rename_ref_available(): add docstring
[git/git.git] / refs.c
1 /*
2 * The backend-independent part of the reference module.
3 */
4
5 #include "cache.h"
6 #include "lockfile.h"
7 #include "refs.h"
8 #include "refs/refs-internal.h"
9 #include "object.h"
10 #include "tag.h"
11
12 /*
13 * How to handle various characters in refnames:
14 * 0: An acceptable character for refs
15 * 1: End-of-component
16 * 2: ., look for a preceding . to reject .. in refs
17 * 3: {, look for a preceding @ to reject @{ in refs
18 * 4: A bad character: ASCII control characters, and
19 * ":", "?", "[", "\", "^", "~", SP, or TAB
20 * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
21 */
22 static unsigned char refname_disposition[256] = {
23 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
24 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
25 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
26 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
27 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
28 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
29 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
30 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
31 };
32
33 /*
34 * Try to read one refname component from the front of refname.
35 * Return the length of the component found, or -1 if the component is
36 * not legal. It is legal if it is something reasonable to have under
37 * ".git/refs/"; We do not like it if:
38 *
39 * - any path component of it begins with ".", or
40 * - it has double dots "..", or
41 * - it has ASCII control characters, or
42 * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
43 * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
44 * - it ends with a "/", or
45 * - it ends with ".lock", or
46 * - it contains a "@{" portion
47 */
48 static int check_refname_component(const char *refname, int *flags)
49 {
50 const char *cp;
51 char last = '\0';
52
53 for (cp = refname; ; cp++) {
54 int ch = *cp & 255;
55 unsigned char disp = refname_disposition[ch];
56 switch (disp) {
57 case 1:
58 goto out;
59 case 2:
60 if (last == '.')
61 return -1; /* Refname contains "..". */
62 break;
63 case 3:
64 if (last == '@')
65 return -1; /* Refname contains "@{". */
66 break;
67 case 4:
68 return -1;
69 case 5:
70 if (!(*flags & REFNAME_REFSPEC_PATTERN))
71 return -1; /* refspec can't be a pattern */
72
73 /*
74 * Unset the pattern flag so that we only accept
75 * a single asterisk for one side of refspec.
76 */
77 *flags &= ~ REFNAME_REFSPEC_PATTERN;
78 break;
79 }
80 last = ch;
81 }
82 out:
83 if (cp == refname)
84 return 0; /* Component has zero length. */
85 if (refname[0] == '.')
86 return -1; /* Component starts with '.'. */
87 if (cp - refname >= LOCK_SUFFIX_LEN &&
88 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
89 return -1; /* Refname ends with ".lock". */
90 return cp - refname;
91 }
92
93 int check_refname_format(const char *refname, int flags)
94 {
95 int component_len, component_count = 0;
96
97 if (!strcmp(refname, "@"))
98 /* Refname is a single character '@'. */
99 return -1;
100
101 while (1) {
102 /* We are at the start of a path component. */
103 component_len = check_refname_component(refname, &flags);
104 if (component_len <= 0)
105 return -1;
106
107 component_count++;
108 if (refname[component_len] == '\0')
109 break;
110 /* Skip to next component. */
111 refname += component_len + 1;
112 }
113
114 if (refname[component_len - 1] == '.')
115 return -1; /* Refname ends with '.'. */
116 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
117 return -1; /* Refname has only one component. */
118 return 0;
119 }
120
121 int refname_is_safe(const char *refname)
122 {
123 const char *rest;
124
125 if (skip_prefix(refname, "refs/", &rest)) {
126 char *buf;
127 int result;
128 size_t restlen = strlen(rest);
129
130 /* rest must not be empty, or start or end with "/" */
131 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
132 return 0;
133
134 /*
135 * Does the refname try to escape refs/?
136 * For example: refs/foo/../bar is safe but refs/foo/../../bar
137 * is not.
138 */
139 buf = xmallocz(restlen);
140 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
141 free(buf);
142 return result;
143 }
144
145 do {
146 if (!isupper(*refname) && *refname != '_')
147 return 0;
148 refname++;
149 } while (*refname);
150 return 1;
151 }
152
153 char *resolve_refdup(const char *refname, int resolve_flags,
154 unsigned char *sha1, int *flags)
155 {
156 return xstrdup_or_null(resolve_ref_unsafe(refname, resolve_flags,
157 sha1, flags));
158 }
159
160 /* The argument to filter_refs */
161 struct ref_filter {
162 const char *pattern;
163 each_ref_fn *fn;
164 void *cb_data;
165 };
166
167 int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
168 {
169 if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags))
170 return 0;
171 return -1;
172 }
173
174 int read_ref(const char *refname, unsigned char *sha1)
175 {
176 return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);
177 }
178
179 int ref_exists(const char *refname)
180 {
181 unsigned char sha1[20];
182 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);
183 }
184
185 static int filter_refs(const char *refname, const struct object_id *oid,
186 int flags, void *data)
187 {
188 struct ref_filter *filter = (struct ref_filter *)data;
189
190 if (wildmatch(filter->pattern, refname, 0, NULL))
191 return 0;
192 return filter->fn(refname, oid, flags, filter->cb_data);
193 }
194
195 enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
196 {
197 struct object *o = lookup_unknown_object(name);
198
199 if (o->type == OBJ_NONE) {
200 int type = sha1_object_info(name, NULL);
201 if (type < 0 || !object_as_type(o, type, 0))
202 return PEEL_INVALID;
203 }
204
205 if (o->type != OBJ_TAG)
206 return PEEL_NON_TAG;
207
208 o = deref_tag_noverify(o);
209 if (!o)
210 return PEEL_INVALID;
211
212 hashcpy(sha1, o->oid.hash);
213 return PEEL_PEELED;
214 }
215
216 struct warn_if_dangling_data {
217 FILE *fp;
218 const char *refname;
219 const struct string_list *refnames;
220 const char *msg_fmt;
221 };
222
223 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
224 int flags, void *cb_data)
225 {
226 struct warn_if_dangling_data *d = cb_data;
227 const char *resolves_to;
228 struct object_id junk;
229
230 if (!(flags & REF_ISSYMREF))
231 return 0;
232
233 resolves_to = resolve_ref_unsafe(refname, 0, junk.hash, NULL);
234 if (!resolves_to
235 || (d->refname
236 ? strcmp(resolves_to, d->refname)
237 : !string_list_has_string(d->refnames, resolves_to))) {
238 return 0;
239 }
240
241 fprintf(d->fp, d->msg_fmt, refname);
242 fputc('\n', d->fp);
243 return 0;
244 }
245
246 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
247 {
248 struct warn_if_dangling_data data;
249
250 data.fp = fp;
251 data.refname = refname;
252 data.refnames = NULL;
253 data.msg_fmt = msg_fmt;
254 for_each_rawref(warn_if_dangling_symref, &data);
255 }
256
257 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
258 {
259 struct warn_if_dangling_data data;
260
261 data.fp = fp;
262 data.refname = NULL;
263 data.refnames = refnames;
264 data.msg_fmt = msg_fmt;
265 for_each_rawref(warn_if_dangling_symref, &data);
266 }
267
268 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
269 {
270 return for_each_ref_in("refs/tags/", fn, cb_data);
271 }
272
273 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
274 {
275 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
276 }
277
278 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
279 {
280 return for_each_ref_in("refs/heads/", fn, cb_data);
281 }
282
283 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
284 {
285 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
286 }
287
288 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
289 {
290 return for_each_ref_in("refs/remotes/", fn, cb_data);
291 }
292
293 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
294 {
295 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
296 }
297
298 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
299 {
300 struct strbuf buf = STRBUF_INIT;
301 int ret = 0;
302 struct object_id oid;
303 int flag;
304
305 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
306 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, oid.hash, &flag))
307 ret = fn(buf.buf, &oid, flag, cb_data);
308 strbuf_release(&buf);
309
310 return ret;
311 }
312
313 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
314 const char *prefix, void *cb_data)
315 {
316 struct strbuf real_pattern = STRBUF_INIT;
317 struct ref_filter filter;
318 int ret;
319
320 if (!prefix && !starts_with(pattern, "refs/"))
321 strbuf_addstr(&real_pattern, "refs/");
322 else if (prefix)
323 strbuf_addstr(&real_pattern, prefix);
324 strbuf_addstr(&real_pattern, pattern);
325
326 if (!has_glob_specials(pattern)) {
327 /* Append implied '/' '*' if not present. */
328 strbuf_complete(&real_pattern, '/');
329 /* No need to check for '*', there is none. */
330 strbuf_addch(&real_pattern, '*');
331 }
332
333 filter.pattern = real_pattern.buf;
334 filter.fn = fn;
335 filter.cb_data = cb_data;
336 ret = for_each_ref(filter_refs, &filter);
337
338 strbuf_release(&real_pattern);
339 return ret;
340 }
341
342 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
343 {
344 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
345 }
346
347 const char *prettify_refname(const char *name)
348 {
349 return name + (
350 starts_with(name, "refs/heads/") ? 11 :
351 starts_with(name, "refs/tags/") ? 10 :
352 starts_with(name, "refs/remotes/") ? 13 :
353 0);
354 }
355
356 static const char *ref_rev_parse_rules[] = {
357 "%.*s",
358 "refs/%.*s",
359 "refs/tags/%.*s",
360 "refs/heads/%.*s",
361 "refs/remotes/%.*s",
362 "refs/remotes/%.*s/HEAD",
363 NULL
364 };
365
366 int refname_match(const char *abbrev_name, const char *full_name)
367 {
368 const char **p;
369 const int abbrev_name_len = strlen(abbrev_name);
370
371 for (p = ref_rev_parse_rules; *p; p++) {
372 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
373 return 1;
374 }
375 }
376
377 return 0;
378 }
379
380 /*
381 * *string and *len will only be substituted, and *string returned (for
382 * later free()ing) if the string passed in is a magic short-hand form
383 * to name a branch.
384 */
385 static char *substitute_branch_name(const char **string, int *len)
386 {
387 struct strbuf buf = STRBUF_INIT;
388 int ret = interpret_branch_name(*string, *len, &buf);
389
390 if (ret == *len) {
391 size_t size;
392 *string = strbuf_detach(&buf, &size);
393 *len = size;
394 return (char *)*string;
395 }
396
397 return NULL;
398 }
399
400 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
401 {
402 char *last_branch = substitute_branch_name(&str, &len);
403 const char **p, *r;
404 int refs_found = 0;
405
406 *ref = NULL;
407 for (p = ref_rev_parse_rules; *p; p++) {
408 char fullref[PATH_MAX];
409 unsigned char sha1_from_ref[20];
410 unsigned char *this_result;
411 int flag;
412
413 this_result = refs_found ? sha1_from_ref : sha1;
414 mksnpath(fullref, sizeof(fullref), *p, len, str);
415 r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING,
416 this_result, &flag);
417 if (r) {
418 if (!refs_found++)
419 *ref = xstrdup(r);
420 if (!warn_ambiguous_refs)
421 break;
422 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
423 warning("ignoring dangling symref %s.", fullref);
424 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
425 warning("ignoring broken ref %s.", fullref);
426 }
427 }
428 free(last_branch);
429 return refs_found;
430 }
431
432 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
433 {
434 char *last_branch = substitute_branch_name(&str, &len);
435 const char **p;
436 int logs_found = 0;
437
438 *log = NULL;
439 for (p = ref_rev_parse_rules; *p; p++) {
440 unsigned char hash[20];
441 char path[PATH_MAX];
442 const char *ref, *it;
443
444 mksnpath(path, sizeof(path), *p, len, str);
445 ref = resolve_ref_unsafe(path, RESOLVE_REF_READING,
446 hash, NULL);
447 if (!ref)
448 continue;
449 if (reflog_exists(path))
450 it = path;
451 else if (strcmp(ref, path) && reflog_exists(ref))
452 it = ref;
453 else
454 continue;
455 if (!logs_found++) {
456 *log = xstrdup(it);
457 hashcpy(sha1, hash);
458 }
459 if (!warn_ambiguous_refs)
460 break;
461 }
462 free(last_branch);
463 return logs_found;
464 }
465
466 static int is_per_worktree_ref(const char *refname)
467 {
468 return !strcmp(refname, "HEAD") ||
469 starts_with(refname, "refs/bisect/");
470 }
471
472 static int is_pseudoref_syntax(const char *refname)
473 {
474 const char *c;
475
476 for (c = refname; *c; c++) {
477 if (!isupper(*c) && *c != '-' && *c != '_')
478 return 0;
479 }
480
481 return 1;
482 }
483
484 enum ref_type ref_type(const char *refname)
485 {
486 if (is_per_worktree_ref(refname))
487 return REF_TYPE_PER_WORKTREE;
488 if (is_pseudoref_syntax(refname))
489 return REF_TYPE_PSEUDOREF;
490 return REF_TYPE_NORMAL;
491 }
492
493 static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
494 const unsigned char *old_sha1, struct strbuf *err)
495 {
496 const char *filename;
497 int fd;
498 static struct lock_file lock;
499 struct strbuf buf = STRBUF_INIT;
500 int ret = -1;
501
502 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
503
504 filename = git_path("%s", pseudoref);
505 fd = hold_lock_file_for_update(&lock, filename, LOCK_DIE_ON_ERROR);
506 if (fd < 0) {
507 strbuf_addf(err, "could not open '%s' for writing: %s",
508 filename, strerror(errno));
509 return -1;
510 }
511
512 if (old_sha1) {
513 unsigned char actual_old_sha1[20];
514
515 if (read_ref(pseudoref, actual_old_sha1))
516 die("could not read ref '%s'", pseudoref);
517 if (hashcmp(actual_old_sha1, old_sha1)) {
518 strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
519 rollback_lock_file(&lock);
520 goto done;
521 }
522 }
523
524 if (write_in_full(fd, buf.buf, buf.len) != buf.len) {
525 strbuf_addf(err, "could not write to '%s'", filename);
526 rollback_lock_file(&lock);
527 goto done;
528 }
529
530 commit_lock_file(&lock);
531 ret = 0;
532 done:
533 strbuf_release(&buf);
534 return ret;
535 }
536
537 static int delete_pseudoref(const char *pseudoref, const unsigned char *old_sha1)
538 {
539 static struct lock_file lock;
540 const char *filename;
541
542 filename = git_path("%s", pseudoref);
543
544 if (old_sha1 && !is_null_sha1(old_sha1)) {
545 int fd;
546 unsigned char actual_old_sha1[20];
547
548 fd = hold_lock_file_for_update(&lock, filename,
549 LOCK_DIE_ON_ERROR);
550 if (fd < 0)
551 die_errno(_("Could not open '%s' for writing"), filename);
552 if (read_ref(pseudoref, actual_old_sha1))
553 die("could not read ref '%s'", pseudoref);
554 if (hashcmp(actual_old_sha1, old_sha1)) {
555 warning("Unexpected sha1 when deleting %s", pseudoref);
556 rollback_lock_file(&lock);
557 return -1;
558 }
559
560 unlink(filename);
561 rollback_lock_file(&lock);
562 } else {
563 unlink(filename);
564 }
565
566 return 0;
567 }
568
569 int delete_ref(const char *refname, const unsigned char *old_sha1,
570 unsigned int flags)
571 {
572 struct ref_transaction *transaction;
573 struct strbuf err = STRBUF_INIT;
574
575 if (ref_type(refname) == REF_TYPE_PSEUDOREF)
576 return delete_pseudoref(refname, old_sha1);
577
578 transaction = ref_transaction_begin(&err);
579 if (!transaction ||
580 ref_transaction_delete(transaction, refname, old_sha1,
581 flags, NULL, &err) ||
582 ref_transaction_commit(transaction, &err)) {
583 error("%s", err.buf);
584 ref_transaction_free(transaction);
585 strbuf_release(&err);
586 return 1;
587 }
588 ref_transaction_free(transaction);
589 strbuf_release(&err);
590 return 0;
591 }
592
593 int copy_reflog_msg(char *buf, const char *msg)
594 {
595 char *cp = buf;
596 char c;
597 int wasspace = 1;
598
599 *cp++ = '\t';
600 while ((c = *msg++)) {
601 if (wasspace && isspace(c))
602 continue;
603 wasspace = isspace(c);
604 if (wasspace)
605 c = ' ';
606 *cp++ = c;
607 }
608 while (buf < cp && isspace(cp[-1]))
609 cp--;
610 *cp++ = '\n';
611 return cp - buf;
612 }
613
614 int should_autocreate_reflog(const char *refname)
615 {
616 if (!log_all_ref_updates)
617 return 0;
618 return starts_with(refname, "refs/heads/") ||
619 starts_with(refname, "refs/remotes/") ||
620 starts_with(refname, "refs/notes/") ||
621 !strcmp(refname, "HEAD");
622 }
623
624 int is_branch(const char *refname)
625 {
626 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
627 }
628
629 struct read_ref_at_cb {
630 const char *refname;
631 unsigned long at_time;
632 int cnt;
633 int reccnt;
634 unsigned char *sha1;
635 int found_it;
636
637 unsigned char osha1[20];
638 unsigned char nsha1[20];
639 int tz;
640 unsigned long date;
641 char **msg;
642 unsigned long *cutoff_time;
643 int *cutoff_tz;
644 int *cutoff_cnt;
645 };
646
647 static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
648 const char *email, unsigned long timestamp, int tz,
649 const char *message, void *cb_data)
650 {
651 struct read_ref_at_cb *cb = cb_data;
652
653 cb->reccnt++;
654 cb->tz = tz;
655 cb->date = timestamp;
656
657 if (timestamp <= cb->at_time || cb->cnt == 0) {
658 if (cb->msg)
659 *cb->msg = xstrdup(message);
660 if (cb->cutoff_time)
661 *cb->cutoff_time = timestamp;
662 if (cb->cutoff_tz)
663 *cb->cutoff_tz = tz;
664 if (cb->cutoff_cnt)
665 *cb->cutoff_cnt = cb->reccnt - 1;
666 /*
667 * we have not yet updated cb->[n|o]sha1 so they still
668 * hold the values for the previous record.
669 */
670 if (!is_null_sha1(cb->osha1)) {
671 hashcpy(cb->sha1, nsha1);
672 if (hashcmp(cb->osha1, nsha1))
673 warning("Log for ref %s has gap after %s.",
674 cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
675 }
676 else if (cb->date == cb->at_time)
677 hashcpy(cb->sha1, nsha1);
678 else if (hashcmp(nsha1, cb->sha1))
679 warning("Log for ref %s unexpectedly ended on %s.",
680 cb->refname, show_date(cb->date, cb->tz,
681 DATE_MODE(RFC2822)));
682 hashcpy(cb->osha1, osha1);
683 hashcpy(cb->nsha1, nsha1);
684 cb->found_it = 1;
685 return 1;
686 }
687 hashcpy(cb->osha1, osha1);
688 hashcpy(cb->nsha1, nsha1);
689 if (cb->cnt > 0)
690 cb->cnt--;
691 return 0;
692 }
693
694 static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
695 const char *email, unsigned long timestamp,
696 int tz, const char *message, void *cb_data)
697 {
698 struct read_ref_at_cb *cb = cb_data;
699
700 if (cb->msg)
701 *cb->msg = xstrdup(message);
702 if (cb->cutoff_time)
703 *cb->cutoff_time = timestamp;
704 if (cb->cutoff_tz)
705 *cb->cutoff_tz = tz;
706 if (cb->cutoff_cnt)
707 *cb->cutoff_cnt = cb->reccnt;
708 hashcpy(cb->sha1, osha1);
709 if (is_null_sha1(cb->sha1))
710 hashcpy(cb->sha1, nsha1);
711 /* We just want the first entry */
712 return 1;
713 }
714
715 int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt,
716 unsigned char *sha1, char **msg,
717 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
718 {
719 struct read_ref_at_cb cb;
720
721 memset(&cb, 0, sizeof(cb));
722 cb.refname = refname;
723 cb.at_time = at_time;
724 cb.cnt = cnt;
725 cb.msg = msg;
726 cb.cutoff_time = cutoff_time;
727 cb.cutoff_tz = cutoff_tz;
728 cb.cutoff_cnt = cutoff_cnt;
729 cb.sha1 = sha1;
730
731 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
732
733 if (!cb.reccnt) {
734 if (flags & GET_SHA1_QUIETLY)
735 exit(128);
736 else
737 die("Log for %s is empty.", refname);
738 }
739 if (cb.found_it)
740 return 0;
741
742 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
743
744 return 1;
745 }
746
747 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
748 {
749 assert(err);
750
751 return xcalloc(1, sizeof(struct ref_transaction));
752 }
753
754 void ref_transaction_free(struct ref_transaction *transaction)
755 {
756 int i;
757
758 if (!transaction)
759 return;
760
761 for (i = 0; i < transaction->nr; i++) {
762 free(transaction->updates[i]->msg);
763 free(transaction->updates[i]);
764 }
765 free(transaction->updates);
766 free(transaction);
767 }
768
769 struct ref_update *ref_transaction_add_update(
770 struct ref_transaction *transaction,
771 const char *refname, unsigned int flags,
772 const unsigned char *new_sha1,
773 const unsigned char *old_sha1,
774 const char *msg)
775 {
776 struct ref_update *update;
777
778 if (transaction->state != REF_TRANSACTION_OPEN)
779 die("BUG: update called for transaction that is not open");
780
781 if ((flags & REF_ISPRUNING) && !(flags & REF_NODEREF))
782 die("BUG: REF_ISPRUNING set without REF_NODEREF");
783
784 FLEX_ALLOC_STR(update, refname, refname);
785 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
786 transaction->updates[transaction->nr++] = update;
787
788 update->flags = flags;
789
790 if (flags & REF_HAVE_NEW)
791 hashcpy(update->new_sha1, new_sha1);
792 if (flags & REF_HAVE_OLD)
793 hashcpy(update->old_sha1, old_sha1);
794 if (msg)
795 update->msg = xstrdup(msg);
796 return update;
797 }
798
799 int ref_transaction_update(struct ref_transaction *transaction,
800 const char *refname,
801 const unsigned char *new_sha1,
802 const unsigned char *old_sha1,
803 unsigned int flags, const char *msg,
804 struct strbuf *err)
805 {
806 assert(err);
807
808 if ((new_sha1 && !is_null_sha1(new_sha1)) ?
809 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
810 !refname_is_safe(refname)) {
811 strbuf_addf(err, "refusing to update ref with bad name '%s'",
812 refname);
813 return -1;
814 }
815
816 flags |= (new_sha1 ? REF_HAVE_NEW : 0) | (old_sha1 ? REF_HAVE_OLD : 0);
817
818 ref_transaction_add_update(transaction, refname, flags,
819 new_sha1, old_sha1, msg);
820 return 0;
821 }
822
823 int ref_transaction_create(struct ref_transaction *transaction,
824 const char *refname,
825 const unsigned char *new_sha1,
826 unsigned int flags, const char *msg,
827 struct strbuf *err)
828 {
829 if (!new_sha1 || is_null_sha1(new_sha1))
830 die("BUG: create called without valid new_sha1");
831 return ref_transaction_update(transaction, refname, new_sha1,
832 null_sha1, flags, msg, err);
833 }
834
835 int ref_transaction_delete(struct ref_transaction *transaction,
836 const char *refname,
837 const unsigned char *old_sha1,
838 unsigned int flags, const char *msg,
839 struct strbuf *err)
840 {
841 if (old_sha1 && is_null_sha1(old_sha1))
842 die("BUG: delete called with old_sha1 set to zeros");
843 return ref_transaction_update(transaction, refname,
844 null_sha1, old_sha1,
845 flags, msg, err);
846 }
847
848 int ref_transaction_verify(struct ref_transaction *transaction,
849 const char *refname,
850 const unsigned char *old_sha1,
851 unsigned int flags,
852 struct strbuf *err)
853 {
854 if (!old_sha1)
855 die("BUG: verify called with old_sha1 set to NULL");
856 return ref_transaction_update(transaction, refname,
857 NULL, old_sha1,
858 flags, NULL, err);
859 }
860
861 int update_ref(const char *msg, const char *refname,
862 const unsigned char *new_sha1, const unsigned char *old_sha1,
863 unsigned int flags, enum action_on_err onerr)
864 {
865 struct ref_transaction *t = NULL;
866 struct strbuf err = STRBUF_INIT;
867 int ret = 0;
868
869 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
870 ret = write_pseudoref(refname, new_sha1, old_sha1, &err);
871 } else {
872 t = ref_transaction_begin(&err);
873 if (!t ||
874 ref_transaction_update(t, refname, new_sha1, old_sha1,
875 flags, msg, &err) ||
876 ref_transaction_commit(t, &err)) {
877 ret = 1;
878 ref_transaction_free(t);
879 }
880 }
881 if (ret) {
882 const char *str = "update_ref failed for ref '%s': %s";
883
884 switch (onerr) {
885 case UPDATE_REFS_MSG_ON_ERR:
886 error(str, refname, err.buf);
887 break;
888 case UPDATE_REFS_DIE_ON_ERR:
889 die(str, refname, err.buf);
890 break;
891 case UPDATE_REFS_QUIET_ON_ERR:
892 break;
893 }
894 strbuf_release(&err);
895 return 1;
896 }
897 strbuf_release(&err);
898 if (t)
899 ref_transaction_free(t);
900 return 0;
901 }
902
903 char *shorten_unambiguous_ref(const char *refname, int strict)
904 {
905 int i;
906 static char **scanf_fmts;
907 static int nr_rules;
908 char *short_name;
909
910 if (!nr_rules) {
911 /*
912 * Pre-generate scanf formats from ref_rev_parse_rules[].
913 * Generate a format suitable for scanf from a
914 * ref_rev_parse_rules rule by interpolating "%s" at the
915 * location of the "%.*s".
916 */
917 size_t total_len = 0;
918 size_t offset = 0;
919
920 /* the rule list is NULL terminated, count them first */
921 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
922 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
923 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
924
925 scanf_fmts = xmalloc(st_add(st_mult(nr_rules, sizeof(char *)), total_len));
926
927 offset = 0;
928 for (i = 0; i < nr_rules; i++) {
929 assert(offset < total_len);
930 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
931 offset += snprintf(scanf_fmts[i], total_len - offset,
932 ref_rev_parse_rules[i], 2, "%s") + 1;
933 }
934 }
935
936 /* bail out if there are no rules */
937 if (!nr_rules)
938 return xstrdup(refname);
939
940 /* buffer for scanf result, at most refname must fit */
941 short_name = xstrdup(refname);
942
943 /* skip first rule, it will always match */
944 for (i = nr_rules - 1; i > 0 ; --i) {
945 int j;
946 int rules_to_fail = i;
947 int short_name_len;
948
949 if (1 != sscanf(refname, scanf_fmts[i], short_name))
950 continue;
951
952 short_name_len = strlen(short_name);
953
954 /*
955 * in strict mode, all (except the matched one) rules
956 * must fail to resolve to a valid non-ambiguous ref
957 */
958 if (strict)
959 rules_to_fail = nr_rules;
960
961 /*
962 * check if the short name resolves to a valid ref,
963 * but use only rules prior to the matched one
964 */
965 for (j = 0; j < rules_to_fail; j++) {
966 const char *rule = ref_rev_parse_rules[j];
967 char refname[PATH_MAX];
968
969 /* skip matched rule */
970 if (i == j)
971 continue;
972
973 /*
974 * the short name is ambiguous, if it resolves
975 * (with this previous rule) to a valid ref
976 * read_ref() returns 0 on success
977 */
978 mksnpath(refname, sizeof(refname),
979 rule, short_name_len, short_name);
980 if (ref_exists(refname))
981 break;
982 }
983
984 /*
985 * short name is non-ambiguous if all previous rules
986 * haven't resolved to a valid ref
987 */
988 if (j == rules_to_fail)
989 return short_name;
990 }
991
992 free(short_name);
993 return xstrdup(refname);
994 }
995
996 static struct string_list *hide_refs;
997
998 int parse_hide_refs_config(const char *var, const char *value, const char *section)
999 {
1000 if (!strcmp("transfer.hiderefs", var) ||
1001 /* NEEDSWORK: use parse_config_key() once both are merged */
1002 (starts_with(var, section) && var[strlen(section)] == '.' &&
1003 !strcmp(var + strlen(section), ".hiderefs"))) {
1004 char *ref;
1005 int len;
1006
1007 if (!value)
1008 return config_error_nonbool(var);
1009 ref = xstrdup(value);
1010 len = strlen(ref);
1011 while (len && ref[len - 1] == '/')
1012 ref[--len] = '\0';
1013 if (!hide_refs) {
1014 hide_refs = xcalloc(1, sizeof(*hide_refs));
1015 hide_refs->strdup_strings = 1;
1016 }
1017 string_list_append(hide_refs, ref);
1018 }
1019 return 0;
1020 }
1021
1022 int ref_is_hidden(const char *refname, const char *refname_full)
1023 {
1024 int i;
1025
1026 if (!hide_refs)
1027 return 0;
1028 for (i = hide_refs->nr - 1; i >= 0; i--) {
1029 const char *match = hide_refs->items[i].string;
1030 const char *subject;
1031 int neg = 0;
1032 int len;
1033
1034 if (*match == '!') {
1035 neg = 1;
1036 match++;
1037 }
1038
1039 if (*match == '^') {
1040 subject = refname_full;
1041 match++;
1042 } else {
1043 subject = refname;
1044 }
1045
1046 /* refname can be NULL when namespaces are used. */
1047 if (!subject || !starts_with(subject, match))
1048 continue;
1049 len = strlen(match);
1050 if (!subject[len] || subject[len] == '/')
1051 return !neg;
1052 }
1053 return 0;
1054 }
1055
1056 const char *find_descendant_ref(const char *dirname,
1057 const struct string_list *extras,
1058 const struct string_list *skip)
1059 {
1060 int pos;
1061
1062 if (!extras)
1063 return NULL;
1064
1065 /*
1066 * Look at the place where dirname would be inserted into
1067 * extras. If there is an entry at that position that starts
1068 * with dirname (remember, dirname includes the trailing
1069 * slash) and is not in skip, then we have a conflict.
1070 */
1071 for (pos = string_list_find_insert_index(extras, dirname, 0);
1072 pos < extras->nr; pos++) {
1073 const char *extra_refname = extras->items[pos].string;
1074
1075 if (!starts_with(extra_refname, dirname))
1076 break;
1077
1078 if (!skip || !string_list_has_string(skip, extra_refname))
1079 return extra_refname;
1080 }
1081 return NULL;
1082 }
1083
1084 int rename_ref_available(const char *old_refname, const char *new_refname)
1085 {
1086 struct string_list skip = STRING_LIST_INIT_NODUP;
1087 struct strbuf err = STRBUF_INIT;
1088 int ok;
1089
1090 string_list_insert(&skip, old_refname);
1091 ok = !verify_refname_available(new_refname, NULL, &skip, &err);
1092 if (!ok)
1093 error("%s", err.buf);
1094
1095 string_list_clear(&skip, 0);
1096 strbuf_release(&err);
1097 return ok;
1098 }
1099
1100 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1101 {
1102 struct object_id oid;
1103 int flag;
1104
1105 if (submodule) {
1106 if (resolve_gitlink_ref(submodule, "HEAD", oid.hash) == 0)
1107 return fn("HEAD", &oid, 0, cb_data);
1108
1109 return 0;
1110 }
1111
1112 if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag))
1113 return fn("HEAD", &oid, flag, cb_data);
1114
1115 return 0;
1116 }
1117
1118 int head_ref(each_ref_fn fn, void *cb_data)
1119 {
1120 return head_ref_submodule(NULL, fn, cb_data);
1121 }
1122
1123 /*
1124 * Call fn for each reference in the specified submodule for which the
1125 * refname begins with prefix. If trim is non-zero, then trim that
1126 * many characters off the beginning of each refname before passing
1127 * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1128 * include broken references in the iteration. If fn ever returns a
1129 * non-zero value, stop the iteration and return that value;
1130 * otherwise, return 0.
1131 */
1132 static int do_for_each_ref(const char *submodule, const char *prefix,
1133 each_ref_fn fn, int trim, int flags, void *cb_data)
1134 {
1135 struct ref_iterator *iter;
1136
1137 iter = files_ref_iterator_begin(submodule, prefix, flags);
1138 iter = prefix_ref_iterator_begin(iter, prefix, trim);
1139
1140 return do_for_each_ref_iterator(iter, fn, cb_data);
1141 }
1142
1143 int for_each_ref(each_ref_fn fn, void *cb_data)
1144 {
1145 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
1146 }
1147
1148 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1149 {
1150 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
1151 }
1152
1153 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1154 {
1155 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
1156 }
1157
1158 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1159 {
1160 unsigned int flag = 0;
1161
1162 if (broken)
1163 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1164 return do_for_each_ref(NULL, prefix, fn, 0, flag, cb_data);
1165 }
1166
1167 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1168 each_ref_fn fn, void *cb_data)
1169 {
1170 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
1171 }
1172
1173 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1174 {
1175 return do_for_each_ref(NULL, git_replace_ref_base, fn,
1176 strlen(git_replace_ref_base), 0, cb_data);
1177 }
1178
1179 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1180 {
1181 struct strbuf buf = STRBUF_INIT;
1182 int ret;
1183 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1184 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1185 strbuf_release(&buf);
1186 return ret;
1187 }
1188
1189 int for_each_rawref(each_ref_fn fn, void *cb_data)
1190 {
1191 return do_for_each_ref(NULL, "", fn, 0,
1192 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1193 }
1194
1195 /* This function needs to return a meaningful errno on failure */
1196 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1197 unsigned char *sha1, int *flags)
1198 {
1199 static struct strbuf sb_refname = STRBUF_INIT;
1200 int unused_flags;
1201 int symref_count;
1202
1203 if (!flags)
1204 flags = &unused_flags;
1205
1206 *flags = 0;
1207
1208 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1209 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1210 !refname_is_safe(refname)) {
1211 errno = EINVAL;
1212 return NULL;
1213 }
1214
1215 /*
1216 * dwim_ref() uses REF_ISBROKEN to distinguish between
1217 * missing refs and refs that were present but invalid,
1218 * to complain about the latter to stderr.
1219 *
1220 * We don't know whether the ref exists, so don't set
1221 * REF_ISBROKEN yet.
1222 */
1223 *flags |= REF_BAD_NAME;
1224 }
1225
1226 for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1227 unsigned int read_flags = 0;
1228
1229 if (read_raw_ref(refname, sha1, &sb_refname, &read_flags)) {
1230 *flags |= read_flags;
1231 if (errno != ENOENT || (resolve_flags & RESOLVE_REF_READING))
1232 return NULL;
1233 hashclr(sha1);
1234 if (*flags & REF_BAD_NAME)
1235 *flags |= REF_ISBROKEN;
1236 return refname;
1237 }
1238
1239 *flags |= read_flags;
1240
1241 if (!(read_flags & REF_ISSYMREF)) {
1242 if (*flags & REF_BAD_NAME) {
1243 hashclr(sha1);
1244 *flags |= REF_ISBROKEN;
1245 }
1246 return refname;
1247 }
1248
1249 refname = sb_refname.buf;
1250 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1251 hashclr(sha1);
1252 return refname;
1253 }
1254 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1255 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1256 !refname_is_safe(refname)) {
1257 errno = EINVAL;
1258 return NULL;
1259 }
1260
1261 *flags |= REF_ISBROKEN | REF_BAD_NAME;
1262 }
1263 }
1264
1265 errno = ELOOP;
1266 return NULL;
1267 }