t3211: demonstrate loss of peeled refs if a packed ref is deleted
[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
bc5fd6d3
MH
7/*
8 * Make sure "ref" is something reasonable to have under ".git/refs/";
9 * We do not like it if:
10 *
11 * - any path component of it begins with ".", or
12 * - it has double dots "..", or
13 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
14 * - it ends with a "/".
15 * - it ends with ".lock"
16 * - it contains a "\" (backslash)
17 */
f4204ab9 18
bc5fd6d3
MH
19/* Return true iff ch is not allowed in reference names. */
20static inline int bad_ref_char(int ch)
21{
22 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
23 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
24 return 1;
25 /* 2.13 Pattern Matching Notation */
26 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
27 return 1;
28 return 0;
29}
30
31/*
32 * Try to read one refname component from the front of refname. Return
33 * the length of the component found, or -1 if the component is not
34 * legal.
35 */
36static int check_refname_component(const char *refname, int flags)
37{
38 const char *cp;
39 char last = '\0';
40
41 for (cp = refname; ; cp++) {
42 char ch = *cp;
43 if (ch == '\0' || ch == '/')
44 break;
45 if (bad_ref_char(ch))
46 return -1; /* Illegal character in refname. */
47 if (last == '.' && ch == '.')
48 return -1; /* Refname contains "..". */
49 if (last == '@' && ch == '{')
50 return -1; /* Refname contains "@{". */
51 last = ch;
52 }
53 if (cp == refname)
dac529e4 54 return 0; /* Component has zero length. */
bc5fd6d3
MH
55 if (refname[0] == '.') {
56 if (!(flags & REFNAME_DOT_COMPONENT))
57 return -1; /* Component starts with '.'. */
58 /*
59 * Even if leading dots are allowed, don't allow "."
60 * as a component (".." is prevented by a rule above).
61 */
62 if (refname[1] == '\0')
63 return -1; /* Component equals ".". */
64 }
65 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
66 return -1; /* Refname ends with ".lock". */
67 return cp - refname;
68}
69
70int check_refname_format(const char *refname, int flags)
71{
72 int component_len, component_count = 0;
73
74 while (1) {
75 /* We are at the start of a path component. */
76 component_len = check_refname_component(refname, flags);
dac529e4 77 if (component_len <= 0) {
bc5fd6d3
MH
78 if ((flags & REFNAME_REFSPEC_PATTERN) &&
79 refname[0] == '*' &&
80 (refname[1] == '\0' || refname[1] == '/')) {
81 /* Accept one wildcard as a full refname component. */
82 flags &= ~REFNAME_REFSPEC_PATTERN;
83 component_len = 1;
84 } else {
85 return -1;
86 }
87 }
88 component_count++;
89 if (refname[component_len] == '\0')
90 break;
91 /* Skip to next component. */
92 refname += component_len + 1;
93 }
94
95 if (refname[component_len - 1] == '.')
96 return -1; /* Refname ends with '.'. */
97 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
98 return -1; /* Refname has only one component. */
99 return 0;
100}
101
102struct ref_entry;
e1e22e37 103
28e6a34e
MH
104/*
105 * Information used (along with the information in ref_entry) to
106 * describe a single cached reference. This data structure only
107 * occurs embedded in a union in struct ref_entry, and only when
108 * (ref_entry->flag & REF_DIR) is zero.
109 */
593f1bb8 110struct ref_value {
6c6f58df
MH
111 /*
112 * The name of the object to which this reference resolves
113 * (which may be a tag object). If REF_ISBROKEN, this is
114 * null. If REF_ISSYMREF, then this is the name of the object
115 * referred to by the last reference in the symlink chain.
116 */
593f1bb8 117 unsigned char sha1[20];
6c6f58df
MH
118
119 /*
120 * If REF_KNOWS_PEELED, then this field holds the peeled value
121 * of this reference, or null if the reference is known not to
2312a793
MH
122 * be peelable. See the documentation for peel_ref() for an
123 * exact definition of "peelable".
6c6f58df 124 */
593f1bb8
MH
125 unsigned char peeled[20];
126};
127
f006c42a
MH
128struct ref_cache;
129
28e6a34e
MH
130/*
131 * Information used (along with the information in ref_entry) to
132 * describe a level in the hierarchy of references. This data
133 * structure only occurs embedded in a union in struct ref_entry, and
134 * only when (ref_entry.flag & REF_DIR) is set. In that case,
135 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
136 * in the directory have already been read:
137 *
138 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
139 * or packed references, already read.
140 *
141 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
142 * references that hasn't been read yet (nor has any of its
143 * subdirectories).
144 *
145 * Entries within a directory are stored within a growable array of
146 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
147 * sorted are sorted by their component name in strcmp() order and the
148 * remaining entries are unsorted.
149 *
150 * Loose references are read lazily, one directory at a time. When a
151 * directory of loose references is read, then all of the references
152 * in that directory are stored, and REF_INCOMPLETE stubs are created
153 * for any subdirectories, but the subdirectories themselves are not
154 * read. The reading is triggered by get_ref_dir().
155 */
d3177275 156struct ref_dir {
e9c4c111 157 int nr, alloc;
e6ed3ca6
MH
158
159 /*
160 * Entries with index 0 <= i < sorted are sorted by name. New
161 * entries are appended to the list unsorted, and are sorted
162 * only when required; thus we avoid the need to sort the list
163 * after the addition of every reference.
164 */
165 int sorted;
166
f006c42a
MH
167 /* A pointer to the ref_cache that contains this ref_dir. */
168 struct ref_cache *ref_cache;
169
d3177275 170 struct ref_entry **entries;
e9c4c111
JP
171};
172
89df9c84
MH
173/*
174 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
175 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
176 * refs.h.
177 */
178
179/*
180 * The field ref_entry->u.value.peeled of this value entry contains
181 * the correct peeled value for the reference, which might be
182 * null_sha1 if the reference is not a tag or if it is broken.
183 */
432ad41e 184#define REF_KNOWS_PEELED 0x08
28e6a34e
MH
185
186/* ref_entry represents a directory of references */
432ad41e 187#define REF_DIR 0x10
cf0adba7 188
28e6a34e
MH
189/*
190 * Entry has not yet been read from disk (used only for REF_DIR
191 * entries representing loose references)
192 */
193#define REF_INCOMPLETE 0x20
194
432ad41e
MH
195/*
196 * A ref_entry represents either a reference or a "subdirectory" of
28e6a34e
MH
197 * references.
198 *
199 * Each directory in the reference namespace is represented by a
200 * ref_entry with (flags & REF_DIR) set and containing a subdir member
201 * that holds the entries in that directory that have been read so
202 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
203 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
204 * used for loose reference directories.
205 *
206 * References are represented by a ref_entry with (flags & REF_DIR)
207 * unset and a value member that describes the reference's value. The
208 * flag member is at the ref_entry level, but it is also needed to
209 * interpret the contents of the value field (in other words, a
210 * ref_value object is not very much use without the enclosing
211 * ref_entry).
432ad41e
MH
212 *
213 * Reference names cannot end with slash and directories' names are
214 * always stored with a trailing slash (except for the top-level
215 * directory, which is always denoted by ""). This has two nice
216 * consequences: (1) when the entries in each subdir are sorted
217 * lexicographically by name (as they usually are), the references in
218 * a whole tree can be generated in lexicographic order by traversing
219 * the tree in left-to-right, depth-first order; (2) the names of
220 * references and subdirectories cannot conflict, and therefore the
221 * presence of an empty subdirectory does not block the creation of a
222 * similarly-named reference. (The fact that reference names with the
223 * same leading components can conflict *with each other* is a
224 * separate issue that is regulated by is_refname_available().)
225 *
226 * Please note that the name field contains the fully-qualified
227 * reference (or subdirectory) name. Space could be saved by only
228 * storing the relative names. But that would require the full names
229 * to be generated on the fly when iterating in do_for_each_ref(), and
230 * would break callback functions, who have always been able to assume
231 * that the name strings that they are passed will not be freed during
232 * the iteration.
233 */
bc5fd6d3
MH
234struct ref_entry {
235 unsigned char flag; /* ISSYMREF? ISPACKED? */
593f1bb8 236 union {
432ad41e
MH
237 struct ref_value value; /* if not (flags&REF_DIR) */
238 struct ref_dir subdir; /* if (flags&REF_DIR) */
593f1bb8 239 } u;
432ad41e
MH
240 /*
241 * The full name of the reference (e.g., "refs/heads/master")
242 * or the full name of the directory with a trailing slash
243 * (e.g., "refs/heads/"):
244 */
bc5fd6d3
MH
245 char name[FLEX_ARRAY];
246};
e1e22e37 247
28e6a34e
MH
248static void read_loose_refs(const char *dirname, struct ref_dir *dir);
249
d7826d54
MH
250static struct ref_dir *get_ref_dir(struct ref_entry *entry)
251{
28e6a34e 252 struct ref_dir *dir;
d7826d54 253 assert(entry->flag & REF_DIR);
28e6a34e
MH
254 dir = &entry->u.subdir;
255 if (entry->flag & REF_INCOMPLETE) {
256 read_loose_refs(entry->name, dir);
257 entry->flag &= ~REF_INCOMPLETE;
258 }
259 return dir;
d7826d54
MH
260}
261
cddc4258
MH
262static struct ref_entry *create_ref_entry(const char *refname,
263 const unsigned char *sha1, int flag,
264 int check_name)
e1e22e37
LT
265{
266 int len;
cddc4258 267 struct ref_entry *ref;
e1e22e37 268
09116a1c 269 if (check_name &&
dfefa935
MH
270 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
271 die("Reference has invalid format: '%s'", refname);
cddc4258
MH
272 len = strlen(refname) + 1;
273 ref = xmalloc(sizeof(struct ref_entry) + len);
593f1bb8
MH
274 hashcpy(ref->u.value.sha1, sha1);
275 hashclr(ref->u.value.peeled);
cddc4258
MH
276 memcpy(ref->name, refname, len);
277 ref->flag = flag;
278 return ref;
279}
280
432ad41e
MH
281static void clear_ref_dir(struct ref_dir *dir);
282
732134ed
MH
283static void free_ref_entry(struct ref_entry *entry)
284{
27b5587c
MH
285 if (entry->flag & REF_DIR) {
286 /*
287 * Do not use get_ref_dir() here, as that might
288 * trigger the reading of loose refs.
289 */
290 clear_ref_dir(&entry->u.subdir);
291 }
732134ed
MH
292 free(entry);
293}
294
432ad41e
MH
295/*
296 * Add a ref_entry to the end of dir (unsorted). Entry is always
297 * stored directly in dir; no recursion into subdirectories is
298 * done.
299 */
300static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
cddc4258 301{
432ad41e
MH
302 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
303 dir->entries[dir->nr++] = entry;
654ad400
MH
304 /* optimize for the case that entries are added in order */
305 if (dir->nr == 1 ||
306 (dir->nr == dir->sorted + 1 &&
307 strcmp(dir->entries[dir->nr - 2]->name,
308 dir->entries[dir->nr - 1]->name) < 0))
309 dir->sorted = dir->nr;
c774aab9
JP
310}
311
432ad41e
MH
312/*
313 * Clear and free all entries in dir, recursively.
314 */
d3177275 315static void clear_ref_dir(struct ref_dir *dir)
bc5fd6d3
MH
316{
317 int i;
d3177275
MH
318 for (i = 0; i < dir->nr; i++)
319 free_ref_entry(dir->entries[i]);
320 free(dir->entries);
321 dir->sorted = dir->nr = dir->alloc = 0;
322 dir->entries = NULL;
bc5fd6d3
MH
323}
324
432ad41e
MH
325/*
326 * Create a struct ref_entry object for the specified dirname.
327 * dirname is the name of the directory with a trailing slash (e.g.,
328 * "refs/heads/") or "" for the top-level directory.
329 */
f006c42a 330static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
b9146f51
RS
331 const char *dirname, size_t len,
332 int incomplete)
432ad41e
MH
333{
334 struct ref_entry *direntry;
432ad41e 335 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
b9146f51
RS
336 memcpy(direntry->name, dirname, len);
337 direntry->name[len] = '\0';
f006c42a 338 direntry->u.subdir.ref_cache = ref_cache;
28e6a34e 339 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
432ad41e
MH
340 return direntry;
341}
342
e9c4c111 343static int ref_entry_cmp(const void *a, const void *b)
c774aab9 344{
e9c4c111
JP
345 struct ref_entry *one = *(struct ref_entry **)a;
346 struct ref_entry *two = *(struct ref_entry **)b;
347 return strcmp(one->name, two->name);
348}
c774aab9 349
d3177275 350static void sort_ref_dir(struct ref_dir *dir);
bc5fd6d3 351
e1980c9d
JH
352struct string_slice {
353 size_t len;
354 const char *str;
355};
356
357static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
358{
359 struct string_slice *key = (struct string_slice *)key_;
360 struct ref_entry *ent = *(struct ref_entry **)ent_;
361 int entlen = strlen(ent->name);
362 int cmplen = key->len < entlen ? key->len : entlen;
363 int cmp = memcmp(key->str, ent->name, cmplen);
364 if (cmp)
365 return cmp;
366 return key->len - entlen;
367}
368
432ad41e 369/*
9fc0a648
MH
370 * Return the index of the entry with the given refname from the
371 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
372 * no such entry is found. dir must already be complete.
432ad41e 373 */
9fc0a648 374static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
bc5fd6d3 375{
e1980c9d
JH
376 struct ref_entry **r;
377 struct string_slice key;
bc5fd6d3 378
432ad41e 379 if (refname == NULL || !dir->nr)
9fc0a648 380 return -1;
bc5fd6d3 381
d3177275 382 sort_ref_dir(dir);
e1980c9d
JH
383 key.len = len;
384 key.str = refname;
385 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
386 ref_entry_cmp_sslice);
bc5fd6d3
MH
387
388 if (r == NULL)
9fc0a648 389 return -1;
bc5fd6d3 390
9fc0a648 391 return r - dir->entries;
bc5fd6d3
MH
392}
393
f348ac92
MH
394/*
395 * Search for a directory entry directly within dir (without
396 * recursing). Sort dir if necessary. subdirname must be a directory
397 * name (i.e., end in '/'). If mkdir is set, then create the
398 * directory if it is missing; otherwise, return NULL if the desired
28e6a34e 399 * directory cannot be found. dir must already be complete.
f348ac92 400 */
3f3aa1bc 401static struct ref_dir *search_for_subdir(struct ref_dir *dir,
dd02e728
RS
402 const char *subdirname, size_t len,
403 int mkdir)
f348ac92 404{
9fc0a648
MH
405 int entry_index = search_ref_dir(dir, subdirname, len);
406 struct ref_entry *entry;
407 if (entry_index == -1) {
f348ac92
MH
408 if (!mkdir)
409 return NULL;
28e6a34e
MH
410 /*
411 * Since dir is complete, the absence of a subdir
412 * means that the subdir really doesn't exist;
413 * therefore, create an empty record for it but mark
414 * the record complete.
415 */
b9146f51 416 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
f348ac92 417 add_entry_to_dir(dir, entry);
9fc0a648
MH
418 } else {
419 entry = dir->entries[entry_index];
f348ac92 420 }
3f3aa1bc 421 return get_ref_dir(entry);
f348ac92
MH
422}
423
432ad41e
MH
424/*
425 * If refname is a reference name, find the ref_dir within the dir
426 * tree that should hold refname. If refname is a directory name
427 * (i.e., ends in '/'), then return that ref_dir itself. dir must
28e6a34e
MH
428 * represent the top-level directory and must already be complete.
429 * Sort ref_dirs and recurse into subdirectories as necessary. If
430 * mkdir is set, then create any missing directories; otherwise,
431 * return NULL if the desired directory cannot be found.
432ad41e
MH
432 */
433static struct ref_dir *find_containing_dir(struct ref_dir *dir,
434 const char *refname, int mkdir)
435{
5fa04418 436 const char *slash;
5fa04418 437 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
dd02e728 438 size_t dirnamelen = slash - refname + 1;
3f3aa1bc 439 struct ref_dir *subdir;
dd02e728 440 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
663c1295
JH
441 if (!subdir) {
442 dir = NULL;
f348ac92 443 break;
432ad41e 444 }
3f3aa1bc 445 dir = subdir;
432ad41e
MH
446 }
447
432ad41e
MH
448 return dir;
449}
450
451/*
452 * Find the value entry with the given name in dir, sorting ref_dirs
453 * and recursing into subdirectories as necessary. If the name is not
454 * found or it corresponds to a directory entry, return NULL.
455 */
456static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
457{
9fc0a648 458 int entry_index;
432ad41e
MH
459 struct ref_entry *entry;
460 dir = find_containing_dir(dir, refname, 0);
461 if (!dir)
462 return NULL;
9fc0a648
MH
463 entry_index = search_ref_dir(dir, refname, strlen(refname));
464 if (entry_index == -1)
465 return NULL;
466 entry = dir->entries[entry_index];
467 return (entry->flag & REF_DIR) ? NULL : entry;
432ad41e
MH
468}
469
506a760d
MH
470/*
471 * Remove the entry with the given name from dir, recursing into
472 * subdirectories as necessary. If refname is the name of a directory
473 * (i.e., ends with '/'), then remove the directory and its contents.
474 * If the removal was successful, return the number of entries
475 * remaining in the directory entry that contained the deleted entry.
476 * If the name was not found, return -1. Please note that this
477 * function only deletes the entry from the cache; it does not delete
478 * it from the filesystem or ensure that other cache entries (which
479 * might be symbolic references to the removed entry) are updated.
480 * Nor does it remove any containing dir entries that might be made
481 * empty by the removal. dir must represent the top-level directory
482 * and must already be complete.
483 */
484static int remove_entry(struct ref_dir *dir, const char *refname)
485{
486 int refname_len = strlen(refname);
487 int entry_index;
488 struct ref_entry *entry;
489 int is_dir = refname[refname_len - 1] == '/';
490 if (is_dir) {
491 /*
492 * refname represents a reference directory. Remove
493 * the trailing slash; otherwise we will get the
494 * directory *representing* refname rather than the
495 * one *containing* it.
496 */
497 char *dirname = xmemdupz(refname, refname_len - 1);
498 dir = find_containing_dir(dir, dirname, 0);
499 free(dirname);
500 } else {
501 dir = find_containing_dir(dir, refname, 0);
502 }
503 if (!dir)
504 return -1;
505 entry_index = search_ref_dir(dir, refname, refname_len);
506 if (entry_index == -1)
507 return -1;
508 entry = dir->entries[entry_index];
509
510 memmove(&dir->entries[entry_index],
511 &dir->entries[entry_index + 1],
512 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
513 );
514 dir->nr--;
515 if (dir->sorted > entry_index)
516 dir->sorted--;
517 free_ref_entry(entry);
518 return dir->nr;
519}
520
432ad41e
MH
521/*
522 * Add a ref_entry to the ref_dir (unsorted), recursing into
523 * subdirectories as necessary. dir must represent the top-level
524 * directory. Return 0 on success.
525 */
526static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
527{
528 dir = find_containing_dir(dir, ref->name, 1);
529 if (!dir)
530 return -1;
531 add_entry_to_dir(dir, ref);
532 return 0;
533}
534
202a56a9
MH
535/*
536 * Emit a warning and return true iff ref1 and ref2 have the same name
537 * and the same sha1. Die if they have the same name but different
538 * sha1s.
539 */
540static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
541{
432ad41e 542 if (strcmp(ref1->name, ref2->name))
202a56a9 543 return 0;
432ad41e
MH
544
545 /* Duplicate name; make sure that they don't conflict: */
546
547 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
548 /* This is impossible by construction */
549 die("Reference directory conflict: %s", ref1->name);
550
551 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
552 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
553
554 warning("Duplicated ref: %s", ref1->name);
555 return 1;
202a56a9
MH
556}
557
e6ed3ca6 558/*
432ad41e
MH
559 * Sort the entries in dir non-recursively (if they are not already
560 * sorted) and remove any duplicate entries.
e6ed3ca6 561 */
d3177275 562static void sort_ref_dir(struct ref_dir *dir)
e9c4c111 563{
202a56a9 564 int i, j;
81a79d8e 565 struct ref_entry *last = NULL;
c774aab9 566
e6ed3ca6
MH
567 /*
568 * This check also prevents passing a zero-length array to qsort(),
569 * which is a problem on some platforms.
570 */
d3177275 571 if (dir->sorted == dir->nr)
e9c4c111 572 return;
c774aab9 573
d3177275 574 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
c774aab9 575
81a79d8e
MH
576 /* Remove any duplicates: */
577 for (i = 0, j = 0; j < dir->nr; j++) {
578 struct ref_entry *entry = dir->entries[j];
579 if (last && is_dup_ref(last, entry))
580 free_ref_entry(entry);
581 else
582 last = dir->entries[i++] = entry;
e9c4c111 583 }
81a79d8e 584 dir->sorted = dir->nr = i;
e9c4c111 585}
c774aab9 586
fcce1703
MH
587/* Include broken references in a do_for_each_ref*() iteration: */
588#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
c774aab9 589
662428f4
MH
590/*
591 * Return true iff the reference described by entry can be resolved to
592 * an object in the database. Emit a warning if the referred-to
593 * object does not exist.
594 */
595static int ref_resolves_to_object(struct ref_entry *entry)
596{
597 if (entry->flag & REF_ISBROKEN)
598 return 0;
599 if (!has_sha1_file(entry->u.value.sha1)) {
600 error("%s does not point to a valid object!", entry->name);
601 return 0;
602 }
603 return 1;
604}
605
7d76fdc8
MH
606/*
607 * current_ref is a performance hack: when iterating over references
608 * using the for_each_ref*() functions, current_ref is set to the
609 * current reference's entry before calling the callback function. If
610 * the callback function calls peel_ref(), then peel_ref() first
611 * checks whether the reference to be peeled is the current reference
612 * (it usually is) and if so, returns that reference's peeled version
613 * if it is available. This avoids a refname lookup in a common case.
614 */
bc5fd6d3 615static struct ref_entry *current_ref;
c774aab9 616
624cac35
MH
617typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
618
619struct ref_entry_cb {
620 const char *base;
621 int trim;
622 int flags;
623 each_ref_fn *fn;
624 void *cb_data;
625};
626
fcce1703 627/*
624cac35
MH
628 * Handle one reference in a do_for_each_ref*()-style iteration,
629 * calling an each_ref_fn for each entry.
fcce1703 630 */
624cac35 631static int do_one_ref(struct ref_entry *entry, void *cb_data)
bc5fd6d3 632{
624cac35 633 struct ref_entry_cb *data = cb_data;
429213e4 634 int retval;
624cac35 635 if (prefixcmp(entry->name, data->base))
bc5fd6d3 636 return 0;
c774aab9 637
624cac35 638 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
662428f4
MH
639 !ref_resolves_to_object(entry))
640 return 0;
641
bc5fd6d3 642 current_ref = entry;
624cac35
MH
643 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
644 entry->flag, data->cb_data);
429213e4
MH
645 current_ref = NULL;
646 return retval;
bc5fd6d3 647}
c774aab9 648
c36b5bc2 649/*
d3177275 650 * Call fn for each reference in dir that has index in the range
432ad41e
MH
651 * offset <= index < dir->nr. Recurse into subdirectories that are in
652 * that index range, sorting them before iterating. This function
624cac35
MH
653 * does not sort dir itself; it should be sorted beforehand. fn is
654 * called for all references, including broken ones.
c36b5bc2 655 */
624cac35
MH
656static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
657 each_ref_entry_fn fn, void *cb_data)
c36b5bc2
MH
658{
659 int i;
d3177275
MH
660 assert(dir->sorted == dir->nr);
661 for (i = offset; i < dir->nr; i++) {
432ad41e
MH
662 struct ref_entry *entry = dir->entries[i];
663 int retval;
664 if (entry->flag & REF_DIR) {
d7826d54
MH
665 struct ref_dir *subdir = get_ref_dir(entry);
666 sort_ref_dir(subdir);
624cac35 667 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
432ad41e 668 } else {
624cac35 669 retval = fn(entry, cb_data);
432ad41e 670 }
c36b5bc2
MH
671 if (retval)
672 return retval;
673 }
674 return 0;
675}
676
b3fd060f 677/*
d3177275 678 * Call fn for each reference in the union of dir1 and dir2, in order
432ad41e
MH
679 * by refname. Recurse into subdirectories. If a value entry appears
680 * in both dir1 and dir2, then only process the version that is in
681 * dir2. The input dirs must already be sorted, but subdirs will be
624cac35
MH
682 * sorted as needed. fn is called for all references, including
683 * broken ones.
b3fd060f 684 */
624cac35
MH
685static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
686 struct ref_dir *dir2,
687 each_ref_entry_fn fn, void *cb_data)
b3fd060f
MH
688{
689 int retval;
690 int i1 = 0, i2 = 0;
691
d3177275
MH
692 assert(dir1->sorted == dir1->nr);
693 assert(dir2->sorted == dir2->nr);
432ad41e
MH
694 while (1) {
695 struct ref_entry *e1, *e2;
696 int cmp;
697 if (i1 == dir1->nr) {
624cac35 698 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
432ad41e
MH
699 }
700 if (i2 == dir2->nr) {
624cac35 701 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
432ad41e
MH
702 }
703 e1 = dir1->entries[i1];
704 e2 = dir2->entries[i2];
705 cmp = strcmp(e1->name, e2->name);
706 if (cmp == 0) {
707 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
708 /* Both are directories; descend them in parallel. */
d7826d54
MH
709 struct ref_dir *subdir1 = get_ref_dir(e1);
710 struct ref_dir *subdir2 = get_ref_dir(e2);
711 sort_ref_dir(subdir1);
712 sort_ref_dir(subdir2);
624cac35
MH
713 retval = do_for_each_entry_in_dirs(
714 subdir1, subdir2, fn, cb_data);
432ad41e
MH
715 i1++;
716 i2++;
717 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
718 /* Both are references; ignore the one from dir1. */
624cac35 719 retval = fn(e2, cb_data);
432ad41e
MH
720 i1++;
721 i2++;
722 } else {
723 die("conflict between reference and directory: %s",
724 e1->name);
725 }
b3fd060f 726 } else {
432ad41e
MH
727 struct ref_entry *e;
728 if (cmp < 0) {
729 e = e1;
b3fd060f 730 i1++;
432ad41e
MH
731 } else {
732 e = e2;
733 i2++;
734 }
735 if (e->flag & REF_DIR) {
d7826d54
MH
736 struct ref_dir *subdir = get_ref_dir(e);
737 sort_ref_dir(subdir);
624cac35
MH
738 retval = do_for_each_entry_in_dir(
739 subdir, 0, fn, cb_data);
432ad41e 740 } else {
624cac35 741 retval = fn(e, cb_data);
b3fd060f
MH
742 }
743 }
744 if (retval)
745 return retval;
746 }
b3fd060f
MH
747}
748
d66da478
MH
749/*
750 * Return true iff refname1 and refname2 conflict with each other.
751 * Two reference names conflict if one of them exactly matches the
752 * leading components of the other; e.g., "foo/bar" conflicts with
753 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
754 * "foo/barbados".
755 */
756static int names_conflict(const char *refname1, const char *refname2)
757{
5a4d4947
MH
758 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
759 ;
760 return (*refname1 == '\0' && *refname2 == '/')
761 || (*refname1 == '/' && *refname2 == '\0');
762}
763
764struct name_conflict_cb {
765 const char *refname;
766 const char *oldrefname;
767 const char *conflicting_refname;
768};
769
624cac35 770static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
5a4d4947
MH
771{
772 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
624cac35 773 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
5a4d4947 774 return 0;
624cac35
MH
775 if (names_conflict(data->refname, entry->name)) {
776 data->conflicting_refname = entry->name;
5a4d4947 777 return 1;
d66da478 778 }
5a4d4947 779 return 0;
d66da478
MH
780}
781
bc5fd6d3
MH
782/*
783 * Return true iff a reference named refname could be created without
624cac35 784 * conflicting with the name of an existing reference in dir. If
5a4d4947
MH
785 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
786 * (e.g., because oldrefname is scheduled for deletion in the same
bc5fd6d3
MH
787 * operation).
788 */
789static int is_refname_available(const char *refname, const char *oldrefname,
d3177275 790 struct ref_dir *dir)
bc5fd6d3 791{
5a4d4947
MH
792 struct name_conflict_cb data;
793 data.refname = refname;
794 data.oldrefname = oldrefname;
795 data.conflicting_refname = NULL;
796
d3177275 797 sort_ref_dir(dir);
624cac35 798 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
5a4d4947
MH
799 error("'%s' exists; cannot create '%s'",
800 data.conflicting_refname, refname);
801 return 0;
bc5fd6d3
MH
802 }
803 return 1;
e1e22e37
LT
804}
805
5e290ff7
JH
806/*
807 * Future: need to be in "struct repository"
808 * when doing a full libification.
809 */
79c7ca54
MH
810static struct ref_cache {
811 struct ref_cache *next;
d12229f5
MH
812 struct ref_entry *loose;
813 struct ref_entry *packed;
ce40979c
MH
814 /* The submodule name, or "" for the main repo. */
815 char name[FLEX_ARRAY];
79c7ca54 816} *ref_cache;
0e88c130 817
760c4512 818static void clear_packed_ref_cache(struct ref_cache *refs)
e1e22e37 819{
d12229f5
MH
820 if (refs->packed) {
821 free_ref_entry(refs->packed);
822 refs->packed = NULL;
823 }
5e290ff7 824}
e1e22e37 825
760c4512
MH
826static void clear_loose_ref_cache(struct ref_cache *refs)
827{
d12229f5
MH
828 if (refs->loose) {
829 free_ref_entry(refs->loose);
830 refs->loose = NULL;
831 }
760c4512
MH
832}
833
79c7ca54 834static struct ref_cache *create_ref_cache(const char *submodule)
e5dbf605 835{
ce40979c 836 int len;
79c7ca54 837 struct ref_cache *refs;
ce40979c
MH
838 if (!submodule)
839 submodule = "";
840 len = strlen(submodule) + 1;
79c7ca54 841 refs = xcalloc(1, sizeof(struct ref_cache) + len);
ce40979c 842 memcpy(refs->name, submodule, len);
e5dbf605
MH
843 return refs;
844}
845
4349a668 846/*
79c7ca54 847 * Return a pointer to a ref_cache for the specified submodule. For
4349a668
MH
848 * the main repository, use submodule==NULL. The returned structure
849 * will be allocated and initialized but not necessarily populated; it
850 * should not be freed.
851 */
79c7ca54 852static struct ref_cache *get_ref_cache(const char *submodule)
4349a668 853{
79c7ca54 854 struct ref_cache *refs = ref_cache;
0e88c130
MH
855 if (!submodule)
856 submodule = "";
857 while (refs) {
858 if (!strcmp(submodule, refs->name))
859 return refs;
860 refs = refs->next;
4349a668 861 }
0e88c130 862
79c7ca54
MH
863 refs = create_ref_cache(submodule);
864 refs->next = ref_cache;
865 ref_cache = refs;
0e88c130 866 return refs;
4349a668
MH
867}
868
8be8bde7 869void invalidate_ref_cache(const char *submodule)
f130b116 870{
c5f29abd
MH
871 struct ref_cache *refs = get_ref_cache(submodule);
872 clear_packed_ref_cache(refs);
873 clear_loose_ref_cache(refs);
5e290ff7 874}
e1e22e37 875
3feb4f0c
MH
876/* The length of a peeled reference line in packed-refs, including EOL: */
877#define PEELED_LINE_LENGTH 42
878
bc5fd6d3
MH
879/*
880 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
881 * Return a pointer to the refname within the line (null-terminated),
882 * or NULL if there was a problem.
883 */
884static const char *parse_ref_line(char *line, unsigned char *sha1)
885{
886 /*
887 * 42: the answer to everything.
888 *
889 * In this case, it happens to be the answer to
890 * 40 (length of sha1 hex representation)
891 * +1 (space in between hex and name)
892 * +1 (newline at the end of the line)
893 */
894 int len = strlen(line) - 42;
895
896 if (len <= 0)
897 return NULL;
898 if (get_sha1_hex(line, sha1) < 0)
899 return NULL;
900 if (!isspace(line[40]))
901 return NULL;
902 line += 41;
903 if (isspace(*line))
904 return NULL;
905 if (line[len] != '\n')
906 return NULL;
907 line[len] = 0;
908
909 return line;
910}
911
c29c46fa
MH
912/*
913 * Read f, which is a packed-refs file, into dir.
914 *
915 * A comment line of the form "# pack-refs with: " may contain zero or
916 * more traits. We interpret the traits as follows:
917 *
918 * No traits:
919 *
920 * Probably no references are peeled. But if the file contains a
921 * peeled value for a reference, we will use it.
922 *
923 * peeled:
924 *
925 * References under "refs/tags/", if they *can* be peeled, *are*
926 * peeled in this file. References outside of "refs/tags/" are
927 * probably not peeled even if they could have been, but if we find
928 * a peeled value for such a reference we will use it.
929 *
930 * fully-peeled:
931 *
932 * All references in the file that can be peeled are peeled.
933 * Inversely (and this is more important), any references in the
934 * file for which no peeled value is recorded is not peelable. This
935 * trait should typically be written alongside "peeled" for
936 * compatibility with older clients, but we do not require it
937 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
938 */
d3177275 939static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 940{
e9c4c111 941 struct ref_entry *last = NULL;
f4204ab9 942 char refline[PATH_MAX];
c29c46fa 943 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
944
945 while (fgets(refline, sizeof(refline), f)) {
946 unsigned char sha1[20];
dfefa935 947 const char *refname;
f4204ab9
JH
948 static const char header[] = "# pack-refs with:";
949
950 if (!strncmp(refline, header, sizeof(header)-1)) {
951 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
952 if (strstr(traits, " fully-peeled "))
953 peeled = PEELED_FULLY;
954 else if (strstr(traits, " peeled "))
955 peeled = PEELED_TAGS;
f4204ab9
JH
956 /* perhaps other traits later as well */
957 continue;
958 }
959
dfefa935
MH
960 refname = parse_ref_line(refline, sha1);
961 if (refname) {
c29c46fa
MH
962 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
963 if (peeled == PEELED_FULLY ||
964 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
965 last->flag |= REF_KNOWS_PEELED;
d3177275 966 add_ref(dir, last);
f4204ab9
JH
967 continue;
968 }
969 if (last &&
970 refline[0] == '^' &&
3feb4f0c
MH
971 strlen(refline) == PEELED_LINE_LENGTH &&
972 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 973 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 974 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
975 /*
976 * Regardless of what the file header said,
977 * we definitely know the value of *this*
978 * reference:
979 */
980 last->flag |= REF_KNOWS_PEELED;
981 }
f4204ab9 982 }
f4204ab9
JH
983}
984
d3177275 985static struct ref_dir *get_packed_refs(struct ref_cache *refs)
5e290ff7 986{
d12229f5 987 if (!refs->packed) {
4349a668
MH
988 const char *packed_refs_file;
989 FILE *f;
0bad611b 990
b9146f51 991 refs->packed = create_dir_entry(refs, "", 0, 0);
316b097a
MH
992 if (*refs->name)
993 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
4349a668
MH
994 else
995 packed_refs_file = git_path("packed-refs");
996 f = fopen(packed_refs_file, "r");
e1e22e37 997 if (f) {
d7826d54 998 read_packed_refs(f, get_ref_dir(refs->packed));
e1e22e37 999 fclose(f);
e1e22e37 1000 }
e1e22e37 1001 }
d7826d54 1002 return get_ref_dir(refs->packed);
e1e22e37
LT
1003}
1004
30249ee6
MH
1005void add_packed_ref(const char *refname, const unsigned char *sha1)
1006{
1007 add_ref(get_packed_refs(get_ref_cache(NULL)),
1008 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1009}
1010
abc39098 1011/*
28e6a34e
MH
1012 * Read the loose references from the namespace dirname into dir
1013 * (without recursing). dirname must end with '/'. dir must be the
1014 * directory entry corresponding to dirname.
abc39098 1015 */
423a1afc 1016static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 1017{
423a1afc 1018 struct ref_cache *refs = dir->ref_cache;
d3177275 1019 DIR *d;
0bad611b 1020 const char *path;
d5fdae67 1021 struct dirent *de;
abc39098 1022 int dirnamelen = strlen(dirname);
72b64b44 1023 struct strbuf refname;
0bad611b 1024
3b124823 1025 if (*refs->name)
66a3d20b 1026 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 1027 else
66a3d20b 1028 path = git_path("%s", dirname);
0bad611b 1029
d3177275 1030 d = opendir(path);
d5fdae67
MH
1031 if (!d)
1032 return;
1033
66a3d20b
MH
1034 strbuf_init(&refname, dirnamelen + 257);
1035 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
1036
1037 while ((de = readdir(d)) != NULL) {
1038 unsigned char sha1[20];
1039 struct stat st;
1040 int flag;
d5fdae67
MH
1041 const char *refdir;
1042
1043 if (de->d_name[0] == '.')
1044 continue;
d5fdae67
MH
1045 if (has_extension(de->d_name, ".lock"))
1046 continue;
72b64b44 1047 strbuf_addstr(&refname, de->d_name);
d5fdae67 1048 refdir = *refs->name
72b64b44
MH
1049 ? git_path_submodule(refs->name, "%s", refname.buf)
1050 : git_path("%s", refname.buf);
1051 if (stat(refdir, &st) < 0) {
1052 ; /* silently ignore */
1053 } else if (S_ISDIR(st.st_mode)) {
abc39098 1054 strbuf_addch(&refname, '/');
28e6a34e 1055 add_entry_to_dir(dir,
b9146f51
RS
1056 create_dir_entry(refs, refname.buf,
1057 refname.len, 1));
72b64b44 1058 } else {
3b124823 1059 if (*refs->name) {
f8948e2f 1060 hashclr(sha1);
0bad611b 1061 flag = 0;
72b64b44 1062 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1063 hashclr(sha1);
98ac34b2 1064 flag |= REF_ISBROKEN;
0bad611b 1065 }
72b64b44 1066 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1067 hashclr(sha1);
1068 flag |= REF_ISBROKEN;
1069 }
9f2fb4a3
MH
1070 add_entry_to_dir(dir,
1071 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1072 }
66a3d20b 1073 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1074 }
72b64b44 1075 strbuf_release(&refname);
d5fdae67 1076 closedir(d);
e1e22e37
LT
1077}
1078
d3177275 1079static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1080{
d12229f5 1081 if (!refs->loose) {
28e6a34e
MH
1082 /*
1083 * Mark the top-level directory complete because we
1084 * are about to read the only subdirectory that can
1085 * hold references:
1086 */
b9146f51 1087 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1088 /*
1089 * Create an incomplete entry for "refs/":
1090 */
1091 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1092 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1093 }
d7826d54 1094 return get_ref_dir(refs->loose);
e1e22e37
LT
1095}
1096
ca8db142
LT
1097/* We allow "recursive" symbolic refs. Only within reason, though */
1098#define MAXDEPTH 5
0ebde32c
LT
1099#define MAXREFLEN (1024)
1100
e5fa45c1
JH
1101/*
1102 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1103 * from the loose refs in ref_cache refs. Find <refname> in the
1104 * packed-refs file for the submodule.
e5fa45c1 1105 */
b0626608 1106static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1107 const char *refname, unsigned char *sha1)
0ebde32c 1108{
2c5c66be 1109 struct ref_entry *ref;
d3177275 1110 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1111
432ad41e 1112 ref = find_ref(dir, refname);
b0626608
MH
1113 if (ref == NULL)
1114 return -1;
1115
593f1bb8 1116 memcpy(sha1, ref->u.value.sha1, 20);
b0626608 1117 return 0;
0ebde32c
LT
1118}
1119
b0626608 1120static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1121 const char *refname, unsigned char *sha1,
dfefa935 1122 int recursion)
0ebde32c 1123{
064d51dc 1124 int fd, len;
0ebde32c 1125 char buffer[128], *p;
064d51dc 1126 char *path;
0ebde32c 1127
064d51dc 1128 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1129 return -1;
064d51dc
MH
1130 path = *refs->name
1131 ? git_path_submodule(refs->name, "%s", refname)
1132 : git_path("%s", refname);
1133 fd = open(path, O_RDONLY);
0ebde32c 1134 if (fd < 0)
b0626608 1135 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1136
1137 len = read(fd, buffer, sizeof(buffer)-1);
1138 close(fd);
1139 if (len < 0)
1140 return -1;
1141 while (len && isspace(buffer[len-1]))
1142 len--;
1143 buffer[len] = 0;
1144
1145 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1146 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1147 return 0;
1148
1149 /* Symref? */
1150 if (strncmp(buffer, "ref:", 4))
1151 return -1;
1152 p = buffer + 4;
1153 while (isspace(*p))
1154 p++;
1155
064d51dc 1156 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1157}
1158
85be1fe3 1159int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1160{
1161 int len = strlen(path), retval;
064d51dc 1162 char *submodule;
b0626608 1163 struct ref_cache *refs;
0ebde32c
LT
1164
1165 while (len && path[len-1] == '/')
1166 len--;
1167 if (!len)
1168 return -1;
b0626608
MH
1169 submodule = xstrndup(path, len);
1170 refs = get_ref_cache(submodule);
1171 free(submodule);
1172
064d51dc 1173 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1174 return retval;
1175}
ca8db142 1176
4886b89f 1177/*
63331581
MH
1178 * Return the ref_entry for the given refname from the packed
1179 * references. If it does not exist, return NULL.
4886b89f 1180 */
63331581 1181static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1182{
63331581 1183 return find_ref(get_packed_refs(get_ref_cache(NULL)), refname);
c224ca7f
MH
1184}
1185
8d68493f 1186const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1187{
0104ca09
HO
1188 int depth = MAXDEPTH;
1189 ssize_t len;
a876ed83 1190 char buffer[256];
dfefa935 1191 static char refname_buffer[256];
ca8db142 1192
8da19775
JH
1193 if (flag)
1194 *flag = 0;
1195
dfefa935 1196 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
8384d788
MH
1197 return NULL;
1198
a876ed83 1199 for (;;) {
55956350 1200 char path[PATH_MAX];
a876ed83
JH
1201 struct stat st;
1202 char *buf;
1203 int fd;
8a65ff76 1204
a876ed83
JH
1205 if (--depth < 0)
1206 return NULL;
ca8db142 1207
dfefa935 1208 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1209
a876ed83 1210 if (lstat(path, &st) < 0) {
63331581
MH
1211 struct ref_entry *entry;
1212
c224ca7f
MH
1213 if (errno != ENOENT)
1214 return NULL;
1215 /*
1216 * The loose reference file does not exist;
1217 * check for a packed reference.
1218 */
63331581
MH
1219 entry = get_packed_ref(refname);
1220 if (entry) {
1221 hashcpy(sha1, entry->u.value.sha1);
c224ca7f
MH
1222 if (flag)
1223 *flag |= REF_ISPACKED;
dfefa935 1224 return refname;
434cd0cd 1225 }
c224ca7f
MH
1226 /* The reference is not a packed reference, either. */
1227 if (reading) {
a876ed83 1228 return NULL;
c224ca7f
MH
1229 } else {
1230 hashclr(sha1);
dfefa935 1231 return refname;
c224ca7f 1232 }
a876ed83 1233 }
ca8db142 1234
a876ed83
JH
1235 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1236 if (S_ISLNK(st.st_mode)) {
1237 len = readlink(path, buffer, sizeof(buffer)-1);
7bb2bf8e
MH
1238 if (len < 0)
1239 return NULL;
b54cb795 1240 buffer[len] = 0;
1f58a038
MH
1241 if (!prefixcmp(buffer, "refs/") &&
1242 !check_refname_format(buffer, 0)) {
dfefa935
MH
1243 strcpy(refname_buffer, buffer);
1244 refname = refname_buffer;
8da19775
JH
1245 if (flag)
1246 *flag |= REF_ISSYMREF;
a876ed83
JH
1247 continue;
1248 }
ca8db142 1249 }
a876ed83 1250
7a21632f
DS
1251 /* Is it a directory? */
1252 if (S_ISDIR(st.st_mode)) {
1253 errno = EISDIR;
1254 return NULL;
1255 }
1256
a876ed83
JH
1257 /*
1258 * Anything else, just open it and try to use it as
1259 * a ref
1260 */
1261 fd = open(path, O_RDONLY);
1262 if (fd < 0)
1263 return NULL;
93d26e4c 1264 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83 1265 close(fd);
28775050
MH
1266 if (len < 0)
1267 return NULL;
1268 while (len && isspace(buffer[len-1]))
1269 len--;
1270 buffer[len] = '\0';
a876ed83
JH
1271
1272 /*
1273 * Is it a symbolic ref?
1274 */
28775050 1275 if (prefixcmp(buffer, "ref:"))
a876ed83 1276 break;
55956350
JH
1277 if (flag)
1278 *flag |= REF_ISSYMREF;
a876ed83 1279 buf = buffer + 4;
28775050
MH
1280 while (isspace(*buf))
1281 buf++;
313fb010 1282 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1283 if (flag)
1284 *flag |= REF_ISBROKEN;
313fb010
MH
1285 return NULL;
1286 }
dfefa935 1287 refname = strcpy(refname_buffer, buf);
8a65ff76 1288 }
f989fea0
MH
1289 /* Please note that FETCH_HEAD has a second line containing other data. */
1290 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
55956350
JH
1291 if (flag)
1292 *flag |= REF_ISBROKEN;
a876ed83 1293 return NULL;
629cd3ac 1294 }
dfefa935 1295 return refname;
a876ed83
JH
1296}
1297
96ec7b1e
NTND
1298char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1299{
8cad4744 1300 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1301 return ret ? xstrdup(ret) : NULL;
1302}
1303
d08bae7e
IL
1304/* The argument to filter_refs */
1305struct ref_filter {
1306 const char *pattern;
1307 each_ref_fn *fn;
1308 void *cb_data;
1309};
1310
dfefa935 1311int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1312{
8d68493f 1313 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1314 return 0;
1315 return -1;
8a65ff76
LT
1316}
1317
dfefa935 1318int read_ref(const char *refname, unsigned char *sha1)
c6893323 1319{
dfefa935 1320 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1321}
1322
bc5fd6d3 1323int ref_exists(const char *refname)
ef06b918 1324{
bc5fd6d3
MH
1325 unsigned char sha1[20];
1326 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1327}
1328
85be1fe3 1329static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1330 void *data)
d08bae7e
IL
1331{
1332 struct ref_filter *filter = (struct ref_filter *)data;
dfefa935 1333 if (fnmatch(filter->pattern, refname, 0))
d08bae7e 1334 return 0;
85be1fe3 1335 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1336}
1337
68cf8703
MH
1338enum peel_status {
1339 /* object was peeled successfully: */
1340 PEEL_PEELED = 0,
1341
1342 /*
1343 * object cannot be peeled because the named object (or an
1344 * object referred to by a tag in the peel chain), does not
1345 * exist.
1346 */
1347 PEEL_INVALID = -1,
1348
1349 /* object cannot be peeled because it is not a tag: */
9a489f3c
MH
1350 PEEL_NON_TAG = -2,
1351
1352 /* ref_entry contains no peeled value because it is a symref: */
1353 PEEL_IS_SYMREF = -3,
1354
1355 /*
1356 * ref_entry cannot be peeled because it is broken (i.e., the
1357 * symbolic reference cannot even be resolved to an object
1358 * name):
1359 */
1360 PEEL_BROKEN = -4
68cf8703
MH
1361};
1362
cb2ae1c4
MH
1363/*
1364 * Peel the named object; i.e., if the object is a tag, resolve the
68cf8703
MH
1365 * tag recursively until a non-tag is found. If successful, store the
1366 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1367 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1368 * and leave sha1 unchanged.
cb2ae1c4 1369 */
68cf8703 1370static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
cb2ae1c4
MH
1371{
1372 struct object *o = lookup_unknown_object(name);
1373
1374 if (o->type == OBJ_NONE) {
1375 int type = sha1_object_info(name, NULL);
1376 if (type < 0)
68cf8703 1377 return PEEL_INVALID;
cb2ae1c4
MH
1378 o->type = type;
1379 }
1380
1381 if (o->type != OBJ_TAG)
68cf8703 1382 return PEEL_NON_TAG;
cb2ae1c4
MH
1383
1384 o = deref_tag_noverify(o);
1385 if (!o)
68cf8703 1386 return PEEL_INVALID;
cb2ae1c4
MH
1387
1388 hashcpy(sha1, o->sha1);
68cf8703 1389 return PEEL_PEELED;
cb2ae1c4
MH
1390}
1391
9a489f3c
MH
1392/*
1393 * Peel the entry (if possible) and return its new peel_status.
1394 */
1395static enum peel_status peel_entry(struct ref_entry *entry)
1396{
1397 enum peel_status status;
1398
1399 if (entry->flag & REF_KNOWS_PEELED)
1400 return is_null_sha1(entry->u.value.peeled) ?
1401 PEEL_NON_TAG : PEEL_PEELED;
1402 if (entry->flag & REF_ISBROKEN)
1403 return PEEL_BROKEN;
1404 if (entry->flag & REF_ISSYMREF)
1405 return PEEL_IS_SYMREF;
1406
1407 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1408 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1409 entry->flag |= REF_KNOWS_PEELED;
1410 return status;
1411}
1412
dfefa935 1413int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1414{
1415 int flag;
1416 unsigned char base[20];
cf0adba7 1417
dfefa935 1418 if (current_ref && (current_ref->name == refname
9a489f3c
MH
1419 || !strcmp(current_ref->name, refname))) {
1420 if (peel_entry(current_ref))
1421 return -1;
1422 hashcpy(sha1, current_ref->u.value.peeled);
1423 return 0;
0ae91be0
SP
1424 }
1425
dfefa935 1426 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1427 return -1;
1428
9a489f3c
MH
1429 /*
1430 * If the reference is packed, read its ref_entry from the
1431 * cache in the hope that we already know its peeled value.
1432 * We only try this optimization on packed references because
1433 * (a) forcing the filling of the loose reference cache could
1434 * be expensive and (b) loose references anyway usually do not
1435 * have REF_KNOWS_PEELED.
1436 */
1437 if (flag & REF_ISPACKED) {
f361baeb 1438 struct ref_entry *r = get_packed_ref(refname);
9a489f3c
MH
1439 if (r) {
1440 if (peel_entry(r))
1441 return -1;
593f1bb8 1442 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1443 return 0;
cf0adba7 1444 }
cf0adba7
JH
1445 }
1446
cb2ae1c4 1447 return peel_object(base, sha1);
cf0adba7
JH
1448}
1449
bc5fd6d3
MH
1450struct warn_if_dangling_data {
1451 FILE *fp;
1452 const char *refname;
1453 const char *msg_fmt;
1454};
1455
1456static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1457 int flags, void *cb_data)
1458{
1459 struct warn_if_dangling_data *d = cb_data;
1460 const char *resolves_to;
1461 unsigned char junk[20];
1462
1463 if (!(flags & REF_ISSYMREF))
1464 return 0;
1465
1466 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1467 if (!resolves_to || strcmp(resolves_to, d->refname))
1468 return 0;
1469
1470 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1471 fputc('\n', d->fp);
bc5fd6d3
MH
1472 return 0;
1473}
1474
1475void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1476{
1477 struct warn_if_dangling_data data;
1478
1479 data.fp = fp;
1480 data.refname = refname;
1481 data.msg_fmt = msg_fmt;
1482 for_each_rawref(warn_if_dangling_symref, &data);
1483}
1484
fcce1703 1485/*
624cac35
MH
1486 * Call fn for each reference in the specified submodule, omitting
1487 * references not in the containing_dir of base. fn is called for all
1488 * references, including broken ones. If fn ever returns a non-zero
fcce1703
MH
1489 * value, stop the iteration and return that value; otherwise, return
1490 * 0.
1491 */
624cac35
MH
1492static int do_for_each_entry(const char *submodule, const char *base,
1493 each_ref_entry_fn fn, void *cb_data)
8a65ff76 1494{
316b097a 1495 struct ref_cache *refs = get_ref_cache(submodule);
933ac036
MH
1496 struct ref_dir *packed_dir = get_packed_refs(refs);
1497 struct ref_dir *loose_dir = get_loose_refs(refs);
1498 int retval = 0;
1499
1500 if (base && *base) {
1501 packed_dir = find_containing_dir(packed_dir, base, 0);
1502 loose_dir = find_containing_dir(loose_dir, base, 0);
1503 }
1504
1505 if (packed_dir && loose_dir) {
1506 sort_ref_dir(packed_dir);
1507 sort_ref_dir(loose_dir);
624cac35
MH
1508 retval = do_for_each_entry_in_dirs(
1509 packed_dir, loose_dir, fn, cb_data);
933ac036
MH
1510 } else if (packed_dir) {
1511 sort_ref_dir(packed_dir);
624cac35
MH
1512 retval = do_for_each_entry_in_dir(
1513 packed_dir, 0, fn, cb_data);
933ac036
MH
1514 } else if (loose_dir) {
1515 sort_ref_dir(loose_dir);
624cac35
MH
1516 retval = do_for_each_entry_in_dir(
1517 loose_dir, 0, fn, cb_data);
933ac036
MH
1518 }
1519
1520 return retval;
8a65ff76
LT
1521}
1522
624cac35
MH
1523/*
1524 * Call fn for each reference in the specified submodule for which the
1525 * refname begins with base. If trim is non-zero, then trim that many
1526 * characters off the beginning of each refname before passing the
1527 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1528 * broken references in the iteration. If fn ever returns a non-zero
1529 * value, stop the iteration and return that value; otherwise, return
1530 * 0.
1531 */
1532static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
1533 int trim, int flags, void *cb_data)
1534{
1535 struct ref_entry_cb data;
1536 data.base = base;
1537 data.trim = trim;
1538 data.flags = flags;
1539 data.fn = fn;
1540 data.cb_data = cb_data;
1541
1542 return do_for_each_entry(submodule, base, do_one_ref, &data);
1543}
1544
0bad611b 1545static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1546{
1547 unsigned char sha1[20];
8da19775
JH
1548 int flag;
1549
0bad611b
HV
1550 if (submodule) {
1551 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1552 return fn("HEAD", sha1, 0, cb_data);
1553
1554 return 0;
1555 }
1556
c6893323 1557 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1558 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1559
2f34ba32 1560 return 0;
723c31fe
LT
1561}
1562
0bad611b
HV
1563int head_ref(each_ref_fn fn, void *cb_data)
1564{
1565 return do_head_ref(NULL, fn, cb_data);
1566}
1567
9ef6aeb0
HV
1568int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1569{
1570 return do_head_ref(submodule, fn, cb_data);
1571}
1572
cb5d709f 1573int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1574{
b3cfc406 1575 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
a62be77f
SE
1576}
1577
9ef6aeb0
HV
1578int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1579{
b3cfc406 1580 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
a62be77f
SE
1581}
1582
2a8177b6
CC
1583int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1584{
0bad611b 1585 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1586}
1587
9ef6aeb0
HV
1588int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1589 each_ref_fn fn, void *cb_data)
1590{
1591 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1592}
1593
cb5d709f 1594int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1595{
2a8177b6 1596 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1597}
1598
9ef6aeb0
HV
1599int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1600{
1601 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1602}
1603
cb5d709f 1604int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1605{
2a8177b6 1606 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1607}
1608
9ef6aeb0
HV
1609int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1610{
1611 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1612}
1613
cb5d709f 1614int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1615{
2a8177b6 1616 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1617}
1618
9ef6aeb0
HV
1619int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1620{
1621 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1622}
1623
29268700
CC
1624int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1625{
0bad611b 1626 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1627}
1628
a1bea2c1
JT
1629int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1630{
1631 struct strbuf buf = STRBUF_INIT;
1632 int ret = 0;
1633 unsigned char sha1[20];
1634 int flag;
1635
1636 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1637 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1638 ret = fn(buf.buf, sha1, flag, cb_data);
1639 strbuf_release(&buf);
1640
1641 return ret;
1642}
1643
1644int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1645{
1646 struct strbuf buf = STRBUF_INIT;
1647 int ret;
1648 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1649 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1650 strbuf_release(&buf);
1651 return ret;
1652}
1653
b09fe971
IL
1654int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1655 const char *prefix, void *cb_data)
d08bae7e
IL
1656{
1657 struct strbuf real_pattern = STRBUF_INIT;
1658 struct ref_filter filter;
d08bae7e
IL
1659 int ret;
1660
b09fe971 1661 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 1662 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1663 else if (prefix)
1664 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1665 strbuf_addstr(&real_pattern, pattern);
1666
894a9d33 1667 if (!has_glob_specials(pattern)) {
9517e6b8 1668 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1669 if (real_pattern.buf[real_pattern.len - 1] != '/')
1670 strbuf_addch(&real_pattern, '/');
1671 /* No need to check for '*', there is none. */
1672 strbuf_addch(&real_pattern, '*');
1673 }
1674
1675 filter.pattern = real_pattern.buf;
1676 filter.fn = fn;
1677 filter.cb_data = cb_data;
1678 ret = for_each_ref(filter_refs, &filter);
1679
1680 strbuf_release(&real_pattern);
1681 return ret;
1682}
1683
b09fe971
IL
1684int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1685{
1686 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1687}
1688
f8948e2f
JH
1689int for_each_rawref(each_ref_fn fn, void *cb_data)
1690{
b3cfc406 1691 return do_for_each_ref(NULL, "", fn, 0,
f8948e2f 1692 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1693}
1694
4577e483 1695const char *prettify_refname(const char *name)
a9c37a72 1696{
a9c37a72
DB
1697 return name + (
1698 !prefixcmp(name, "refs/heads/") ? 11 :
1699 !prefixcmp(name, "refs/tags/") ? 10 :
1700 !prefixcmp(name, "refs/remotes/") ? 13 :
1701 0);
1702}
1703
79803322
SP
1704const char *ref_rev_parse_rules[] = {
1705 "%.*s",
1706 "refs/%.*s",
1707 "refs/tags/%.*s",
1708 "refs/heads/%.*s",
1709 "refs/remotes/%.*s",
1710 "refs/remotes/%.*s/HEAD",
1711 NULL
1712};
1713
1714int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1715{
1716 const char **p;
1717 const int abbrev_name_len = strlen(abbrev_name);
1718
1719 for (p = rules; *p; p++) {
1720 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1721 return 1;
1722 }
1723 }
1724
1725 return 0;
1726}
1727
e5f38ec3 1728static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1729 const unsigned char *old_sha1, int mustexist)
1730{
c6893323 1731 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1732 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1733 unlock_ref(lock);
1734 return NULL;
1735 }
a89fccd2 1736 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1737 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1738 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1739 unlock_ref(lock);
1740 return NULL;
1741 }
1742 return lock;
1743}
1744
7155b727 1745static int remove_empty_directories(const char *file)
bc7127ef
JH
1746{
1747 /* we want to create a file but there is a directory there;
1748 * if that is an empty directory (or a directory that contains
1749 * only empty directories), remove them.
1750 */
7155b727
JS
1751 struct strbuf path;
1752 int result;
bc7127ef 1753
7155b727
JS
1754 strbuf_init(&path, 20);
1755 strbuf_addstr(&path, file);
1756
a0f4afbe 1757 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1758
1759 strbuf_release(&path);
1760
1761 return result;
bc7127ef
JH
1762}
1763
ff74f7f1
JH
1764/*
1765 * *string and *len will only be substituted, and *string returned (for
1766 * later free()ing) if the string passed in is a magic short-hand form
1767 * to name a branch.
1768 */
1769static char *substitute_branch_name(const char **string, int *len)
1770{
1771 struct strbuf buf = STRBUF_INIT;
1772 int ret = interpret_branch_name(*string, &buf);
1773
1774 if (ret == *len) {
1775 size_t size;
1776 *string = strbuf_detach(&buf, &size);
1777 *len = size;
1778 return (char *)*string;
1779 }
1780
1781 return NULL;
1782}
1783
1784int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1785{
1786 char *last_branch = substitute_branch_name(&str, &len);
1787 const char **p, *r;
1788 int refs_found = 0;
1789
1790 *ref = NULL;
1791 for (p = ref_rev_parse_rules; *p; p++) {
1792 char fullref[PATH_MAX];
1793 unsigned char sha1_from_ref[20];
1794 unsigned char *this_result;
1795 int flag;
1796
1797 this_result = refs_found ? sha1_from_ref : sha1;
1798 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1799 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1800 if (r) {
1801 if (!refs_found++)
1802 *ref = xstrdup(r);
1803 if (!warn_ambiguous_refs)
1804 break;
55956350 1805 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1806 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1807 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1808 warning("ignoring broken ref %s.", fullref);
1809 }
ff74f7f1
JH
1810 }
1811 free(last_branch);
1812 return refs_found;
1813}
1814
1815int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1816{
1817 char *last_branch = substitute_branch_name(&str, &len);
1818 const char **p;
1819 int logs_found = 0;
1820
1821 *log = NULL;
1822 for (p = ref_rev_parse_rules; *p; p++) {
1823 struct stat st;
1824 unsigned char hash[20];
1825 char path[PATH_MAX];
1826 const char *ref, *it;
1827
1828 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 1829 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
1830 if (!ref)
1831 continue;
1832 if (!stat(git_path("logs/%s", path), &st) &&
1833 S_ISREG(st.st_mode))
1834 it = path;
1835 else if (strcmp(ref, path) &&
1836 !stat(git_path("logs/%s", ref), &st) &&
1837 S_ISREG(st.st_mode))
1838 it = ref;
1839 else
1840 continue;
1841 if (!logs_found++) {
1842 *log = xstrdup(it);
1843 hashcpy(sha1, hash);
1844 }
1845 if (!warn_ambiguous_refs)
1846 break;
1847 }
1848 free(last_branch);
1849 return logs_found;
1850}
1851
dfefa935
MH
1852static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1853 const unsigned char *old_sha1,
1854 int flags, int *type_p)
4bd18c43 1855{
434cd0cd 1856 char *ref_file;
dfefa935 1857 const char *orig_refname = refname;
4bd18c43 1858 struct ref_lock *lock;
5cc3cef9 1859 int last_errno = 0;
acd3b9ec 1860 int type, lflags;
4431fcc4 1861 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1862 int missing = 0;
4bd18c43
SP
1863
1864 lock = xcalloc(1, sizeof(struct ref_lock));
1865 lock->lock_fd = -1;
1866
8d68493f 1867 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 1868 if (!refname && errno == EISDIR) {
bc7127ef
JH
1869 /* we are trying to lock foo but we used to
1870 * have foo/bar which now does not exist;
1871 * it is normal for the empty directory 'foo'
1872 * to remain.
1873 */
dfefa935 1874 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
1875 if (remove_empty_directories(ref_file)) {
1876 last_errno = errno;
dfefa935 1877 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
1878 goto error_return;
1879 }
8d68493f 1880 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 1881 }
68db31cc
SV
1882 if (type_p)
1883 *type_p = type;
dfefa935 1884 if (!refname) {
5cc3cef9 1885 last_errno = errno;
818f477c 1886 error("unable to resolve reference %s: %s",
dfefa935 1887 orig_refname, strerror(errno));
5cc3cef9 1888 goto error_return;
4bd18c43 1889 }
5bdd8d4a 1890 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1891 /* When the ref did not exist and we are creating it,
1892 * make sure there is no existing ref that is packed
1893 * whose name begins with our refname, nor a ref whose
1894 * name is a proper prefix of our refname.
1895 */
5bdd8d4a 1896 if (missing &&
316b097a 1897 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
f475e08e 1898 last_errno = ENOTDIR;
c976d415 1899 goto error_return;
f475e08e 1900 }
22a3844e 1901
c33d5174 1902 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1903
acd3b9ec
JH
1904 lflags = LOCK_DIE_ON_ERROR;
1905 if (flags & REF_NODEREF) {
dfefa935 1906 refname = orig_refname;
acd3b9ec
JH
1907 lflags |= LOCK_NODEREF;
1908 }
dfefa935
MH
1909 lock->ref_name = xstrdup(refname);
1910 lock->orig_ref_name = xstrdup(orig_refname);
1911 ref_file = git_path("%s", refname);
5bdd8d4a 1912 if (missing)
68db31cc
SV
1913 lock->force_write = 1;
1914 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1915 lock->force_write = 1;
4bd18c43 1916
5cc3cef9
JH
1917 if (safe_create_leading_directories(ref_file)) {
1918 last_errno = errno;
1919 error("unable to create directory for %s", ref_file);
1920 goto error_return;
1921 }
4bd18c43 1922
acd3b9ec 1923 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1924 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1925
1926 error_return:
1927 unlock_ref(lock);
1928 errno = last_errno;
1929 return NULL;
4bd18c43
SP
1930}
1931
dfefa935 1932struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 1933{
53cce84c 1934 char refpath[PATH_MAX];
dfefa935 1935 if (check_refname_format(refname, 0))
4bd18c43 1936 return NULL;
dfefa935 1937 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 1938 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1939}
1940
dfefa935
MH
1941struct ref_lock *lock_any_ref_for_update(const char *refname,
1942 const unsigned char *old_sha1, int flags)
4bd18c43 1943{
dfefa935 1944 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 1945 return NULL;
dfefa935 1946 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
c0277d15
JH
1947}
1948
506a760d 1949static int repack_ref_fn(struct ref_entry *entry, void *cb_data)
d66da478 1950{
506a760d 1951 int *fd = cb_data;
d66da478
MH
1952 char line[PATH_MAX + 100];
1953 int len;
1954
ab292bc4
MH
1955 if (entry->flag & REF_ISBROKEN) {
1956 /* This shouldn't happen to packed refs. */
1957 error("%s is broken!", entry->name);
1958 return 0;
1959 }
1960 if (!has_sha1_file(entry->u.value.sha1)) {
1961 unsigned char sha1[20];
1962 int flags;
1963
1964 if (read_ref_full(entry->name, sha1, 0, &flags))
1965 /* We should at least have found the packed ref. */
1966 die("Internal error");
1967 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED))
1968 /*
1969 * This packed reference is overridden by a
1970 * loose reference, so it is OK that its value
1971 * is no longer valid; for example, it might
1972 * refer to an object that has been garbage
1973 * collected. For this purpose we don't even
1974 * care whether the loose reference itself is
1975 * invalid, broken, symbolic, etc. Silently
1976 * omit the packed reference from the output.
1977 */
1978 return 0;
1979 /*
1980 * There is no overriding loose reference, so the fact
1981 * that this reference doesn't refer to a valid object
1982 * indicates some kind of repository corruption.
1983 * Report the problem, then omit the reference from
1984 * the output.
1985 */
1986 error("%s does not point to a valid object!", entry->name);
1987 return 0;
1988 }
1989
d66da478 1990 len = snprintf(line, sizeof(line), "%s %s\n",
624cac35 1991 sha1_to_hex(entry->u.value.sha1), entry->name);
d66da478
MH
1992 /* this should not happen but just being defensive */
1993 if (len > sizeof(line))
624cac35 1994 die("too long a refname '%s'", entry->name);
506a760d 1995 write_or_die(*fd, line, len);
d66da478
MH
1996 return 0;
1997}
1998
26a063a1
JH
1999static struct lock_file packlock;
2000
c0277d15
JH
2001static int repack_without_ref(const char *refname)
2002{
506a760d 2003 int fd;
b3f1280e 2004 struct ref_cache *refs = get_ref_cache(NULL);
7618fd80
MH
2005 struct ref_dir *packed;
2006
2007 if (!get_packed_ref(refname))
2008 return 0; /* refname does not exist in packed refs */
2009
506a760d
MH
2010 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
2011 if (fd < 0) {
1b018fd9 2012 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 2013 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 2014 }
b3f1280e
JK
2015 clear_packed_ref_cache(refs);
2016 packed = get_packed_refs(refs);
506a760d
MH
2017 /* Remove refname from the cache. */
2018 if (remove_entry(packed, refname) == -1) {
2019 /*
2020 * The packed entry disappeared while we were
2021 * acquiring the lock.
2022 */
2023 rollback_lock_file(&packlock);
2024 return 0;
2025 }
2026 do_for_each_entry_in_dir(packed, 0, repack_ref_fn, &fd);
c0277d15
JH
2027 return commit_lock_file(&packlock);
2028}
2029
eca35a25 2030int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
2031{
2032 struct ref_lock *lock;
eca35a25 2033 int err, i = 0, ret = 0, flag = 0;
c0277d15 2034
547d058f 2035 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
2036 if (!lock)
2037 return 1;
045a476f 2038 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 2039 /* loose */
547d058f
RS
2040 i = strlen(lock->lk->filename) - 5; /* .lock */
2041 lock->lk->filename[i] = 0;
2042 err = unlink_or_warn(lock->lk->filename);
691f1a28 2043 if (err && errno != ENOENT)
c0277d15 2044 ret = 1;
691f1a28 2045
547d058f 2046 lock->lk->filename[i] = '.';
c0277d15
JH
2047 }
2048 /* removing the loose one could have resurrected an earlier
2049 * packed one. Also, if it was not loose we need to repack
2050 * without it.
2051 */
b274a714 2052 ret |= repack_without_ref(lock->ref_name);
c0277d15 2053
691f1a28 2054 unlink_or_warn(git_path("logs/%s", lock->ref_name));
506a760d 2055 clear_loose_ref_cache(get_ref_cache(NULL));
c0277d15
JH
2056 unlock_ref(lock);
2057 return ret;
4bd18c43
SP
2058}
2059
765c2258
PH
2060/*
2061 * People using contrib's git-new-workdir have .git/logs/refs ->
2062 * /some/other/path/.git/logs/refs, and that may live on another device.
2063 *
2064 * IOW, to avoid cross device rename errors, the temporary renamed log must
2065 * live into logs/refs.
2066 */
2067#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2068
dfefa935 2069int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 2070{
c976d415
LH
2071 unsigned char sha1[20], orig_sha1[20];
2072 int flag = 0, logmoved = 0;
2073 struct ref_lock *lock;
c976d415 2074 struct stat loginfo;
dfefa935 2075 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 2076 const char *symref = NULL;
316b097a 2077 struct ref_cache *refs = get_ref_cache(NULL);
c976d415 2078
450d4c0f 2079 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 2080 return error("reflog for %s is a symlink", oldrefname);
c976d415 2081
8d68493f 2082 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 2083 if (flag & REF_ISSYMREF)
fa58186c 2084 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 2085 oldrefname);
eca35a25 2086 if (!symref)
dfefa935 2087 return error("refname %s not found", oldrefname);
c976d415 2088
316b097a 2089 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
c976d415
LH
2090 return 1;
2091
316b097a 2092 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
c976d415
LH
2093 return 1;
2094
dfefa935 2095 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 2096 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 2097 oldrefname, strerror(errno));
c976d415 2098
dfefa935
MH
2099 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2100 error("unable to delete old %s", oldrefname);
c976d415
LH
2101 goto rollback;
2102 }
2103
dfefa935
MH
2104 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2105 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 2106 if (errno==EISDIR) {
dfefa935
MH
2107 if (remove_empty_directories(git_path("%s", newrefname))) {
2108 error("Directory not empty: %s", newrefname);
c976d415
LH
2109 goto rollback;
2110 }
2111 } else {
dfefa935 2112 error("unable to delete existing %s", newrefname);
c976d415
LH
2113 goto rollback;
2114 }
2115 }
2116
dfefa935
MH
2117 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2118 error("unable to create directory for %s", newrefname);
c976d415
LH
2119 goto rollback;
2120 }
2121
2122 retry:
dfefa935 2123 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
d9e74d57
JR
2124 if (errno==EISDIR || errno==ENOTDIR) {
2125 /*
2126 * rename(a, b) when b is an existing
2127 * directory ought to result in ISDIR, but
2128 * Solaris 5.8 gives ENOTDIR. Sheesh.
2129 */
dfefa935
MH
2130 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2131 error("Directory not empty: logs/%s", newrefname);
c976d415
LH
2132 goto rollback;
2133 }
2134 goto retry;
2135 } else {
765c2258 2136 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
dfefa935 2137 newrefname, strerror(errno));
c976d415
LH
2138 goto rollback;
2139 }
2140 }
2141 logmoved = log;
2142
dfefa935 2143 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2144 if (!lock) {
dfefa935 2145 error("unable to lock %s for update", newrefname);
c976d415
LH
2146 goto rollback;
2147 }
c976d415
LH
2148 lock->force_write = 1;
2149 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2150 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2151 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2152 goto rollback;
2153 }
2154
2155 return 0;
2156
2157 rollback:
dfefa935 2158 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2159 if (!lock) {
dfefa935 2160 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2161 goto rollbacklog;
2162 }
2163
2164 lock->force_write = 1;
2165 flag = log_all_ref_updates;
2166 log_all_ref_updates = 0;
2167 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2168 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2169 log_all_ref_updates = flag;
2170
2171 rollbacklog:
dfefa935 2172 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2173 error("unable to restore logfile %s from %s: %s",
dfefa935 2174 oldrefname, newrefname, strerror(errno));
c976d415 2175 if (!logmoved && log &&
dfefa935 2176 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2177 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2178 oldrefname, strerror(errno));
c976d415
LH
2179
2180 return 1;
2181}
2182
435fc852 2183int close_ref(struct ref_lock *lock)
b531394d
BC
2184{
2185 if (close_lock_file(lock->lk))
2186 return -1;
2187 lock->lock_fd = -1;
2188 return 0;
2189}
2190
435fc852 2191int commit_ref(struct ref_lock *lock)
b531394d
BC
2192{
2193 if (commit_lock_file(lock->lk))
2194 return -1;
2195 lock->lock_fd = -1;
2196 return 0;
2197}
2198
e5f38ec3 2199void unlock_ref(struct ref_lock *lock)
4bd18c43 2200{
4ed7cd3a
BC
2201 /* Do not free lock->lk -- atexit() still looks at them */
2202 if (lock->lk)
2203 rollback_lock_file(lock->lk);
434cd0cd 2204 free(lock->ref_name);
1655707c 2205 free(lock->orig_ref_name);
4bd18c43
SP
2206 free(lock);
2207}
2208
0ec29a47
JH
2209/*
2210 * copy the reflog message msg to buf, which has been allocated sufficiently
2211 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2212 * because reflog file is one line per entry.
2213 */
2214static int copy_msg(char *buf, const char *msg)
2215{
2216 char *cp = buf;
2217 char c;
2218 int wasspace = 1;
2219
2220 *cp++ = '\t';
2221 while ((c = *msg++)) {
2222 if (wasspace && isspace(c))
2223 continue;
2224 wasspace = isspace(c);
2225 if (wasspace)
2226 c = ' ';
2227 *cp++ = c;
2228 }
2229 while (buf < cp && isspace(cp[-1]))
2230 cp--;
2231 *cp++ = '\n';
2232 return cp - buf;
2233}
2234
dfefa935 2235int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2236{
859c3017 2237 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2238
dfefa935 2239 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2240 if (log_all_ref_updates &&
dfefa935
MH
2241 (!prefixcmp(refname, "refs/heads/") ||
2242 !prefixcmp(refname, "refs/remotes/") ||
2243 !prefixcmp(refname, "refs/notes/") ||
2244 !strcmp(refname, "HEAD"))) {
157aaea5 2245 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2246 return error("unable to create directory for %s",
157aaea5 2247 logfile);
6de08ae6
SP
2248 oflags |= O_CREAT;
2249 }
2250
157aaea5 2251 logfd = open(logfile, oflags, 0666);
6de08ae6 2252 if (logfd < 0) {
1974bf62 2253 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2254 return 0;
3b463c3f
JH
2255
2256 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2257 if (remove_empty_directories(logfile)) {
3b463c3f 2258 return error("There are still logs under '%s'",
157aaea5 2259 logfile);
3b463c3f 2260 }
157aaea5 2261 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2262 }
2263
2264 if (logfd < 0)
2265 return error("Unable to append to %s: %s",
157aaea5 2266 logfile, strerror(errno));
6de08ae6
SP
2267 }
2268
157aaea5 2269 adjust_shared_perm(logfile);
859c3017
EM
2270 close(logfd);
2271 return 0;
2272}
443b92b6 2273
dfefa935 2274static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2275 const unsigned char *new_sha1, const char *msg)
2276{
2277 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2278 unsigned maxlen, len;
2279 int msglen;
157aaea5 2280 char log_file[PATH_MAX];
859c3017
EM
2281 char *logrec;
2282 const char *committer;
2283
2284 if (log_all_ref_updates < 0)
2285 log_all_ref_updates = !is_bare_repository();
2286
dfefa935 2287 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2288 if (result)
2289 return result;
2290
2291 logfd = open(log_file, oflags);
2292 if (logfd < 0)
2293 return 0;
0ec29a47 2294 msglen = msg ? strlen(msg) : 0;
774751a8 2295 committer = git_committer_info(0);
8ac65937
JH
2296 maxlen = strlen(committer) + msglen + 100;
2297 logrec = xmalloc(maxlen);
2298 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2299 sha1_to_hex(old_sha1),
2300 sha1_to_hex(new_sha1),
8ac65937
JH
2301 committer);
2302 if (msglen)
0ec29a47 2303 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2304 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2305 free(logrec);
91c8d590 2306 if (close(logfd) != 0 || written != len)
9a13f0b7 2307 return error("Unable to append to %s", log_file);
6de08ae6
SP
2308 return 0;
2309}
2310
c3b0dec5
LT
2311static int is_branch(const char *refname)
2312{
2313 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2314}
2315
4bd18c43
SP
2316int write_ref_sha1(struct ref_lock *lock,
2317 const unsigned char *sha1, const char *logmsg)
2318{
2319 static char term = '\n';
c3b0dec5 2320 struct object *o;
4bd18c43
SP
2321
2322 if (!lock)
95fc7512 2323 return -1;
a89fccd2 2324 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2325 unlock_ref(lock);
2326 return 0;
95fc7512 2327 }
c3b0dec5
LT
2328 o = parse_object(sha1);
2329 if (!o) {
7be8b3ba 2330 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2331 lock->ref_name, sha1_to_hex(sha1));
2332 unlock_ref(lock);
2333 return -1;
2334 }
2335 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2336 error("Trying to write non-commit object %s to branch %s",
2337 sha1_to_hex(sha1), lock->ref_name);
2338 unlock_ref(lock);
2339 return -1;
2340 }
93822c22
AW
2341 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2342 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2343 || close_ref(lock) < 0) {
c33d5174 2344 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2345 unlock_ref(lock);
2346 return -1;
2347 }
8bf90dc9 2348 clear_loose_ref_cache(get_ref_cache(NULL));
bd104db1
NP
2349 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2350 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2351 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2352 unlock_ref(lock);
2353 return -1;
2354 }
605fac8b
NP
2355 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2356 /*
2357 * Special hack: If a branch is updated directly and HEAD
2358 * points to it (may happen on the remote side of a push
2359 * for example) then logically the HEAD reflog should be
2360 * updated too.
2361 * A generic solution implies reverse symref information,
2362 * but finding all symrefs pointing to the given branch
2363 * would be rather costly for this rare event (the direct
2364 * update of a branch) to be worth it. So let's cheat and
2365 * check with HEAD only which should cover 99% of all usage
2366 * scenarios (even 100% of the default ones).
2367 */
2368 unsigned char head_sha1[20];
2369 int head_flag;
2370 const char *head_ref;
8cad4744 2371 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2372 if (head_ref && (head_flag & REF_ISSYMREF) &&
2373 !strcmp(head_ref, lock->ref_name))
2374 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2375 }
b531394d 2376 if (commit_ref(lock)) {
434cd0cd 2377 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2378 unlock_ref(lock);
2379 return -1;
2380 }
4bd18c43
SP
2381 unlock_ref(lock);
2382 return 0;
95fc7512 2383}
d556fae2 2384
8b5157e4
NP
2385int create_symref(const char *ref_target, const char *refs_heads_master,
2386 const char *logmsg)
41b625b0
NP
2387{
2388 const char *lockpath;
2389 char ref[1000];
2390 int fd, len, written;
a4f34cbb 2391 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2392 unsigned char old_sha1[20], new_sha1[20];
2393
2394 if (logmsg && read_ref(ref_target, old_sha1))
2395 hashclr(old_sha1);
41b625b0 2396
d48744d1
JH
2397 if (safe_create_leading_directories(git_HEAD) < 0)
2398 return error("unable to create directory for %s", git_HEAD);
2399
41b625b0
NP
2400#ifndef NO_SYMLINK_HEAD
2401 if (prefer_symlink_refs) {
2402 unlink(git_HEAD);
2403 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2404 goto done;
41b625b0
NP
2405 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2406 }
2407#endif
2408
2409 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2410 if (sizeof(ref) <= len) {
2411 error("refname too long: %s", refs_heads_master);
47fc52e2 2412 goto error_free_return;
41b625b0
NP
2413 }
2414 lockpath = mkpath("%s.lock", git_HEAD);
2415 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2416 if (fd < 0) {
2417 error("Unable to open %s for writing", lockpath);
47fc52e2 2418 goto error_free_return;
41b625b0
NP
2419 }
2420 written = write_in_full(fd, ref, len);
91c8d590 2421 if (close(fd) != 0 || written != len) {
41b625b0 2422 error("Unable to write to %s", lockpath);
47fc52e2 2423 goto error_unlink_return;
41b625b0
NP
2424 }
2425 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2426 error("Unable to create %s", git_HEAD);
47fc52e2 2427 goto error_unlink_return;
41b625b0
NP
2428 }
2429 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2430 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2431 error_unlink_return:
691f1a28 2432 unlink_or_warn(lockpath);
47fc52e2
JH
2433 error_free_return:
2434 free(git_HEAD);
2435 return -1;
41b625b0 2436 }
8b5157e4 2437
ee96d11b 2438#ifndef NO_SYMLINK_HEAD
8b5157e4 2439 done:
ee96d11b 2440#endif
8b5157e4
NP
2441 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2442 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2443
47fc52e2 2444 free(git_HEAD);
41b625b0
NP
2445 return 0;
2446}
2447
16d7cc90
JH
2448static char *ref_msg(const char *line, const char *endp)
2449{
2450 const char *ep;
16d7cc90 2451 line += 82;
182af834
PH
2452 ep = memchr(line, '\n', endp - line);
2453 if (!ep)
2454 ep = endp;
2455 return xmemdupz(line, ep - line);
16d7cc90
JH
2456}
2457
dfefa935
MH
2458int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2459 unsigned char *sha1, char **msg,
2460 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2461{
e5229042 2462 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2463 char *tz_c;
e29cb53a 2464 int logfd, tz, reccnt = 0;
d556fae2
SP
2465 struct stat st;
2466 unsigned long date;
e5229042 2467 unsigned char logged_sha1[20];
cb48cb58 2468 void *log_mapped;
dc49cd76 2469 size_t mapsz;
d556fae2 2470
dfefa935 2471 logfile = git_path("logs/%s", refname);
d556fae2
SP
2472 logfd = open(logfile, O_RDONLY, 0);
2473 if (logfd < 0)
d824cbba 2474 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2475 fstat(logfd, &st);
2476 if (!st.st_size)
2477 die("Log %s is empty.", logfile);
dc49cd76
SP
2478 mapsz = xsize_t(st.st_size);
2479 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2480 logdata = log_mapped;
d556fae2
SP
2481 close(logfd);
2482
e5229042 2483 lastrec = NULL;
d556fae2
SP
2484 rec = logend = logdata + st.st_size;
2485 while (logdata < rec) {
e29cb53a 2486 reccnt++;
d556fae2
SP
2487 if (logdata < rec && *(rec-1) == '\n')
2488 rec--;
e5229042
SP
2489 lastgt = NULL;
2490 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2491 rec--;
e5229042
SP
2492 if (*rec == '>')
2493 lastgt = rec;
2494 }
2495 if (!lastgt)
d556fae2 2496 die("Log %s is corrupt.", logfile);
e5229042 2497 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2498 if (date <= at_time || cnt == 0) {
76a44c5c 2499 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2500 if (msg)
2501 *msg = ref_msg(rec, logend);
2502 if (cutoff_time)
2503 *cutoff_time = date;
2504 if (cutoff_tz)
2505 *cutoff_tz = tz;
2506 if (cutoff_cnt)
76a44c5c 2507 *cutoff_cnt = reccnt - 1;
e5229042
SP
2508 if (lastrec) {
2509 if (get_sha1_hex(lastrec, logged_sha1))
2510 die("Log %s is corrupt.", logfile);
2511 if (get_sha1_hex(rec + 41, sha1))
2512 die("Log %s is corrupt.", logfile);
a89fccd2 2513 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2514 warning("Log %s has gap after %s.",
73013afd 2515 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 2516 }
e5f38ec3
JH
2517 }
2518 else if (date == at_time) {
e5229042
SP
2519 if (get_sha1_hex(rec + 41, sha1))
2520 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
2521 }
2522 else {
e5229042
SP
2523 if (get_sha1_hex(rec + 41, logged_sha1))
2524 die("Log %s is corrupt.", logfile);
a89fccd2 2525 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2526 warning("Log %s unexpectedly ended on %s.",
73013afd 2527 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
2528 }
2529 }
dc49cd76 2530 munmap(log_mapped, mapsz);
d556fae2
SP
2531 return 0;
2532 }
e5229042 2533 lastrec = rec;
ab2a1a32
JH
2534 if (cnt > 0)
2535 cnt--;
d556fae2
SP
2536 }
2537
e5229042
SP
2538 rec = logdata;
2539 while (rec < logend && *rec != '>' && *rec != '\n')
2540 rec++;
2541 if (rec == logend || *rec == '\n')
d556fae2 2542 die("Log %s is corrupt.", logfile);
e5229042 2543 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
2544 tz = strtoul(tz_c, NULL, 10);
2545 if (get_sha1_hex(logdata, sha1))
2546 die("Log %s is corrupt.", logfile);
d1a4489a
JK
2547 if (is_null_sha1(sha1)) {
2548 if (get_sha1_hex(logdata + 41, sha1))
2549 die("Log %s is corrupt.", logfile);
2550 }
16d7cc90
JH
2551 if (msg)
2552 *msg = ref_msg(logdata, logend);
dc49cd76 2553 munmap(log_mapped, mapsz);
16d7cc90
JH
2554
2555 if (cutoff_time)
2556 *cutoff_time = date;
2557 if (cutoff_tz)
2558 *cutoff_tz = tz;
2559 if (cutoff_cnt)
2560 *cutoff_cnt = reccnt;
2561 return 1;
d556fae2 2562}
2ff81662 2563
dfefa935 2564int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
2565{
2566 const char *logfile;
2567 FILE *logfp;
8ca78803 2568 struct strbuf sb = STRBUF_INIT;
2266bf27 2569 int ret = 0;
2ff81662 2570
dfefa935 2571 logfile = git_path("logs/%s", refname);
2ff81662
JH
2572 logfp = fopen(logfile, "r");
2573 if (!logfp)
883d60fa 2574 return -1;
101d15e0
JH
2575
2576 if (ofs) {
2577 struct stat statbuf;
2578 if (fstat(fileno(logfp), &statbuf) ||
2579 statbuf.st_size < ofs ||
2580 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 2581 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 2582 fclose(logfp);
8ca78803 2583 strbuf_release(&sb);
101d15e0 2584 return -1;
9d33f7c2 2585 }
101d15e0
JH
2586 }
2587
8ca78803 2588 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 2589 unsigned char osha1[20], nsha1[20];
883d60fa
JS
2590 char *email_end, *message;
2591 unsigned long timestamp;
8ca78803 2592 int tz;
2ff81662
JH
2593
2594 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
2595 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
2596 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
2597 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
2598 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
2599 email_end[1] != ' ' ||
2600 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2601 !message || message[0] != ' ' ||
2602 (message[1] != '+' && message[1] != '-') ||
2603 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 2604 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 2605 continue; /* corrupt? */
883d60fa
JS
2606 email_end[1] = '\0';
2607 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
2608 if (message[6] != '\t')
2609 message += 6;
2610 else
2611 message += 7;
8ca78803
RS
2612 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
2613 cb_data);
883d60fa 2614 if (ret)
2266bf27 2615 break;
2ff81662
JH
2616 }
2617 fclose(logfp);
8ca78803 2618 strbuf_release(&sb);
2266bf27 2619 return ret;
2ff81662 2620}
e29cb53a 2621
dfefa935 2622int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 2623{
dfefa935 2624 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
101d15e0
JH
2625}
2626
989c0e5d
MH
2627/*
2628 * Call fn for each reflog in the namespace indicated by name. name
2629 * must be empty or end with '/'. Name will be used as a scratch
2630 * space, but its contents will be restored before return.
2631 */
2632static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 2633{
989c0e5d 2634 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 2635 int retval = 0;
93c603fc 2636 struct dirent *de;
989c0e5d 2637 int oldlen = name->len;
eb8381c8 2638
93c603fc 2639 if (!d)
989c0e5d 2640 return name->len ? errno : 0;
eb8381c8 2641
93c603fc
MH
2642 while ((de = readdir(d)) != NULL) {
2643 struct stat st;
eb8381c8 2644
93c603fc
MH
2645 if (de->d_name[0] == '.')
2646 continue;
93c603fc
MH
2647 if (has_extension(de->d_name, ".lock"))
2648 continue;
989c0e5d
MH
2649 strbuf_addstr(name, de->d_name);
2650 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2651 ; /* silently ignore */
93c603fc 2652 } else {
eb8381c8 2653 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
2654 strbuf_addch(name, '/');
2655 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
2656 } else {
2657 unsigned char sha1[20];
989c0e5d
MH
2658 if (read_ref_full(name->buf, sha1, 0, NULL))
2659 retval = error("bad ref for %s", name->buf);
eb8381c8 2660 else
989c0e5d 2661 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
2662 }
2663 if (retval)
2664 break;
2665 }
989c0e5d 2666 strbuf_setlen(name, oldlen);
eb8381c8 2667 }
93c603fc 2668 closedir(d);
eb8381c8
NP
2669 return retval;
2670}
2671
2672int for_each_reflog(each_ref_fn fn, void *cb_data)
2673{
989c0e5d
MH
2674 int retval;
2675 struct strbuf name;
2676 strbuf_init(&name, PATH_MAX);
2677 retval = do_for_each_reflog(&name, fn, cb_data);
2678 strbuf_release(&name);
2679 return retval;
eb8381c8 2680}
3d9f037c
CR
2681
2682int update_ref(const char *action, const char *refname,
2683 const unsigned char *sha1, const unsigned char *oldval,
2684 int flags, enum action_on_err onerr)
2685{
2686 static struct ref_lock *lock;
2687 lock = lock_any_ref_for_update(refname, oldval, flags);
2688 if (!lock) {
2689 const char *str = "Cannot lock the ref '%s'.";
2690 switch (onerr) {
2691 case MSG_ON_ERR: error(str, refname); break;
2692 case DIE_ON_ERR: die(str, refname); break;
2693 case QUIET_ON_ERR: break;
2694 }
2695 return 1;
2696 }
2697 if (write_ref_sha1(lock, sha1, action) < 0) {
2698 const char *str = "Cannot update the ref '%s'.";
2699 switch (onerr) {
2700 case MSG_ON_ERR: error(str, refname); break;
2701 case DIE_ON_ERR: die(str, refname); break;
2702 case QUIET_ON_ERR: break;
2703 }
2704 return 1;
2705 }
2706 return 0;
2707}
cda69f48 2708
5483f799 2709struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
2710{
2711 for ( ; list; list = list->next)
2712 if (!strcmp(list->name, name))
5483f799 2713 return (struct ref *)list;
cda69f48
JK
2714 return NULL;
2715}
7c2b3029
JK
2716
2717/*
2718 * generate a format suitable for scanf from a ref_rev_parse_rules
2719 * rule, that is replace the "%.*s" spec with a "%s" spec
2720 */
2721static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2722{
2723 char *spec;
2724
2725 spec = strstr(rule, "%.*s");
2726 if (!spec || strstr(spec + 4, "%.*s"))
2727 die("invalid rule in ref_rev_parse_rules: %s", rule);
2728
2729 /* copy all until spec */
2730 strncpy(scanf_fmt, rule, spec - rule);
2731 scanf_fmt[spec - rule] = '\0';
2732 /* copy new spec */
2733 strcat(scanf_fmt, "%s");
2734 /* copy remaining rule */
2735 strcat(scanf_fmt, spec + 4);
2736
2737 return;
2738}
2739
dfefa935 2740char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
2741{
2742 int i;
2743 static char **scanf_fmts;
2744 static int nr_rules;
2745 char *short_name;
2746
2747 /* pre generate scanf formats from ref_rev_parse_rules[] */
2748 if (!nr_rules) {
2749 size_t total_len = 0;
2750
2751 /* the rule list is NULL terminated, count them first */
2752 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2753 /* no +1 because strlen("%s") < strlen("%.*s") */
2754 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2755
2756 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2757
2758 total_len = 0;
2759 for (i = 0; i < nr_rules; i++) {
2760 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2761 + total_len;
2762 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2763 total_len += strlen(ref_rev_parse_rules[i]);
2764 }
2765 }
2766
2767 /* bail out if there are no rules */
2768 if (!nr_rules)
dfefa935 2769 return xstrdup(refname);
7c2b3029 2770
dfefa935
MH
2771 /* buffer for scanf result, at most refname must fit */
2772 short_name = xstrdup(refname);
7c2b3029
JK
2773
2774 /* skip first rule, it will always match */
2775 for (i = nr_rules - 1; i > 0 ; --i) {
2776 int j;
6e7b3309 2777 int rules_to_fail = i;
7c2b3029
JK
2778 int short_name_len;
2779
dfefa935 2780 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
2781 continue;
2782
2783 short_name_len = strlen(short_name);
2784
6e7b3309
BW
2785 /*
2786 * in strict mode, all (except the matched one) rules
2787 * must fail to resolve to a valid non-ambiguous ref
2788 */
2789 if (strict)
2790 rules_to_fail = nr_rules;
2791
7c2b3029
JK
2792 /*
2793 * check if the short name resolves to a valid ref,
2794 * but use only rules prior to the matched one
2795 */
6e7b3309 2796 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 2797 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
2798 char refname[PATH_MAX];
2799
6e7b3309
BW
2800 /* skip matched rule */
2801 if (i == j)
2802 continue;
2803
7c2b3029
JK
2804 /*
2805 * the short name is ambiguous, if it resolves
2806 * (with this previous rule) to a valid ref
2807 * read_ref() returns 0 on success
2808 */
2809 mksnpath(refname, sizeof(refname),
2810 rule, short_name_len, short_name);
c6893323 2811 if (ref_exists(refname))
7c2b3029
JK
2812 break;
2813 }
2814
2815 /*
2816 * short name is non-ambiguous if all previous rules
2817 * haven't resolved to a valid ref
2818 */
6e7b3309 2819 if (j == rules_to_fail)
7c2b3029
JK
2820 return short_name;
2821 }
2822
2823 free(short_name);
dfefa935 2824 return xstrdup(refname);
7c2b3029 2825}