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