setup_revisions(): Allow walking history in a submodule
[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
454 tmp = read_gitfile_gently(gitdir);
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);
521 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
ed378ec7
LT
522 buffer[len] = 0;
523 strcpy(ref_buffer, buffer);
524 ref = ref_buffer;
8da19775
JH
525 if (flag)
526 *flag |= REF_ISSYMREF;
a876ed83
JH
527 continue;
528 }
ca8db142 529 }
a876ed83 530
7a21632f
DS
531 /* Is it a directory? */
532 if (S_ISDIR(st.st_mode)) {
533 errno = EISDIR;
534 return NULL;
535 }
536
a876ed83
JH
537 /*
538 * Anything else, just open it and try to use it as
539 * a ref
540 */
541 fd = open(path, O_RDONLY);
542 if (fd < 0)
543 return NULL;
93d26e4c 544 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83
JH
545 close(fd);
546
547 /*
548 * Is it a symbolic ref?
549 */
550 if (len < 4 || memcmp("ref:", buffer, 4))
551 break;
552 buf = buffer + 4;
553 len -= 4;
554 while (len && isspace(*buf))
555 buf++, len--;
556 while (len && isspace(buf[len-1]))
ed378ec7
LT
557 len--;
558 buf[len] = 0;
559 memcpy(ref_buffer, buf, len + 1);
560 ref = ref_buffer;
8da19775
JH
561 if (flag)
562 *flag |= REF_ISSYMREF;
8a65ff76 563 }
a876ed83
JH
564 if (len < 40 || get_sha1_hex(buffer, sha1))
565 return NULL;
ed378ec7 566 return ref;
a876ed83
JH
567}
568
d08bae7e
IL
569/* The argument to filter_refs */
570struct ref_filter {
571 const char *pattern;
572 each_ref_fn *fn;
573 void *cb_data;
574};
575
ed378ec7 576int read_ref(const char *ref, unsigned char *sha1)
a876ed83 577{
8da19775 578 if (resolve_ref(ref, sha1, 1, NULL))
a876ed83
JH
579 return 0;
580 return -1;
8a65ff76
LT
581}
582
f8948e2f 583#define DO_FOR_EACH_INCLUDE_BROKEN 01
ef06b918 584static int do_one_ref(const char *base, each_ref_fn fn, int trim,
f8948e2f 585 int flags, void *cb_data, struct ref_list *entry)
ef06b918
JH
586{
587 if (strncmp(base, entry->name, trim))
588 return 0;
e01de1c9 589
f8948e2f 590 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
e01de1c9
JH
591 if (entry->flag & REF_BROKEN)
592 return 0; /* ignore dangling symref */
f8948e2f
JH
593 if (!has_sha1_file(entry->sha1)) {
594 error("%s does not point to a valid object!", entry->name);
595 return 0;
596 }
ef06b918 597 }
0ae91be0 598 current_ref = entry;
ef06b918
JH
599 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
600}
601
d08bae7e
IL
602static int filter_refs(const char *ref, const unsigned char *sha, int flags,
603 void *data)
604{
605 struct ref_filter *filter = (struct ref_filter *)data;
606 if (fnmatch(filter->pattern, ref, 0))
607 return 0;
608 return filter->fn(ref, sha, flags, filter->cb_data);
609}
610
cf0adba7
JH
611int peel_ref(const char *ref, unsigned char *sha1)
612{
613 int flag;
614 unsigned char base[20];
615 struct object *o;
616
0ae91be0
SP
617 if (current_ref && (current_ref->name == ref
618 || !strcmp(current_ref->name, ref))) {
619 if (current_ref->flag & REF_KNOWS_PEELED) {
620 hashcpy(sha1, current_ref->peeled);
621 return 0;
622 }
623 hashcpy(base, current_ref->sha1);
624 goto fallback;
625 }
626
cf0adba7
JH
627 if (!resolve_ref(ref, base, 1, &flag))
628 return -1;
629
630 if ((flag & REF_ISPACKED)) {
0bad611b 631 struct ref_list *list = get_packed_refs(NULL);
cf0adba7
JH
632
633 while (list) {
f4204ab9
JH
634 if (!strcmp(list->name, ref)) {
635 if (list->flag & REF_KNOWS_PEELED) {
636 hashcpy(sha1, list->peeled);
637 return 0;
638 }
639 /* older pack-refs did not leave peeled ones */
640 break;
cf0adba7
JH
641 }
642 list = list->next;
643 }
cf0adba7
JH
644 }
645
0ae91be0 646fallback:
cf0adba7 647 o = parse_object(base);
8c87dc77 648 if (o && o->type == OBJ_TAG) {
cf0adba7
JH
649 o = deref_tag(o, ref, 0);
650 if (o) {
651 hashcpy(sha1, o->sha1);
652 return 0;
653 }
654 }
655 return -1;
656}
657
0bad611b
HV
658static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
659 int trim, int flags, void *cb_data)
8a65ff76 660{
0ae91be0 661 int retval = 0;
0bad611b
HV
662 struct ref_list *packed = get_packed_refs(submodule);
663 struct ref_list *loose = get_loose_refs(submodule);
8a65ff76 664
e142a3c6
DB
665 struct ref_list *extra;
666
667 for (extra = extra_refs; extra; extra = extra->next)
f8948e2f 668 retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
e142a3c6 669
e1e22e37
LT
670 while (packed && loose) {
671 struct ref_list *entry;
672 int cmp = strcmp(packed->name, loose->name);
673 if (!cmp) {
674 packed = packed->next;
675 continue;
6cada6a9 676 }
e1e22e37
LT
677 if (cmp > 0) {
678 entry = loose;
679 loose = loose->next;
680 } else {
681 entry = packed;
682 packed = packed->next;
683 }
f8948e2f 684 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
e1e22e37 685 if (retval)
0ae91be0 686 goto end_each;
e1e22e37 687 }
8a65ff76 688
ef06b918 689 for (packed = packed ? packed : loose; packed; packed = packed->next) {
f8948e2f 690 retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
ef06b918 691 if (retval)
0ae91be0 692 goto end_each;
8a65ff76 693 }
0ae91be0
SP
694
695end_each:
696 current_ref = NULL;
697 return retval;
8a65ff76
LT
698}
699
0bad611b
HV
700
701static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
702{
703 unsigned char sha1[20];
8da19775
JH
704 int flag;
705
0bad611b
HV
706 if (submodule) {
707 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
708 return fn("HEAD", sha1, 0, cb_data);
709
710 return 0;
711 }
712
8da19775
JH
713 if (resolve_ref("HEAD", sha1, 1, &flag))
714 return fn("HEAD", sha1, flag, cb_data);
0bad611b 715
2f34ba32 716 return 0;
723c31fe
LT
717}
718
0bad611b
HV
719int head_ref(each_ref_fn fn, void *cb_data)
720{
721 return do_head_ref(NULL, fn, cb_data);
722}
723
9ef6aeb0
HV
724int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
725{
726 return do_head_ref(submodule, fn, cb_data);
727}
728
cb5d709f 729int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 730{
0bad611b 731 return do_for_each_ref(NULL, "refs/", fn, 0, 0, cb_data);
a62be77f
SE
732}
733
9ef6aeb0
HV
734int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
735{
736 return do_for_each_ref(submodule, "refs/", fn, 0, 0, cb_data);
737}
738
2a8177b6
CC
739int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
740{
0bad611b 741 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
742}
743
9ef6aeb0
HV
744int for_each_ref_in_submodule(const char *submodule, const char *prefix,
745 each_ref_fn fn, void *cb_data)
746{
747 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
748}
749
cb5d709f 750int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 751{
2a8177b6 752 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
753}
754
9ef6aeb0
HV
755int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
756{
757 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
758}
759
cb5d709f 760int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 761{
2a8177b6 762 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
763}
764
9ef6aeb0
HV
765int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
766{
767 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
768}
769
cb5d709f 770int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 771{
2a8177b6 772 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
773}
774
9ef6aeb0
HV
775int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
776{
777 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
778}
779
29268700
CC
780int for_each_replace_ref(each_ref_fn fn, void *cb_data)
781{
0bad611b 782 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
783}
784
b09fe971
IL
785int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
786 const char *prefix, void *cb_data)
d08bae7e
IL
787{
788 struct strbuf real_pattern = STRBUF_INIT;
789 struct ref_filter filter;
d08bae7e
IL
790 int ret;
791
b09fe971 792 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 793 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
794 else if (prefix)
795 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
796 strbuf_addstr(&real_pattern, pattern);
797
894a9d33 798 if (!has_glob_specials(pattern)) {
9517e6b8 799 /* Append implied '/' '*' if not present. */
d08bae7e
IL
800 if (real_pattern.buf[real_pattern.len - 1] != '/')
801 strbuf_addch(&real_pattern, '/');
802 /* No need to check for '*', there is none. */
803 strbuf_addch(&real_pattern, '*');
804 }
805
806 filter.pattern = real_pattern.buf;
807 filter.fn = fn;
808 filter.cb_data = cb_data;
809 ret = for_each_ref(filter_refs, &filter);
810
811 strbuf_release(&real_pattern);
812 return ret;
813}
814
b09fe971
IL
815int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
816{
817 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
818}
819
f8948e2f
JH
820int for_each_rawref(each_ref_fn fn, void *cb_data)
821{
0bad611b 822 return do_for_each_ref(NULL, "refs/", fn, 0,
f8948e2f 823 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
824}
825
03feddd6
JH
826/*
827 * Make sure "ref" is something reasonable to have under ".git/refs/";
828 * We do not like it if:
829 *
830 * - any path component of it begins with ".", or
831 * - it has double dots "..", or
832 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
833 * - it ends with a "/".
3e262b95 834 * - it ends with ".lock"
a4c2e699 835 * - it contains a "\" (backslash)
03feddd6
JH
836 */
837
838static inline int bad_ref_char(int ch)
839{
8558fd9e 840 if (((unsigned) ch) <= ' ' ||
a4c2e699 841 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
8558fd9e
DB
842 return 1;
843 /* 2.13 Pattern Matching Notation */
844 if (ch == '?' || ch == '[') /* Unsupported */
845 return 1;
846 if (ch == '*') /* Supported at the end */
847 return 2;
848 return 0;
03feddd6
JH
849}
850
95fc7512
DB
851int check_ref_format(const char *ref)
852{
cbdffe40 853 int ch, level, bad_type, last;
abd2bde7 854 int ret = CHECK_REF_FORMAT_OK;
03feddd6
JH
855 const char *cp = ref;
856
857 level = 0;
858 while (1) {
859 while ((ch = *cp++) == '/')
860 ; /* tolerate duplicated slashes */
861 if (!ch)
5f7b202a
JH
862 /* should not end with slashes */
863 return CHECK_REF_FORMAT_ERROR;
03feddd6
JH
864
865 /* we are at the beginning of the path component */
8558fd9e 866 if (ch == '.')
5f7b202a 867 return CHECK_REF_FORMAT_ERROR;
8558fd9e
DB
868 bad_type = bad_ref_char(ch);
869 if (bad_type) {
abd2bde7
DB
870 if (bad_type == 2 && (!*cp || *cp == '/') &&
871 ret == CHECK_REF_FORMAT_OK)
872 ret = CHECK_REF_FORMAT_WILDCARD;
873 else
874 return CHECK_REF_FORMAT_ERROR;
8558fd9e 875 }
03feddd6 876
cbdffe40 877 last = ch;
03feddd6
JH
878 /* scan the rest of the path component */
879 while ((ch = *cp++) != 0) {
8558fd9e 880 bad_type = bad_ref_char(ch);
cbdffe40 881 if (bad_type)
08fbdb30 882 return CHECK_REF_FORMAT_ERROR;
03feddd6
JH
883 if (ch == '/')
884 break;
cbdffe40
JH
885 if (last == '.' && ch == '.')
886 return CHECK_REF_FORMAT_ERROR;
887 if (last == '@' && ch == '{')
5f7b202a 888 return CHECK_REF_FORMAT_ERROR;
cbdffe40 889 last = ch;
03feddd6
JH
890 }
891 level++;
892 if (!ch) {
cbdffe40
JH
893 if (ref <= cp - 2 && cp[-2] == '.')
894 return CHECK_REF_FORMAT_ERROR;
03feddd6 895 if (level < 2)
5f7b202a 896 return CHECK_REF_FORMAT_ONELEVEL;
3e262b95
SP
897 if (has_extension(ref, ".lock"))
898 return CHECK_REF_FORMAT_ERROR;
abd2bde7 899 return ret;
03feddd6
JH
900 }
901 }
95fc7512
DB
902}
903
4577e483 904const char *prettify_refname(const char *name)
a9c37a72 905{
a9c37a72
DB
906 return name + (
907 !prefixcmp(name, "refs/heads/") ? 11 :
908 !prefixcmp(name, "refs/tags/") ? 10 :
909 !prefixcmp(name, "refs/remotes/") ? 13 :
910 0);
911}
912
79803322
SP
913const char *ref_rev_parse_rules[] = {
914 "%.*s",
915 "refs/%.*s",
916 "refs/tags/%.*s",
917 "refs/heads/%.*s",
918 "refs/remotes/%.*s",
919 "refs/remotes/%.*s/HEAD",
920 NULL
921};
922
605b4978
SP
923const char *ref_fetch_rules[] = {
924 "%.*s",
925 "refs/%.*s",
926 "refs/heads/%.*s",
927 NULL
928};
929
79803322
SP
930int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
931{
932 const char **p;
933 const int abbrev_name_len = strlen(abbrev_name);
934
935 for (p = rules; *p; p++) {
936 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
937 return 1;
938 }
939 }
940
941 return 0;
942}
943
e5f38ec3 944static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
945 const unsigned char *old_sha1, int mustexist)
946{
8da19775 947 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 948 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
949 unlock_ref(lock);
950 return NULL;
951 }
a89fccd2 952 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 953 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
954 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
955 unlock_ref(lock);
956 return NULL;
957 }
958 return lock;
959}
960
7155b727 961static int remove_empty_directories(const char *file)
bc7127ef
JH
962{
963 /* we want to create a file but there is a directory there;
964 * if that is an empty directory (or a directory that contains
965 * only empty directories), remove them.
966 */
7155b727
JS
967 struct strbuf path;
968 int result;
bc7127ef 969
7155b727
JS
970 strbuf_init(&path, 20);
971 strbuf_addstr(&path, file);
972
a0f4afbe 973 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
974
975 strbuf_release(&path);
976
977 return result;
bc7127ef
JH
978}
979
c976d415
LH
980static int is_refname_available(const char *ref, const char *oldref,
981 struct ref_list *list, int quiet)
982{
983 int namlen = strlen(ref); /* e.g. 'foo/bar' */
984 while (list) {
985 /* list->name could be 'foo' or 'foo/bar/baz' */
986 if (!oldref || strcmp(oldref, list->name)) {
987 int len = strlen(list->name);
988 int cmplen = (namlen < len) ? namlen : len;
989 const char *lead = (namlen < len) ? list->name : ref;
990 if (!strncmp(ref, list->name, cmplen) &&
991 lead[cmplen] == '/') {
992 if (!quiet)
993 error("'%s' exists; cannot create '%s'",
994 list->name, ref);
995 return 0;
996 }
997 }
998 list = list->next;
999 }
1000 return 1;
1001}
1002
68db31cc 1003static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
4bd18c43 1004{
434cd0cd 1005 char *ref_file;
ed378ec7 1006 const char *orig_ref = ref;
4bd18c43 1007 struct ref_lock *lock;
5cc3cef9 1008 int last_errno = 0;
acd3b9ec 1009 int type, lflags;
4431fcc4 1010 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1011 int missing = 0;
4bd18c43
SP
1012
1013 lock = xcalloc(1, sizeof(struct ref_lock));
1014 lock->lock_fd = -1;
1015
68db31cc 1016 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
bc7127ef
JH
1017 if (!ref && errno == EISDIR) {
1018 /* we are trying to lock foo but we used to
1019 * have foo/bar which now does not exist;
1020 * it is normal for the empty directory 'foo'
1021 * to remain.
1022 */
1023 ref_file = git_path("%s", orig_ref);
5cc3cef9
JH
1024 if (remove_empty_directories(ref_file)) {
1025 last_errno = errno;
1026 error("there are still refs under '%s'", orig_ref);
1027 goto error_return;
1028 }
68db31cc 1029 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
bc7127ef 1030 }
68db31cc
SV
1031 if (type_p)
1032 *type_p = type;
ed378ec7 1033 if (!ref) {
5cc3cef9 1034 last_errno = errno;
818f477c 1035 error("unable to resolve reference %s: %s",
ed378ec7 1036 orig_ref, strerror(errno));
5cc3cef9 1037 goto error_return;
4bd18c43 1038 }
5bdd8d4a 1039 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1040 /* When the ref did not exist and we are creating it,
1041 * make sure there is no existing ref that is packed
1042 * whose name begins with our refname, nor a ref whose
1043 * name is a proper prefix of our refname.
1044 */
5bdd8d4a 1045 if (missing &&
0bad611b 1046 !is_refname_available(ref, NULL, get_packed_refs(NULL), 0)) {
f475e08e 1047 last_errno = ENOTDIR;
c976d415 1048 goto error_return;
f475e08e 1049 }
22a3844e 1050
c33d5174 1051 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1052
acd3b9ec
JH
1053 lflags = LOCK_DIE_ON_ERROR;
1054 if (flags & REF_NODEREF) {
68db31cc 1055 ref = orig_ref;
acd3b9ec
JH
1056 lflags |= LOCK_NODEREF;
1057 }
434cd0cd 1058 lock->ref_name = xstrdup(ref);
1655707c 1059 lock->orig_ref_name = xstrdup(orig_ref);
7c1a278d 1060 ref_file = git_path("%s", ref);
5bdd8d4a 1061 if (missing)
68db31cc
SV
1062 lock->force_write = 1;
1063 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1064 lock->force_write = 1;
4bd18c43 1065
5cc3cef9
JH
1066 if (safe_create_leading_directories(ref_file)) {
1067 last_errno = errno;
1068 error("unable to create directory for %s", ref_file);
1069 goto error_return;
1070 }
4bd18c43 1071
acd3b9ec 1072 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1073 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1074
1075 error_return:
1076 unlock_ref(lock);
1077 errno = last_errno;
1078 return NULL;
4bd18c43
SP
1079}
1080
4431fcc4 1081struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
95fc7512 1082{
53cce84c 1083 char refpath[PATH_MAX];
95fc7512 1084 if (check_ref_format(ref))
4bd18c43 1085 return NULL;
53cce84c 1086 strcpy(refpath, mkpath("refs/%s", ref));
68db31cc 1087 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1088}
1089
68db31cc 1090struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
4bd18c43 1091{
5f7b202a 1092 switch (check_ref_format(ref)) {
5f7b202a 1093 default:
257f3020
JH
1094 return NULL;
1095 case 0:
1096 case CHECK_REF_FORMAT_ONELEVEL:
5f7b202a
JH
1097 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
1098 }
c0277d15
JH
1099}
1100
26a063a1
JH
1101static struct lock_file packlock;
1102
c0277d15
JH
1103static int repack_without_ref(const char *refname)
1104{
1105 struct ref_list *list, *packed_ref_list;
1106 int fd;
1107 int found = 0;
c0277d15 1108
0bad611b 1109 packed_ref_list = get_packed_refs(NULL);
c0277d15
JH
1110 for (list = packed_ref_list; list; list = list->next) {
1111 if (!strcmp(refname, list->name)) {
1112 found = 1;
1113 break;
1114 }
1115 }
1116 if (!found)
1117 return 0;
c0277d15 1118 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1b018fd9
MV
1119 if (fd < 0) {
1120 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 1121 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 1122 }
c0277d15
JH
1123
1124 for (list = packed_ref_list; list; list = list->next) {
1125 char line[PATH_MAX + 100];
1126 int len;
1127
1128 if (!strcmp(refname, list->name))
1129 continue;
1130 len = snprintf(line, sizeof(line), "%s %s\n",
1131 sha1_to_hex(list->sha1), list->name);
1132 /* this should not happen but just being defensive */
1133 if (len > sizeof(line))
1134 die("too long a refname '%s'", list->name);
1135 write_or_die(fd, line, len);
1136 }
1137 return commit_lock_file(&packlock);
1138}
1139
eca35a25 1140int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
1141{
1142 struct ref_lock *lock;
eca35a25 1143 int err, i = 0, ret = 0, flag = 0;
c0277d15 1144
68db31cc 1145 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
c0277d15
JH
1146 if (!lock)
1147 return 1;
045a476f 1148 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 1149 /* loose */
eca35a25
MV
1150 const char *path;
1151
1152 if (!(delopt & REF_NODEREF)) {
1153 i = strlen(lock->lk->filename) - 5; /* .lock */
1154 lock->lk->filename[i] = 0;
1155 path = lock->lk->filename;
1156 } else {
9db56f71 1157 path = git_path("%s", refname);
eca35a25 1158 }
691f1a28
AR
1159 err = unlink_or_warn(path);
1160 if (err && errno != ENOENT)
c0277d15 1161 ret = 1;
691f1a28 1162
eca35a25
MV
1163 if (!(delopt & REF_NODEREF))
1164 lock->lk->filename[i] = '.';
c0277d15
JH
1165 }
1166 /* removing the loose one could have resurrected an earlier
1167 * packed one. Also, if it was not loose we need to repack
1168 * without it.
1169 */
1170 ret |= repack_without_ref(refname);
1171
691f1a28 1172 unlink_or_warn(git_path("logs/%s", lock->ref_name));
c0277d15
JH
1173 invalidate_cached_refs();
1174 unlock_ref(lock);
1175 return ret;
4bd18c43
SP
1176}
1177
678d0f4c 1178int rename_ref(const char *oldref, const char *newref, const char *logmsg)
c976d415
LH
1179{
1180 static const char renamed_ref[] = "RENAMED-REF";
1181 unsigned char sha1[20], orig_sha1[20];
1182 int flag = 0, logmoved = 0;
1183 struct ref_lock *lock;
c976d415 1184 struct stat loginfo;
16c2bfbb 1185 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
eca35a25 1186 const char *symref = NULL;
c976d415 1187
450d4c0f 1188 if (log && S_ISLNK(loginfo.st_mode))
c976d415
LH
1189 return error("reflog for %s is a symlink", oldref);
1190
eca35a25
MV
1191 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1192 if (flag & REF_ISSYMREF)
fa58186c
MV
1193 return error("refname %s is a symbolic ref, renaming it is not supported",
1194 oldref);
eca35a25 1195 if (!symref)
c976d415
LH
1196 return error("refname %s not found", oldref);
1197
0bad611b 1198 if (!is_refname_available(newref, oldref, get_packed_refs(NULL), 0))
c976d415
LH
1199 return 1;
1200
0bad611b 1201 if (!is_refname_available(newref, oldref, get_loose_refs(NULL), 0))
c976d415
LH
1202 return 1;
1203
68db31cc 1204 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
c976d415
LH
1205 if (!lock)
1206 return error("unable to lock %s", renamed_ref);
1207 lock->force_write = 1;
678d0f4c 1208 if (write_ref_sha1(lock, orig_sha1, logmsg))
c976d415
LH
1209 return error("unable to save current sha1 in %s", renamed_ref);
1210
1211 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
1212 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
1213 oldref, strerror(errno));
1214
eca35a25 1215 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
c976d415
LH
1216 error("unable to delete old %s", oldref);
1217 goto rollback;
1218 }
1219
eca35a25 1220 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
c976d415
LH
1221 if (errno==EISDIR) {
1222 if (remove_empty_directories(git_path("%s", newref))) {
1223 error("Directory not empty: %s", newref);
1224 goto rollback;
1225 }
1226 } else {
1227 error("unable to delete existing %s", newref);
1228 goto rollback;
1229 }
1230 }
1231
1232 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1233 error("unable to create directory for %s", newref);
1234 goto rollback;
1235 }
1236
1237 retry:
1238 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
d9e74d57
JR
1239 if (errno==EISDIR || errno==ENOTDIR) {
1240 /*
1241 * rename(a, b) when b is an existing
1242 * directory ought to result in ISDIR, but
1243 * Solaris 5.8 gives ENOTDIR. Sheesh.
1244 */
c976d415
LH
1245 if (remove_empty_directories(git_path("logs/%s", newref))) {
1246 error("Directory not empty: logs/%s", newref);
1247 goto rollback;
1248 }
1249 goto retry;
1250 } else {
1251 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
1252 newref, strerror(errno));
1253 goto rollback;
1254 }
1255 }
1256 logmoved = log;
1257
68db31cc 1258 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
c976d415
LH
1259 if (!lock) {
1260 error("unable to lock %s for update", newref);
1261 goto rollback;
1262 }
c976d415
LH
1263 lock->force_write = 1;
1264 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 1265 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
c976d415
LH
1266 error("unable to write current sha1 into %s", newref);
1267 goto rollback;
1268 }
1269
1270 return 0;
1271
1272 rollback:
68db31cc 1273 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
c976d415
LH
1274 if (!lock) {
1275 error("unable to lock %s for rollback", oldref);
1276 goto rollbacklog;
1277 }
1278
1279 lock->force_write = 1;
1280 flag = log_all_ref_updates;
1281 log_all_ref_updates = 0;
1282 if (write_ref_sha1(lock, orig_sha1, NULL))
1283 error("unable to write current sha1 into %s", oldref);
1284 log_all_ref_updates = flag;
1285
1286 rollbacklog:
1287 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1288 error("unable to restore logfile %s from %s: %s",
1289 oldref, newref, strerror(errno));
1290 if (!logmoved && log &&
1291 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1292 error("unable to restore logfile %s from tmp-renamed-log: %s",
1293 oldref, strerror(errno));
1294
1295 return 1;
1296}
1297
435fc852 1298int close_ref(struct ref_lock *lock)
b531394d
BC
1299{
1300 if (close_lock_file(lock->lk))
1301 return -1;
1302 lock->lock_fd = -1;
1303 return 0;
1304}
1305
435fc852 1306int commit_ref(struct ref_lock *lock)
b531394d
BC
1307{
1308 if (commit_lock_file(lock->lk))
1309 return -1;
1310 lock->lock_fd = -1;
1311 return 0;
1312}
1313
e5f38ec3 1314void unlock_ref(struct ref_lock *lock)
4bd18c43 1315{
4ed7cd3a
BC
1316 /* Do not free lock->lk -- atexit() still looks at them */
1317 if (lock->lk)
1318 rollback_lock_file(lock->lk);
434cd0cd 1319 free(lock->ref_name);
1655707c 1320 free(lock->orig_ref_name);
4bd18c43
SP
1321 free(lock);
1322}
1323
0ec29a47
JH
1324/*
1325 * copy the reflog message msg to buf, which has been allocated sufficiently
1326 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1327 * because reflog file is one line per entry.
1328 */
1329static int copy_msg(char *buf, const char *msg)
1330{
1331 char *cp = buf;
1332 char c;
1333 int wasspace = 1;
1334
1335 *cp++ = '\t';
1336 while ((c = *msg++)) {
1337 if (wasspace && isspace(c))
1338 continue;
1339 wasspace = isspace(c);
1340 if (wasspace)
1341 c = ' ';
1342 *cp++ = c;
1343 }
1344 while (buf < cp && isspace(cp[-1]))
1345 cp--;
1346 *cp++ = '\n';
1347 return cp - buf;
1348}
1349
157aaea5 1350int log_ref_setup(const char *ref_name, char *logfile, int bufsize)
6de08ae6 1351{
859c3017 1352 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 1353
157aaea5 1354 git_snpath(logfile, bufsize, "logs/%s", ref_name);
4057deb5 1355 if (log_all_ref_updates &&
cc44c765
JH
1356 (!prefixcmp(ref_name, "refs/heads/") ||
1357 !prefixcmp(ref_name, "refs/remotes/") ||
b2e256b0 1358 !prefixcmp(ref_name, "refs/notes/") ||
bd104db1 1359 !strcmp(ref_name, "HEAD"))) {
157aaea5 1360 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 1361 return error("unable to create directory for %s",
157aaea5 1362 logfile);
6de08ae6
SP
1363 oflags |= O_CREAT;
1364 }
1365
157aaea5 1366 logfd = open(logfile, oflags, 0666);
6de08ae6 1367 if (logfd < 0) {
1974bf62 1368 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 1369 return 0;
3b463c3f
JH
1370
1371 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 1372 if (remove_empty_directories(logfile)) {
3b463c3f 1373 return error("There are still logs under '%s'",
157aaea5 1374 logfile);
3b463c3f 1375 }
157aaea5 1376 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
1377 }
1378
1379 if (logfd < 0)
1380 return error("Unable to append to %s: %s",
157aaea5 1381 logfile, strerror(errno));
6de08ae6
SP
1382 }
1383
157aaea5 1384 adjust_shared_perm(logfile);
859c3017
EM
1385 close(logfd);
1386 return 0;
1387}
443b92b6 1388
859c3017
EM
1389static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1390 const unsigned char *new_sha1, const char *msg)
1391{
1392 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1393 unsigned maxlen, len;
1394 int msglen;
157aaea5 1395 char log_file[PATH_MAX];
859c3017
EM
1396 char *logrec;
1397 const char *committer;
1398
1399 if (log_all_ref_updates < 0)
1400 log_all_ref_updates = !is_bare_repository();
1401
157aaea5 1402 result = log_ref_setup(ref_name, log_file, sizeof(log_file));
859c3017
EM
1403 if (result)
1404 return result;
1405
1406 logfd = open(log_file, oflags);
1407 if (logfd < 0)
1408 return 0;
0ec29a47 1409 msglen = msg ? strlen(msg) : 0;
774751a8 1410 committer = git_committer_info(0);
8ac65937
JH
1411 maxlen = strlen(committer) + msglen + 100;
1412 logrec = xmalloc(maxlen);
1413 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
1414 sha1_to_hex(old_sha1),
1415 sha1_to_hex(new_sha1),
8ac65937
JH
1416 committer);
1417 if (msglen)
0ec29a47 1418 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 1419 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 1420 free(logrec);
91c8d590 1421 if (close(logfd) != 0 || written != len)
9a13f0b7 1422 return error("Unable to append to %s", log_file);
6de08ae6
SP
1423 return 0;
1424}
1425
c3b0dec5
LT
1426static int is_branch(const char *refname)
1427{
1428 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1429}
1430
4bd18c43
SP
1431int write_ref_sha1(struct ref_lock *lock,
1432 const unsigned char *sha1, const char *logmsg)
1433{
1434 static char term = '\n';
c3b0dec5 1435 struct object *o;
4bd18c43
SP
1436
1437 if (!lock)
95fc7512 1438 return -1;
a89fccd2 1439 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
1440 unlock_ref(lock);
1441 return 0;
95fc7512 1442 }
c3b0dec5
LT
1443 o = parse_object(sha1);
1444 if (!o) {
1445 error("Trying to write ref %s with nonexistant object %s",
1446 lock->ref_name, sha1_to_hex(sha1));
1447 unlock_ref(lock);
1448 return -1;
1449 }
1450 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1451 error("Trying to write non-commit object %s to branch %s",
1452 sha1_to_hex(sha1), lock->ref_name);
1453 unlock_ref(lock);
1454 return -1;
1455 }
93822c22
AW
1456 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1457 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 1458 || close_ref(lock) < 0) {
c33d5174 1459 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
1460 unlock_ref(lock);
1461 return -1;
1462 }
5e290ff7 1463 invalidate_cached_refs();
bd104db1
NP
1464 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1465 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1466 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
1467 unlock_ref(lock);
1468 return -1;
1469 }
605fac8b
NP
1470 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1471 /*
1472 * Special hack: If a branch is updated directly and HEAD
1473 * points to it (may happen on the remote side of a push
1474 * for example) then logically the HEAD reflog should be
1475 * updated too.
1476 * A generic solution implies reverse symref information,
1477 * but finding all symrefs pointing to the given branch
1478 * would be rather costly for this rare event (the direct
1479 * update of a branch) to be worth it. So let's cheat and
1480 * check with HEAD only which should cover 99% of all usage
1481 * scenarios (even 100% of the default ones).
1482 */
1483 unsigned char head_sha1[20];
1484 int head_flag;
1485 const char *head_ref;
1486 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1487 if (head_ref && (head_flag & REF_ISSYMREF) &&
1488 !strcmp(head_ref, lock->ref_name))
1489 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1490 }
b531394d 1491 if (commit_ref(lock)) {
434cd0cd 1492 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
1493 unlock_ref(lock);
1494 return -1;
1495 }
4bd18c43
SP
1496 unlock_ref(lock);
1497 return 0;
95fc7512 1498}
d556fae2 1499
8b5157e4
NP
1500int create_symref(const char *ref_target, const char *refs_heads_master,
1501 const char *logmsg)
41b625b0
NP
1502{
1503 const char *lockpath;
1504 char ref[1000];
1505 int fd, len, written;
a4f34cbb 1506 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
1507 unsigned char old_sha1[20], new_sha1[20];
1508
1509 if (logmsg && read_ref(ref_target, old_sha1))
1510 hashclr(old_sha1);
41b625b0 1511
d48744d1
JH
1512 if (safe_create_leading_directories(git_HEAD) < 0)
1513 return error("unable to create directory for %s", git_HEAD);
1514
41b625b0
NP
1515#ifndef NO_SYMLINK_HEAD
1516 if (prefer_symlink_refs) {
1517 unlink(git_HEAD);
1518 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 1519 goto done;
41b625b0
NP
1520 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1521 }
1522#endif
1523
1524 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1525 if (sizeof(ref) <= len) {
1526 error("refname too long: %s", refs_heads_master);
47fc52e2 1527 goto error_free_return;
41b625b0
NP
1528 }
1529 lockpath = mkpath("%s.lock", git_HEAD);
1530 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1531 if (fd < 0) {
1532 error("Unable to open %s for writing", lockpath);
47fc52e2 1533 goto error_free_return;
41b625b0
NP
1534 }
1535 written = write_in_full(fd, ref, len);
91c8d590 1536 if (close(fd) != 0 || written != len) {
41b625b0 1537 error("Unable to write to %s", lockpath);
47fc52e2 1538 goto error_unlink_return;
41b625b0
NP
1539 }
1540 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 1541 error("Unable to create %s", git_HEAD);
47fc52e2 1542 goto error_unlink_return;
41b625b0
NP
1543 }
1544 if (adjust_shared_perm(git_HEAD)) {
41b625b0 1545 error("Unable to fix permissions on %s", lockpath);
47fc52e2 1546 error_unlink_return:
691f1a28 1547 unlink_or_warn(lockpath);
47fc52e2
JH
1548 error_free_return:
1549 free(git_HEAD);
1550 return -1;
41b625b0 1551 }
8b5157e4 1552
ee96d11b 1553#ifndef NO_SYMLINK_HEAD
8b5157e4 1554 done:
ee96d11b 1555#endif
8b5157e4
NP
1556 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1557 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1558
47fc52e2 1559 free(git_HEAD);
41b625b0
NP
1560 return 0;
1561}
1562
16d7cc90
JH
1563static char *ref_msg(const char *line, const char *endp)
1564{
1565 const char *ep;
16d7cc90 1566 line += 82;
182af834
PH
1567 ep = memchr(line, '\n', endp - line);
1568 if (!ep)
1569 ep = endp;
1570 return xmemdupz(line, ep - line);
16d7cc90
JH
1571}
1572
1573int 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 1574{
e5229042 1575 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 1576 char *tz_c;
e29cb53a 1577 int logfd, tz, reccnt = 0;
d556fae2
SP
1578 struct stat st;
1579 unsigned long date;
e5229042 1580 unsigned char logged_sha1[20];
cb48cb58 1581 void *log_mapped;
dc49cd76 1582 size_t mapsz;
d556fae2
SP
1583
1584 logfile = git_path("logs/%s", ref);
1585 logfd = open(logfile, O_RDONLY, 0);
1586 if (logfd < 0)
d824cbba 1587 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
1588 fstat(logfd, &st);
1589 if (!st.st_size)
1590 die("Log %s is empty.", logfile);
dc49cd76
SP
1591 mapsz = xsize_t(st.st_size);
1592 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 1593 logdata = log_mapped;
d556fae2
SP
1594 close(logfd);
1595
e5229042 1596 lastrec = NULL;
d556fae2
SP
1597 rec = logend = logdata + st.st_size;
1598 while (logdata < rec) {
e29cb53a 1599 reccnt++;
d556fae2
SP
1600 if (logdata < rec && *(rec-1) == '\n')
1601 rec--;
e5229042
SP
1602 lastgt = NULL;
1603 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 1604 rec--;
e5229042
SP
1605 if (*rec == '>')
1606 lastgt = rec;
1607 }
1608 if (!lastgt)
d556fae2 1609 die("Log %s is corrupt.", logfile);
e5229042 1610 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 1611 if (date <= at_time || cnt == 0) {
76a44c5c 1612 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
1613 if (msg)
1614 *msg = ref_msg(rec, logend);
1615 if (cutoff_time)
1616 *cutoff_time = date;
1617 if (cutoff_tz)
1618 *cutoff_tz = tz;
1619 if (cutoff_cnt)
76a44c5c 1620 *cutoff_cnt = reccnt - 1;
e5229042
SP
1621 if (lastrec) {
1622 if (get_sha1_hex(lastrec, logged_sha1))
1623 die("Log %s is corrupt.", logfile);
1624 if (get_sha1_hex(rec + 41, sha1))
1625 die("Log %s is corrupt.", logfile);
a89fccd2 1626 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 1627 warning("Log %s has gap after %s.",
73013afd 1628 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 1629 }
e5f38ec3
JH
1630 }
1631 else if (date == at_time) {
e5229042
SP
1632 if (get_sha1_hex(rec + 41, sha1))
1633 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
1634 }
1635 else {
e5229042
SP
1636 if (get_sha1_hex(rec + 41, logged_sha1))
1637 die("Log %s is corrupt.", logfile);
a89fccd2 1638 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 1639 warning("Log %s unexpectedly ended on %s.",
73013afd 1640 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
1641 }
1642 }
dc49cd76 1643 munmap(log_mapped, mapsz);
d556fae2
SP
1644 return 0;
1645 }
e5229042 1646 lastrec = rec;
ab2a1a32
JH
1647 if (cnt > 0)
1648 cnt--;
d556fae2
SP
1649 }
1650
e5229042
SP
1651 rec = logdata;
1652 while (rec < logend && *rec != '>' && *rec != '\n')
1653 rec++;
1654 if (rec == logend || *rec == '\n')
d556fae2 1655 die("Log %s is corrupt.", logfile);
e5229042 1656 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
1657 tz = strtoul(tz_c, NULL, 10);
1658 if (get_sha1_hex(logdata, sha1))
1659 die("Log %s is corrupt.", logfile);
d1a4489a
JK
1660 if (is_null_sha1(sha1)) {
1661 if (get_sha1_hex(logdata + 41, sha1))
1662 die("Log %s is corrupt.", logfile);
1663 }
16d7cc90
JH
1664 if (msg)
1665 *msg = ref_msg(logdata, logend);
dc49cd76 1666 munmap(log_mapped, mapsz);
16d7cc90
JH
1667
1668 if (cutoff_time)
1669 *cutoff_time = date;
1670 if (cutoff_tz)
1671 *cutoff_tz = tz;
1672 if (cutoff_cnt)
1673 *cutoff_cnt = reccnt;
1674 return 1;
d556fae2 1675}
2ff81662 1676
101d15e0 1677int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
1678{
1679 const char *logfile;
1680 FILE *logfp;
8ca78803 1681 struct strbuf sb = STRBUF_INIT;
2266bf27 1682 int ret = 0;
2ff81662
JH
1683
1684 logfile = git_path("logs/%s", ref);
1685 logfp = fopen(logfile, "r");
1686 if (!logfp)
883d60fa 1687 return -1;
101d15e0
JH
1688
1689 if (ofs) {
1690 struct stat statbuf;
1691 if (fstat(fileno(logfp), &statbuf) ||
1692 statbuf.st_size < ofs ||
1693 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 1694 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 1695 fclose(logfp);
8ca78803 1696 strbuf_release(&sb);
101d15e0 1697 return -1;
9d33f7c2 1698 }
101d15e0
JH
1699 }
1700
8ca78803 1701 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 1702 unsigned char osha1[20], nsha1[20];
883d60fa
JS
1703 char *email_end, *message;
1704 unsigned long timestamp;
8ca78803 1705 int tz;
2ff81662
JH
1706
1707 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
1708 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
1709 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
1710 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
1711 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
1712 email_end[1] != ' ' ||
1713 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1714 !message || message[0] != ' ' ||
1715 (message[1] != '+' && message[1] != '-') ||
1716 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 1717 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 1718 continue; /* corrupt? */
883d60fa
JS
1719 email_end[1] = '\0';
1720 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
1721 if (message[6] != '\t')
1722 message += 6;
1723 else
1724 message += 7;
8ca78803
RS
1725 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
1726 cb_data);
883d60fa 1727 if (ret)
2266bf27 1728 break;
2ff81662
JH
1729 }
1730 fclose(logfp);
8ca78803 1731 strbuf_release(&sb);
2266bf27 1732 return ret;
2ff81662 1733}
e29cb53a 1734
101d15e0
JH
1735int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1736{
1737 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1738}
1739
eb8381c8
NP
1740static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1741{
1742 DIR *dir = opendir(git_path("logs/%s", base));
fcee5a14 1743 int retval = 0;
eb8381c8
NP
1744
1745 if (dir) {
1746 struct dirent *de;
1747 int baselen = strlen(base);
1748 char *log = xmalloc(baselen + 257);
1749
1750 memcpy(log, base, baselen);
1751 if (baselen && base[baselen-1] != '/')
1752 log[baselen++] = '/';
1753
1754 while ((de = readdir(dir)) != NULL) {
1755 struct stat st;
1756 int namelen;
1757
1758 if (de->d_name[0] == '.')
1759 continue;
1760 namelen = strlen(de->d_name);
1761 if (namelen > 255)
1762 continue;
1763 if (has_extension(de->d_name, ".lock"))
1764 continue;
1765 memcpy(log + baselen, de->d_name, namelen+1);
1766 if (stat(git_path("logs/%s", log), &st) < 0)
1767 continue;
1768 if (S_ISDIR(st.st_mode)) {
1769 retval = do_for_each_reflog(log, fn, cb_data);
1770 } else {
1771 unsigned char sha1[20];
1772 if (!resolve_ref(log, sha1, 0, NULL))
1773 retval = error("bad ref for %s", log);
1774 else
1775 retval = fn(log, sha1, 0, cb_data);
1776 }
1777 if (retval)
1778 break;
1779 }
1780 free(log);
1781 closedir(dir);
1782 }
acb39f64 1783 else if (*base)
fcee5a14 1784 return errno;
eb8381c8
NP
1785 return retval;
1786}
1787
1788int for_each_reflog(each_ref_fn fn, void *cb_data)
1789{
1790 return do_for_each_reflog("", fn, cb_data);
1791}
3d9f037c
CR
1792
1793int update_ref(const char *action, const char *refname,
1794 const unsigned char *sha1, const unsigned char *oldval,
1795 int flags, enum action_on_err onerr)
1796{
1797 static struct ref_lock *lock;
1798 lock = lock_any_ref_for_update(refname, oldval, flags);
1799 if (!lock) {
1800 const char *str = "Cannot lock the ref '%s'.";
1801 switch (onerr) {
1802 case MSG_ON_ERR: error(str, refname); break;
1803 case DIE_ON_ERR: die(str, refname); break;
1804 case QUIET_ON_ERR: break;
1805 }
1806 return 1;
1807 }
1808 if (write_ref_sha1(lock, sha1, action) < 0) {
1809 const char *str = "Cannot update the ref '%s'.";
1810 switch (onerr) {
1811 case MSG_ON_ERR: error(str, refname); break;
1812 case DIE_ON_ERR: die(str, refname); break;
1813 case QUIET_ON_ERR: break;
1814 }
1815 return 1;
1816 }
1817 return 0;
1818}
cda69f48 1819
5483f799 1820struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
1821{
1822 for ( ; list; list = list->next)
1823 if (!strcmp(list->name, name))
5483f799 1824 return (struct ref *)list;
cda69f48
JK
1825 return NULL;
1826}
7c2b3029
JK
1827
1828/*
1829 * generate a format suitable for scanf from a ref_rev_parse_rules
1830 * rule, that is replace the "%.*s" spec with a "%s" spec
1831 */
1832static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1833{
1834 char *spec;
1835
1836 spec = strstr(rule, "%.*s");
1837 if (!spec || strstr(spec + 4, "%.*s"))
1838 die("invalid rule in ref_rev_parse_rules: %s", rule);
1839
1840 /* copy all until spec */
1841 strncpy(scanf_fmt, rule, spec - rule);
1842 scanf_fmt[spec - rule] = '\0';
1843 /* copy new spec */
1844 strcat(scanf_fmt, "%s");
1845 /* copy remaining rule */
1846 strcat(scanf_fmt, spec + 4);
1847
1848 return;
1849}
1850
6e7b3309 1851char *shorten_unambiguous_ref(const char *ref, int strict)
7c2b3029
JK
1852{
1853 int i;
1854 static char **scanf_fmts;
1855 static int nr_rules;
1856 char *short_name;
1857
1858 /* pre generate scanf formats from ref_rev_parse_rules[] */
1859 if (!nr_rules) {
1860 size_t total_len = 0;
1861
1862 /* the rule list is NULL terminated, count them first */
1863 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
1864 /* no +1 because strlen("%s") < strlen("%.*s") */
1865 total_len += strlen(ref_rev_parse_rules[nr_rules]);
1866
1867 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
1868
1869 total_len = 0;
1870 for (i = 0; i < nr_rules; i++) {
1871 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
1872 + total_len;
1873 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
1874 total_len += strlen(ref_rev_parse_rules[i]);
1875 }
1876 }
1877
1878 /* bail out if there are no rules */
1879 if (!nr_rules)
1880 return xstrdup(ref);
1881
1882 /* buffer for scanf result, at most ref must fit */
1883 short_name = xstrdup(ref);
1884
1885 /* skip first rule, it will always match */
1886 for (i = nr_rules - 1; i > 0 ; --i) {
1887 int j;
6e7b3309 1888 int rules_to_fail = i;
7c2b3029
JK
1889 int short_name_len;
1890
1891 if (1 != sscanf(ref, scanf_fmts[i], short_name))
1892 continue;
1893
1894 short_name_len = strlen(short_name);
1895
6e7b3309
BW
1896 /*
1897 * in strict mode, all (except the matched one) rules
1898 * must fail to resolve to a valid non-ambiguous ref
1899 */
1900 if (strict)
1901 rules_to_fail = nr_rules;
1902
7c2b3029
JK
1903 /*
1904 * check if the short name resolves to a valid ref,
1905 * but use only rules prior to the matched one
1906 */
6e7b3309 1907 for (j = 0; j < rules_to_fail; j++) {
7c2b3029
JK
1908 const char *rule = ref_rev_parse_rules[j];
1909 unsigned char short_objectname[20];
1910 char refname[PATH_MAX];
1911
6e7b3309
BW
1912 /* skip matched rule */
1913 if (i == j)
1914 continue;
1915
7c2b3029
JK
1916 /*
1917 * the short name is ambiguous, if it resolves
1918 * (with this previous rule) to a valid ref
1919 * read_ref() returns 0 on success
1920 */
1921 mksnpath(refname, sizeof(refname),
1922 rule, short_name_len, short_name);
1923 if (!read_ref(refname, short_objectname))
1924 break;
1925 }
1926
1927 /*
1928 * short name is non-ambiguous if all previous rules
1929 * haven't resolved to a valid ref
1930 */
6e7b3309 1931 if (j == rules_to_fail)
7c2b3029
JK
1932 return short_name;
1933 }
1934
1935 free(short_name);
1936 return xstrdup(ref);
1937}