resolve_ref(): only follow a symlink that contains a valid, normalized refname
[git/git.git] / refs.c
CommitLineData
95fc7512 1#include "cache.h"
85023577 2#include "refs.h"
cf0adba7
JH
3#include "object.h"
4#include "tag.h"
7155b727 5#include "dir.h"
95fc7512 6
f4204ab9
JH
7/* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8#define REF_KNOWS_PEELED 04
e01de1c9 9#define REF_BROKEN 010
f4204ab9 10
e1e22e37
LT
11struct ref_list {
12 struct ref_list *next;
f4204ab9 13 unsigned char flag; /* ISSYMREF? ISPACKED? */
e1e22e37 14 unsigned char sha1[20];
f4204ab9 15 unsigned char peeled[20];
e1e22e37
LT
16 char name[FLEX_ARRAY];
17};
18
f4204ab9 19static const char *parse_ref_line(char *line, unsigned char *sha1)
e1e22e37
LT
20{
21 /*
22 * 42: the answer to everything.
23 *
24 * In this case, it happens to be the answer to
25 * 40 (length of sha1 hex representation)
26 * +1 (space in between hex and name)
27 * +1 (newline at the end of the line)
28 */
29 int len = strlen(line) - 42;
30
31 if (len <= 0)
32 return NULL;
33 if (get_sha1_hex(line, sha1) < 0)
34 return NULL;
35 if (!isspace(line[40]))
36 return NULL;
37 line += 41;
f4204ab9
JH
38 if (isspace(*line))
39 return NULL;
e1e22e37
LT
40 if (line[len] != '\n')
41 return NULL;
42 line[len] = 0;
cf0adba7 43
e1e22e37
LT
44 return line;
45}
46
8da19775 47static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
f4204ab9
JH
48 int flag, struct ref_list *list,
49 struct ref_list **new_entry)
e1e22e37
LT
50{
51 int len;
c774aab9 52 struct ref_list *entry;
e1e22e37
LT
53
54 /* Allocate it and add it in.. */
55 len = strlen(name) + 1;
56 entry = xmalloc(sizeof(struct ref_list) + len);
57 hashcpy(entry->sha1, sha1);
f4204ab9 58 hashclr(entry->peeled);
e1e22e37 59 memcpy(entry->name, name, len);
8da19775 60 entry->flag = flag;
c774aab9 61 entry->next = list;
f4204ab9
JH
62 if (new_entry)
63 *new_entry = entry;
c774aab9
JP
64 return entry;
65}
66
67/* merge sort the ref list */
68static struct ref_list *sort_ref_list(struct ref_list *list)
69{
70 int psize, qsize, last_merge_count, cmp;
71 struct ref_list *p, *q, *l, *e;
72 struct ref_list *new_list = list;
73 int k = 1;
74 int merge_count = 0;
75
76 if (!list)
77 return list;
78
79 do {
80 last_merge_count = merge_count;
81 merge_count = 0;
82
83 psize = 0;
84
85 p = new_list;
86 q = new_list;
87 new_list = NULL;
88 l = NULL;
89
90 while (p) {
91 merge_count++;
92
93 while (psize < k && q->next) {
94 q = q->next;
95 psize++;
96 }
97 qsize = k;
98
99 while ((psize > 0) || (qsize > 0 && q)) {
100 if (qsize == 0 || !q) {
101 e = p;
102 p = p->next;
103 psize--;
104 } else if (psize == 0) {
105 e = q;
106 q = q->next;
107 qsize--;
108 } else {
109 cmp = strcmp(q->name, p->name);
110 if (cmp < 0) {
111 e = q;
112 q = q->next;
113 qsize--;
114 } else if (cmp > 0) {
115 e = p;
116 p = p->next;
117 psize--;
118 } else {
119 if (hashcmp(q->sha1, p->sha1))
120 die("Duplicated ref, and SHA1s don't match: %s",
121 q->name);
122 warning("Duplicated ref: %s", q->name);
123 e = q;
124 q = q->next;
125 qsize--;
126 free(e);
127 e = p;
128 p = p->next;
129 psize--;
130 }
131 }
132
133 e->next = NULL;
134
135 if (l)
136 l->next = e;
137 if (!new_list)
138 new_list = e;
139 l = e;
140 }
141
142 p = q;
143 };
144
145 k = k * 2;
146 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
147
148 return new_list;
e1e22e37
LT
149}
150
5e290ff7
JH
151/*
152 * Future: need to be in "struct repository"
153 * when doing a full libification.
154 */
4175e9e3 155static struct cached_refs {
5e290ff7
JH
156 char did_loose;
157 char did_packed;
158 struct ref_list *loose;
159 struct ref_list *packed;
0bad611b 160} cached_refs, submodule_refs;
0ae91be0 161static struct ref_list *current_ref;
5e290ff7 162
e142a3c6
DB
163static struct ref_list *extra_refs;
164
5e290ff7
JH
165static void free_ref_list(struct ref_list *list)
166{
167 struct ref_list *next;
168 for ( ; list; list = next) {
169 next = list->next;
170 free(list);
171 }
172}
173
174static void invalidate_cached_refs(void)
e1e22e37 175{
5e290ff7
JH
176 struct cached_refs *ca = &cached_refs;
177
178 if (ca->did_loose && ca->loose)
179 free_ref_list(ca->loose);
180 if (ca->did_packed && ca->packed)
181 free_ref_list(ca->packed);
182 ca->loose = ca->packed = NULL;
183 ca->did_loose = ca->did_packed = 0;
184}
e1e22e37 185
f4204ab9
JH
186static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
187{
188 struct ref_list *list = NULL;
189 struct ref_list *last = NULL;
190 char refline[PATH_MAX];
191 int flag = REF_ISPACKED;
192
193 while (fgets(refline, sizeof(refline), f)) {
194 unsigned char sha1[20];
195 const char *name;
196 static const char header[] = "# pack-refs with:";
197
198 if (!strncmp(refline, header, sizeof(header)-1)) {
199 const char *traits = refline + sizeof(header) - 1;
200 if (strstr(traits, " peeled "))
201 flag |= REF_KNOWS_PEELED;
202 /* perhaps other traits later as well */
203 continue;
204 }
205
206 name = parse_ref_line(refline, sha1);
207 if (name) {
208 list = add_ref(name, sha1, flag, list, &last);
209 continue;
210 }
211 if (last &&
212 refline[0] == '^' &&
213 strlen(refline) == 42 &&
214 refline[41] == '\n' &&
215 !get_sha1_hex(refline + 1, sha1))
216 hashcpy(last->peeled, sha1);
217 }
c774aab9 218 cached_refs->packed = sort_ref_list(list);
f4204ab9
JH
219}
220
e142a3c6
DB
221void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
222{
223 extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
224}
225
226void clear_extra_refs(void)
227{
228 free_ref_list(extra_refs);
229 extra_refs = NULL;
230}
231
0bad611b 232static struct ref_list *get_packed_refs(const char *submodule)
5e290ff7 233{
0bad611b
HV
234 const char *packed_refs_file;
235 struct cached_refs *refs;
236
237 if (submodule) {
238 packed_refs_file = git_path_submodule(submodule, "packed-refs");
239 refs = &submodule_refs;
240 free_ref_list(refs->packed);
241 } else {
242 packed_refs_file = git_path("packed-refs");
243 refs = &cached_refs;
244 }
245
246 if (!refs->did_packed || submodule) {
247 FILE *f = fopen(packed_refs_file, "r");
248 refs->packed = NULL;
e1e22e37 249 if (f) {
0bad611b 250 read_packed_refs(f, refs);
e1e22e37 251 fclose(f);
e1e22e37 252 }
0bad611b 253 refs->did_packed = 1;
e1e22e37 254 }
0bad611b 255 return refs->packed;
e1e22e37
LT
256}
257
0bad611b
HV
258static struct ref_list *get_ref_dir(const char *submodule, const char *base,
259 struct ref_list *list)
e1e22e37 260{
0bad611b
HV
261 DIR *dir;
262 const char *path;
263
264 if (submodule)
265 path = git_path_submodule(submodule, "%s", base);
266 else
267 path = git_path("%s", base);
268
269
270 dir = opendir(path);
e1e22e37
LT
271
272 if (dir) {
273 struct dirent *de;
274 int baselen = strlen(base);
ed378ec7 275 char *ref = xmalloc(baselen + 257);
e1e22e37 276
ed378ec7 277 memcpy(ref, base, baselen);
e1e22e37 278 if (baselen && base[baselen-1] != '/')
ed378ec7 279 ref[baselen++] = '/';
e1e22e37
LT
280
281 while ((de = readdir(dir)) != NULL) {
282 unsigned char sha1[20];
283 struct stat st;
8da19775 284 int flag;
e1e22e37 285 int namelen;
0bad611b 286 const char *refdir;
e1e22e37
LT
287
288 if (de->d_name[0] == '.')
289 continue;
290 namelen = strlen(de->d_name);
291 if (namelen > 255)
292 continue;
293 if (has_extension(de->d_name, ".lock"))
294 continue;
ed378ec7 295 memcpy(ref + baselen, de->d_name, namelen+1);
0bad611b
HV
296 refdir = submodule
297 ? git_path_submodule(submodule, "%s", ref)
298 : git_path("%s", ref);
299 if (stat(refdir, &st) < 0)
e1e22e37
LT
300 continue;
301 if (S_ISDIR(st.st_mode)) {
0bad611b 302 list = get_ref_dir(submodule, ref, list);
e1e22e37
LT
303 continue;
304 }
0bad611b 305 if (submodule) {
f8948e2f 306 hashclr(sha1);
0bad611b
HV
307 flag = 0;
308 if (resolve_gitlink_ref(submodule, ref, sha1) < 0) {
309 hashclr(sha1);
310 flag |= REF_BROKEN;
311 }
312 } else
313 if (!resolve_ref(ref, sha1, 1, &flag)) {
314 hashclr(sha1);
315 flag |= REF_BROKEN;
316 }
f4204ab9 317 list = add_ref(ref, sha1, flag, list, NULL);
e1e22e37 318 }
ed378ec7 319 free(ref);
e1e22e37
LT
320 closedir(dir);
321 }
c774aab9 322 return sort_ref_list(list);
e1e22e37
LT
323}
324
f8948e2f 325struct warn_if_dangling_data {
3cf6134a 326 FILE *fp;
f8948e2f
JH
327 const char *refname;
328 const char *msg_fmt;
329};
330
331static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
332 int flags, void *cb_data)
333{
334 struct warn_if_dangling_data *d = cb_data;
335 const char *resolves_to;
336 unsigned char junk[20];
337
338 if (!(flags & REF_ISSYMREF))
339 return 0;
340
341 resolves_to = resolve_ref(refname, junk, 0, NULL);
342 if (!resolves_to || strcmp(resolves_to, d->refname))
343 return 0;
344
3cf6134a 345 fprintf(d->fp, d->msg_fmt, refname);
f8948e2f
JH
346 return 0;
347}
348
3cf6134a 349void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
f8948e2f 350{
66dbfd55
GV
351 struct warn_if_dangling_data data;
352
353 data.fp = fp;
354 data.refname = refname;
355 data.msg_fmt = msg_fmt;
f8948e2f
JH
356 for_each_rawref(warn_if_dangling_symref, &data);
357}
358
0bad611b 359static struct ref_list *get_loose_refs(const char *submodule)
e1e22e37 360{
0bad611b
HV
361 if (submodule) {
362 free_ref_list(submodule_refs.loose);
363 submodule_refs.loose = get_ref_dir(submodule, "refs", NULL);
364 return submodule_refs.loose;
365 }
366
5e290ff7 367 if (!cached_refs.did_loose) {
0bad611b 368 cached_refs.loose = get_ref_dir(NULL, "refs", NULL);
5e290ff7 369 cached_refs.did_loose = 1;
e1e22e37 370 }
5e290ff7 371 return cached_refs.loose;
e1e22e37
LT
372}
373
ca8db142
LT
374/* We allow "recursive" symbolic refs. Only within reason, though */
375#define MAXDEPTH 5
0ebde32c
LT
376#define MAXREFLEN (1024)
377
378static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
379{
380 FILE *f;
381 struct cached_refs refs;
382 struct ref_list *ref;
383 int retval;
384
385 strcpy(name + pathlen, "packed-refs");
386 f = fopen(name, "r");
387 if (!f)
388 return -1;
389 read_packed_refs(f, &refs);
390 fclose(f);
391 ref = refs.packed;
392 retval = -1;
393 while (ref) {
394 if (!strcmp(ref->name, refname)) {
395 retval = 0;
396 memcpy(result, ref->sha1, 20);
397 break;
398 }
399 ref = ref->next;
400 }
401 free_ref_list(refs.packed);
402 return retval;
403}
404
405static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
406{
407 int fd, len = strlen(refname);
408 char buffer[128], *p;
409
410 if (recursion > MAXDEPTH || len > MAXREFLEN)
411 return -1;
412 memcpy(name + pathlen, refname, len+1);
413 fd = open(name, O_RDONLY);
414 if (fd < 0)
415 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
416
417 len = read(fd, buffer, sizeof(buffer)-1);
418 close(fd);
419 if (len < 0)
420 return -1;
421 while (len && isspace(buffer[len-1]))
422 len--;
423 buffer[len] = 0;
424
425 /* Was it a detached head or an old-fashioned symlink? */
426 if (!get_sha1_hex(buffer, result))
427 return 0;
428
429 /* Symref? */
430 if (strncmp(buffer, "ref:", 4))
431 return -1;
432 p = buffer + 4;
433 while (isspace(*p))
434 p++;
435
436 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
437}
438
439int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
440{
441 int len = strlen(path), retval;
442 char *gitdir;
842abf06 443 const char *tmp;
0ebde32c
LT
444
445 while (len && path[len-1] == '/')
446 len--;
447 if (!len)
448 return -1;
449 gitdir = xmalloc(len + MAXREFLEN + 8);
450 memcpy(gitdir, path, len);
842abf06
LH
451 memcpy(gitdir + len, "/.git", 6);
452 len += 5;
453
13d6ec91 454 tmp = read_gitfile(gitdir);
842abf06
LH
455 if (tmp) {
456 free(gitdir);
457 len = strlen(tmp);
458 gitdir = xmalloc(len + MAXREFLEN + 3);
459 memcpy(gitdir, tmp, len);
460 }
461 gitdir[len] = '/';
462 gitdir[++len] = '\0';
463 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
0ebde32c
LT
464 free(gitdir);
465 return retval;
466}
ca8db142 467
4886b89f
CC
468/*
469 * If the "reading" argument is set, this function finds out what _object_
470 * the ref points at by "reading" the ref. The ref, if it is not symbolic,
471 * has to exist, and if it is symbolic, it has to point at an existing ref,
472 * because the "read" goes through the symref to the ref it points at.
473 *
474 * The access that is not "reading" may often be "writing", but does not
475 * have to; it can be merely checking _where it leads to_. If it is a
476 * prelude to "writing" to the ref, a write to a symref that points at
477 * yet-to-be-born ref will create the real ref pointed by the symref.
478 * reading=0 allows the caller to check where such a symref leads to.
479 */
8da19775 480const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
8a65ff76 481{
0104ca09
HO
482 int depth = MAXDEPTH;
483 ssize_t len;
a876ed83 484 char buffer[256];
ed378ec7 485 static char ref_buffer[256];
ca8db142 486
8da19775
JH
487 if (flag)
488 *flag = 0;
489
a876ed83 490 for (;;) {
958a4789 491 char path[PATH_MAX];
a876ed83
JH
492 struct stat st;
493 char *buf;
494 int fd;
8a65ff76 495
a876ed83
JH
496 if (--depth < 0)
497 return NULL;
ca8db142 498
958a4789 499 git_snpath(path, sizeof(path), "%s", ref);
4886b89f 500 /* Special case: non-existing file. */
a876ed83 501 if (lstat(path, &st) < 0) {
0bad611b 502 struct ref_list *list = get_packed_refs(NULL);
434cd0cd 503 while (list) {
f4204ab9 504 if (!strcmp(ref, list->name)) {
434cd0cd 505 hashcpy(sha1, list->sha1);
8da19775
JH
506 if (flag)
507 *flag |= REF_ISPACKED;
434cd0cd
LT
508 return ref;
509 }
510 list = list->next;
511 }
a876ed83
JH
512 if (reading || errno != ENOENT)
513 return NULL;
e702496e 514 hashclr(sha1);
ed378ec7 515 return ref;
a876ed83 516 }
ca8db142 517
a876ed83
JH
518 /* Follow "normalized" - ie "refs/.." symlinks by hand */
519 if (S_ISLNK(st.st_mode)) {
520 len = readlink(path, buffer, sizeof(buffer)-1);
7bb2bf8e
MH
521 if (len < 0)
522 return NULL;
b54cb795 523 buffer[len] = 0;
1f58a038
MH
524 if (!prefixcmp(buffer, "refs/") &&
525 !check_refname_format(buffer, 0)) {
ed378ec7
LT
526 strcpy(ref_buffer, buffer);
527 ref = ref_buffer;
8da19775
JH
528 if (flag)
529 *flag |= REF_ISSYMREF;
a876ed83
JH
530 continue;
531 }
ca8db142 532 }
a876ed83 533
7a21632f
DS
534 /* Is it a directory? */
535 if (S_ISDIR(st.st_mode)) {
536 errno = EISDIR;
537 return NULL;
538 }
539
a876ed83
JH
540 /*
541 * Anything else, just open it and try to use it as
542 * a ref
543 */
544 fd = open(path, O_RDONLY);
545 if (fd < 0)
546 return NULL;
93d26e4c 547 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83
JH
548 close(fd);
549
550 /*
551 * Is it a symbolic ref?
552 */
553 if (len < 4 || memcmp("ref:", buffer, 4))
554 break;
555 buf = buffer + 4;
556 len -= 4;
557 while (len && isspace(*buf))
558 buf++, len--;
559 while (len && isspace(buf[len-1]))
ed378ec7
LT
560 len--;
561 buf[len] = 0;
562 memcpy(ref_buffer, buf, len + 1);
563 ref = ref_buffer;
8da19775
JH
564 if (flag)
565 *flag |= REF_ISSYMREF;
8a65ff76 566 }
a876ed83
JH
567 if (len < 40 || get_sha1_hex(buffer, sha1))
568 return NULL;
ed378ec7 569 return ref;
a876ed83
JH
570}
571
d08bae7e
IL
572/* The argument to filter_refs */
573struct ref_filter {
574 const char *pattern;
575 each_ref_fn *fn;
576 void *cb_data;
577};
578
ed378ec7 579int read_ref(const char *ref, unsigned char *sha1)
a876ed83 580{
8da19775 581 if (resolve_ref(ref, sha1, 1, NULL))
a876ed83
JH
582 return 0;
583 return -1;
8a65ff76
LT
584}
585
f8948e2f 586#define DO_FOR_EACH_INCLUDE_BROKEN 01
ef06b918 587static int do_one_ref(const char *base, each_ref_fn fn, int trim,
f8948e2f 588 int flags, void *cb_data, struct ref_list *entry)
ef06b918 589{
b3cfc406 590 if (prefixcmp(entry->name, base))
ef06b918 591 return 0;
e01de1c9 592
f8948e2f 593 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
e01de1c9
JH
594 if (entry->flag & REF_BROKEN)
595 return 0; /* ignore dangling symref */
f8948e2f
JH
596 if (!has_sha1_file(entry->sha1)) {
597 error("%s does not point to a valid object!", entry->name);
598 return 0;
599 }
ef06b918 600 }
0ae91be0 601 current_ref = entry;
ef06b918
JH
602 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
603}
604
d08bae7e
IL
605static int filter_refs(const char *ref, const unsigned char *sha, int flags,
606 void *data)
607{
608 struct ref_filter *filter = (struct ref_filter *)data;
609 if (fnmatch(filter->pattern, ref, 0))
610 return 0;
611 return filter->fn(ref, sha, flags, filter->cb_data);
612}
613
cf0adba7
JH
614int peel_ref(const char *ref, unsigned char *sha1)
615{
616 int flag;
617 unsigned char base[20];
618 struct object *o;
619
0ae91be0
SP
620 if (current_ref && (current_ref->name == ref
621 || !strcmp(current_ref->name, ref))) {
622 if (current_ref->flag & REF_KNOWS_PEELED) {
623 hashcpy(sha1, current_ref->peeled);
624 return 0;
625 }
626 hashcpy(base, current_ref->sha1);
627 goto fallback;
628 }
629
cf0adba7
JH
630 if (!resolve_ref(ref, base, 1, &flag))
631 return -1;
632
633 if ((flag & REF_ISPACKED)) {
0bad611b 634 struct ref_list *list = get_packed_refs(NULL);
cf0adba7
JH
635
636 while (list) {
f4204ab9
JH
637 if (!strcmp(list->name, ref)) {
638 if (list->flag & REF_KNOWS_PEELED) {
639 hashcpy(sha1, list->peeled);
640 return 0;
641 }
642 /* older pack-refs did not leave peeled ones */
643 break;
cf0adba7
JH
644 }
645 list = list->next;
646 }
cf0adba7
JH
647 }
648
0ae91be0 649fallback:
cf0adba7 650 o = parse_object(base);
8c87dc77 651 if (o && o->type == OBJ_TAG) {
cf0adba7
JH
652 o = deref_tag(o, ref, 0);
653 if (o) {
654 hashcpy(sha1, o->sha1);
655 return 0;
656 }
657 }
658 return -1;
659}
660
0bad611b
HV
661static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
662 int trim, int flags, void *cb_data)
8a65ff76 663{
0ae91be0 664 int retval = 0;
0bad611b
HV
665 struct ref_list *packed = get_packed_refs(submodule);
666 struct ref_list *loose = get_loose_refs(submodule);
8a65ff76 667
e142a3c6
DB
668 struct ref_list *extra;
669
670 for (extra = extra_refs; extra; extra = extra->next)
f8948e2f 671 retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
e142a3c6 672
e1e22e37
LT
673 while (packed && loose) {
674 struct ref_list *entry;
675 int cmp = strcmp(packed->name, loose->name);
676 if (!cmp) {
677 packed = packed->next;
678 continue;
6cada6a9 679 }
e1e22e37
LT
680 if (cmp > 0) {
681 entry = loose;
682 loose = loose->next;
683 } else {
684 entry = packed;
685 packed = packed->next;
686 }
f8948e2f 687 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
e1e22e37 688 if (retval)
0ae91be0 689 goto end_each;
e1e22e37 690 }
8a65ff76 691
ef06b918 692 for (packed = packed ? packed : loose; packed; packed = packed->next) {
f8948e2f 693 retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
ef06b918 694 if (retval)
0ae91be0 695 goto end_each;
8a65ff76 696 }
0ae91be0
SP
697
698end_each:
699 current_ref = NULL;
700 return retval;
8a65ff76
LT
701}
702
0bad611b
HV
703
704static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
705{
706 unsigned char sha1[20];
8da19775
JH
707 int flag;
708
0bad611b
HV
709 if (submodule) {
710 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
711 return fn("HEAD", sha1, 0, cb_data);
712
713 return 0;
714 }
715
8da19775
JH
716 if (resolve_ref("HEAD", sha1, 1, &flag))
717 return fn("HEAD", sha1, flag, cb_data);
0bad611b 718
2f34ba32 719 return 0;
723c31fe
LT
720}
721
0bad611b
HV
722int head_ref(each_ref_fn fn, void *cb_data)
723{
724 return do_head_ref(NULL, fn, cb_data);
725}
726
9ef6aeb0
HV
727int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
728{
729 return do_head_ref(submodule, fn, cb_data);
730}
731
cb5d709f 732int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 733{
b3cfc406 734 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
a62be77f
SE
735}
736
9ef6aeb0
HV
737int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
738{
b3cfc406 739 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
a62be77f
SE
740}
741
2a8177b6
CC
742int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
743{
0bad611b 744 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
745}
746
9ef6aeb0
HV
747int for_each_ref_in_submodule(const char *submodule, const char *prefix,
748 each_ref_fn fn, void *cb_data)
749{
750 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
751}
752
cb5d709f 753int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 754{
2a8177b6 755 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
756}
757
9ef6aeb0
HV
758int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
759{
760 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
761}
762
cb5d709f 763int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 764{
2a8177b6 765 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
766}
767
9ef6aeb0
HV
768int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
769{
770 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
771}
772
cb5d709f 773int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 774{
2a8177b6 775 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
776}
777
9ef6aeb0
HV
778int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
779{
780 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
781}
782
29268700
CC
783int for_each_replace_ref(each_ref_fn fn, void *cb_data)
784{
0bad611b 785 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
786}
787
a1bea2c1
JT
788int head_ref_namespaced(each_ref_fn fn, void *cb_data)
789{
790 struct strbuf buf = STRBUF_INIT;
791 int ret = 0;
792 unsigned char sha1[20];
793 int flag;
794
795 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
796 if (resolve_ref(buf.buf, sha1, 1, &flag))
797 ret = fn(buf.buf, sha1, flag, cb_data);
798 strbuf_release(&buf);
799
800 return ret;
801}
802
803int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
804{
805 struct strbuf buf = STRBUF_INIT;
806 int ret;
807 strbuf_addf(&buf, "%srefs/", get_git_namespace());
808 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
809 strbuf_release(&buf);
810 return ret;
811}
812
b09fe971
IL
813int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
814 const char *prefix, void *cb_data)
d08bae7e
IL
815{
816 struct strbuf real_pattern = STRBUF_INIT;
817 struct ref_filter filter;
d08bae7e
IL
818 int ret;
819
b09fe971 820 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 821 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
822 else if (prefix)
823 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
824 strbuf_addstr(&real_pattern, pattern);
825
894a9d33 826 if (!has_glob_specials(pattern)) {
9517e6b8 827 /* Append implied '/' '*' if not present. */
d08bae7e
IL
828 if (real_pattern.buf[real_pattern.len - 1] != '/')
829 strbuf_addch(&real_pattern, '/');
830 /* No need to check for '*', there is none. */
831 strbuf_addch(&real_pattern, '*');
832 }
833
834 filter.pattern = real_pattern.buf;
835 filter.fn = fn;
836 filter.cb_data = cb_data;
837 ret = for_each_ref(filter_refs, &filter);
838
839 strbuf_release(&real_pattern);
840 return ret;
841}
842
b09fe971
IL
843int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
844{
845 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
846}
847
f8948e2f
JH
848int for_each_rawref(each_ref_fn fn, void *cb_data)
849{
b3cfc406 850 return do_for_each_ref(NULL, "", fn, 0,
f8948e2f 851 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
852}
853
03feddd6
JH
854/*
855 * Make sure "ref" is something reasonable to have under ".git/refs/";
856 * We do not like it if:
857 *
858 * - any path component of it begins with ".", or
859 * - it has double dots "..", or
860 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
861 * - it ends with a "/".
3e262b95 862 * - it ends with ".lock"
a4c2e699 863 * - it contains a "\" (backslash)
03feddd6
JH
864 */
865
9224b73b 866/* Return true iff ch is not allowed in reference names. */
03feddd6
JH
867static inline int bad_ref_char(int ch)
868{
f3738c1c 869 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
a4c2e699 870 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
8558fd9e
DB
871 return 1;
872 /* 2.13 Pattern Matching Notation */
9224b73b 873 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
8558fd9e 874 return 1;
8558fd9e 875 return 0;
03feddd6
JH
876}
877
49295d4e
MH
878/*
879 * Try to read one refname component from the front of ref. Return
880 * the length of the component found, or -1 if the component is not
881 * legal.
882 */
883static int check_refname_component(const char *ref)
884{
885 const char *cp;
886 char last = '\0';
887
888 for (cp = ref; ; cp++) {
889 char ch = *cp;
890 if (ch == '\0' || ch == '/')
891 break;
892 if (bad_ref_char(ch))
893 return -1; /* Illegal character in refname. */
894 if (last == '.' && ch == '.')
895 return -1; /* Refname contains "..". */
896 if (last == '@' && ch == '{')
897 return -1; /* Refname contains "@{". */
898 last = ch;
899 }
900 if (cp == ref)
901 return -1; /* Component has zero length. */
902 if (ref[0] == '.')
903 return -1; /* Component starts with '.'. */
7e9d2fe9
MH
904 if (cp - ref >= 5 && !memcmp(cp - 5, ".lock", 5))
905 return -1; /* Refname ends with ".lock". */
49295d4e
MH
906 return cp - ref;
907}
908
8d9c5010 909int check_refname_format(const char *ref, int flags)
95fc7512 910{
49295d4e 911 int component_len, component_count = 0;
03feddd6 912
03feddd6 913 while (1) {
49295d4e
MH
914 /* We are at the start of a path component. */
915 component_len = check_refname_component(ref);
916 if (component_len < 0) {
917 if ((flags & REFNAME_REFSPEC_PATTERN) &&
918 ref[0] == '*' &&
919 (ref[1] == '\0' || ref[1] == '/')) {
8d9c5010
MH
920 /* Accept one wildcard as a full refname component. */
921 flags &= ~REFNAME_REFSPEC_PATTERN;
49295d4e
MH
922 component_len = 1;
923 } else {
8d9c5010 924 return -1;
49295d4e 925 }
03feddd6 926 }
49295d4e
MH
927 component_count++;
928 if (ref[component_len] == '\0')
929 break;
930 /* Skip to next component. */
931 ref += component_len + 1;
03feddd6 932 }
49295d4e
MH
933
934 if (ref[component_len - 1] == '.')
935 return -1; /* Refname ends with '.'. */
49295d4e
MH
936 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
937 return -1; /* Refname has only one component. */
938 return 0;
95fc7512
DB
939}
940
4577e483 941const char *prettify_refname(const char *name)
a9c37a72 942{
a9c37a72
DB
943 return name + (
944 !prefixcmp(name, "refs/heads/") ? 11 :
945 !prefixcmp(name, "refs/tags/") ? 10 :
946 !prefixcmp(name, "refs/remotes/") ? 13 :
947 0);
948}
949
79803322
SP
950const char *ref_rev_parse_rules[] = {
951 "%.*s",
952 "refs/%.*s",
953 "refs/tags/%.*s",
954 "refs/heads/%.*s",
955 "refs/remotes/%.*s",
956 "refs/remotes/%.*s/HEAD",
957 NULL
958};
959
605b4978
SP
960const char *ref_fetch_rules[] = {
961 "%.*s",
962 "refs/%.*s",
963 "refs/heads/%.*s",
964 NULL
965};
966
79803322
SP
967int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
968{
969 const char **p;
970 const int abbrev_name_len = strlen(abbrev_name);
971
972 for (p = rules; *p; p++) {
973 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
974 return 1;
975 }
976 }
977
978 return 0;
979}
980
e5f38ec3 981static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
982 const unsigned char *old_sha1, int mustexist)
983{
8da19775 984 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 985 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
986 unlock_ref(lock);
987 return NULL;
988 }
a89fccd2 989 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 990 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
991 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
992 unlock_ref(lock);
993 return NULL;
994 }
995 return lock;
996}
997
7155b727 998static int remove_empty_directories(const char *file)
bc7127ef
JH
999{
1000 /* we want to create a file but there is a directory there;
1001 * if that is an empty directory (or a directory that contains
1002 * only empty directories), remove them.
1003 */
7155b727
JS
1004 struct strbuf path;
1005 int result;
bc7127ef 1006
7155b727
JS
1007 strbuf_init(&path, 20);
1008 strbuf_addstr(&path, file);
1009
a0f4afbe 1010 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1011
1012 strbuf_release(&path);
1013
1014 return result;
bc7127ef
JH
1015}
1016
c976d415
LH
1017static int is_refname_available(const char *ref, const char *oldref,
1018 struct ref_list *list, int quiet)
1019{
1020 int namlen = strlen(ref); /* e.g. 'foo/bar' */
1021 while (list) {
1022 /* list->name could be 'foo' or 'foo/bar/baz' */
1023 if (!oldref || strcmp(oldref, list->name)) {
1024 int len = strlen(list->name);
1025 int cmplen = (namlen < len) ? namlen : len;
1026 const char *lead = (namlen < len) ? list->name : ref;
1027 if (!strncmp(ref, list->name, cmplen) &&
1028 lead[cmplen] == '/') {
1029 if (!quiet)
1030 error("'%s' exists; cannot create '%s'",
1031 list->name, ref);
1032 return 0;
1033 }
1034 }
1035 list = list->next;
1036 }
1037 return 1;
1038}
1039
68db31cc 1040static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
4bd18c43 1041{
434cd0cd 1042 char *ref_file;
ed378ec7 1043 const char *orig_ref = ref;
4bd18c43 1044 struct ref_lock *lock;
5cc3cef9 1045 int last_errno = 0;
acd3b9ec 1046 int type, lflags;
4431fcc4 1047 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1048 int missing = 0;
4bd18c43
SP
1049
1050 lock = xcalloc(1, sizeof(struct ref_lock));
1051 lock->lock_fd = -1;
1052
68db31cc 1053 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
bc7127ef
JH
1054 if (!ref && errno == EISDIR) {
1055 /* we are trying to lock foo but we used to
1056 * have foo/bar which now does not exist;
1057 * it is normal for the empty directory 'foo'
1058 * to remain.
1059 */
1060 ref_file = git_path("%s", orig_ref);
5cc3cef9
JH
1061 if (remove_empty_directories(ref_file)) {
1062 last_errno = errno;
1063 error("there are still refs under '%s'", orig_ref);
1064 goto error_return;
1065 }
68db31cc 1066 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
bc7127ef 1067 }
68db31cc
SV
1068 if (type_p)
1069 *type_p = type;
ed378ec7 1070 if (!ref) {
5cc3cef9 1071 last_errno = errno;
818f477c 1072 error("unable to resolve reference %s: %s",
ed378ec7 1073 orig_ref, strerror(errno));
5cc3cef9 1074 goto error_return;
4bd18c43 1075 }
5bdd8d4a 1076 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1077 /* When the ref did not exist and we are creating it,
1078 * make sure there is no existing ref that is packed
1079 * whose name begins with our refname, nor a ref whose
1080 * name is a proper prefix of our refname.
1081 */
5bdd8d4a 1082 if (missing &&
0bad611b 1083 !is_refname_available(ref, NULL, get_packed_refs(NULL), 0)) {
f475e08e 1084 last_errno = ENOTDIR;
c976d415 1085 goto error_return;
f475e08e 1086 }
22a3844e 1087
c33d5174 1088 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1089
acd3b9ec
JH
1090 lflags = LOCK_DIE_ON_ERROR;
1091 if (flags & REF_NODEREF) {
68db31cc 1092 ref = orig_ref;
acd3b9ec
JH
1093 lflags |= LOCK_NODEREF;
1094 }
434cd0cd 1095 lock->ref_name = xstrdup(ref);
1655707c 1096 lock->orig_ref_name = xstrdup(orig_ref);
7c1a278d 1097 ref_file = git_path("%s", ref);
5bdd8d4a 1098 if (missing)
68db31cc
SV
1099 lock->force_write = 1;
1100 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1101 lock->force_write = 1;
4bd18c43 1102
5cc3cef9
JH
1103 if (safe_create_leading_directories(ref_file)) {
1104 last_errno = errno;
1105 error("unable to create directory for %s", ref_file);
1106 goto error_return;
1107 }
4bd18c43 1108
acd3b9ec 1109 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1110 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1111
1112 error_return:
1113 unlock_ref(lock);
1114 errno = last_errno;
1115 return NULL;
4bd18c43
SP
1116}
1117
4431fcc4 1118struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
95fc7512 1119{
53cce84c 1120 char refpath[PATH_MAX];
8d9c5010 1121 if (check_refname_format(ref, 0))
4bd18c43 1122 return NULL;
53cce84c 1123 strcpy(refpath, mkpath("refs/%s", ref));
68db31cc 1124 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1125}
1126
68db31cc 1127struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
4bd18c43 1128{
8d9c5010 1129 if (check_refname_format(ref, REFNAME_ALLOW_ONELEVEL))
257f3020 1130 return NULL;
8d9c5010 1131 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
c0277d15
JH
1132}
1133
26a063a1
JH
1134static struct lock_file packlock;
1135
c0277d15
JH
1136static int repack_without_ref(const char *refname)
1137{
1138 struct ref_list *list, *packed_ref_list;
1139 int fd;
1140 int found = 0;
c0277d15 1141
0bad611b 1142 packed_ref_list = get_packed_refs(NULL);
c0277d15
JH
1143 for (list = packed_ref_list; list; list = list->next) {
1144 if (!strcmp(refname, list->name)) {
1145 found = 1;
1146 break;
1147 }
1148 }
1149 if (!found)
1150 return 0;
c0277d15 1151 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1b018fd9
MV
1152 if (fd < 0) {
1153 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 1154 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 1155 }
c0277d15
JH
1156
1157 for (list = packed_ref_list; list; list = list->next) {
1158 char line[PATH_MAX + 100];
1159 int len;
1160
1161 if (!strcmp(refname, list->name))
1162 continue;
1163 len = snprintf(line, sizeof(line), "%s %s\n",
1164 sha1_to_hex(list->sha1), list->name);
1165 /* this should not happen but just being defensive */
1166 if (len > sizeof(line))
1167 die("too long a refname '%s'", list->name);
1168 write_or_die(fd, line, len);
1169 }
1170 return commit_lock_file(&packlock);
1171}
1172
eca35a25 1173int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
1174{
1175 struct ref_lock *lock;
eca35a25 1176 int err, i = 0, ret = 0, flag = 0;
c0277d15 1177
68db31cc 1178 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
c0277d15
JH
1179 if (!lock)
1180 return 1;
045a476f 1181 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 1182 /* loose */
eca35a25
MV
1183 const char *path;
1184
1185 if (!(delopt & REF_NODEREF)) {
1186 i = strlen(lock->lk->filename) - 5; /* .lock */
1187 lock->lk->filename[i] = 0;
1188 path = lock->lk->filename;
1189 } else {
9db56f71 1190 path = git_path("%s", refname);
eca35a25 1191 }
691f1a28
AR
1192 err = unlink_or_warn(path);
1193 if (err && errno != ENOENT)
c0277d15 1194 ret = 1;
691f1a28 1195
eca35a25
MV
1196 if (!(delopt & REF_NODEREF))
1197 lock->lk->filename[i] = '.';
c0277d15
JH
1198 }
1199 /* removing the loose one could have resurrected an earlier
1200 * packed one. Also, if it was not loose we need to repack
1201 * without it.
1202 */
1203 ret |= repack_without_ref(refname);
1204
691f1a28 1205 unlink_or_warn(git_path("logs/%s", lock->ref_name));
c0277d15
JH
1206 invalidate_cached_refs();
1207 unlock_ref(lock);
1208 return ret;
4bd18c43
SP
1209}
1210
765c2258
PH
1211/*
1212 * People using contrib's git-new-workdir have .git/logs/refs ->
1213 * /some/other/path/.git/logs/refs, and that may live on another device.
1214 *
1215 * IOW, to avoid cross device rename errors, the temporary renamed log must
1216 * live into logs/refs.
1217 */
1218#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1219
678d0f4c 1220int rename_ref(const char *oldref, const char *newref, const char *logmsg)
c976d415
LH
1221{
1222 static const char renamed_ref[] = "RENAMED-REF";
1223 unsigned char sha1[20], orig_sha1[20];
1224 int flag = 0, logmoved = 0;
1225 struct ref_lock *lock;
c976d415 1226 struct stat loginfo;
16c2bfbb 1227 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
eca35a25 1228 const char *symref = NULL;
c976d415 1229
450d4c0f 1230 if (log && S_ISLNK(loginfo.st_mode))
c976d415
LH
1231 return error("reflog for %s is a symlink", oldref);
1232
eca35a25
MV
1233 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1234 if (flag & REF_ISSYMREF)
fa58186c
MV
1235 return error("refname %s is a symbolic ref, renaming it is not supported",
1236 oldref);
eca35a25 1237 if (!symref)
c976d415
LH
1238 return error("refname %s not found", oldref);
1239
0bad611b 1240 if (!is_refname_available(newref, oldref, get_packed_refs(NULL), 0))
c976d415
LH
1241 return 1;
1242
0bad611b 1243 if (!is_refname_available(newref, oldref, get_loose_refs(NULL), 0))
c976d415
LH
1244 return 1;
1245
68db31cc 1246 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
c976d415
LH
1247 if (!lock)
1248 return error("unable to lock %s", renamed_ref);
1249 lock->force_write = 1;
678d0f4c 1250 if (write_ref_sha1(lock, orig_sha1, logmsg))
c976d415
LH
1251 return error("unable to save current sha1 in %s", renamed_ref);
1252
765c2258
PH
1253 if (log && rename(git_path("logs/%s", oldref), git_path(TMP_RENAMED_LOG)))
1254 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
c976d415
LH
1255 oldref, strerror(errno));
1256
eca35a25 1257 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
c976d415
LH
1258 error("unable to delete old %s", oldref);
1259 goto rollback;
1260 }
1261
eca35a25 1262 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
c976d415
LH
1263 if (errno==EISDIR) {
1264 if (remove_empty_directories(git_path("%s", newref))) {
1265 error("Directory not empty: %s", newref);
1266 goto rollback;
1267 }
1268 } else {
1269 error("unable to delete existing %s", newref);
1270 goto rollback;
1271 }
1272 }
1273
1274 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1275 error("unable to create directory for %s", newref);
1276 goto rollback;
1277 }
1278
1279 retry:
765c2258 1280 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newref))) {
d9e74d57
JR
1281 if (errno==EISDIR || errno==ENOTDIR) {
1282 /*
1283 * rename(a, b) when b is an existing
1284 * directory ought to result in ISDIR, but
1285 * Solaris 5.8 gives ENOTDIR. Sheesh.
1286 */
c976d415
LH
1287 if (remove_empty_directories(git_path("logs/%s", newref))) {
1288 error("Directory not empty: logs/%s", newref);
1289 goto rollback;
1290 }
1291 goto retry;
1292 } else {
765c2258 1293 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
c976d415
LH
1294 newref, strerror(errno));
1295 goto rollback;
1296 }
1297 }
1298 logmoved = log;
1299
68db31cc 1300 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
c976d415
LH
1301 if (!lock) {
1302 error("unable to lock %s for update", newref);
1303 goto rollback;
1304 }
c976d415
LH
1305 lock->force_write = 1;
1306 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 1307 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
c976d415
LH
1308 error("unable to write current sha1 into %s", newref);
1309 goto rollback;
1310 }
1311
1312 return 0;
1313
1314 rollback:
68db31cc 1315 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
c976d415
LH
1316 if (!lock) {
1317 error("unable to lock %s for rollback", oldref);
1318 goto rollbacklog;
1319 }
1320
1321 lock->force_write = 1;
1322 flag = log_all_ref_updates;
1323 log_all_ref_updates = 0;
1324 if (write_ref_sha1(lock, orig_sha1, NULL))
1325 error("unable to write current sha1 into %s", oldref);
1326 log_all_ref_updates = flag;
1327
1328 rollbacklog:
1329 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1330 error("unable to restore logfile %s from %s: %s",
1331 oldref, newref, strerror(errno));
1332 if (!logmoved && log &&
765c2258
PH
1333 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldref)))
1334 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
c976d415
LH
1335 oldref, strerror(errno));
1336
1337 return 1;
1338}
1339
435fc852 1340int close_ref(struct ref_lock *lock)
b531394d
BC
1341{
1342 if (close_lock_file(lock->lk))
1343 return -1;
1344 lock->lock_fd = -1;
1345 return 0;
1346}
1347
435fc852 1348int commit_ref(struct ref_lock *lock)
b531394d
BC
1349{
1350 if (commit_lock_file(lock->lk))
1351 return -1;
1352 lock->lock_fd = -1;
1353 return 0;
1354}
1355
e5f38ec3 1356void unlock_ref(struct ref_lock *lock)
4bd18c43 1357{
4ed7cd3a
BC
1358 /* Do not free lock->lk -- atexit() still looks at them */
1359 if (lock->lk)
1360 rollback_lock_file(lock->lk);
434cd0cd 1361 free(lock->ref_name);
1655707c 1362 free(lock->orig_ref_name);
4bd18c43
SP
1363 free(lock);
1364}
1365
0ec29a47
JH
1366/*
1367 * copy the reflog message msg to buf, which has been allocated sufficiently
1368 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1369 * because reflog file is one line per entry.
1370 */
1371static int copy_msg(char *buf, const char *msg)
1372{
1373 char *cp = buf;
1374 char c;
1375 int wasspace = 1;
1376
1377 *cp++ = '\t';
1378 while ((c = *msg++)) {
1379 if (wasspace && isspace(c))
1380 continue;
1381 wasspace = isspace(c);
1382 if (wasspace)
1383 c = ' ';
1384 *cp++ = c;
1385 }
1386 while (buf < cp && isspace(cp[-1]))
1387 cp--;
1388 *cp++ = '\n';
1389 return cp - buf;
1390}
1391
157aaea5 1392int log_ref_setup(const char *ref_name, char *logfile, int bufsize)
6de08ae6 1393{
859c3017 1394 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 1395
157aaea5 1396 git_snpath(logfile, bufsize, "logs/%s", ref_name);
4057deb5 1397 if (log_all_ref_updates &&
cc44c765
JH
1398 (!prefixcmp(ref_name, "refs/heads/") ||
1399 !prefixcmp(ref_name, "refs/remotes/") ||
b2e256b0 1400 !prefixcmp(ref_name, "refs/notes/") ||
bd104db1 1401 !strcmp(ref_name, "HEAD"))) {
157aaea5 1402 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 1403 return error("unable to create directory for %s",
157aaea5 1404 logfile);
6de08ae6
SP
1405 oflags |= O_CREAT;
1406 }
1407
157aaea5 1408 logfd = open(logfile, oflags, 0666);
6de08ae6 1409 if (logfd < 0) {
1974bf62 1410 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 1411 return 0;
3b463c3f
JH
1412
1413 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 1414 if (remove_empty_directories(logfile)) {
3b463c3f 1415 return error("There are still logs under '%s'",
157aaea5 1416 logfile);
3b463c3f 1417 }
157aaea5 1418 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
1419 }
1420
1421 if (logfd < 0)
1422 return error("Unable to append to %s: %s",
157aaea5 1423 logfile, strerror(errno));
6de08ae6
SP
1424 }
1425
157aaea5 1426 adjust_shared_perm(logfile);
859c3017
EM
1427 close(logfd);
1428 return 0;
1429}
443b92b6 1430
859c3017
EM
1431static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1432 const unsigned char *new_sha1, const char *msg)
1433{
1434 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1435 unsigned maxlen, len;
1436 int msglen;
157aaea5 1437 char log_file[PATH_MAX];
859c3017
EM
1438 char *logrec;
1439 const char *committer;
1440
1441 if (log_all_ref_updates < 0)
1442 log_all_ref_updates = !is_bare_repository();
1443
157aaea5 1444 result = log_ref_setup(ref_name, log_file, sizeof(log_file));
859c3017
EM
1445 if (result)
1446 return result;
1447
1448 logfd = open(log_file, oflags);
1449 if (logfd < 0)
1450 return 0;
0ec29a47 1451 msglen = msg ? strlen(msg) : 0;
774751a8 1452 committer = git_committer_info(0);
8ac65937
JH
1453 maxlen = strlen(committer) + msglen + 100;
1454 logrec = xmalloc(maxlen);
1455 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
1456 sha1_to_hex(old_sha1),
1457 sha1_to_hex(new_sha1),
8ac65937
JH
1458 committer);
1459 if (msglen)
0ec29a47 1460 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 1461 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 1462 free(logrec);
91c8d590 1463 if (close(logfd) != 0 || written != len)
9a13f0b7 1464 return error("Unable to append to %s", log_file);
6de08ae6
SP
1465 return 0;
1466}
1467
c3b0dec5
LT
1468static int is_branch(const char *refname)
1469{
1470 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1471}
1472
4bd18c43
SP
1473int write_ref_sha1(struct ref_lock *lock,
1474 const unsigned char *sha1, const char *logmsg)
1475{
1476 static char term = '\n';
c3b0dec5 1477 struct object *o;
4bd18c43
SP
1478
1479 if (!lock)
95fc7512 1480 return -1;
a89fccd2 1481 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
1482 unlock_ref(lock);
1483 return 0;
95fc7512 1484 }
c3b0dec5
LT
1485 o = parse_object(sha1);
1486 if (!o) {
7be8b3ba 1487 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
1488 lock->ref_name, sha1_to_hex(sha1));
1489 unlock_ref(lock);
1490 return -1;
1491 }
1492 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1493 error("Trying to write non-commit object %s to branch %s",
1494 sha1_to_hex(sha1), lock->ref_name);
1495 unlock_ref(lock);
1496 return -1;
1497 }
93822c22
AW
1498 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1499 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 1500 || close_ref(lock) < 0) {
c33d5174 1501 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
1502 unlock_ref(lock);
1503 return -1;
1504 }
5e290ff7 1505 invalidate_cached_refs();
bd104db1
NP
1506 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1507 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1508 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
1509 unlock_ref(lock);
1510 return -1;
1511 }
605fac8b
NP
1512 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1513 /*
1514 * Special hack: If a branch is updated directly and HEAD
1515 * points to it (may happen on the remote side of a push
1516 * for example) then logically the HEAD reflog should be
1517 * updated too.
1518 * A generic solution implies reverse symref information,
1519 * but finding all symrefs pointing to the given branch
1520 * would be rather costly for this rare event (the direct
1521 * update of a branch) to be worth it. So let's cheat and
1522 * check with HEAD only which should cover 99% of all usage
1523 * scenarios (even 100% of the default ones).
1524 */
1525 unsigned char head_sha1[20];
1526 int head_flag;
1527 const char *head_ref;
1528 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1529 if (head_ref && (head_flag & REF_ISSYMREF) &&
1530 !strcmp(head_ref, lock->ref_name))
1531 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1532 }
b531394d 1533 if (commit_ref(lock)) {
434cd0cd 1534 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
1535 unlock_ref(lock);
1536 return -1;
1537 }
4bd18c43
SP
1538 unlock_ref(lock);
1539 return 0;
95fc7512 1540}
d556fae2 1541
8b5157e4
NP
1542int create_symref(const char *ref_target, const char *refs_heads_master,
1543 const char *logmsg)
41b625b0
NP
1544{
1545 const char *lockpath;
1546 char ref[1000];
1547 int fd, len, written;
a4f34cbb 1548 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
1549 unsigned char old_sha1[20], new_sha1[20];
1550
1551 if (logmsg && read_ref(ref_target, old_sha1))
1552 hashclr(old_sha1);
41b625b0 1553
d48744d1
JH
1554 if (safe_create_leading_directories(git_HEAD) < 0)
1555 return error("unable to create directory for %s", git_HEAD);
1556
41b625b0
NP
1557#ifndef NO_SYMLINK_HEAD
1558 if (prefer_symlink_refs) {
1559 unlink(git_HEAD);
1560 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 1561 goto done;
41b625b0
NP
1562 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1563 }
1564#endif
1565
1566 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1567 if (sizeof(ref) <= len) {
1568 error("refname too long: %s", refs_heads_master);
47fc52e2 1569 goto error_free_return;
41b625b0
NP
1570 }
1571 lockpath = mkpath("%s.lock", git_HEAD);
1572 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1573 if (fd < 0) {
1574 error("Unable to open %s for writing", lockpath);
47fc52e2 1575 goto error_free_return;
41b625b0
NP
1576 }
1577 written = write_in_full(fd, ref, len);
91c8d590 1578 if (close(fd) != 0 || written != len) {
41b625b0 1579 error("Unable to write to %s", lockpath);
47fc52e2 1580 goto error_unlink_return;
41b625b0
NP
1581 }
1582 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 1583 error("Unable to create %s", git_HEAD);
47fc52e2 1584 goto error_unlink_return;
41b625b0
NP
1585 }
1586 if (adjust_shared_perm(git_HEAD)) {
41b625b0 1587 error("Unable to fix permissions on %s", lockpath);
47fc52e2 1588 error_unlink_return:
691f1a28 1589 unlink_or_warn(lockpath);
47fc52e2
JH
1590 error_free_return:
1591 free(git_HEAD);
1592 return -1;
41b625b0 1593 }
8b5157e4 1594
ee96d11b 1595#ifndef NO_SYMLINK_HEAD
8b5157e4 1596 done:
ee96d11b 1597#endif
8b5157e4
NP
1598 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1599 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1600
47fc52e2 1601 free(git_HEAD);
41b625b0
NP
1602 return 0;
1603}
1604
16d7cc90
JH
1605static char *ref_msg(const char *line, const char *endp)
1606{
1607 const char *ep;
16d7cc90 1608 line += 82;
182af834
PH
1609 ep = memchr(line, '\n', endp - line);
1610 if (!ep)
1611 ep = endp;
1612 return xmemdupz(line, ep - line);
16d7cc90
JH
1613}
1614
1615int 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)
d556fae2 1616{
e5229042 1617 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 1618 char *tz_c;
e29cb53a 1619 int logfd, tz, reccnt = 0;
d556fae2
SP
1620 struct stat st;
1621 unsigned long date;
e5229042 1622 unsigned char logged_sha1[20];
cb48cb58 1623 void *log_mapped;
dc49cd76 1624 size_t mapsz;
d556fae2
SP
1625
1626 logfile = git_path("logs/%s", ref);
1627 logfd = open(logfile, O_RDONLY, 0);
1628 if (logfd < 0)
d824cbba 1629 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
1630 fstat(logfd, &st);
1631 if (!st.st_size)
1632 die("Log %s is empty.", logfile);
dc49cd76
SP
1633 mapsz = xsize_t(st.st_size);
1634 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 1635 logdata = log_mapped;
d556fae2
SP
1636 close(logfd);
1637
e5229042 1638 lastrec = NULL;
d556fae2
SP
1639 rec = logend = logdata + st.st_size;
1640 while (logdata < rec) {
e29cb53a 1641 reccnt++;
d556fae2
SP
1642 if (logdata < rec && *(rec-1) == '\n')
1643 rec--;
e5229042
SP
1644 lastgt = NULL;
1645 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 1646 rec--;
e5229042
SP
1647 if (*rec == '>')
1648 lastgt = rec;
1649 }
1650 if (!lastgt)
d556fae2 1651 die("Log %s is corrupt.", logfile);
e5229042 1652 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 1653 if (date <= at_time || cnt == 0) {
76a44c5c 1654 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
1655 if (msg)
1656 *msg = ref_msg(rec, logend);
1657 if (cutoff_time)
1658 *cutoff_time = date;
1659 if (cutoff_tz)
1660 *cutoff_tz = tz;
1661 if (cutoff_cnt)
76a44c5c 1662 *cutoff_cnt = reccnt - 1;
e5229042
SP
1663 if (lastrec) {
1664 if (get_sha1_hex(lastrec, logged_sha1))
1665 die("Log %s is corrupt.", logfile);
1666 if (get_sha1_hex(rec + 41, sha1))
1667 die("Log %s is corrupt.", logfile);
a89fccd2 1668 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 1669 warning("Log %s has gap after %s.",
73013afd 1670 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 1671 }
e5f38ec3
JH
1672 }
1673 else if (date == at_time) {
e5229042
SP
1674 if (get_sha1_hex(rec + 41, sha1))
1675 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
1676 }
1677 else {
e5229042
SP
1678 if (get_sha1_hex(rec + 41, logged_sha1))
1679 die("Log %s is corrupt.", logfile);
a89fccd2 1680 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 1681 warning("Log %s unexpectedly ended on %s.",
73013afd 1682 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
1683 }
1684 }
dc49cd76 1685 munmap(log_mapped, mapsz);
d556fae2
SP
1686 return 0;
1687 }
e5229042 1688 lastrec = rec;
ab2a1a32
JH
1689 if (cnt > 0)
1690 cnt--;
d556fae2
SP
1691 }
1692
e5229042
SP
1693 rec = logdata;
1694 while (rec < logend && *rec != '>' && *rec != '\n')
1695 rec++;
1696 if (rec == logend || *rec == '\n')
d556fae2 1697 die("Log %s is corrupt.", logfile);
e5229042 1698 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
1699 tz = strtoul(tz_c, NULL, 10);
1700 if (get_sha1_hex(logdata, sha1))
1701 die("Log %s is corrupt.", logfile);
d1a4489a
JK
1702 if (is_null_sha1(sha1)) {
1703 if (get_sha1_hex(logdata + 41, sha1))
1704 die("Log %s is corrupt.", logfile);
1705 }
16d7cc90
JH
1706 if (msg)
1707 *msg = ref_msg(logdata, logend);
dc49cd76 1708 munmap(log_mapped, mapsz);
16d7cc90
JH
1709
1710 if (cutoff_time)
1711 *cutoff_time = date;
1712 if (cutoff_tz)
1713 *cutoff_tz = tz;
1714 if (cutoff_cnt)
1715 *cutoff_cnt = reccnt;
1716 return 1;
d556fae2 1717}
2ff81662 1718
101d15e0 1719int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
1720{
1721 const char *logfile;
1722 FILE *logfp;
8ca78803 1723 struct strbuf sb = STRBUF_INIT;
2266bf27 1724 int ret = 0;
2ff81662
JH
1725
1726 logfile = git_path("logs/%s", ref);
1727 logfp = fopen(logfile, "r");
1728 if (!logfp)
883d60fa 1729 return -1;
101d15e0
JH
1730
1731 if (ofs) {
1732 struct stat statbuf;
1733 if (fstat(fileno(logfp), &statbuf) ||
1734 statbuf.st_size < ofs ||
1735 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 1736 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 1737 fclose(logfp);
8ca78803 1738 strbuf_release(&sb);
101d15e0 1739 return -1;
9d33f7c2 1740 }
101d15e0
JH
1741 }
1742
8ca78803 1743 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 1744 unsigned char osha1[20], nsha1[20];
883d60fa
JS
1745 char *email_end, *message;
1746 unsigned long timestamp;
8ca78803 1747 int tz;
2ff81662
JH
1748
1749 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
1750 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
1751 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
1752 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
1753 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
1754 email_end[1] != ' ' ||
1755 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1756 !message || message[0] != ' ' ||
1757 (message[1] != '+' && message[1] != '-') ||
1758 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 1759 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 1760 continue; /* corrupt? */
883d60fa
JS
1761 email_end[1] = '\0';
1762 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
1763 if (message[6] != '\t')
1764 message += 6;
1765 else
1766 message += 7;
8ca78803
RS
1767 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
1768 cb_data);
883d60fa 1769 if (ret)
2266bf27 1770 break;
2ff81662
JH
1771 }
1772 fclose(logfp);
8ca78803 1773 strbuf_release(&sb);
2266bf27 1774 return ret;
2ff81662 1775}
e29cb53a 1776
101d15e0
JH
1777int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1778{
1779 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1780}
1781
eb8381c8
NP
1782static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1783{
1784 DIR *dir = opendir(git_path("logs/%s", base));
fcee5a14 1785 int retval = 0;
eb8381c8
NP
1786
1787 if (dir) {
1788 struct dirent *de;
1789 int baselen = strlen(base);
1790 char *log = xmalloc(baselen + 257);
1791
1792 memcpy(log, base, baselen);
1793 if (baselen && base[baselen-1] != '/')
1794 log[baselen++] = '/';
1795
1796 while ((de = readdir(dir)) != NULL) {
1797 struct stat st;
1798 int namelen;
1799
1800 if (de->d_name[0] == '.')
1801 continue;
1802 namelen = strlen(de->d_name);
1803 if (namelen > 255)
1804 continue;
1805 if (has_extension(de->d_name, ".lock"))
1806 continue;
1807 memcpy(log + baselen, de->d_name, namelen+1);
1808 if (stat(git_path("logs/%s", log), &st) < 0)
1809 continue;
1810 if (S_ISDIR(st.st_mode)) {
1811 retval = do_for_each_reflog(log, fn, cb_data);
1812 } else {
1813 unsigned char sha1[20];
1814 if (!resolve_ref(log, sha1, 0, NULL))
1815 retval = error("bad ref for %s", log);
1816 else
1817 retval = fn(log, sha1, 0, cb_data);
1818 }
1819 if (retval)
1820 break;
1821 }
1822 free(log);
1823 closedir(dir);
1824 }
acb39f64 1825 else if (*base)
fcee5a14 1826 return errno;
eb8381c8
NP
1827 return retval;
1828}
1829
1830int for_each_reflog(each_ref_fn fn, void *cb_data)
1831{
1832 return do_for_each_reflog("", fn, cb_data);
1833}
3d9f037c
CR
1834
1835int update_ref(const char *action, const char *refname,
1836 const unsigned char *sha1, const unsigned char *oldval,
1837 int flags, enum action_on_err onerr)
1838{
1839 static struct ref_lock *lock;
1840 lock = lock_any_ref_for_update(refname, oldval, flags);
1841 if (!lock) {
1842 const char *str = "Cannot lock the ref '%s'.";
1843 switch (onerr) {
1844 case MSG_ON_ERR: error(str, refname); break;
1845 case DIE_ON_ERR: die(str, refname); break;
1846 case QUIET_ON_ERR: break;
1847 }
1848 return 1;
1849 }
1850 if (write_ref_sha1(lock, sha1, action) < 0) {
1851 const char *str = "Cannot update the ref '%s'.";
1852 switch (onerr) {
1853 case MSG_ON_ERR: error(str, refname); break;
1854 case DIE_ON_ERR: die(str, refname); break;
1855 case QUIET_ON_ERR: break;
1856 }
1857 return 1;
1858 }
1859 return 0;
1860}
cda69f48 1861
c17b2294
JH
1862int ref_exists(char *refname)
1863{
1864 unsigned char sha1[20];
1865 return !!resolve_ref(refname, sha1, 1, NULL);
1866}
1867
5483f799 1868struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
1869{
1870 for ( ; list; list = list->next)
1871 if (!strcmp(list->name, name))
5483f799 1872 return (struct ref *)list;
cda69f48
JK
1873 return NULL;
1874}
7c2b3029
JK
1875
1876/*
1877 * generate a format suitable for scanf from a ref_rev_parse_rules
1878 * rule, that is replace the "%.*s" spec with a "%s" spec
1879 */
1880static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1881{
1882 char *spec;
1883
1884 spec = strstr(rule, "%.*s");
1885 if (!spec || strstr(spec + 4, "%.*s"))
1886 die("invalid rule in ref_rev_parse_rules: %s", rule);
1887
1888 /* copy all until spec */
1889 strncpy(scanf_fmt, rule, spec - rule);
1890 scanf_fmt[spec - rule] = '\0';
1891 /* copy new spec */
1892 strcat(scanf_fmt, "%s");
1893 /* copy remaining rule */
1894 strcat(scanf_fmt, spec + 4);
1895
1896 return;
1897}
1898
6e7b3309 1899char *shorten_unambiguous_ref(const char *ref, int strict)
7c2b3029
JK
1900{
1901 int i;
1902 static char **scanf_fmts;
1903 static int nr_rules;
1904 char *short_name;
1905
1906 /* pre generate scanf formats from ref_rev_parse_rules[] */
1907 if (!nr_rules) {
1908 size_t total_len = 0;
1909
1910 /* the rule list is NULL terminated, count them first */
1911 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
1912 /* no +1 because strlen("%s") < strlen("%.*s") */
1913 total_len += strlen(ref_rev_parse_rules[nr_rules]);
1914
1915 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
1916
1917 total_len = 0;
1918 for (i = 0; i < nr_rules; i++) {
1919 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
1920 + total_len;
1921 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
1922 total_len += strlen(ref_rev_parse_rules[i]);
1923 }
1924 }
1925
1926 /* bail out if there are no rules */
1927 if (!nr_rules)
1928 return xstrdup(ref);
1929
1930 /* buffer for scanf result, at most ref must fit */
1931 short_name = xstrdup(ref);
1932
1933 /* skip first rule, it will always match */
1934 for (i = nr_rules - 1; i > 0 ; --i) {
1935 int j;
6e7b3309 1936 int rules_to_fail = i;
7c2b3029
JK
1937 int short_name_len;
1938
1939 if (1 != sscanf(ref, scanf_fmts[i], short_name))
1940 continue;
1941
1942 short_name_len = strlen(short_name);
1943
6e7b3309
BW
1944 /*
1945 * in strict mode, all (except the matched one) rules
1946 * must fail to resolve to a valid non-ambiguous ref
1947 */
1948 if (strict)
1949 rules_to_fail = nr_rules;
1950
7c2b3029
JK
1951 /*
1952 * check if the short name resolves to a valid ref,
1953 * but use only rules prior to the matched one
1954 */
6e7b3309 1955 for (j = 0; j < rules_to_fail; j++) {
7c2b3029
JK
1956 const char *rule = ref_rev_parse_rules[j];
1957 unsigned char short_objectname[20];
1958 char refname[PATH_MAX];
1959
6e7b3309
BW
1960 /* skip matched rule */
1961 if (i == j)
1962 continue;
1963
7c2b3029
JK
1964 /*
1965 * the short name is ambiguous, if it resolves
1966 * (with this previous rule) to a valid ref
1967 * read_ref() returns 0 on success
1968 */
1969 mksnpath(refname, sizeof(refname),
1970 rule, short_name_len, short_name);
1971 if (!read_ref(refname, short_objectname))
1972 break;
1973 }
1974
1975 /*
1976 * short name is non-ambiguous if all previous rules
1977 * haven't resolved to a valid ref
1978 */
6e7b3309 1979 if (j == rules_to_fail)
7c2b3029
JK
1980 return short_name;
1981 }
1982
1983 free(short_name);
1984 return xstrdup(ref);
1985}