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1420 !(email_end = strchr(buf + 82, '>')) ||
1421 email_end[1] != ' ' ||
1422 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1423 !message || message[0] != ' ' ||
1424 (message[1] != '+' && message[1] != '-') ||
1425 !isdigit(message[2]) || !isdigit(message[3]) ||
1426 !isdigit(message[4]) || !isdigit(message[5]))
1427 continue; /* corrupt? */
1428 email_end[1] = '\0';
1429 tz = strtol(message + 1, NULL, 10);
1430 if (message[6] != '\t')
1431 message += 6;
1432 else
1433 message += 7;
1434 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1435 if (ret)
1436 break;
1437 }
1438 fclose(logfp);
1439 return ret;
1440 }
1441
1442 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1443 {
1444 DIR *dir = opendir(git_path("logs/%s", base));
1445 int retval = 0;
1446
1447 if (dir) {
1448 struct dirent *de;
1449 int baselen = strlen(base);
1450 char *log = xmalloc(baselen + 257);
1451
1452 memcpy(log, base, baselen);
1453 if (baselen && base[baselen-1] != '/')
1454 log[baselen++] = '/';
1455
1456 while ((de = readdir(dir)) != NULL) {
1457 struct stat st;
1458 int namelen;
1459
1460 if (de->d_name[0] == '.')
1461 continue;
1462 namelen = strlen(de->d_name);
1463 if (namelen > 255)
1464 continue;
1465 if (has_extension(de->d_name, ".lock"))
1466 continue;
1467 memcpy(log + baselen, de->d_name, namelen+1);
1468 if (stat(git_path("logs/%s", log), &st) < 0)
1469 continue;
1470 if (S_ISDIR(st.st_mode)) {
1471 retval = do_for_each_reflog(log, fn, cb_data);
1472 } else {
1473 unsigned char sha1[20];
1474 if (!resolve_ref(log, sha1, 0, NULL))
1475 retval = error("bad ref for %s", log);
1476 else
1477 retval = fn(log, sha1, 0, cb_data);
1478 }
1479 if (retval)
1480 break;
1481 }
1482 free(log);
1483 closedir(dir);
1484 }
1485 else if (*base)
1486 return errno;
1487 return retval;
1488 }
1489
1490 int for_each_reflog(each_ref_fn fn, void *cb_data)
1491 {
1492 return do_for_each_reflog("", fn, cb_data);
1493 }
1494
1495 int update_ref(const char *action, const char *refname,
1496 const unsigned char *sha1, const unsigned char *oldval,
1497 int flags, enum action_on_err onerr)
1498 {
1499 static struct ref_lock *lock;
1500 lock = lock_any_ref_for_update(refname, oldval, flags);
1501 if (!lock) {
1502 const char *str = "Cannot lock the ref '%s'.";
1503 switch (onerr) {
1504 case MSG_ON_ERR: error(str, refname); break;
1505 case DIE_ON_ERR: die(str, refname); break;
1506 case QUIET_ON_ERR: break;
1507 }
1508 return 1;
1509 }
1510 if (write_ref_sha1(lock, sha1, action) < 0) {
1511 const char *str = "Cannot update the ref '%s'.";
1512 switch (onerr) {
1513 case MSG_ON_ERR: error(str, refname); break;
1514 case DIE_ON_ERR: die(str, refname); break;
1515 case QUIET_ON_ERR: break;
1516 }
1517 return 1;
1518 }
1519 return 0;
1520 }
1521
1522 struct ref *find_ref_by_name(struct ref *list, const char *name)
1523 {
1524 for ( ; list; list = list->next)
1525 if (!strcmp(list->name, name))
1526 return list;
1527 return NULL;
1528 }