Don't sort ref_list too early
[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 }
b4f223c6 322 return 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);
b4f223c6 364 submodule_refs.loose = sort_ref_list(submodule_refs.loose);
0bad611b
HV
365 return submodule_refs.loose;
366 }
367
5e290ff7 368 if (!cached_refs.did_loose) {
0bad611b 369 cached_refs.loose = get_ref_dir(NULL, "refs", NULL);
b4f223c6 370 cached_refs.loose = sort_ref_list(cached_refs.loose);
5e290ff7 371 cached_refs.did_loose = 1;
e1e22e37 372 }
5e290ff7 373 return cached_refs.loose;
e1e22e37
LT
374}
375
ca8db142
LT
376/* We allow "recursive" symbolic refs. Only within reason, though */
377#define MAXDEPTH 5
0ebde32c
LT
378#define MAXREFLEN (1024)
379
380static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
381{
382 FILE *f;
383 struct cached_refs refs;
384 struct ref_list *ref;
385 int retval;
386
387 strcpy(name + pathlen, "packed-refs");
388 f = fopen(name, "r");
389 if (!f)
390 return -1;
391 read_packed_refs(f, &refs);
392 fclose(f);
393 ref = refs.packed;
394 retval = -1;
395 while (ref) {
396 if (!strcmp(ref->name, refname)) {
397 retval = 0;
398 memcpy(result, ref->sha1, 20);
399 break;
400 }
401 ref = ref->next;
402 }
403 free_ref_list(refs.packed);
404 return retval;
405}
406
407static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
408{
409 int fd, len = strlen(refname);
410 char buffer[128], *p;
411
412 if (recursion > MAXDEPTH || len > MAXREFLEN)
413 return -1;
414 memcpy(name + pathlen, refname, len+1);
415 fd = open(name, O_RDONLY);
416 if (fd < 0)
417 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
418
419 len = read(fd, buffer, sizeof(buffer)-1);
420 close(fd);
421 if (len < 0)
422 return -1;
423 while (len && isspace(buffer[len-1]))
424 len--;
425 buffer[len] = 0;
426
427 /* Was it a detached head or an old-fashioned symlink? */
428 if (!get_sha1_hex(buffer, result))
429 return 0;
430
431 /* Symref? */
432 if (strncmp(buffer, "ref:", 4))
433 return -1;
434 p = buffer + 4;
435 while (isspace(*p))
436 p++;
437
438 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
439}
440
441int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
442{
443 int len = strlen(path), retval;
444 char *gitdir;
842abf06 445 const char *tmp;
0ebde32c
LT
446
447 while (len && path[len-1] == '/')
448 len--;
449 if (!len)
450 return -1;
451 gitdir = xmalloc(len + MAXREFLEN + 8);
452 memcpy(gitdir, path, len);
842abf06
LH
453 memcpy(gitdir + len, "/.git", 6);
454 len += 5;
455
456 tmp = read_gitfile_gently(gitdir);
457 if (tmp) {
458 free(gitdir);
459 len = strlen(tmp);
460 gitdir = xmalloc(len + MAXREFLEN + 3);
461 memcpy(gitdir, tmp, len);
462 }
463 gitdir[len] = '/';
464 gitdir[++len] = '\0';
465 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
0ebde32c
LT
466 free(gitdir);
467 return retval;
468}
ca8db142 469
4886b89f
CC
470/*
471 * If the "reading" argument is set, this function finds out what _object_
472 * the ref points at by "reading" the ref. The ref, if it is not symbolic,
473 * has to exist, and if it is symbolic, it has to point at an existing ref,
474 * because the "read" goes through the symref to the ref it points at.
475 *
476 * The access that is not "reading" may often be "writing", but does not
477 * have to; it can be merely checking _where it leads to_. If it is a
478 * prelude to "writing" to the ref, a write to a symref that points at
479 * yet-to-be-born ref will create the real ref pointed by the symref.
480 * reading=0 allows the caller to check where such a symref leads to.
481 */
8da19775 482const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
8a65ff76 483{
0104ca09
HO
484 int depth = MAXDEPTH;
485 ssize_t len;
a876ed83 486 char buffer[256];
ed378ec7 487 static char ref_buffer[256];
ca8db142 488
8da19775
JH
489 if (flag)
490 *flag = 0;
491
a876ed83 492 for (;;) {
958a4789 493 char path[PATH_MAX];
a876ed83
JH
494 struct stat st;
495 char *buf;
496 int fd;
8a65ff76 497
a876ed83
JH
498 if (--depth < 0)
499 return NULL;
ca8db142 500
958a4789 501 git_snpath(path, sizeof(path), "%s", ref);
4886b89f 502 /* Special case: non-existing file. */
a876ed83 503 if (lstat(path, &st) < 0) {
0bad611b 504 struct ref_list *list = get_packed_refs(NULL);
434cd0cd 505 while (list) {
f4204ab9 506 if (!strcmp(ref, list->name)) {
434cd0cd 507 hashcpy(sha1, list->sha1);
8da19775
JH
508 if (flag)
509 *flag |= REF_ISPACKED;
434cd0cd
LT
510 return ref;
511 }
512 list = list->next;
513 }
a876ed83
JH
514 if (reading || errno != ENOENT)
515 return NULL;
e702496e 516 hashclr(sha1);
ed378ec7 517 return ref;
a876ed83 518 }
ca8db142 519
a876ed83
JH
520 /* Follow "normalized" - ie "refs/.." symlinks by hand */
521 if (S_ISLNK(st.st_mode)) {
522 len = readlink(path, buffer, sizeof(buffer)-1);
523 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
ed378ec7
LT
524 buffer[len] = 0;
525 strcpy(ref_buffer, buffer);
526 ref = ref_buffer;
8da19775
JH
527 if (flag)
528 *flag |= REF_ISSYMREF;
a876ed83
JH
529 continue;
530 }
ca8db142 531 }
a876ed83 532
7a21632f
DS
533 /* Is it a directory? */
534 if (S_ISDIR(st.st_mode)) {
535 errno = EISDIR;
536 return NULL;
537 }
538
a876ed83
JH
539 /*
540 * Anything else, just open it and try to use it as
541 * a ref
542 */
543 fd = open(path, O_RDONLY);
544 if (fd < 0)
545 return NULL;
93d26e4c 546 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83
JH
547 close(fd);
548
549 /*
550 * Is it a symbolic ref?
551 */
552 if (len < 4 || memcmp("ref:", buffer, 4))
553 break;
554 buf = buffer + 4;
555 len -= 4;
556 while (len && isspace(*buf))
557 buf++, len--;
558 while (len && isspace(buf[len-1]))
ed378ec7
LT
559 len--;
560 buf[len] = 0;
561 memcpy(ref_buffer, buf, len + 1);
562 ref = ref_buffer;
8da19775
JH
563 if (flag)
564 *flag |= REF_ISSYMREF;
8a65ff76 565 }
a876ed83
JH
566 if (len < 40 || get_sha1_hex(buffer, sha1))
567 return NULL;
ed378ec7 568 return ref;
a876ed83
JH
569}
570
d08bae7e
IL
571/* The argument to filter_refs */
572struct ref_filter {
573 const char *pattern;
574 each_ref_fn *fn;
575 void *cb_data;
576};
577
ed378ec7 578int read_ref(const char *ref, unsigned char *sha1)
a876ed83 579{
8da19775 580 if (resolve_ref(ref, sha1, 1, NULL))
a876ed83
JH
581 return 0;
582 return -1;
8a65ff76
LT
583}
584
f8948e2f 585#define DO_FOR_EACH_INCLUDE_BROKEN 01
ef06b918 586static int do_one_ref(const char *base, each_ref_fn fn, int trim,
f8948e2f 587 int flags, void *cb_data, struct ref_list *entry)
ef06b918
JH
588{
589 if (strncmp(base, entry->name, trim))
590 return 0;
e01de1c9 591
f8948e2f 592 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
e01de1c9
JH
593 if (entry->flag & REF_BROKEN)
594 return 0; /* ignore dangling symref */
f8948e2f
JH
595 if (!has_sha1_file(entry->sha1)) {
596 error("%s does not point to a valid object!", entry->name);
597 return 0;
598 }
ef06b918 599 }
0ae91be0 600 current_ref = entry;
ef06b918
JH
601 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
602}
603
d08bae7e
IL
604static int filter_refs(const char *ref, const unsigned char *sha, int flags,
605 void *data)
606{
607 struct ref_filter *filter = (struct ref_filter *)data;
608 if (fnmatch(filter->pattern, ref, 0))
609 return 0;
610 return filter->fn(ref, sha, flags, filter->cb_data);
611}
612
cf0adba7
JH
613int peel_ref(const char *ref, unsigned char *sha1)
614{
615 int flag;
616 unsigned char base[20];
617 struct object *o;
618
0ae91be0
SP
619 if (current_ref && (current_ref->name == ref
620 || !strcmp(current_ref->name, ref))) {
621 if (current_ref->flag & REF_KNOWS_PEELED) {
622 hashcpy(sha1, current_ref->peeled);
623 return 0;
624 }
625 hashcpy(base, current_ref->sha1);
626 goto fallback;
627 }
628
cf0adba7
JH
629 if (!resolve_ref(ref, base, 1, &flag))
630 return -1;
631
632 if ((flag & REF_ISPACKED)) {
0bad611b 633 struct ref_list *list = get_packed_refs(NULL);
cf0adba7
JH
634
635 while (list) {
f4204ab9
JH
636 if (!strcmp(list->name, ref)) {
637 if (list->flag & REF_KNOWS_PEELED) {
638 hashcpy(sha1, list->peeled);
639 return 0;
640 }
641 /* older pack-refs did not leave peeled ones */
642 break;
cf0adba7
JH
643 }
644 list = list->next;
645 }
cf0adba7
JH
646 }
647
0ae91be0 648fallback:
cf0adba7 649 o = parse_object(base);
8c87dc77 650 if (o && o->type == OBJ_TAG) {
cf0adba7
JH
651 o = deref_tag(o, ref, 0);
652 if (o) {
653 hashcpy(sha1, o->sha1);
654 return 0;
655 }
656 }
657 return -1;
658}
659
0bad611b
HV
660static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
661 int trim, int flags, void *cb_data)
8a65ff76 662{
0ae91be0 663 int retval = 0;
0bad611b
HV
664 struct ref_list *packed = get_packed_refs(submodule);
665 struct ref_list *loose = get_loose_refs(submodule);
8a65ff76 666
e142a3c6
DB
667 struct ref_list *extra;
668
669 for (extra = extra_refs; extra; extra = extra->next)
f8948e2f 670 retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
e142a3c6 671
e1e22e37
LT
672 while (packed && loose) {
673 struct ref_list *entry;
674 int cmp = strcmp(packed->name, loose->name);
675 if (!cmp) {
676 packed = packed->next;
677 continue;
6cada6a9 678 }
e1e22e37
LT
679 if (cmp > 0) {
680 entry = loose;
681 loose = loose->next;
682 } else {
683 entry = packed;
684 packed = packed->next;
685 }
f8948e2f 686 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
e1e22e37 687 if (retval)
0ae91be0 688 goto end_each;
e1e22e37 689 }
8a65ff76 690
ef06b918 691 for (packed = packed ? packed : loose; packed; packed = packed->next) {
f8948e2f 692 retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
ef06b918 693 if (retval)
0ae91be0 694 goto end_each;
8a65ff76 695 }
0ae91be0
SP
696
697end_each:
698 current_ref = NULL;
699 return retval;
8a65ff76
LT
700}
701
0bad611b
HV
702
703static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
704{
705 unsigned char sha1[20];
8da19775
JH
706 int flag;
707
0bad611b
HV
708 if (submodule) {
709 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
710 return fn("HEAD", sha1, 0, cb_data);
711
712 return 0;
713 }
714
8da19775
JH
715 if (resolve_ref("HEAD", sha1, 1, &flag))
716 return fn("HEAD", sha1, flag, cb_data);
0bad611b 717
2f34ba32 718 return 0;
723c31fe
LT
719}
720
0bad611b
HV
721int head_ref(each_ref_fn fn, void *cb_data)
722{
723 return do_head_ref(NULL, fn, cb_data);
724}
725
9ef6aeb0
HV
726int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
727{
728 return do_head_ref(submodule, fn, cb_data);
729}
730
cb5d709f 731int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 732{
0bad611b 733 return do_for_each_ref(NULL, "refs/", fn, 0, 0, cb_data);
a62be77f
SE
734}
735
9ef6aeb0
HV
736int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
737{
738 return do_for_each_ref(submodule, "refs/", fn, 0, 0, cb_data);
a62be77f
SE
739}
740
2a8177b6
CC
741int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
742{
0bad611b 743 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
744}
745
9ef6aeb0
HV
746int for_each_ref_in_submodule(const char *submodule, const char *prefix,
747 each_ref_fn fn, void *cb_data)
748{
749 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
750}
751
cb5d709f 752int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 753{
2a8177b6 754 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
755}
756
9ef6aeb0
HV
757int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
758{
759 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
760}
761
cb5d709f 762int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 763{
2a8177b6 764 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
765}
766
9ef6aeb0
HV
767int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
768{
769 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
770}
771
cb5d709f 772int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 773{
2a8177b6 774 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
775}
776
9ef6aeb0
HV
777int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
778{
779 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
780}
781
29268700
CC
782int for_each_replace_ref(each_ref_fn fn, void *cb_data)
783{
0bad611b 784 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
785}
786
b09fe971
IL
787int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
788 const char *prefix, void *cb_data)
d08bae7e
IL
789{
790 struct strbuf real_pattern = STRBUF_INIT;
791 struct ref_filter filter;
d08bae7e
IL
792 int ret;
793
b09fe971 794 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 795 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
796 else if (prefix)
797 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
798 strbuf_addstr(&real_pattern, pattern);
799
894a9d33 800 if (!has_glob_specials(pattern)) {
9517e6b8 801 /* Append implied '/' '*' if not present. */
d08bae7e
IL
802 if (real_pattern.buf[real_pattern.len - 1] != '/')
803 strbuf_addch(&real_pattern, '/');
804 /* No need to check for '*', there is none. */
805 strbuf_addch(&real_pattern, '*');
806 }
807
808 filter.pattern = real_pattern.buf;
809 filter.fn = fn;
810 filter.cb_data = cb_data;
811 ret = for_each_ref(filter_refs, &filter);
812
813 strbuf_release(&real_pattern);
814 return ret;
815}
816
b09fe971
IL
817int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
818{
819 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
820}
821
f8948e2f
JH
822int for_each_rawref(each_ref_fn fn, void *cb_data)
823{
0bad611b 824 return do_for_each_ref(NULL, "refs/", fn, 0,
f8948e2f 825 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
826}
827
03feddd6
JH
828/*
829 * Make sure "ref" is something reasonable to have under ".git/refs/";
830 * We do not like it if:
831 *
832 * - any path component of it begins with ".", or
833 * - it has double dots "..", or
834 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
835 * - it ends with a "/".
3e262b95 836 * - it ends with ".lock"
a4c2e699 837 * - it contains a "\" (backslash)
03feddd6
JH
838 */
839
840static inline int bad_ref_char(int ch)
841{
8558fd9e 842 if (((unsigned) ch) <= ' ' ||
a4c2e699 843 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
8558fd9e
DB
844 return 1;
845 /* 2.13 Pattern Matching Notation */
846 if (ch == '?' || ch == '[') /* Unsupported */
847 return 1;
848 if (ch == '*') /* Supported at the end */
849 return 2;
850 return 0;
03feddd6
JH
851}
852
95fc7512
DB
853int check_ref_format(const char *ref)
854{
cbdffe40 855 int ch, level, bad_type, last;
abd2bde7 856 int ret = CHECK_REF_FORMAT_OK;
03feddd6
JH
857 const char *cp = ref;
858
859 level = 0;
860 while (1) {
861 while ((ch = *cp++) == '/')
862 ; /* tolerate duplicated slashes */
863 if (!ch)
5f7b202a
JH
864 /* should not end with slashes */
865 return CHECK_REF_FORMAT_ERROR;
03feddd6
JH
866
867 /* we are at the beginning of the path component */
8558fd9e 868 if (ch == '.')
5f7b202a 869 return CHECK_REF_FORMAT_ERROR;
8558fd9e
DB
870 bad_type = bad_ref_char(ch);
871 if (bad_type) {
abd2bde7
DB
872 if (bad_type == 2 && (!*cp || *cp == '/') &&
873 ret == CHECK_REF_FORMAT_OK)
874 ret = CHECK_REF_FORMAT_WILDCARD;
875 else
876 return CHECK_REF_FORMAT_ERROR;
8558fd9e 877 }
03feddd6 878
cbdffe40 879 last = ch;
03feddd6
JH
880 /* scan the rest of the path component */
881 while ((ch = *cp++) != 0) {
8558fd9e 882 bad_type = bad_ref_char(ch);
cbdffe40 883 if (bad_type)
08fbdb30 884 return CHECK_REF_FORMAT_ERROR;
03feddd6
JH
885 if (ch == '/')
886 break;
cbdffe40
JH
887 if (last == '.' && ch == '.')
888 return CHECK_REF_FORMAT_ERROR;
889 if (last == '@' && ch == '{')
5f7b202a 890 return CHECK_REF_FORMAT_ERROR;
cbdffe40 891 last = ch;
03feddd6
JH
892 }
893 level++;
894 if (!ch) {
cbdffe40
JH
895 if (ref <= cp - 2 && cp[-2] == '.')
896 return CHECK_REF_FORMAT_ERROR;
03feddd6 897 if (level < 2)
5f7b202a 898 return CHECK_REF_FORMAT_ONELEVEL;
3e262b95
SP
899 if (has_extension(ref, ".lock"))
900 return CHECK_REF_FORMAT_ERROR;
abd2bde7 901 return ret;
03feddd6
JH
902 }
903 }
95fc7512
DB
904}
905
4577e483 906const char *prettify_refname(const char *name)
a9c37a72 907{
a9c37a72
DB
908 return name + (
909 !prefixcmp(name, "refs/heads/") ? 11 :
910 !prefixcmp(name, "refs/tags/") ? 10 :
911 !prefixcmp(name, "refs/remotes/") ? 13 :
912 0);
913}
914
79803322
SP
915const char *ref_rev_parse_rules[] = {
916 "%.*s",
917 "refs/%.*s",
918 "refs/tags/%.*s",
919 "refs/heads/%.*s",
920 "refs/remotes/%.*s",
921 "refs/remotes/%.*s/HEAD",
922 NULL
923};
924
605b4978
SP
925const char *ref_fetch_rules[] = {
926 "%.*s",
927 "refs/%.*s",
928 "refs/heads/%.*s",
929 NULL
930};
931
79803322
SP
932int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
933{
934 const char **p;
935 const int abbrev_name_len = strlen(abbrev_name);
936
937 for (p = rules; *p; p++) {
938 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
939 return 1;
940 }
941 }
942
943 return 0;
944}
945
e5f38ec3 946static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
947 const unsigned char *old_sha1, int mustexist)
948{
8da19775 949 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 950 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
951 unlock_ref(lock);
952 return NULL;
953 }
a89fccd2 954 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 955 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
956 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
957 unlock_ref(lock);
958 return NULL;
959 }
960 return lock;
961}
962
7155b727 963static int remove_empty_directories(const char *file)
bc7127ef
JH
964{
965 /* we want to create a file but there is a directory there;
966 * if that is an empty directory (or a directory that contains
967 * only empty directories), remove them.
968 */
7155b727
JS
969 struct strbuf path;
970 int result;
bc7127ef 971
7155b727
JS
972 strbuf_init(&path, 20);
973 strbuf_addstr(&path, file);
974
a0f4afbe 975 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
976
977 strbuf_release(&path);
978
979 return result;
bc7127ef
JH
980}
981
c976d415
LH
982static int is_refname_available(const char *ref, const char *oldref,
983 struct ref_list *list, int quiet)
984{
985 int namlen = strlen(ref); /* e.g. 'foo/bar' */
986 while (list) {
987 /* list->name could be 'foo' or 'foo/bar/baz' */
988 if (!oldref || strcmp(oldref, list->name)) {
989 int len = strlen(list->name);
990 int cmplen = (namlen < len) ? namlen : len;
991 const char *lead = (namlen < len) ? list->name : ref;
992 if (!strncmp(ref, list->name, cmplen) &&
993 lead[cmplen] == '/') {
994 if (!quiet)
995 error("'%s' exists; cannot create '%s'",
996 list->name, ref);
997 return 0;
998 }
999 }
1000 list = list->next;
1001 }
1002 return 1;
1003}
1004
68db31cc 1005static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
4bd18c43 1006{
434cd0cd 1007 char *ref_file;
ed378ec7 1008 const char *orig_ref = ref;
4bd18c43 1009 struct ref_lock *lock;
5cc3cef9 1010 int last_errno = 0;
acd3b9ec 1011 int type, lflags;
4431fcc4 1012 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1013 int missing = 0;
4bd18c43
SP
1014
1015 lock = xcalloc(1, sizeof(struct ref_lock));
1016 lock->lock_fd = -1;
1017
68db31cc 1018 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
bc7127ef
JH
1019 if (!ref && errno == EISDIR) {
1020 /* we are trying to lock foo but we used to
1021 * have foo/bar which now does not exist;
1022 * it is normal for the empty directory 'foo'
1023 * to remain.
1024 */
1025 ref_file = git_path("%s", orig_ref);
5cc3cef9
JH
1026 if (remove_empty_directories(ref_file)) {
1027 last_errno = errno;
1028 error("there are still refs under '%s'", orig_ref);
1029 goto error_return;
1030 }
68db31cc 1031 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
bc7127ef 1032 }
68db31cc
SV
1033 if (type_p)
1034 *type_p = type;
ed378ec7 1035 if (!ref) {
5cc3cef9 1036 last_errno = errno;
818f477c 1037 error("unable to resolve reference %s: %s",
ed378ec7 1038 orig_ref, strerror(errno));
5cc3cef9 1039 goto error_return;
4bd18c43 1040 }
5bdd8d4a 1041 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1042 /* When the ref did not exist and we are creating it,
1043 * make sure there is no existing ref that is packed
1044 * whose name begins with our refname, nor a ref whose
1045 * name is a proper prefix of our refname.
1046 */
5bdd8d4a 1047 if (missing &&
0bad611b 1048 !is_refname_available(ref, NULL, get_packed_refs(NULL), 0)) {
f475e08e 1049 last_errno = ENOTDIR;
c976d415 1050 goto error_return;
f475e08e 1051 }
22a3844e 1052
c33d5174 1053 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1054
acd3b9ec
JH
1055 lflags = LOCK_DIE_ON_ERROR;
1056 if (flags & REF_NODEREF) {
68db31cc 1057 ref = orig_ref;
acd3b9ec
JH
1058 lflags |= LOCK_NODEREF;
1059 }
434cd0cd 1060 lock->ref_name = xstrdup(ref);
1655707c 1061 lock->orig_ref_name = xstrdup(orig_ref);
7c1a278d 1062 ref_file = git_path("%s", ref);
5bdd8d4a 1063 if (missing)
68db31cc
SV
1064 lock->force_write = 1;
1065 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1066 lock->force_write = 1;
4bd18c43 1067
5cc3cef9
JH
1068 if (safe_create_leading_directories(ref_file)) {
1069 last_errno = errno;
1070 error("unable to create directory for %s", ref_file);
1071 goto error_return;
1072 }
4bd18c43 1073
acd3b9ec 1074 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1075 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1076
1077 error_return:
1078 unlock_ref(lock);
1079 errno = last_errno;
1080 return NULL;
4bd18c43
SP
1081}
1082
4431fcc4 1083struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
95fc7512 1084{
53cce84c 1085 char refpath[PATH_MAX];
95fc7512 1086 if (check_ref_format(ref))
4bd18c43 1087 return NULL;
53cce84c 1088 strcpy(refpath, mkpath("refs/%s", ref));
68db31cc 1089 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1090}
1091
68db31cc 1092struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
4bd18c43 1093{
5f7b202a 1094 switch (check_ref_format(ref)) {
5f7b202a 1095 default:
257f3020
JH
1096 return NULL;
1097 case 0:
1098 case CHECK_REF_FORMAT_ONELEVEL:
5f7b202a
JH
1099 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
1100 }
c0277d15
JH
1101}
1102
26a063a1
JH
1103static struct lock_file packlock;
1104
c0277d15
JH
1105static int repack_without_ref(const char *refname)
1106{
1107 struct ref_list *list, *packed_ref_list;
1108 int fd;
1109 int found = 0;
c0277d15 1110
0bad611b 1111 packed_ref_list = get_packed_refs(NULL);
c0277d15
JH
1112 for (list = packed_ref_list; list; list = list->next) {
1113 if (!strcmp(refname, list->name)) {
1114 found = 1;
1115 break;
1116 }
1117 }
1118 if (!found)
1119 return 0;
c0277d15 1120 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1b018fd9
MV
1121 if (fd < 0) {
1122 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 1123 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 1124 }
c0277d15
JH
1125
1126 for (list = packed_ref_list; list; list = list->next) {
1127 char line[PATH_MAX + 100];
1128 int len;
1129
1130 if (!strcmp(refname, list->name))
1131 continue;
1132 len = snprintf(line, sizeof(line), "%s %s\n",
1133 sha1_to_hex(list->sha1), list->name);
1134 /* this should not happen but just being defensive */
1135 if (len > sizeof(line))
1136 die("too long a refname '%s'", list->name);
1137 write_or_die(fd, line, len);
1138 }
1139 return commit_lock_file(&packlock);
1140}
1141
eca35a25 1142int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
1143{
1144 struct ref_lock *lock;
eca35a25 1145 int err, i = 0, ret = 0, flag = 0;
c0277d15 1146
68db31cc 1147 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
c0277d15
JH
1148 if (!lock)
1149 return 1;
045a476f 1150 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 1151 /* loose */
eca35a25
MV
1152 const char *path;
1153
1154 if (!(delopt & REF_NODEREF)) {
1155 i = strlen(lock->lk->filename) - 5; /* .lock */
1156 lock->lk->filename[i] = 0;
1157 path = lock->lk->filename;
1158 } else {
9db56f71 1159 path = git_path("%s", refname);
eca35a25 1160 }
691f1a28
AR
1161 err = unlink_or_warn(path);
1162 if (err && errno != ENOENT)
c0277d15 1163 ret = 1;
691f1a28 1164
eca35a25
MV
1165 if (!(delopt & REF_NODEREF))
1166 lock->lk->filename[i] = '.';
c0277d15
JH
1167 }
1168 /* removing the loose one could have resurrected an earlier
1169 * packed one. Also, if it was not loose we need to repack
1170 * without it.
1171 */
1172 ret |= repack_without_ref(refname);
1173
691f1a28 1174 unlink_or_warn(git_path("logs/%s", lock->ref_name));
c0277d15
JH
1175 invalidate_cached_refs();
1176 unlock_ref(lock);
1177 return ret;
4bd18c43
SP
1178}
1179
765c2258
PH
1180/*
1181 * People using contrib's git-new-workdir have .git/logs/refs ->
1182 * /some/other/path/.git/logs/refs, and that may live on another device.
1183 *
1184 * IOW, to avoid cross device rename errors, the temporary renamed log must
1185 * live into logs/refs.
1186 */
1187#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1188
678d0f4c 1189int rename_ref(const char *oldref, const char *newref, const char *logmsg)
c976d415
LH
1190{
1191 static const char renamed_ref[] = "RENAMED-REF";
1192 unsigned char sha1[20], orig_sha1[20];
1193 int flag = 0, logmoved = 0;
1194 struct ref_lock *lock;
c976d415 1195 struct stat loginfo;
16c2bfbb 1196 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
eca35a25 1197 const char *symref = NULL;
c976d415 1198
450d4c0f 1199 if (log && S_ISLNK(loginfo.st_mode))
c976d415
LH
1200 return error("reflog for %s is a symlink", oldref);
1201
eca35a25
MV
1202 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1203 if (flag & REF_ISSYMREF)
fa58186c
MV
1204 return error("refname %s is a symbolic ref, renaming it is not supported",
1205 oldref);
eca35a25 1206 if (!symref)
c976d415
LH
1207 return error("refname %s not found", oldref);
1208
0bad611b 1209 if (!is_refname_available(newref, oldref, get_packed_refs(NULL), 0))
c976d415
LH
1210 return 1;
1211
0bad611b 1212 if (!is_refname_available(newref, oldref, get_loose_refs(NULL), 0))
c976d415
LH
1213 return 1;
1214
68db31cc 1215 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
c976d415
LH
1216 if (!lock)
1217 return error("unable to lock %s", renamed_ref);
1218 lock->force_write = 1;
678d0f4c 1219 if (write_ref_sha1(lock, orig_sha1, logmsg))
c976d415
LH
1220 return error("unable to save current sha1 in %s", renamed_ref);
1221
765c2258
PH
1222 if (log && rename(git_path("logs/%s", oldref), git_path(TMP_RENAMED_LOG)))
1223 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
c976d415
LH
1224 oldref, strerror(errno));
1225
eca35a25 1226 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
c976d415
LH
1227 error("unable to delete old %s", oldref);
1228 goto rollback;
1229 }
1230
eca35a25 1231 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
c976d415
LH
1232 if (errno==EISDIR) {
1233 if (remove_empty_directories(git_path("%s", newref))) {
1234 error("Directory not empty: %s", newref);
1235 goto rollback;
1236 }
1237 } else {
1238 error("unable to delete existing %s", newref);
1239 goto rollback;
1240 }
1241 }
1242
1243 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1244 error("unable to create directory for %s", newref);
1245 goto rollback;
1246 }
1247
1248 retry:
765c2258 1249 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newref))) {
d9e74d57
JR
1250 if (errno==EISDIR || errno==ENOTDIR) {
1251 /*
1252 * rename(a, b) when b is an existing
1253 * directory ought to result in ISDIR, but
1254 * Solaris 5.8 gives ENOTDIR. Sheesh.
1255 */
c976d415
LH
1256 if (remove_empty_directories(git_path("logs/%s", newref))) {
1257 error("Directory not empty: logs/%s", newref);
1258 goto rollback;
1259 }
1260 goto retry;
1261 } else {
765c2258 1262 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
c976d415
LH
1263 newref, strerror(errno));
1264 goto rollback;
1265 }
1266 }
1267 logmoved = log;
1268
68db31cc 1269 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
c976d415
LH
1270 if (!lock) {
1271 error("unable to lock %s for update", newref);
1272 goto rollback;
1273 }
c976d415
LH
1274 lock->force_write = 1;
1275 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 1276 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
c976d415
LH
1277 error("unable to write current sha1 into %s", newref);
1278 goto rollback;
1279 }
1280
1281 return 0;
1282
1283 rollback:
68db31cc 1284 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
c976d415
LH
1285 if (!lock) {
1286 error("unable to lock %s for rollback", oldref);
1287 goto rollbacklog;
1288 }
1289
1290 lock->force_write = 1;
1291 flag = log_all_ref_updates;
1292 log_all_ref_updates = 0;
1293 if (write_ref_sha1(lock, orig_sha1, NULL))
1294 error("unable to write current sha1 into %s", oldref);
1295 log_all_ref_updates = flag;
1296
1297 rollbacklog:
1298 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1299 error("unable to restore logfile %s from %s: %s",
1300 oldref, newref, strerror(errno));
1301 if (!logmoved && log &&
765c2258
PH
1302 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldref)))
1303 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
c976d415
LH
1304 oldref, strerror(errno));
1305
1306 return 1;
1307}
1308
435fc852 1309int close_ref(struct ref_lock *lock)
b531394d
BC
1310{
1311 if (close_lock_file(lock->lk))
1312 return -1;
1313 lock->lock_fd = -1;
1314 return 0;
1315}
1316
435fc852 1317int commit_ref(struct ref_lock *lock)
b531394d
BC
1318{
1319 if (commit_lock_file(lock->lk))
1320 return -1;
1321 lock->lock_fd = -1;
1322 return 0;
1323}
1324
e5f38ec3 1325void unlock_ref(struct ref_lock *lock)
4bd18c43 1326{
4ed7cd3a
BC
1327 /* Do not free lock->lk -- atexit() still looks at them */
1328 if (lock->lk)
1329 rollback_lock_file(lock->lk);
434cd0cd 1330 free(lock->ref_name);
1655707c 1331 free(lock->orig_ref_name);
4bd18c43
SP
1332 free(lock);
1333}
1334
0ec29a47
JH
1335/*
1336 * copy the reflog message msg to buf, which has been allocated sufficiently
1337 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1338 * because reflog file is one line per entry.
1339 */
1340static int copy_msg(char *buf, const char *msg)
1341{
1342 char *cp = buf;
1343 char c;
1344 int wasspace = 1;
1345
1346 *cp++ = '\t';
1347 while ((c = *msg++)) {
1348 if (wasspace && isspace(c))
1349 continue;
1350 wasspace = isspace(c);
1351 if (wasspace)
1352 c = ' ';
1353 *cp++ = c;
1354 }
1355 while (buf < cp && isspace(cp[-1]))
1356 cp--;
1357 *cp++ = '\n';
1358 return cp - buf;
1359}
1360
157aaea5 1361int log_ref_setup(const char *ref_name, char *logfile, int bufsize)
6de08ae6 1362{
859c3017 1363 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 1364
157aaea5 1365 git_snpath(logfile, bufsize, "logs/%s", ref_name);
4057deb5 1366 if (log_all_ref_updates &&
cc44c765
JH
1367 (!prefixcmp(ref_name, "refs/heads/") ||
1368 !prefixcmp(ref_name, "refs/remotes/") ||
b2e256b0 1369 !prefixcmp(ref_name, "refs/notes/") ||
bd104db1 1370 !strcmp(ref_name, "HEAD"))) {
157aaea5 1371 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 1372 return error("unable to create directory for %s",
157aaea5 1373 logfile);
6de08ae6
SP
1374 oflags |= O_CREAT;
1375 }
1376
157aaea5 1377 logfd = open(logfile, oflags, 0666);
6de08ae6 1378 if (logfd < 0) {
1974bf62 1379 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 1380 return 0;
3b463c3f
JH
1381
1382 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 1383 if (remove_empty_directories(logfile)) {
3b463c3f 1384 return error("There are still logs under '%s'",
157aaea5 1385 logfile);
3b463c3f 1386 }
157aaea5 1387 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
1388 }
1389
1390 if (logfd < 0)
1391 return error("Unable to append to %s: %s",
157aaea5 1392 logfile, strerror(errno));
6de08ae6
SP
1393 }
1394
157aaea5 1395 adjust_shared_perm(logfile);
859c3017
EM
1396 close(logfd);
1397 return 0;
1398}
443b92b6 1399
859c3017
EM
1400static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1401 const unsigned char *new_sha1, const char *msg)
1402{
1403 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1404 unsigned maxlen, len;
1405 int msglen;
157aaea5 1406 char log_file[PATH_MAX];
859c3017
EM
1407 char *logrec;
1408 const char *committer;
1409
1410 if (log_all_ref_updates < 0)
1411 log_all_ref_updates = !is_bare_repository();
1412
157aaea5 1413 result = log_ref_setup(ref_name, log_file, sizeof(log_file));
859c3017
EM
1414 if (result)
1415 return result;
1416
1417 logfd = open(log_file, oflags);
1418 if (logfd < 0)
1419 return 0;
0ec29a47 1420 msglen = msg ? strlen(msg) : 0;
774751a8 1421 committer = git_committer_info(0);
8ac65937
JH
1422 maxlen = strlen(committer) + msglen + 100;
1423 logrec = xmalloc(maxlen);
1424 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
1425 sha1_to_hex(old_sha1),
1426 sha1_to_hex(new_sha1),
8ac65937
JH
1427 committer);
1428 if (msglen)
0ec29a47 1429 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 1430 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 1431 free(logrec);
91c8d590 1432 if (close(logfd) != 0 || written != len)
9a13f0b7 1433 return error("Unable to append to %s", log_file);
6de08ae6
SP
1434 return 0;
1435}
1436
c3b0dec5
LT
1437static int is_branch(const char *refname)
1438{
1439 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1440}
1441
4bd18c43
SP
1442int write_ref_sha1(struct ref_lock *lock,
1443 const unsigned char *sha1, const char *logmsg)
1444{
1445 static char term = '\n';
c3b0dec5 1446 struct object *o;
4bd18c43
SP
1447
1448 if (!lock)
95fc7512 1449 return -1;
a89fccd2 1450 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
1451 unlock_ref(lock);
1452 return 0;
95fc7512 1453 }
c3b0dec5
LT
1454 o = parse_object(sha1);
1455 if (!o) {
1456 error("Trying to write ref %s with nonexistant object %s",
1457 lock->ref_name, sha1_to_hex(sha1));
1458 unlock_ref(lock);
1459 return -1;
1460 }
1461 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1462 error("Trying to write non-commit object %s to branch %s",
1463 sha1_to_hex(sha1), lock->ref_name);
1464 unlock_ref(lock);
1465 return -1;
1466 }
93822c22
AW
1467 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1468 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 1469 || close_ref(lock) < 0) {
c33d5174 1470 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
1471 unlock_ref(lock);
1472 return -1;
1473 }
5e290ff7 1474 invalidate_cached_refs();
bd104db1
NP
1475 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1476 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1477 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
1478 unlock_ref(lock);
1479 return -1;
1480 }
605fac8b
NP
1481 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1482 /*
1483 * Special hack: If a branch is updated directly and HEAD
1484 * points to it (may happen on the remote side of a push
1485 * for example) then logically the HEAD reflog should be
1486 * updated too.
1487 * A generic solution implies reverse symref information,
1488 * but finding all symrefs pointing to the given branch
1489 * would be rather costly for this rare event (the direct
1490 * update of a branch) to be worth it. So let's cheat and
1491 * check with HEAD only which should cover 99% of all usage
1492 * scenarios (even 100% of the default ones).
1493 */
1494 unsigned char head_sha1[20];
1495 int head_flag;
1496 const char *head_ref;
1497 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1498 if (head_ref && (head_flag & REF_ISSYMREF) &&
1499 !strcmp(head_ref, lock->ref_name))
1500 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1501 }
b531394d 1502 if (commit_ref(lock)) {
434cd0cd 1503 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
1504 unlock_ref(lock);
1505 return -1;
1506 }
4bd18c43
SP
1507 unlock_ref(lock);
1508 return 0;
95fc7512 1509}
d556fae2 1510
8b5157e4
NP
1511int create_symref(const char *ref_target, const char *refs_heads_master,
1512 const char *logmsg)
41b625b0
NP
1513{
1514 const char *lockpath;
1515 char ref[1000];
1516 int fd, len, written;
a4f34cbb 1517 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
1518 unsigned char old_sha1[20], new_sha1[20];
1519
1520 if (logmsg && read_ref(ref_target, old_sha1))
1521 hashclr(old_sha1);
41b625b0 1522
d48744d1
JH
1523 if (safe_create_leading_directories(git_HEAD) < 0)
1524 return error("unable to create directory for %s", git_HEAD);
1525
41b625b0
NP
1526#ifndef NO_SYMLINK_HEAD
1527 if (prefer_symlink_refs) {
1528 unlink(git_HEAD);
1529 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 1530 goto done;
41b625b0
NP
1531 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1532 }
1533#endif
1534
1535 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1536 if (sizeof(ref) <= len) {
1537 error("refname too long: %s", refs_heads_master);
47fc52e2 1538 goto error_free_return;
41b625b0
NP
1539 }
1540 lockpath = mkpath("%s.lock", git_HEAD);
1541 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1542 if (fd < 0) {
1543 error("Unable to open %s for writing", lockpath);
47fc52e2 1544 goto error_free_return;
41b625b0
NP
1545 }
1546 written = write_in_full(fd, ref, len);
91c8d590 1547 if (close(fd) != 0 || written != len) {
41b625b0 1548 error("Unable to write to %s", lockpath);
47fc52e2 1549 goto error_unlink_return;
41b625b0
NP
1550 }
1551 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 1552 error("Unable to create %s", git_HEAD);
47fc52e2 1553 goto error_unlink_return;
41b625b0
NP
1554 }
1555 if (adjust_shared_perm(git_HEAD)) {
41b625b0 1556 error("Unable to fix permissions on %s", lockpath);
47fc52e2 1557 error_unlink_return:
691f1a28 1558 unlink_or_warn(lockpath);
47fc52e2
JH
1559 error_free_return:
1560 free(git_HEAD);
1561 return -1;
41b625b0 1562 }
8b5157e4 1563
ee96d11b 1564#ifndef NO_SYMLINK_HEAD
8b5157e4 1565 done:
ee96d11b 1566#endif
8b5157e4
NP
1567 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1568 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1569
47fc52e2 1570 free(git_HEAD);
41b625b0
NP
1571 return 0;
1572}
1573
16d7cc90
JH
1574static char *ref_msg(const char *line, const char *endp)
1575{
1576 const char *ep;
16d7cc90 1577 line += 82;
182af834
PH
1578 ep = memchr(line, '\n', endp - line);
1579 if (!ep)
1580 ep = endp;
1581 return xmemdupz(line, ep - line);
16d7cc90
JH
1582}
1583
1584int 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 1585{
e5229042 1586 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 1587 char *tz_c;
e29cb53a 1588 int logfd, tz, reccnt = 0;
d556fae2
SP
1589 struct stat st;
1590 unsigned long date;
e5229042 1591 unsigned char logged_sha1[20];
cb48cb58 1592 void *log_mapped;
dc49cd76 1593 size_t mapsz;
d556fae2
SP
1594
1595 logfile = git_path("logs/%s", ref);
1596 logfd = open(logfile, O_RDONLY, 0);
1597 if (logfd < 0)
d824cbba 1598 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
1599 fstat(logfd, &st);
1600 if (!st.st_size)
1601 die("Log %s is empty.", logfile);
dc49cd76
SP
1602 mapsz = xsize_t(st.st_size);
1603 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 1604 logdata = log_mapped;
d556fae2
SP
1605 close(logfd);
1606
e5229042 1607 lastrec = NULL;
d556fae2
SP
1608 rec = logend = logdata + st.st_size;
1609 while (logdata < rec) {
e29cb53a 1610 reccnt++;
d556fae2
SP
1611 if (logdata < rec && *(rec-1) == '\n')
1612 rec--;
e5229042
SP
1613 lastgt = NULL;
1614 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 1615 rec--;
e5229042
SP
1616 if (*rec == '>')
1617 lastgt = rec;
1618 }
1619 if (!lastgt)
d556fae2 1620 die("Log %s is corrupt.", logfile);
e5229042 1621 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 1622 if (date <= at_time || cnt == 0) {
76a44c5c 1623 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
1624 if (msg)
1625 *msg = ref_msg(rec, logend);
1626 if (cutoff_time)
1627 *cutoff_time = date;
1628 if (cutoff_tz)
1629 *cutoff_tz = tz;
1630 if (cutoff_cnt)
76a44c5c 1631 *cutoff_cnt = reccnt - 1;
e5229042
SP
1632 if (lastrec) {
1633 if (get_sha1_hex(lastrec, logged_sha1))
1634 die("Log %s is corrupt.", logfile);
1635 if (get_sha1_hex(rec + 41, sha1))
1636 die("Log %s is corrupt.", logfile);
a89fccd2 1637 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 1638 warning("Log %s has gap after %s.",
73013afd 1639 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 1640 }
e5f38ec3
JH
1641 }
1642 else if (date == at_time) {
e5229042
SP
1643 if (get_sha1_hex(rec + 41, sha1))
1644 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
1645 }
1646 else {
e5229042
SP
1647 if (get_sha1_hex(rec + 41, logged_sha1))
1648 die("Log %s is corrupt.", logfile);
a89fccd2 1649 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 1650 warning("Log %s unexpectedly ended on %s.",
73013afd 1651 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
1652 }
1653 }
dc49cd76 1654 munmap(log_mapped, mapsz);
d556fae2
SP
1655 return 0;
1656 }
e5229042 1657 lastrec = rec;
ab2a1a32
JH
1658 if (cnt > 0)
1659 cnt--;
d556fae2
SP
1660 }
1661
e5229042
SP
1662 rec = logdata;
1663 while (rec < logend && *rec != '>' && *rec != '\n')
1664 rec++;
1665 if (rec == logend || *rec == '\n')
d556fae2 1666 die("Log %s is corrupt.", logfile);
e5229042 1667 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
1668 tz = strtoul(tz_c, NULL, 10);
1669 if (get_sha1_hex(logdata, sha1))
1670 die("Log %s is corrupt.", logfile);
d1a4489a
JK
1671 if (is_null_sha1(sha1)) {
1672 if (get_sha1_hex(logdata + 41, sha1))
1673 die("Log %s is corrupt.", logfile);
1674 }
16d7cc90
JH
1675 if (msg)
1676 *msg = ref_msg(logdata, logend);
dc49cd76 1677 munmap(log_mapped, mapsz);
16d7cc90
JH
1678
1679 if (cutoff_time)
1680 *cutoff_time = date;
1681 if (cutoff_tz)
1682 *cutoff_tz = tz;
1683 if (cutoff_cnt)
1684 *cutoff_cnt = reccnt;
1685 return 1;
d556fae2 1686}
2ff81662 1687
101d15e0 1688int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
1689{
1690 const char *logfile;
1691 FILE *logfp;
8ca78803 1692 struct strbuf sb = STRBUF_INIT;
2266bf27 1693 int ret = 0;
2ff81662
JH
1694
1695 logfile = git_path("logs/%s", ref);
1696 logfp = fopen(logfile, "r");
1697 if (!logfp)
883d60fa 1698 return -1;
101d15e0
JH
1699
1700 if (ofs) {
1701 struct stat statbuf;
1702 if (fstat(fileno(logfp), &statbuf) ||
1703 statbuf.st_size < ofs ||
1704 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 1705 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 1706 fclose(logfp);
8ca78803 1707 strbuf_release(&sb);
101d15e0 1708 return -1;
9d33f7c2 1709 }
101d15e0
JH
1710 }
1711
8ca78803 1712 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 1713 unsigned char osha1[20], nsha1[20];
883d60fa
JS
1714 char *email_end, *message;
1715 unsigned long timestamp;
8ca78803 1716 int tz;
2ff81662
JH
1717
1718 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
1719 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
1720 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
1721 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
1722 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
1723 email_end[1] != ' ' ||
1724 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1725 !message || message[0] != ' ' ||
1726 (message[1] != '+' && message[1] != '-') ||
1727 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 1728 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 1729 continue; /* corrupt? */
883d60fa
JS
1730 email_end[1] = '\0';
1731 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
1732 if (message[6] != '\t')
1733 message += 6;
1734 else
1735 message += 7;
8ca78803
RS
1736 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
1737 cb_data);
883d60fa 1738 if (ret)
2266bf27 1739 break;
2ff81662
JH
1740 }
1741 fclose(logfp);
8ca78803 1742 strbuf_release(&sb);
2266bf27 1743 return ret;
2ff81662 1744}
e29cb53a 1745
101d15e0
JH
1746int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1747{
1748 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1749}
1750
eb8381c8
NP
1751static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1752{
1753 DIR *dir = opendir(git_path("logs/%s", base));
fcee5a14 1754 int retval = 0;
eb8381c8
NP
1755
1756 if (dir) {
1757 struct dirent *de;
1758 int baselen = strlen(base);
1759 char *log = xmalloc(baselen + 257);
1760
1761 memcpy(log, base, baselen);
1762 if (baselen && base[baselen-1] != '/')
1763 log[baselen++] = '/';
1764
1765 while ((de = readdir(dir)) != NULL) {
1766 struct stat st;
1767 int namelen;
1768
1769 if (de->d_name[0] == '.')
1770 continue;
1771 namelen = strlen(de->d_name);
1772 if (namelen > 255)
1773 continue;
1774 if (has_extension(de->d_name, ".lock"))
1775 continue;
1776 memcpy(log + baselen, de->d_name, namelen+1);
1777 if (stat(git_path("logs/%s", log), &st) < 0)
1778 continue;
1779 if (S_ISDIR(st.st_mode)) {
1780 retval = do_for_each_reflog(log, fn, cb_data);
1781 } else {
1782 unsigned char sha1[20];
1783 if (!resolve_ref(log, sha1, 0, NULL))
1784 retval = error("bad ref for %s", log);
1785 else
1786 retval = fn(log, sha1, 0, cb_data);
1787 }
1788 if (retval)
1789 break;
1790 }
1791 free(log);
1792 closedir(dir);
1793 }
acb39f64 1794 else if (*base)
fcee5a14 1795 return errno;
eb8381c8
NP
1796 return retval;
1797}
1798
1799int for_each_reflog(each_ref_fn fn, void *cb_data)
1800{
1801 return do_for_each_reflog("", fn, cb_data);
1802}
3d9f037c
CR
1803
1804int update_ref(const char *action, const char *refname,
1805 const unsigned char *sha1, const unsigned char *oldval,
1806 int flags, enum action_on_err onerr)
1807{
1808 static struct ref_lock *lock;
1809 lock = lock_any_ref_for_update(refname, oldval, flags);
1810 if (!lock) {
1811 const char *str = "Cannot lock the ref '%s'.";
1812 switch (onerr) {
1813 case MSG_ON_ERR: error(str, refname); break;
1814 case DIE_ON_ERR: die(str, refname); break;
1815 case QUIET_ON_ERR: break;
1816 }
1817 return 1;
1818 }
1819 if (write_ref_sha1(lock, sha1, action) < 0) {
1820 const char *str = "Cannot update the ref '%s'.";
1821 switch (onerr) {
1822 case MSG_ON_ERR: error(str, refname); break;
1823 case DIE_ON_ERR: die(str, refname); break;
1824 case QUIET_ON_ERR: break;
1825 }
1826 return 1;
1827 }
1828 return 0;
1829}
cda69f48 1830
5483f799 1831struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
1832{
1833 for ( ; list; list = list->next)
1834 if (!strcmp(list->name, name))
5483f799 1835 return (struct ref *)list;
cda69f48
JK
1836 return NULL;
1837}
7c2b3029
JK
1838
1839/*
1840 * generate a format suitable for scanf from a ref_rev_parse_rules
1841 * rule, that is replace the "%.*s" spec with a "%s" spec
1842 */
1843static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1844{
1845 char *spec;
1846
1847 spec = strstr(rule, "%.*s");
1848 if (!spec || strstr(spec + 4, "%.*s"))
1849 die("invalid rule in ref_rev_parse_rules: %s", rule);
1850
1851 /* copy all until spec */
1852 strncpy(scanf_fmt, rule, spec - rule);
1853 scanf_fmt[spec - rule] = '\0';
1854 /* copy new spec */
1855 strcat(scanf_fmt, "%s");
1856 /* copy remaining rule */
1857 strcat(scanf_fmt, spec + 4);
1858
1859 return;
1860}
1861
6e7b3309 1862char *shorten_unambiguous_ref(const char *ref, int strict)
7c2b3029
JK
1863{
1864 int i;
1865 static char **scanf_fmts;
1866 static int nr_rules;
1867 char *short_name;
1868
1869 /* pre generate scanf formats from ref_rev_parse_rules[] */
1870 if (!nr_rules) {
1871 size_t total_len = 0;
1872
1873 /* the rule list is NULL terminated, count them first */
1874 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
1875 /* no +1 because strlen("%s") < strlen("%.*s") */
1876 total_len += strlen(ref_rev_parse_rules[nr_rules]);
1877
1878 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
1879
1880 total_len = 0;
1881 for (i = 0; i < nr_rules; i++) {
1882 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
1883 + total_len;
1884 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
1885 total_len += strlen(ref_rev_parse_rules[i]);
1886 }
1887 }
1888
1889 /* bail out if there are no rules */
1890 if (!nr_rules)
1891 return xstrdup(ref);
1892
1893 /* buffer for scanf result, at most ref must fit */
1894 short_name = xstrdup(ref);
1895
1896 /* skip first rule, it will always match */
1897 for (i = nr_rules - 1; i > 0 ; --i) {
1898 int j;
6e7b3309 1899 int rules_to_fail = i;
7c2b3029
JK
1900 int short_name_len;
1901
1902 if (1 != sscanf(ref, scanf_fmts[i], short_name))
1903 continue;
1904
1905 short_name_len = strlen(short_name);
1906
6e7b3309
BW
1907 /*
1908 * in strict mode, all (except the matched one) rules
1909 * must fail to resolve to a valid non-ambiguous ref
1910 */
1911 if (strict)
1912 rules_to_fail = nr_rules;
1913
7c2b3029
JK
1914 /*
1915 * check if the short name resolves to a valid ref,
1916 * but use only rules prior to the matched one
1917 */
6e7b3309 1918 for (j = 0; j < rules_to_fail; j++) {
7c2b3029
JK
1919 const char *rule = ref_rev_parse_rules[j];
1920 unsigned char short_objectname[20];
1921 char refname[PATH_MAX];
1922
6e7b3309
BW
1923 /* skip matched rule */
1924 if (i == j)
1925 continue;
1926
7c2b3029
JK
1927 /*
1928 * the short name is ambiguous, if it resolves
1929 * (with this previous rule) to a valid ref
1930 * read_ref() returns 0 on success
1931 */
1932 mksnpath(refname, sizeof(refname),
1933 rule, short_name_len, short_name);
1934 if (!read_ref(refname, short_objectname))
1935 break;
1936 }
1937
1938 /*
1939 * short name is non-ambiguous if all previous rules
1940 * haven't resolved to a valid ref
1941 */
6e7b3309 1942 if (j == rules_to_fail)
7c2b3029
JK
1943 return short_name;
1944 }
1945
1946 free(short_name);
1947 return xstrdup(ref);
1948}