1#include "cache.h" 2#include "refs.h" 3#include "object.h" 4#include "tag.h" 5#include "dir.h" 6 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 */ 18 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) 54 return 0; /* Component has zero length. */ 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); 77 if (component_len <= 0) { 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; 103 104/* 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 */ 110struct ref_value { 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 */ 117 unsigned char sha1[20]; 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 122 * be peelable. See the documentation for peel_ref() for an 123 * exact definition of "peelable". 124 */ 125 unsigned char peeled[20]; 126}; 127 128struct ref_cache; 129 130/* 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 */ 156struct ref_dir { 157 int nr, alloc; 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; 166 167 /* A pointer to the ref_cache that contains this ref_dir. */ 168 struct ref_cache *ref_cache; 169 170 struct ref_entry **entries; 171}; 172 173/* 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 */ 184#define REF_KNOWS_PEELED 0x08 185 186/* ref_entry represents a directory of references */ 187#define REF_DIR 0x10 188 189/* 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 194 195/* 196 * A ref_entry represents either a reference or a "subdirectory" of 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). 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 */ 234struct ref_entry { 235 unsigned char flag; /* ISSYMREF? ISPACKED? */ 236 union { 237 struct ref_value value; /* if not (flags&REF_DIR) */ 238 struct ref_dir subdir; /* if (flags&REF_DIR) */ 239 } u; 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 */ 245 char name[FLEX_ARRAY]; 246}; 247 248static void read_loose_refs(const char *dirname, struct ref_dir *dir); 249 250static struct ref_dir *get_ref_dir(struct ref_entry *entry) 251{ 252 struct ref_dir *dir; 253 assert(entry->flag & REF_DIR); 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; 260} 261 262static struct ref_entry *create_ref_entry(const char *refname, 263 const unsigned char *sha1, int flag, 264 int check_name) 265{ 266 int len; 267 struct ref_entry *ref; 268 269 if (check_name && 270 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT)) 271 die("Reference has invalid format: '%s'", refname); 272 len = strlen(refname) + 1; 273 ref = xmalloc(sizeof(struct ref_entry) + len); 274 hashcpy(ref->u.value.sha1, sha1); 275 hashclr(ref->u.value.peeled); 276 memcpy(ref->name, refname, len); 277 ref->flag = flag; 278 return ref; 279} 280 281static void clear_ref_dir(struct ref_dir *dir); 282 283static void free_ref_entry(struct ref_entry *entry) 284{ 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 } 292 free(entry); 293} 294 295/* 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) 301{ 302 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); 303 dir->entries[dir->nr++] = entry; 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; 310} 311 312/* 313 * Clear and free all entries in dir, recursively. 314 */ 315static void clear_ref_dir(struct ref_dir *dir) 316{ 317 int i; 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; 323} 324 325/* 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 */ 330static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 331 const char *dirname, size_t len, 332 int incomplete) 333{ 334 struct ref_entry *direntry; 335 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1); 336 memcpy(direntry->name, dirname, len); 337 direntry->name[len] = '\0'; 338 direntry->u.subdir.ref_cache = ref_cache; 339 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); 340 return direntry; 341} 342 343static int ref_entry_cmp(const void *a, const void *b) 344{ 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} 349 350static void sort_ref_dir(struct ref_dir *dir); 351 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} 368 369/* 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. 373 */ 374static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) 375{ 376 struct ref_entry **r; 377 struct string_slice key; 378 379 if (refname == NULL || !dir->nr) 380 return -1; 381 382 sort_ref_dir(dir); 383 key.len = len; 384 key.str = refname; 385 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), 386 ref_entry_cmp_sslice); 387 388 if (r == NULL) 389 return -1; 390 391 return r - dir->entries; 392} 393 394/* 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 399 * directory cannot be found. dir must already be complete. 400 */ 401static struct ref_dir *search_for_subdir(struct ref_dir *dir, 402 const char *subdirname, size_t len, 403 int mkdir) 404{ 405 int entry_index = search_ref_dir(dir, subdirname, len); 406 struct ref_entry *entry; 407 if (entry_index == -1) { 408 if (!mkdir) 409 return NULL; 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 */ 416 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0); 417 add_entry_to_dir(dir, entry); 418 } else { 419 entry = dir->entries[entry_index]; 420 } 421 return get_ref_dir(entry); 422} 423 424/* 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 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. 432 */ 433static struct ref_dir *find_containing_dir(struct ref_dir *dir, 434 const char *refname, int mkdir) 435{ 436 const char *slash; 437 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 438 size_t dirnamelen = slash - refname + 1; 439 struct ref_dir *subdir; 440 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); 441 if (!subdir) { 442 dir = NULL; 443 break; 444 } 445 dir = subdir; 446 } 447 448 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{ 458 int entry_index; 459 struct ref_entry *entry; 460 dir = find_containing_dir(dir, refname, 0); 461 if (!dir) 462 return NULL; 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; 468} 469 470/* 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} 520 521/* 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} 534 535/* 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{ 542 if (strcmp(ref1->name, ref2->name)) 543 return 0; 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; 556} 557 558/* 559 * Sort the entries in dir non-recursively (if they are not already 560 * sorted) and remove any duplicate entries. 561 */ 562static void sort_ref_dir(struct ref_dir *dir) 563{ 564 int i, j; 565 struct ref_entry *last = NULL; 566 567 /* 568 * This check also prevents passing a zero-length array to qsort(), 569 * which is a problem on some platforms. 570 */ 571 if (dir->sorted == dir->nr) 572 return; 573 574 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); 575 576 /* 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; 583 } 584 dir->sorted = dir->nr = i; 585} 586 587/* Include broken references in a do_for_each_ref*() iteration: */ 588#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 589 590/* 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} 605 606/* 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 */ 615static struct ref_entry *current_ref; 616 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}; 626 627/* 628 * Handle one reference in a do_for_each_ref*()-style iteration, 629 * calling an each_ref_fn for each entry. 630 */ 631static int do_one_ref(struct ref_entry *entry, void *cb_data) 632{ 633 struct ref_entry_cb *data = cb_data; 634 int retval; 635 if (prefixcmp(entry->name, data->base)) 636 return 0; 637 638 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 639 !ref_resolves_to_object(entry)) 640 return 0; 641 642 current_ref = entry; 643 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 644 entry->flag, data->cb_data); 645 current_ref = NULL; 646 return retval; 647} 648 649/* 650 * Call fn for each reference in dir that has index in the range 651 * offset <= index < dir->nr. Recurse into subdirectories that are in 652 * that index range, sorting them before iterating. This function 653 * does not sort dir itself; it should be sorted beforehand. fn is 654 * called for all references, including broken ones. 655 */ 656static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, 657 each_ref_entry_fn fn, void *cb_data) 658{ 659 int i; 660 assert(dir->sorted == dir->nr); 661 for (i = offset; i < dir->nr; i++) { 662 struct ref_entry *entry = dir->entries[i]; 663 int retval; 664 if (entry->flag & REF_DIR) { 665 struct ref_dir *subdir = get_ref_dir(entry); 666 sort_ref_dir(subdir); 667 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); 668 } else { 669 retval = fn(entry, cb_data); 670 } 671 if (retval) 672 return retval; 673 } 674 return 0; 675} 676 677/* 678 * Call fn for each reference in the union of dir1 and dir2, in order 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 682 * sorted as needed. fn is called for all references, including 683 * broken ones. 684 */ 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) 688{ 689 int retval; 690 int i1 = 0, i2 = 0; 691 692 assert(dir1->sorted == dir1->nr); 693 assert(dir2->sorted == dir2->nr); 694 while (1) { 695 struct ref_entry *e1, *e2; 696 int cmp; 697 if (i1 == dir1->nr) { 698 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data); 699 } 700 if (i2 == dir2->nr) { 701 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data); 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. */ 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); 713 retval = do_for_each_entry_in_dirs( 714 subdir1, subdir2, fn, cb_data); 715 i1++; 716 i2++; 717 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 718 /* Both are references; ignore the one from dir1. */ 719 retval = fn(e2, cb_data); 720 i1++; 721 i2++; 722 } else { 723 die("conflict between reference and directory: %s", 724 e1->name); 725 } 726 } else { 727 struct ref_entry *e; 728 if (cmp < 0) { 729 e = e1; 730 i1++; 731 } else { 732 e = e2; 733 i2++; 734 } 735 if (e->flag & REF_DIR) { 736 struct ref_dir *subdir = get_ref_dir(e); 737 sort_ref_dir(subdir); 738 retval = do_for_each_entry_in_dir( 739 subdir, 0, fn, cb_data); 740 } else { 741 retval = fn(e, cb_data); 742 } 743 } 744 if (retval) 745 return retval; 746 } 747} 748 749/* 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{ 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 770static int name_conflict_fn(struct ref_entry *entry, void *cb_data) 771{ 772 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data; 773 if (data->oldrefname && !strcmp(data->oldrefname, entry->name)) 774 return 0; 775 if (names_conflict(data->refname, entry->name)) { 776 data->conflicting_refname = entry->name; 777 return 1; 778 } 779 return 0; 780} 781 782/* 783 * Return true iff a reference named refname could be created without 784 * conflicting with the name of an existing reference in dir. If 785 * oldrefname is non-NULL, ignore potential conflicts with oldrefname 786 * (e.g., because oldrefname is scheduled for deletion in the same 787 * operation). 788 */ 789static int is_refname_available(const char *refname, const char *oldrefname, 790 struct ref_dir *dir) 791{ 792 struct name_conflict_cb data; 793 data.refname = refname; 794 data.oldrefname = oldrefname; 795 data.conflicting_refname = NULL; 796 797 sort_ref_dir(dir); 798 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) { 799 error("'%s' exists; cannot create '%s'", 800 data.conflicting_refname, refname); 801 return 0; 802 } 803 return 1; 804} 805 806/* 807 * Future: need to be in "struct repository" 808 * when doing a full libification. 809 */ 810static struct ref_cache { 811 struct ref_cache *next; 812 struct ref_entry *loose; 813 struct ref_entry *packed; 814 /* The submodule name, or "" for the main repo. */ 815 char name[FLEX_ARRAY]; 816} *ref_cache; 817 818static void clear_packed_ref_cache(struct ref_cache *refs) 819{ 820 if (refs->packed) { 821 free_ref_entry(refs->packed); 822 refs->packed = NULL; 823 } 824} 825 826static void clear_loose_ref_cache(struct ref_cache *refs) 827{ 828 if (refs->loose) { 829 free_ref_entry(refs->loose); 830 refs->loose = NULL; 831 } 832} 833 834static struct ref_cache *create_ref_cache(const char *submodule) 835{ 836 int len; 837 struct ref_cache *refs; 838 if (!submodule) 839 submodule = ""; 840 len = strlen(submodule) + 1; 841 refs = xcalloc(1, sizeof(struct ref_cache) + len); 842 memcpy(refs->name, submodule, len); 843 return refs; 844} 845 846/* 847 * Return a pointer to a ref_cache for the specified submodule. For 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 */ 852static struct ref_cache *get_ref_cache(const char *submodule) 853{ 854 struct ref_cache *refs = ref_cache; 855 if (!submodule) 856 submodule = ""; 857 while (refs) { 858 if (!strcmp(submodule, refs->name)) 859 return refs; 860 refs = refs->next; 861 } 862 863 refs = create_ref_cache(submodule); 864 refs->next = ref_cache; 865 ref_cache = refs; 866 return refs; 867} 868 869void invalidate_ref_cache(const char *submodule) 870{ 871 struct ref_cache *refs = get_ref_cache(submodule); 872 clear_packed_ref_cache(refs); 873 clear_loose_ref_cache(refs); 874} 875 876/* The length of a peeled reference line in packed-refs, including EOL: */ 877#define PEELED_LINE_LENGTH 42 878 879/* 880 * The packed-refs header line that we write out. Perhaps other 881 * traits will be added later. The trailing space is required. 882 */ 883static const char PACKED_REFS_HEADER[] = 884 "# pack-refs with: peeled fully-peeled \n"; 885 886/* 887 * Parse one line from a packed-refs file. Write the SHA1 to sha1. 888 * Return a pointer to the refname within the line (null-terminated), 889 * or NULL if there was a problem. 890 */ 891static const char *parse_ref_line(char *line, unsigned char *sha1) 892{ 893 /* 894 * 42: the answer to everything. 895 * 896 * In this case, it happens to be the answer to 897 * 40 (length of sha1 hex representation) 898 * +1 (space in between hex and name) 899 * +1 (newline at the end of the line) 900 */ 901 int len = strlen(line) - 42; 902 903 if (len <= 0) 904 return NULL; 905 if (get_sha1_hex(line, sha1) < 0) 906 return NULL; 907 if (!isspace(line[40])) 908 return NULL; 909 line += 41; 910 if (isspace(*line)) 911 return NULL; 912 if (line[len] != '\n') 913 return NULL; 914 line[len] = 0; 915 916 return line; 917} 918 919/* 920 * Read f, which is a packed-refs file, into dir. 921 * 922 * A comment line of the form "# pack-refs with: " may contain zero or 923 * more traits. We interpret the traits as follows: 924 * 925 * No traits: 926 * 927 * Probably no references are peeled. But if the file contains a 928 * peeled value for a reference, we will use it. 929 * 930 * peeled: 931 * 932 * References under "refs/tags/", if they *can* be peeled, *are* 933 * peeled in this file. References outside of "refs/tags/" are 934 * probably not peeled even if they could have been, but if we find 935 * a peeled value for such a reference we will use it. 936 * 937 * fully-peeled: 938 * 939 * All references in the file that can be peeled are peeled. 940 * Inversely (and this is more important), any references in the 941 * file for which no peeled value is recorded is not peelable. This 942 * trait should typically be written alongside "peeled" for 943 * compatibility with older clients, but we do not require it 944 * (i.e., "peeled" is a no-op if "fully-peeled" is set). 945 */ 946static void read_packed_refs(FILE *f, struct ref_dir *dir) 947{ 948 struct ref_entry *last = NULL; 949 char refline[PATH_MAX]; 950 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; 951 952 while (fgets(refline, sizeof(refline), f)) { 953 unsigned char sha1[20]; 954 const char *refname; 955 static const char header[] = "# pack-refs with:"; 956 957 if (!strncmp(refline, header, sizeof(header)-1)) { 958 const char *traits = refline + sizeof(header) - 1; 959 if (strstr(traits, " fully-peeled ")) 960 peeled = PEELED_FULLY; 961 else if (strstr(traits, " peeled ")) 962 peeled = PEELED_TAGS; 963 /* perhaps other traits later as well */ 964 continue; 965 } 966 967 refname = parse_ref_line(refline, sha1); 968 if (refname) { 969 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1); 970 if (peeled == PEELED_FULLY || 971 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/"))) 972 last->flag |= REF_KNOWS_PEELED; 973 add_ref(dir, last); 974 continue; 975 } 976 if (last && 977 refline[0] == '^' && 978 strlen(refline) == PEELED_LINE_LENGTH && 979 refline[PEELED_LINE_LENGTH - 1] == '\n' && 980 !get_sha1_hex(refline + 1, sha1)) { 981 hashcpy(last->u.value.peeled, sha1); 982 /* 983 * Regardless of what the file header said, 984 * we definitely know the value of *this* 985 * reference: 986 */ 987 last->flag |= REF_KNOWS_PEELED; 988 } 989 } 990} 991 992static struct ref_dir *get_packed_refs(struct ref_cache *refs) 993{ 994 if (!refs->packed) { 995 const char *packed_refs_file; 996 FILE *f; 997 998 refs->packed = create_dir_entry(refs, "", 0, 0); 999 if (*refs->name)1000 packed_refs_file = git_path_submodule(refs->name, "packed-refs");1001 else1002 packed_refs_file = git_path("packed-refs");1003 f = fopen(packed_refs_file, "r");1004 if (f) {1005 read_packed_refs(f, get_ref_dir(refs->packed));1006 fclose(f);1007 }1008 }1009 return get_ref_dir(refs->packed);1010}10111012void add_packed_ref(const char *refname, const unsigned char *sha1)1013{1014 add_ref(get_packed_refs(get_ref_cache(NULL)),1015 create_ref_entry(refname, sha1, REF_ISPACKED, 1));1016}10171018/*1019 * Read the loose references from the namespace dirname into dir1020 * (without recursing). dirname must end with '/'. dir must be the1021 * directory entry corresponding to dirname.1022 */1023static void read_loose_refs(const char *dirname, struct ref_dir *dir)1024{1025 struct ref_cache *refs = dir->ref_cache;1026 DIR *d;1027 const char *path;1028 struct dirent *de;1029 int dirnamelen = strlen(dirname);1030 struct strbuf refname;10311032 if (*refs->name)1033 path = git_path_submodule(refs->name, "%s", dirname);1034 else1035 path = git_path("%s", dirname);10361037 d = opendir(path);1038 if (!d)1039 return;10401041 strbuf_init(&refname, dirnamelen + 257);1042 strbuf_add(&refname, dirname, dirnamelen);10431044 while ((de = readdir(d)) != NULL) {1045 unsigned char sha1[20];1046 struct stat st;1047 int flag;1048 const char *refdir;10491050 if (de->d_name[0] == '.')1051 continue;1052 if (has_extension(de->d_name, ".lock"))1053 continue;1054 strbuf_addstr(&refname, de->d_name);1055 refdir = *refs->name1056 ? git_path_submodule(refs->name, "%s", refname.buf)1057 : git_path("%s", refname.buf);1058 if (stat(refdir, &st) < 0) {1059 ; /* silently ignore */1060 } else if (S_ISDIR(st.st_mode)) {1061 strbuf_addch(&refname, '/');1062 add_entry_to_dir(dir,1063 create_dir_entry(refs, refname.buf,1064 refname.len, 1));1065 } else {1066 if (*refs->name) {1067 hashclr(sha1);1068 flag = 0;1069 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {1070 hashclr(sha1);1071 flag |= REF_ISBROKEN;1072 }1073 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {1074 hashclr(sha1);1075 flag |= REF_ISBROKEN;1076 }1077 add_entry_to_dir(dir,1078 create_ref_entry(refname.buf, sha1, flag, 1));1079 }1080 strbuf_setlen(&refname, dirnamelen);1081 }1082 strbuf_release(&refname);1083 closedir(d);1084}10851086static struct ref_dir *get_loose_refs(struct ref_cache *refs)1087{1088 if (!refs->loose) {1089 /*1090 * Mark the top-level directory complete because we1091 * are about to read the only subdirectory that can1092 * hold references:1093 */1094 refs->loose = create_dir_entry(refs, "", 0, 0);1095 /*1096 * Create an incomplete entry for "refs/":1097 */1098 add_entry_to_dir(get_ref_dir(refs->loose),1099 create_dir_entry(refs, "refs/", 5, 1));1100 }1101 return get_ref_dir(refs->loose);1102}11031104/* We allow "recursive" symbolic refs. Only within reason, though */1105#define MAXDEPTH 51106#define MAXREFLEN (1024)11071108/*1109 * Called by resolve_gitlink_ref_recursive() after it failed to read1110 * from the loose refs in ref_cache refs. Find <refname> in the1111 * packed-refs file for the submodule.1112 */1113static int resolve_gitlink_packed_ref(struct ref_cache *refs,1114 const char *refname, unsigned char *sha1)1115{1116 struct ref_entry *ref;1117 struct ref_dir *dir = get_packed_refs(refs);11181119 ref = find_ref(dir, refname);1120 if (ref == NULL)1121 return -1;11221123 memcpy(sha1, ref->u.value.sha1, 20);1124 return 0;1125}11261127static int resolve_gitlink_ref_recursive(struct ref_cache *refs,1128 const char *refname, unsigned char *sha1,1129 int recursion)1130{1131 int fd, len;1132 char buffer[128], *p;1133 char *path;11341135 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)1136 return -1;1137 path = *refs->name1138 ? git_path_submodule(refs->name, "%s", refname)1139 : git_path("%s", refname);1140 fd = open(path, O_RDONLY);1141 if (fd < 0)1142 return resolve_gitlink_packed_ref(refs, refname, sha1);11431144 len = read(fd, buffer, sizeof(buffer)-1);1145 close(fd);1146 if (len < 0)1147 return -1;1148 while (len && isspace(buffer[len-1]))1149 len--;1150 buffer[len] = 0;11511152 /* Was it a detached head or an old-fashioned symlink? */1153 if (!get_sha1_hex(buffer, sha1))1154 return 0;11551156 /* Symref? */1157 if (strncmp(buffer, "ref:", 4))1158 return -1;1159 p = buffer + 4;1160 while (isspace(*p))1161 p++;11621163 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1164}11651166int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)1167{1168 int len = strlen(path), retval;1169 char *submodule;1170 struct ref_cache *refs;11711172 while (len && path[len-1] == '/')1173 len--;1174 if (!len)1175 return -1;1176 submodule = xstrndup(path, len);1177 refs = get_ref_cache(submodule);1178 free(submodule);11791180 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);1181 return retval;1182}11831184/*1185 * Return the ref_entry for the given refname from the packed1186 * references. If it does not exist, return NULL.1187 */1188static struct ref_entry *get_packed_ref(const char *refname)1189{1190 return find_ref(get_packed_refs(get_ref_cache(NULL)), refname);1191}11921193const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)1194{1195 int depth = MAXDEPTH;1196 ssize_t len;1197 char buffer[256];1198 static char refname_buffer[256];11991200 if (flag)1201 *flag = 0;12021203 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1204 return NULL;12051206 for (;;) {1207 char path[PATH_MAX];1208 struct stat st;1209 char *buf;1210 int fd;12111212 if (--depth < 0)1213 return NULL;12141215 git_snpath(path, sizeof(path), "%s", refname);12161217 if (lstat(path, &st) < 0) {1218 struct ref_entry *entry;12191220 if (errno != ENOENT)1221 return NULL;1222 /*1223 * The loose reference file does not exist;1224 * check for a packed reference.1225 */1226 entry = get_packed_ref(refname);1227 if (entry) {1228 hashcpy(sha1, entry->u.value.sha1);1229 if (flag)1230 *flag |= REF_ISPACKED;1231 return refname;1232 }1233 /* The reference is not a packed reference, either. */1234 if (reading) {1235 return NULL;1236 } else {1237 hashclr(sha1);1238 return refname;1239 }1240 }12411242 /* Follow "normalized" - ie "refs/.." symlinks by hand */1243 if (S_ISLNK(st.st_mode)) {1244 len = readlink(path, buffer, sizeof(buffer)-1);1245 if (len < 0)1246 return NULL;1247 buffer[len] = 0;1248 if (!prefixcmp(buffer, "refs/") &&1249 !check_refname_format(buffer, 0)) {1250 strcpy(refname_buffer, buffer);1251 refname = refname_buffer;1252 if (flag)1253 *flag |= REF_ISSYMREF;1254 continue;1255 }1256 }12571258 /* Is it a directory? */1259 if (S_ISDIR(st.st_mode)) {1260 errno = EISDIR;1261 return NULL;1262 }12631264 /*1265 * Anything else, just open it and try to use it as1266 * a ref1267 */1268 fd = open(path, O_RDONLY);1269 if (fd < 0)1270 return NULL;1271 len = read_in_full(fd, buffer, sizeof(buffer)-1);1272 close(fd);1273 if (len < 0)1274 return NULL;1275 while (len && isspace(buffer[len-1]))1276 len--;1277 buffer[len] = '\0';12781279 /*1280 * Is it a symbolic ref?1281 */1282 if (prefixcmp(buffer, "ref:"))1283 break;1284 if (flag)1285 *flag |= REF_ISSYMREF;1286 buf = buffer + 4;1287 while (isspace(*buf))1288 buf++;1289 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1290 if (flag)1291 *flag |= REF_ISBROKEN;1292 return NULL;1293 }1294 refname = strcpy(refname_buffer, buf);1295 }1296 /* Please note that FETCH_HEAD has a second line containing other data. */1297 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {1298 if (flag)1299 *flag |= REF_ISBROKEN;1300 return NULL;1301 }1302 return refname;1303}13041305char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)1306{1307 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);1308 return ret ? xstrdup(ret) : NULL;1309}13101311/* The argument to filter_refs */1312struct ref_filter {1313 const char *pattern;1314 each_ref_fn *fn;1315 void *cb_data;1316};13171318int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)1319{1320 if (resolve_ref_unsafe(refname, sha1, reading, flags))1321 return 0;1322 return -1;1323}13241325int read_ref(const char *refname, unsigned char *sha1)1326{1327 return read_ref_full(refname, sha1, 1, NULL);1328}13291330int ref_exists(const char *refname)1331{1332 unsigned char sha1[20];1333 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);1334}13351336static int filter_refs(const char *refname, const unsigned char *sha1, int flags,1337 void *data)1338{1339 struct ref_filter *filter = (struct ref_filter *)data;1340 if (fnmatch(filter->pattern, refname, 0))1341 return 0;1342 return filter->fn(refname, sha1, flags, filter->cb_data);1343}13441345enum peel_status {1346 /* object was peeled successfully: */1347 PEEL_PEELED = 0,13481349 /*1350 * object cannot be peeled because the named object (or an1351 * object referred to by a tag in the peel chain), does not1352 * exist.1353 */1354 PEEL_INVALID = -1,13551356 /* object cannot be peeled because it is not a tag: */1357 PEEL_NON_TAG = -2,13581359 /* ref_entry contains no peeled value because it is a symref: */1360 PEEL_IS_SYMREF = -3,13611362 /*1363 * ref_entry cannot be peeled because it is broken (i.e., the1364 * symbolic reference cannot even be resolved to an object1365 * name):1366 */1367 PEEL_BROKEN = -41368};13691370/*1371 * Peel the named object; i.e., if the object is a tag, resolve the1372 * tag recursively until a non-tag is found. If successful, store the1373 * result to sha1 and return PEEL_PEELED. If the object is not a tag1374 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1375 * and leave sha1 unchanged.1376 */1377static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)1378{1379 struct object *o = lookup_unknown_object(name);13801381 if (o->type == OBJ_NONE) {1382 int type = sha1_object_info(name, NULL);1383 if (type < 0)1384 return PEEL_INVALID;1385 o->type = type;1386 }13871388 if (o->type != OBJ_TAG)1389 return PEEL_NON_TAG;13901391 o = deref_tag_noverify(o);1392 if (!o)1393 return PEEL_INVALID;13941395 hashcpy(sha1, o->sha1);1396 return PEEL_PEELED;1397}13981399/*1400 * Peel the entry (if possible) and return its new peel_status. If1401 * repeel is true, re-peel the entry even if there is an old peeled1402 * value that is already stored in it.1403 *1404 * It is OK to call this function with a packed reference entry that1405 * might be stale and might even refer to an object that has since1406 * been garbage-collected. In such a case, if the entry has1407 * REF_KNOWS_PEELED then leave the status unchanged and return1408 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1409 */1410static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1411{1412 enum peel_status status;14131414 if (entry->flag & REF_KNOWS_PEELED) {1415 if (repeel) {1416 entry->flag &= ~REF_KNOWS_PEELED;1417 hashclr(entry->u.value.peeled);1418 } else {1419 return is_null_sha1(entry->u.value.peeled) ?1420 PEEL_NON_TAG : PEEL_PEELED;1421 }1422 }1423 if (entry->flag & REF_ISBROKEN)1424 return PEEL_BROKEN;1425 if (entry->flag & REF_ISSYMREF)1426 return PEEL_IS_SYMREF;14271428 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);1429 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1430 entry->flag |= REF_KNOWS_PEELED;1431 return status;1432}14331434int peel_ref(const char *refname, unsigned char *sha1)1435{1436 int flag;1437 unsigned char base[20];14381439 if (current_ref && (current_ref->name == refname1440 || !strcmp(current_ref->name, refname))) {1441 if (peel_entry(current_ref, 0))1442 return -1;1443 hashcpy(sha1, current_ref->u.value.peeled);1444 return 0;1445 }14461447 if (read_ref_full(refname, base, 1, &flag))1448 return -1;14491450 /*1451 * If the reference is packed, read its ref_entry from the1452 * cache in the hope that we already know its peeled value.1453 * We only try this optimization on packed references because1454 * (a) forcing the filling of the loose reference cache could1455 * be expensive and (b) loose references anyway usually do not1456 * have REF_KNOWS_PEELED.1457 */1458 if (flag & REF_ISPACKED) {1459 struct ref_entry *r = get_packed_ref(refname);1460 if (r) {1461 if (peel_entry(r, 0))1462 return -1;1463 hashcpy(sha1, r->u.value.peeled);1464 return 0;1465 }1466 }14671468 return peel_object(base, sha1);1469}14701471struct warn_if_dangling_data {1472 FILE *fp;1473 const char *refname;1474 const char *msg_fmt;1475};14761477static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,1478 int flags, void *cb_data)1479{1480 struct warn_if_dangling_data *d = cb_data;1481 const char *resolves_to;1482 unsigned char junk[20];14831484 if (!(flags & REF_ISSYMREF))1485 return 0;14861487 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);1488 if (!resolves_to || strcmp(resolves_to, d->refname))1489 return 0;14901491 fprintf(d->fp, d->msg_fmt, refname);1492 fputc('\n', d->fp);1493 return 0;1494}14951496void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)1497{1498 struct warn_if_dangling_data data;14991500 data.fp = fp;1501 data.refname = refname;1502 data.msg_fmt = msg_fmt;1503 for_each_rawref(warn_if_dangling_symref, &data);1504}15051506/*1507 * Call fn for each reference in the specified submodule, omitting1508 * references not in the containing_dir of base. fn is called for all1509 * references, including broken ones. If fn ever returns a non-zero1510 * value, stop the iteration and return that value; otherwise, return1511 * 0.1512 */1513static int do_for_each_entry(const char *submodule, const char *base,1514 each_ref_entry_fn fn, void *cb_data)1515{1516 struct ref_cache *refs = get_ref_cache(submodule);1517 struct ref_dir *packed_dir = get_packed_refs(refs);1518 struct ref_dir *loose_dir = get_loose_refs(refs);1519 int retval = 0;15201521 if (base && *base) {1522 packed_dir = find_containing_dir(packed_dir, base, 0);1523 loose_dir = find_containing_dir(loose_dir, base, 0);1524 }15251526 if (packed_dir && loose_dir) {1527 sort_ref_dir(packed_dir);1528 sort_ref_dir(loose_dir);1529 retval = do_for_each_entry_in_dirs(1530 packed_dir, loose_dir, fn, cb_data);1531 } else if (packed_dir) {1532 sort_ref_dir(packed_dir);1533 retval = do_for_each_entry_in_dir(1534 packed_dir, 0, fn, cb_data);1535 } else if (loose_dir) {1536 sort_ref_dir(loose_dir);1537 retval = do_for_each_entry_in_dir(1538 loose_dir, 0, fn, cb_data);1539 }15401541 return retval;1542}15431544/*1545 * Call fn for each reference in the specified submodule for which the1546 * refname begins with base. If trim is non-zero, then trim that many1547 * characters off the beginning of each refname before passing the1548 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1549 * broken references in the iteration. If fn ever returns a non-zero1550 * value, stop the iteration and return that value; otherwise, return1551 * 0.1552 */1553static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,1554 int trim, int flags, void *cb_data)1555{1556 struct ref_entry_cb data;1557 data.base = base;1558 data.trim = trim;1559 data.flags = flags;1560 data.fn = fn;1561 data.cb_data = cb_data;15621563 return do_for_each_entry(submodule, base, do_one_ref, &data);1564}15651566static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)1567{1568 unsigned char sha1[20];1569 int flag;15701571 if (submodule) {1572 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)1573 return fn("HEAD", sha1, 0, cb_data);15741575 return 0;1576 }15771578 if (!read_ref_full("HEAD", sha1, 1, &flag))1579 return fn("HEAD", sha1, flag, cb_data);15801581 return 0;1582}15831584int head_ref(each_ref_fn fn, void *cb_data)1585{1586 return do_head_ref(NULL, fn, cb_data);1587}15881589int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1590{1591 return do_head_ref(submodule, fn, cb_data);1592}15931594int for_each_ref(each_ref_fn fn, void *cb_data)1595{1596 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);1597}15981599int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1600{1601 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);1602}16031604int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)1605{1606 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);1607}16081609int for_each_ref_in_submodule(const char *submodule, const char *prefix,1610 each_ref_fn fn, void *cb_data)1611{1612 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);1613}16141615int for_each_tag_ref(each_ref_fn fn, void *cb_data)1616{1617 return for_each_ref_in("refs/tags/", fn, cb_data);1618}16191620int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1621{1622 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);1623}16241625int for_each_branch_ref(each_ref_fn fn, void *cb_data)1626{1627 return for_each_ref_in("refs/heads/", fn, cb_data);1628}16291630int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1631{1632 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);1633}16341635int for_each_remote_ref(each_ref_fn fn, void *cb_data)1636{1637 return for_each_ref_in("refs/remotes/", fn, cb_data);1638}16391640int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1641{1642 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);1643}16441645int for_each_replace_ref(each_ref_fn fn, void *cb_data)1646{1647 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);1648}16491650int head_ref_namespaced(each_ref_fn fn, void *cb_data)1651{1652 struct strbuf buf = STRBUF_INIT;1653 int ret = 0;1654 unsigned char sha1[20];1655 int flag;16561657 strbuf_addf(&buf, "%sHEAD", get_git_namespace());1658 if (!read_ref_full(buf.buf, sha1, 1, &flag))1659 ret = fn(buf.buf, sha1, flag, cb_data);1660 strbuf_release(&buf);16611662 return ret;1663}16641665int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)1666{1667 struct strbuf buf = STRBUF_INIT;1668 int ret;1669 strbuf_addf(&buf, "%srefs/", get_git_namespace());1670 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);1671 strbuf_release(&buf);1672 return ret;1673}16741675int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,1676 const char *prefix, void *cb_data)1677{1678 struct strbuf real_pattern = STRBUF_INIT;1679 struct ref_filter filter;1680 int ret;16811682 if (!prefix && prefixcmp(pattern, "refs/"))1683 strbuf_addstr(&real_pattern, "refs/");1684 else if (prefix)1685 strbuf_addstr(&real_pattern, prefix);1686 strbuf_addstr(&real_pattern, pattern);16871688 if (!has_glob_specials(pattern)) {1689 /* Append implied '/' '*' if not present. */1690 if (real_pattern.buf[real_pattern.len - 1] != '/')1691 strbuf_addch(&real_pattern, '/');1692 /* No need to check for '*', there is none. */1693 strbuf_addch(&real_pattern, '*');1694 }16951696 filter.pattern = real_pattern.buf;1697 filter.fn = fn;1698 filter.cb_data = cb_data;1699 ret = for_each_ref(filter_refs, &filter);17001701 strbuf_release(&real_pattern);1702 return ret;1703}17041705int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)1706{1707 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);1708}17091710int for_each_rawref(each_ref_fn fn, void *cb_data)1711{1712 return do_for_each_ref(NULL, "", fn, 0,1713 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);1714}17151716const char *prettify_refname(const char *name)1717{1718 return name + (1719 !prefixcmp(name, "refs/heads/") ? 11 :1720 !prefixcmp(name, "refs/tags/") ? 10 :1721 !prefixcmp(name, "refs/remotes/") ? 13 :1722 0);1723}17241725const char *ref_rev_parse_rules[] = {1726 "%.*s",1727 "refs/%.*s",1728 "refs/tags/%.*s",1729 "refs/heads/%.*s",1730 "refs/remotes/%.*s",1731 "refs/remotes/%.*s/HEAD",1732 NULL1733};17341735int refname_match(const char *abbrev_name, const char *full_name, const char **rules)1736{1737 const char **p;1738 const int abbrev_name_len = strlen(abbrev_name);17391740 for (p = rules; *p; p++) {1741 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {1742 return 1;1743 }1744 }17451746 return 0;1747}17481749static struct ref_lock *verify_lock(struct ref_lock *lock,1750 const unsigned char *old_sha1, int mustexist)1751{1752 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {1753 error("Can't verify ref %s", lock->ref_name);1754 unlock_ref(lock);1755 return NULL;1756 }1757 if (hashcmp(lock->old_sha1, old_sha1)) {1758 error("Ref %s is at %s but expected %s", lock->ref_name,1759 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));1760 unlock_ref(lock);1761 return NULL;1762 }1763 return lock;1764}17651766static int remove_empty_directories(const char *file)1767{1768 /* we want to create a file but there is a directory there;1769 * if that is an empty directory (or a directory that contains1770 * only empty directories), remove them.1771 */1772 struct strbuf path;1773 int result;17741775 strbuf_init(&path, 20);1776 strbuf_addstr(&path, file);17771778 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);17791780 strbuf_release(&path);17811782 return result;1783}17841785/*1786 * *string and *len will only be substituted, and *string returned (for1787 * later free()ing) if the string passed in is a magic short-hand form1788 * to name a branch.1789 */1790static char *substitute_branch_name(const char **string, int *len)1791{1792 struct strbuf buf = STRBUF_INIT;1793 int ret = interpret_branch_name(*string, &buf);17941795 if (ret == *len) {1796 size_t size;1797 *string = strbuf_detach(&buf, &size);1798 *len = size;1799 return (char *)*string;1800 }18011802 return NULL;1803}18041805int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)1806{1807 char *last_branch = substitute_branch_name(&str, &len);1808 const char **p, *r;1809 int refs_found = 0;18101811 *ref = NULL;1812 for (p = ref_rev_parse_rules; *p; p++) {1813 char fullref[PATH_MAX];1814 unsigned char sha1_from_ref[20];1815 unsigned char *this_result;1816 int flag;18171818 this_result = refs_found ? sha1_from_ref : sha1;1819 mksnpath(fullref, sizeof(fullref), *p, len, str);1820 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);1821 if (r) {1822 if (!refs_found++)1823 *ref = xstrdup(r);1824 if (!warn_ambiguous_refs)1825 break;1826 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {1827 warning("ignoring dangling symref %s.", fullref);1828 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {1829 warning("ignoring broken ref %s.", fullref);1830 }1831 }1832 free(last_branch);1833 return refs_found;1834}18351836int dwim_log(const char *str, int len, unsigned char *sha1, char **log)1837{1838 char *last_branch = substitute_branch_name(&str, &len);1839 const char **p;1840 int logs_found = 0;18411842 *log = NULL;1843 for (p = ref_rev_parse_rules; *p; p++) {1844 struct stat st;1845 unsigned char hash[20];1846 char path[PATH_MAX];1847 const char *ref, *it;18481849 mksnpath(path, sizeof(path), *p, len, str);1850 ref = resolve_ref_unsafe(path, hash, 1, NULL);1851 if (!ref)1852 continue;1853 if (!stat(git_path("logs/%s", path), &st) &&1854 S_ISREG(st.st_mode))1855 it = path;1856 else if (strcmp(ref, path) &&1857 !stat(git_path("logs/%s", ref), &st) &&1858 S_ISREG(st.st_mode))1859 it = ref;1860 else1861 continue;1862 if (!logs_found++) {1863 *log = xstrdup(it);1864 hashcpy(sha1, hash);1865 }1866 if (!warn_ambiguous_refs)1867 break;1868 }1869 free(last_branch);1870 return logs_found;1871}18721873static struct ref_lock *lock_ref_sha1_basic(const char *refname,1874 const unsigned char *old_sha1,1875 int flags, int *type_p)1876{1877 char *ref_file;1878 const char *orig_refname = refname;1879 struct ref_lock *lock;1880 int last_errno = 0;1881 int type, lflags;1882 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1883 int missing = 0;18841885 lock = xcalloc(1, sizeof(struct ref_lock));1886 lock->lock_fd = -1;18871888 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);1889 if (!refname && errno == EISDIR) {1890 /* we are trying to lock foo but we used to1891 * have foo/bar which now does not exist;1892 * it is normal for the empty directory 'foo'1893 * to remain.1894 */1895 ref_file = git_path("%s", orig_refname);1896 if (remove_empty_directories(ref_file)) {1897 last_errno = errno;1898 error("there are still refs under '%s'", orig_refname);1899 goto error_return;1900 }1901 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);1902 }1903 if (type_p)1904 *type_p = type;1905 if (!refname) {1906 last_errno = errno;1907 error("unable to resolve reference %s: %s",1908 orig_refname, strerror(errno));1909 goto error_return;1910 }1911 missing = is_null_sha1(lock->old_sha1);1912 /* When the ref did not exist and we are creating it,1913 * make sure there is no existing ref that is packed1914 * whose name begins with our refname, nor a ref whose1915 * name is a proper prefix of our refname.1916 */1917 if (missing &&1918 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {1919 last_errno = ENOTDIR;1920 goto error_return;1921 }19221923 lock->lk = xcalloc(1, sizeof(struct lock_file));19241925 lflags = LOCK_DIE_ON_ERROR;1926 if (flags & REF_NODEREF) {1927 refname = orig_refname;1928 lflags |= LOCK_NODEREF;1929 }1930 lock->ref_name = xstrdup(refname);1931 lock->orig_ref_name = xstrdup(orig_refname);1932 ref_file = git_path("%s", refname);1933 if (missing)1934 lock->force_write = 1;1935 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))1936 lock->force_write = 1;19371938 if (safe_create_leading_directories(ref_file)) {1939 last_errno = errno;1940 error("unable to create directory for %s", ref_file);1941 goto error_return;1942 }19431944 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);1945 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;19461947 error_return:1948 unlock_ref(lock);1949 errno = last_errno;1950 return NULL;1951}19521953struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)1954{1955 char refpath[PATH_MAX];1956 if (check_refname_format(refname, 0))1957 return NULL;1958 strcpy(refpath, mkpath("refs/%s", refname));1959 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);1960}19611962struct ref_lock *lock_any_ref_for_update(const char *refname,1963 const unsigned char *old_sha1, int flags)1964{1965 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1966 return NULL;1967 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);1968}19691970/*1971 * Write an entry to the packed-refs file for the specified refname.1972 * If peeled is non-NULL, write it as the entry's peeled value.1973 */1974static void write_packed_entry(int fd, char *refname, unsigned char *sha1,1975 unsigned char *peeled)1976{1977 char line[PATH_MAX + 100];1978 int len;19791980 len = snprintf(line, sizeof(line), "%s %s\n",1981 sha1_to_hex(sha1), refname);1982 /* this should not happen but just being defensive */1983 if (len > sizeof(line))1984 die("too long a refname '%s'", refname);1985 write_or_die(fd, line, len);19861987 if (peeled) {1988 if (snprintf(line, sizeof(line), "^%s\n",1989 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)1990 die("internal error");1991 write_or_die(fd, line, PEELED_LINE_LENGTH);1992 }1993}19941995struct ref_to_prune {1996 struct ref_to_prune *next;1997 unsigned char sha1[20];1998 char name[FLEX_ARRAY];1999};20002001struct pack_refs_cb_data {2002 unsigned int flags;2003 struct ref_to_prune *ref_to_prune;2004 int fd;2005};20062007static int pack_one_ref(struct ref_entry *entry, void *cb_data)2008{2009 struct pack_refs_cb_data *cb = cb_data;2010 enum peel_status peel_status;2011 int is_tag_ref = !prefixcmp(entry->name, "refs/tags/");20122013 /* ALWAYS pack refs that were already packed or are tags */2014 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref &&2015 !(entry->flag & REF_ISPACKED))2016 return 0;20172018 /* Do not pack symbolic or broken refs: */2019 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2020 return 0;20212022 peel_status = peel_entry(entry, 1);2023 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2024 die("internal error peeling reference %s (%s)",2025 entry->name, sha1_to_hex(entry->u.value.sha1));2026 write_packed_entry(cb->fd, entry->name, entry->u.value.sha1,2027 peel_status == PEEL_PEELED ?2028 entry->u.value.peeled : NULL);20292030 /* If the ref was already packed, there is no need to prune it. */2031 if ((cb->flags & PACK_REFS_PRUNE) && !(entry->flag & REF_ISPACKED)) {2032 int namelen = strlen(entry->name) + 1;2033 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);2034 hashcpy(n->sha1, entry->u.value.sha1);2035 strcpy(n->name, entry->name);2036 n->next = cb->ref_to_prune;2037 cb->ref_to_prune = n;2038 }2039 return 0;2040}20412042/*2043 * Remove empty parents, but spare refs/ and immediate subdirs.2044 * Note: munges *name.2045 */2046static void try_remove_empty_parents(char *name)2047{2048 char *p, *q;2049 int i;2050 p = name;2051 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2052 while (*p && *p != '/')2053 p++;2054 /* tolerate duplicate slashes; see check_refname_format() */2055 while (*p == '/')2056 p++;2057 }2058 for (q = p; *q; q++)2059 ;2060 while (1) {2061 while (q > p && *q != '/')2062 q--;2063 while (q > p && *(q-1) == '/')2064 q--;2065 if (q == p)2066 break;2067 *q = '\0';2068 if (rmdir(git_path("%s", name)))2069 break;2070 }2071}20722073/* make sure nobody touched the ref, and unlink */2074static void prune_ref(struct ref_to_prune *r)2075{2076 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);20772078 if (lock) {2079 unlink_or_warn(git_path("%s", r->name));2080 unlock_ref(lock);2081 try_remove_empty_parents(r->name);2082 }2083}20842085static void prune_refs(struct ref_to_prune *r)2086{2087 while (r) {2088 prune_ref(r);2089 r = r->next;2090 }2091}20922093static struct lock_file packlock;20942095int pack_refs(unsigned int flags)2096{2097 struct pack_refs_cb_data cbdata;20982099 memset(&cbdata, 0, sizeof(cbdata));2100 cbdata.flags = flags;21012102 cbdata.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"),2103 LOCK_DIE_ON_ERROR);21042105 write_or_die(cbdata.fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));21062107 do_for_each_entry(NULL, "", pack_one_ref, &cbdata);2108 if (commit_lock_file(&packlock) < 0)2109 die_errno("unable to overwrite old ref-pack file");2110 prune_refs(cbdata.ref_to_prune);2111 return 0;2112}21132114static int repack_ref_fn(struct ref_entry *entry, void *cb_data)2115{2116 int *fd = cb_data;2117 enum peel_status peel_status;21182119 if (entry->flag & REF_ISBROKEN) {2120 /* This shouldn't happen to packed refs. */2121 error("%s is broken!", entry->name);2122 return 0;2123 }2124 if (!has_sha1_file(entry->u.value.sha1)) {2125 unsigned char sha1[20];2126 int flags;21272128 if (read_ref_full(entry->name, sha1, 0, &flags))2129 /* We should at least have found the packed ref. */2130 die("Internal error");2131 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED))2132 /*2133 * This packed reference is overridden by a2134 * loose reference, so it is OK that its value2135 * is no longer valid; for example, it might2136 * refer to an object that has been garbage2137 * collected. For this purpose we don't even2138 * care whether the loose reference itself is2139 * invalid, broken, symbolic, etc. Silently2140 * omit the packed reference from the output.2141 */2142 return 0;2143 /*2144 * There is no overriding loose reference, so the fact2145 * that this reference doesn't refer to a valid object2146 * indicates some kind of repository corruption.2147 * Report the problem, then omit the reference from2148 * the output.2149 */2150 error("%s does not point to a valid object!", entry->name);2151 return 0;2152 }21532154 peel_status = peel_entry(entry, 0);2155 write_packed_entry(*fd, entry->name, entry->u.value.sha1,2156 peel_status == PEEL_PEELED ?2157 entry->u.value.peeled : NULL);21582159 return 0;2160}21612162static int repack_without_ref(const char *refname)2163{2164 int fd;2165 struct ref_cache *refs = get_ref_cache(NULL);2166 struct ref_dir *packed;21672168 if (!get_packed_ref(refname))2169 return 0; /* refname does not exist in packed refs */21702171 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);2172 if (fd < 0) {2173 unable_to_lock_error(git_path("packed-refs"), errno);2174 return error("cannot delete '%s' from packed refs", refname);2175 }2176 clear_packed_ref_cache(refs);2177 packed = get_packed_refs(refs);2178 /* Remove refname from the cache. */2179 if (remove_entry(packed, refname) == -1) {2180 /*2181 * The packed entry disappeared while we were2182 * acquiring the lock.2183 */2184 rollback_lock_file(&packlock);2185 return 0;2186 }2187 write_or_die(fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));2188 do_for_each_entry_in_dir(packed, 0, repack_ref_fn, &fd);2189 return commit_lock_file(&packlock);2190}21912192int delete_ref(const char *refname, const unsigned char *sha1, int delopt)2193{2194 struct ref_lock *lock;2195 int err, i = 0, ret = 0, flag = 0;21962197 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);2198 if (!lock)2199 return 1;2200 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2201 /* loose */2202 i = strlen(lock->lk->filename) - 5; /* .lock */2203 lock->lk->filename[i] = 0;2204 err = unlink_or_warn(lock->lk->filename);2205 if (err && errno != ENOENT)2206 ret = 1;22072208 lock->lk->filename[i] = '.';2209 }2210 /* removing the loose one could have resurrected an earlier2211 * packed one. Also, if it was not loose we need to repack2212 * without it.2213 */2214 ret |= repack_without_ref(lock->ref_name);22152216 unlink_or_warn(git_path("logs/%s", lock->ref_name));2217 clear_loose_ref_cache(get_ref_cache(NULL));2218 unlock_ref(lock);2219 return ret;2220}22212222/*2223 * People using contrib's git-new-workdir have .git/logs/refs ->2224 * /some/other/path/.git/logs/refs, and that may live on another device.2225 *2226 * IOW, to avoid cross device rename errors, the temporary renamed log must2227 * live into logs/refs.2228 */2229#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"22302231int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)2232{2233 unsigned char sha1[20], orig_sha1[20];2234 int flag = 0, logmoved = 0;2235 struct ref_lock *lock;2236 struct stat loginfo;2237 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2238 const char *symref = NULL;2239 struct ref_cache *refs = get_ref_cache(NULL);22402241 if (log && S_ISLNK(loginfo.st_mode))2242 return error("reflog for %s is a symlink", oldrefname);22432244 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);2245 if (flag & REF_ISSYMREF)2246 return error("refname %s is a symbolic ref, renaming it is not supported",2247 oldrefname);2248 if (!symref)2249 return error("refname %s not found", oldrefname);22502251 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))2252 return 1;22532254 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))2255 return 1;22562257 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2258 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2259 oldrefname, strerror(errno));22602261 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2262 error("unable to delete old %s", oldrefname);2263 goto rollback;2264 }22652266 if (!read_ref_full(newrefname, sha1, 1, &flag) &&2267 delete_ref(newrefname, sha1, REF_NODEREF)) {2268 if (errno==EISDIR) {2269 if (remove_empty_directories(git_path("%s", newrefname))) {2270 error("Directory not empty: %s", newrefname);2271 goto rollback;2272 }2273 } else {2274 error("unable to delete existing %s", newrefname);2275 goto rollback;2276 }2277 }22782279 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {2280 error("unable to create directory for %s", newrefname);2281 goto rollback;2282 }22832284 retry:2285 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {2286 if (errno==EISDIR || errno==ENOTDIR) {2287 /*2288 * rename(a, b) when b is an existing2289 * directory ought to result in ISDIR, but2290 * Solaris 5.8 gives ENOTDIR. Sheesh.2291 */2292 if (remove_empty_directories(git_path("logs/%s", newrefname))) {2293 error("Directory not empty: logs/%s", newrefname);2294 goto rollback;2295 }2296 goto retry;2297 } else {2298 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2299 newrefname, strerror(errno));2300 goto rollback;2301 }2302 }2303 logmoved = log;23042305 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);2306 if (!lock) {2307 error("unable to lock %s for update", newrefname);2308 goto rollback;2309 }2310 lock->force_write = 1;2311 hashcpy(lock->old_sha1, orig_sha1);2312 if (write_ref_sha1(lock, orig_sha1, logmsg)) {2313 error("unable to write current sha1 into %s", newrefname);2314 goto rollback;2315 }23162317 return 0;23182319 rollback:2320 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);2321 if (!lock) {2322 error("unable to lock %s for rollback", oldrefname);2323 goto rollbacklog;2324 }23252326 lock->force_write = 1;2327 flag = log_all_ref_updates;2328 log_all_ref_updates = 0;2329 if (write_ref_sha1(lock, orig_sha1, NULL))2330 error("unable to write current sha1 into %s", oldrefname);2331 log_all_ref_updates = flag;23322333 rollbacklog:2334 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2335 error("unable to restore logfile %s from %s: %s",2336 oldrefname, newrefname, strerror(errno));2337 if (!logmoved && log &&2338 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2339 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2340 oldrefname, strerror(errno));23412342 return 1;2343}23442345int close_ref(struct ref_lock *lock)2346{2347 if (close_lock_file(lock->lk))2348 return -1;2349 lock->lock_fd = -1;2350 return 0;2351}23522353int commit_ref(struct ref_lock *lock)2354{2355 if (commit_lock_file(lock->lk))2356 return -1;2357 lock->lock_fd = -1;2358 return 0;2359}23602361void unlock_ref(struct ref_lock *lock)2362{2363 /* Do not free lock->lk -- atexit() still looks at them */2364 if (lock->lk)2365 rollback_lock_file(lock->lk);2366 free(lock->ref_name);2367 free(lock->orig_ref_name);2368 free(lock);2369}23702371/*2372 * copy the reflog message msg to buf, which has been allocated sufficiently2373 * large, while cleaning up the whitespaces. Especially, convert LF to space,2374 * because reflog file is one line per entry.2375 */2376static int copy_msg(char *buf, const char *msg)2377{2378 char *cp = buf;2379 char c;2380 int wasspace = 1;23812382 *cp++ = '\t';2383 while ((c = *msg++)) {2384 if (wasspace && isspace(c))2385 continue;2386 wasspace = isspace(c);2387 if (wasspace)2388 c = ' ';2389 *cp++ = c;2390 }2391 while (buf < cp && isspace(cp[-1]))2392 cp--;2393 *cp++ = '\n';2394 return cp - buf;2395}23962397int log_ref_setup(const char *refname, char *logfile, int bufsize)2398{2399 int logfd, oflags = O_APPEND | O_WRONLY;24002401 git_snpath(logfile, bufsize, "logs/%s", refname);2402 if (log_all_ref_updates &&2403 (!prefixcmp(refname, "refs/heads/") ||2404 !prefixcmp(refname, "refs/remotes/") ||2405 !prefixcmp(refname, "refs/notes/") ||2406 !strcmp(refname, "HEAD"))) {2407 if (safe_create_leading_directories(logfile) < 0)2408 return error("unable to create directory for %s",2409 logfile);2410 oflags |= O_CREAT;2411 }24122413 logfd = open(logfile, oflags, 0666);2414 if (logfd < 0) {2415 if (!(oflags & O_CREAT) && errno == ENOENT)2416 return 0;24172418 if ((oflags & O_CREAT) && errno == EISDIR) {2419 if (remove_empty_directories(logfile)) {2420 return error("There are still logs under '%s'",2421 logfile);2422 }2423 logfd = open(logfile, oflags, 0666);2424 }24252426 if (logfd < 0)2427 return error("Unable to append to %s: %s",2428 logfile, strerror(errno));2429 }24302431 adjust_shared_perm(logfile);2432 close(logfd);2433 return 0;2434}24352436static int log_ref_write(const char *refname, const unsigned char *old_sha1,2437 const unsigned char *new_sha1, const char *msg)2438{2439 int logfd, result, written, oflags = O_APPEND | O_WRONLY;2440 unsigned maxlen, len;2441 int msglen;2442 char log_file[PATH_MAX];2443 char *logrec;2444 const char *committer;24452446 if (log_all_ref_updates < 0)2447 log_all_ref_updates = !is_bare_repository();24482449 result = log_ref_setup(refname, log_file, sizeof(log_file));2450 if (result)2451 return result;24522453 logfd = open(log_file, oflags);2454 if (logfd < 0)2455 return 0;2456 msglen = msg ? strlen(msg) : 0;2457 committer = git_committer_info(0);2458 maxlen = strlen(committer) + msglen + 100;2459 logrec = xmalloc(maxlen);2460 len = sprintf(logrec, "%s %s %s\n",2461 sha1_to_hex(old_sha1),2462 sha1_to_hex(new_sha1),2463 committer);2464 if (msglen)2465 len += copy_msg(logrec + len - 1, msg) - 1;2466 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;2467 free(logrec);2468 if (close(logfd) != 0 || written != len)2469 return error("Unable to append to %s", log_file);2470 return 0;2471}24722473static int is_branch(const char *refname)2474{2475 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");2476}24772478int write_ref_sha1(struct ref_lock *lock,2479 const unsigned char *sha1, const char *logmsg)2480{2481 static char term = '\n';2482 struct object *o;24832484 if (!lock)2485 return -1;2486 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {2487 unlock_ref(lock);2488 return 0;2489 }2490 o = parse_object(sha1);2491 if (!o) {2492 error("Trying to write ref %s with nonexistent object %s",2493 lock->ref_name, sha1_to_hex(sha1));2494 unlock_ref(lock);2495 return -1;2496 }2497 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2498 error("Trying to write non-commit object %s to branch %s",2499 sha1_to_hex(sha1), lock->ref_name);2500 unlock_ref(lock);2501 return -1;2502 }2503 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||2504 write_in_full(lock->lock_fd, &term, 1) != 12505 || close_ref(lock) < 0) {2506 error("Couldn't write %s", lock->lk->filename);2507 unlock_ref(lock);2508 return -1;2509 }2510 clear_loose_ref_cache(get_ref_cache(NULL));2511 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||2512 (strcmp(lock->ref_name, lock->orig_ref_name) &&2513 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {2514 unlock_ref(lock);2515 return -1;2516 }2517 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {2518 /*2519 * Special hack: If a branch is updated directly and HEAD2520 * points to it (may happen on the remote side of a push2521 * for example) then logically the HEAD reflog should be2522 * updated too.2523 * A generic solution implies reverse symref information,2524 * but finding all symrefs pointing to the given branch2525 * would be rather costly for this rare event (the direct2526 * update of a branch) to be worth it. So let's cheat and2527 * check with HEAD only which should cover 99% of all usage2528 * scenarios (even 100% of the default ones).2529 */2530 unsigned char head_sha1[20];2531 int head_flag;2532 const char *head_ref;2533 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);2534 if (head_ref && (head_flag & REF_ISSYMREF) &&2535 !strcmp(head_ref, lock->ref_name))2536 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);2537 }2538 if (commit_ref(lock)) {2539 error("Couldn't set %s", lock->ref_name);2540 unlock_ref(lock);2541 return -1;2542 }2543 unlock_ref(lock);2544 return 0;2545}25462547int create_symref(const char *ref_target, const char *refs_heads_master,2548 const char *logmsg)2549{2550 const char *lockpath;2551 char ref[1000];2552 int fd, len, written;2553 char *git_HEAD = git_pathdup("%s", ref_target);2554 unsigned char old_sha1[20], new_sha1[20];25552556 if (logmsg && read_ref(ref_target, old_sha1))2557 hashclr(old_sha1);25582559 if (safe_create_leading_directories(git_HEAD) < 0)2560 return error("unable to create directory for %s", git_HEAD);25612562#ifndef NO_SYMLINK_HEAD2563 if (prefer_symlink_refs) {2564 unlink(git_HEAD);2565 if (!symlink(refs_heads_master, git_HEAD))2566 goto done;2567 fprintf(stderr, "no symlink - falling back to symbolic ref\n");2568 }2569#endif25702571 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);2572 if (sizeof(ref) <= len) {2573 error("refname too long: %s", refs_heads_master);2574 goto error_free_return;2575 }2576 lockpath = mkpath("%s.lock", git_HEAD);2577 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);2578 if (fd < 0) {2579 error("Unable to open %s for writing", lockpath);2580 goto error_free_return;2581 }2582 written = write_in_full(fd, ref, len);2583 if (close(fd) != 0 || written != len) {2584 error("Unable to write to %s", lockpath);2585 goto error_unlink_return;2586 }2587 if (rename(lockpath, git_HEAD) < 0) {2588 error("Unable to create %s", git_HEAD);2589 goto error_unlink_return;2590 }2591 if (adjust_shared_perm(git_HEAD)) {2592 error("Unable to fix permissions on %s", lockpath);2593 error_unlink_return:2594 unlink_or_warn(lockpath);2595 error_free_return:2596 free(git_HEAD);2597 return -1;2598 }25992600#ifndef NO_SYMLINK_HEAD2601 done:2602#endif2603 if (logmsg && !read_ref(refs_heads_master, new_sha1))2604 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);26052606 free(git_HEAD);2607 return 0;2608}26092610static char *ref_msg(const char *line, const char *endp)2611{2612 const char *ep;2613 line += 82;2614 ep = memchr(line, '\n', endp - line);2615 if (!ep)2616 ep = endp;2617 return xmemdupz(line, ep - line);2618}26192620int read_ref_at(const char *refname, unsigned long at_time, int cnt,2621 unsigned char *sha1, char **msg,2622 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)2623{2624 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;2625 char *tz_c;2626 int logfd, tz, reccnt = 0;2627 struct stat st;2628 unsigned long date;2629 unsigned char logged_sha1[20];2630 void *log_mapped;2631 size_t mapsz;26322633 logfile = git_path("logs/%s", refname);2634 logfd = open(logfile, O_RDONLY, 0);2635 if (logfd < 0)2636 die_errno("Unable to read log '%s'", logfile);2637 fstat(logfd, &st);2638 if (!st.st_size)2639 die("Log %s is empty.", logfile);2640 mapsz = xsize_t(st.st_size);2641 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);2642 logdata = log_mapped;2643 close(logfd);26442645 lastrec = NULL;2646 rec = logend = logdata + st.st_size;2647 while (logdata < rec) {2648 reccnt++;2649 if (logdata < rec && *(rec-1) == '\n')2650 rec--;2651 lastgt = NULL;2652 while (logdata < rec && *(rec-1) != '\n') {2653 rec--;2654 if (*rec == '>')2655 lastgt = rec;2656 }2657 if (!lastgt)2658 die("Log %s is corrupt.", logfile);2659 date = strtoul(lastgt + 1, &tz_c, 10);2660 if (date <= at_time || cnt == 0) {2661 tz = strtoul(tz_c, NULL, 10);2662 if (msg)2663 *msg = ref_msg(rec, logend);2664 if (cutoff_time)2665 *cutoff_time = date;2666 if (cutoff_tz)2667 *cutoff_tz = tz;2668 if (cutoff_cnt)2669 *cutoff_cnt = reccnt - 1;2670 if (lastrec) {2671 if (get_sha1_hex(lastrec, logged_sha1))2672 die("Log %s is corrupt.", logfile);2673 if (get_sha1_hex(rec + 41, sha1))2674 die("Log %s is corrupt.", logfile);2675 if (hashcmp(logged_sha1, sha1)) {2676 warning("Log %s has gap after %s.",2677 logfile, show_date(date, tz, DATE_RFC2822));2678 }2679 }2680 else if (date == at_time) {2681 if (get_sha1_hex(rec + 41, sha1))2682 die("Log %s is corrupt.", logfile);2683 }2684 else {2685 if (get_sha1_hex(rec + 41, logged_sha1))2686 die("Log %s is corrupt.", logfile);2687 if (hashcmp(logged_sha1, sha1)) {2688 warning("Log %s unexpectedly ended on %s.",2689 logfile, show_date(date, tz, DATE_RFC2822));2690 }2691 }2692 munmap(log_mapped, mapsz);2693 return 0;2694 }2695 lastrec = rec;2696 if (cnt > 0)2697 cnt--;2698 }26992700 rec = logdata;2701 while (rec < logend && *rec != '>' && *rec != '\n')2702 rec++;2703 if (rec == logend || *rec == '\n')2704 die("Log %s is corrupt.", logfile);2705 date = strtoul(rec + 1, &tz_c, 10);2706 tz = strtoul(tz_c, NULL, 10);2707 if (get_sha1_hex(logdata, sha1))2708 die("Log %s is corrupt.", logfile);2709 if (is_null_sha1(sha1)) {2710 if (get_sha1_hex(logdata + 41, sha1))2711 die("Log %s is corrupt.", logfile);2712 }2713 if (msg)2714 *msg = ref_msg(logdata, logend);2715 munmap(log_mapped, mapsz);27162717 if (cutoff_time)2718 *cutoff_time = date;2719 if (cutoff_tz)2720 *cutoff_tz = tz;2721 if (cutoff_cnt)2722 *cutoff_cnt = reccnt;2723 return 1;2724}27252726int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)2727{2728 const char *logfile;2729 FILE *logfp;2730 struct strbuf sb = STRBUF_INIT;2731 int ret = 0;27322733 logfile = git_path("logs/%s", refname);2734 logfp = fopen(logfile, "r");2735 if (!logfp)2736 return -1;27372738 if (ofs) {2739 struct stat statbuf;2740 if (fstat(fileno(logfp), &statbuf) ||2741 statbuf.st_size < ofs ||2742 fseek(logfp, -ofs, SEEK_END) ||2743 strbuf_getwholeline(&sb, logfp, '\n')) {2744 fclose(logfp);2745 strbuf_release(&sb);2746 return -1;2747 }2748 }27492750 while (!strbuf_getwholeline(&sb, logfp, '\n')) {2751 unsigned char osha1[20], nsha1[20];2752 char *email_end, *message;2753 unsigned long timestamp;2754 int tz;27552756 /* old SP new SP name <email> SP time TAB msg LF */2757 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||2758 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||2759 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||2760 !(email_end = strchr(sb.buf + 82, '>')) ||2761 email_end[1] != ' ' ||2762 !(timestamp = strtoul(email_end + 2, &message, 10)) ||2763 !message || message[0] != ' ' ||2764 (message[1] != '+' && message[1] != '-') ||2765 !isdigit(message[2]) || !isdigit(message[3]) ||2766 !isdigit(message[4]) || !isdigit(message[5]))2767 continue; /* corrupt? */2768 email_end[1] = '\0';2769 tz = strtol(message + 1, NULL, 10);2770 if (message[6] != '\t')2771 message += 6;2772 else2773 message += 7;2774 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,2775 cb_data);2776 if (ret)2777 break;2778 }2779 fclose(logfp);2780 strbuf_release(&sb);2781 return ret;2782}27832784int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)2785{2786 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);2787}27882789/*2790 * Call fn for each reflog in the namespace indicated by name. name2791 * must be empty or end with '/'. Name will be used as a scratch2792 * space, but its contents will be restored before return.2793 */2794static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)2795{2796 DIR *d = opendir(git_path("logs/%s", name->buf));2797 int retval = 0;2798 struct dirent *de;2799 int oldlen = name->len;28002801 if (!d)2802 return name->len ? errno : 0;28032804 while ((de = readdir(d)) != NULL) {2805 struct stat st;28062807 if (de->d_name[0] == '.')2808 continue;2809 if (has_extension(de->d_name, ".lock"))2810 continue;2811 strbuf_addstr(name, de->d_name);2812 if (stat(git_path("logs/%s", name->buf), &st) < 0) {2813 ; /* silently ignore */2814 } else {2815 if (S_ISDIR(st.st_mode)) {2816 strbuf_addch(name, '/');2817 retval = do_for_each_reflog(name, fn, cb_data);2818 } else {2819 unsigned char sha1[20];2820 if (read_ref_full(name->buf, sha1, 0, NULL))2821 retval = error("bad ref for %s", name->buf);2822 else2823 retval = fn(name->buf, sha1, 0, cb_data);2824 }2825 if (retval)2826 break;2827 }2828 strbuf_setlen(name, oldlen);2829 }2830 closedir(d);2831 return retval;2832}28332834int for_each_reflog(each_ref_fn fn, void *cb_data)2835{2836 int retval;2837 struct strbuf name;2838 strbuf_init(&name, PATH_MAX);2839 retval = do_for_each_reflog(&name, fn, cb_data);2840 strbuf_release(&name);2841 return retval;2842}28432844int update_ref(const char *action, const char *refname,2845 const unsigned char *sha1, const unsigned char *oldval,2846 int flags, enum action_on_err onerr)2847{2848 static struct ref_lock *lock;2849 lock = lock_any_ref_for_update(refname, oldval, flags);2850 if (!lock) {2851 const char *str = "Cannot lock the ref '%s'.";2852 switch (onerr) {2853 case MSG_ON_ERR: error(str, refname); break;2854 case DIE_ON_ERR: die(str, refname); break;2855 case QUIET_ON_ERR: break;2856 }2857 return 1;2858 }2859 if (write_ref_sha1(lock, sha1, action) < 0) {2860 const char *str = "Cannot update the ref '%s'.";2861 switch (onerr) {2862 case MSG_ON_ERR: error(str, refname); break;2863 case DIE_ON_ERR: die(str, refname); break;2864 case QUIET_ON_ERR: break;2865 }2866 return 1;2867 }2868 return 0;2869}28702871struct ref *find_ref_by_name(const struct ref *list, const char *name)2872{2873 for ( ; list; list = list->next)2874 if (!strcmp(list->name, name))2875 return (struct ref *)list;2876 return NULL;2877}28782879/*2880 * generate a format suitable for scanf from a ref_rev_parse_rules2881 * rule, that is replace the "%.*s" spec with a "%s" spec2882 */2883static void gen_scanf_fmt(char *scanf_fmt, const char *rule)2884{2885 char *spec;28862887 spec = strstr(rule, "%.*s");2888 if (!spec || strstr(spec + 4, "%.*s"))2889 die("invalid rule in ref_rev_parse_rules: %s", rule);28902891 /* copy all until spec */2892 strncpy(scanf_fmt, rule, spec - rule);2893 scanf_fmt[spec - rule] = '\0';2894 /* copy new spec */2895 strcat(scanf_fmt, "%s");2896 /* copy remaining rule */2897 strcat(scanf_fmt, spec + 4);28982899 return;2900}29012902char *shorten_unambiguous_ref(const char *refname, int strict)2903{2904 int i;2905 static char **scanf_fmts;2906 static int nr_rules;2907 char *short_name;29082909 /* pre generate scanf formats from ref_rev_parse_rules[] */2910 if (!nr_rules) {2911 size_t total_len = 0;29122913 /* the rule list is NULL terminated, count them first */2914 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)2915 /* no +1 because strlen("%s") < strlen("%.*s") */2916 total_len += strlen(ref_rev_parse_rules[nr_rules]);29172918 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);29192920 total_len = 0;2921 for (i = 0; i < nr_rules; i++) {2922 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]2923 + total_len;2924 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);2925 total_len += strlen(ref_rev_parse_rules[i]);2926 }2927 }29282929 /* bail out if there are no rules */2930 if (!nr_rules)2931 return xstrdup(refname);29322933 /* buffer for scanf result, at most refname must fit */2934 short_name = xstrdup(refname);29352936 /* skip first rule, it will always match */2937 for (i = nr_rules - 1; i > 0 ; --i) {2938 int j;2939 int rules_to_fail = i;2940 int short_name_len;29412942 if (1 != sscanf(refname, scanf_fmts[i], short_name))2943 continue;29442945 short_name_len = strlen(short_name);29462947 /*2948 * in strict mode, all (except the matched one) rules2949 * must fail to resolve to a valid non-ambiguous ref2950 */2951 if (strict)2952 rules_to_fail = nr_rules;29532954 /*2955 * check if the short name resolves to a valid ref,2956 * but use only rules prior to the matched one2957 */2958 for (j = 0; j < rules_to_fail; j++) {2959 const char *rule = ref_rev_parse_rules[j];2960 char refname[PATH_MAX];29612962 /* skip matched rule */2963 if (i == j)2964 continue;29652966 /*2967 * the short name is ambiguous, if it resolves2968 * (with this previous rule) to a valid ref2969 * read_ref() returns 0 on success2970 */2971 mksnpath(refname, sizeof(refname),2972 rule, short_name_len, short_name);2973 if (ref_exists(refname))2974 break;2975 }29762977 /*2978 * short name is non-ambiguous if all previous rules2979 * haven't resolved to a valid ref2980 */2981 if (j == rules_to_fail)2982 return short_name;2983 }29842985 free(short_name);2986 return xstrdup(refname);2987}