Fix parsing of @{-1}@{1}
[git/git.git] / sha1_name.c
CommitLineData
9938af6a 1#include "cache.h"
5385f52d 2#include "tag.h"
9938af6a 3#include "commit.h"
5385f52d
JH
4#include "tree.h"
5#include "blob.h"
f3ab49db 6#include "tree-walk.h"
d556fae2 7#include "refs.h"
9938af6a
JH
8
9static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
10{
99a19b43 11 struct alternate_object_database *alt;
9938af6a 12 char hex[40];
99a19b43
JH
13 int found = 0;
14 static struct alternate_object_database *fakeent;
15
16 if (!fakeent) {
17 const char *objdir = get_object_directory();
18 int objdir_len = strlen(objdir);
19 int entlen = objdir_len + 43;
20 fakeent = xmalloc(sizeof(*fakeent) + entlen);
21 memcpy(fakeent->base, objdir, objdir_len);
22 fakeent->name = fakeent->base + objdir_len + 1;
23 fakeent->name[-1] = '/';
24 }
25 fakeent->next = alt_odb_list;
9938af6a 26
9938af6a 27 sprintf(hex, "%.2s", name);
99a19b43 28 for (alt = fakeent; alt && found < 2; alt = alt->next) {
9938af6a 29 struct dirent *de;
99a19b43
JH
30 DIR *dir;
31 sprintf(alt->name, "%.2s/", name);
32 dir = opendir(alt->base);
33 if (!dir)
34 continue;
9938af6a
JH
35 while ((de = readdir(dir)) != NULL) {
36 if (strlen(de->d_name) != 38)
37 continue;
99a19b43 38 if (memcmp(de->d_name, name + 2, len - 2))
9938af6a 39 continue;
99a19b43
JH
40 if (!found) {
41 memcpy(hex + 2, de->d_name, 38);
42 found++;
43 }
44 else if (memcmp(hex + 2, de->d_name, 38)) {
45 found = 2;
9938af6a 46 break;
99a19b43 47 }
9938af6a
JH
48 }
49 closedir(dir);
50 }
51 if (found == 1)
52 return get_sha1_hex(hex, sha1) == 0;
99a19b43 53 return found;
9938af6a
JH
54}
55
56static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
57{
58 do {
59 if (*a != *b)
60 return 0;
61 a++;
62 b++;
63 len -= 2;
64 } while (len > 1);
65 if (len)
66 if ((*a ^ *b) & 0xf0)
67 return 0;
68 return 1;
69}
70
71static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
72{
73 struct packed_git *p;
d72308e0 74 const unsigned char *found_sha1 = NULL;
99a19b43 75 int found = 0;
9938af6a
JH
76
77 prepare_packed_git();
99a19b43 78 for (p = packed_git; p && found < 2; p = p->next) {
1055880e
JB
79 uint32_t num, last;
80 uint32_t first = 0;
81 open_pack_index(p);
82 num = p->num_objects;
83 last = num;
9938af6a 84 while (first < last) {
326bf396 85 uint32_t mid = (first + last) / 2;
d72308e0 86 const unsigned char *now;
9938af6a
JH
87 int cmp;
88
d72308e0 89 now = nth_packed_object_sha1(p, mid);
a89fccd2 90 cmp = hashcmp(match, now);
9938af6a
JH
91 if (!cmp) {
92 first = mid;
93 break;
94 }
95 if (cmp > 0) {
96 first = mid+1;
97 continue;
98 }
99 last = mid;
100 }
101 if (first < num) {
d72308e0
NP
102 const unsigned char *now, *next;
103 now = nth_packed_object_sha1(p, first);
9938af6a 104 if (match_sha(len, match, now)) {
d72308e0
NP
105 next = nth_packed_object_sha1(p, first+1);
106 if (!next|| !match_sha(len, match, next)) {
0bc45890
JH
107 /* unique within this pack */
108 if (!found) {
d72308e0 109 found_sha1 = now;
0bc45890
JH
110 found++;
111 }
a89fccd2 112 else if (hashcmp(found_sha1, now)) {
0bc45890
JH
113 found = 2;
114 break;
115 }
99a19b43 116 }
0bc45890
JH
117 else {
118 /* not even unique within this pack */
99a19b43
JH
119 found = 2;
120 break;
9938af6a
JH
121 }
122 }
123 }
124 }
99a19b43 125 if (found == 1)
e702496e 126 hashcpy(sha1, found_sha1);
99a19b43
JH
127 return found;
128}
129
013f276e
JH
130#define SHORT_NAME_NOT_FOUND (-1)
131#define SHORT_NAME_AMBIGUOUS (-2)
132
99a19b43
JH
133static int find_unique_short_object(int len, char *canonical,
134 unsigned char *res, unsigned char *sha1)
135{
136 int has_unpacked, has_packed;
137 unsigned char unpacked_sha1[20], packed_sha1[20];
138
693d2bc6 139 prepare_alt_odb();
99a19b43
JH
140 has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
141 has_packed = find_short_packed_object(len, res, packed_sha1);
142 if (!has_unpacked && !has_packed)
013f276e 143 return SHORT_NAME_NOT_FOUND;
99a19b43 144 if (1 < has_unpacked || 1 < has_packed)
013f276e 145 return SHORT_NAME_AMBIGUOUS;
99a19b43 146 if (has_unpacked != has_packed) {
e702496e 147 hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1));
99a19b43
JH
148 return 0;
149 }
150 /* Both have unique ones -- do they match? */
a89fccd2 151 if (hashcmp(packed_sha1, unpacked_sha1))
e974c9ab 152 return SHORT_NAME_AMBIGUOUS;
e702496e 153 hashcpy(sha1, packed_sha1);
9938af6a
JH
154 return 0;
155}
156
013f276e
JH
157static int get_short_sha1(const char *name, int len, unsigned char *sha1,
158 int quietly)
9938af6a 159{
013f276e 160 int i, status;
9938af6a
JH
161 char canonical[40];
162 unsigned char res[20];
163
8a83157e 164 if (len < MINIMUM_ABBREV || len > 40)
af61c6e0 165 return -1;
a8e0d16d 166 hashclr(res);
9938af6a 167 memset(canonical, 'x', 40);
af61c6e0 168 for (i = 0; i < len ;i++) {
9938af6a
JH
169 unsigned char c = name[i];
170 unsigned char val;
9938af6a
JH
171 if (c >= '0' && c <= '9')
172 val = c - '0';
173 else if (c >= 'a' && c <= 'f')
174 val = c - 'a' + 10;
175 else if (c >= 'A' && c <='F') {
176 val = c - 'A' + 10;
177 c -= 'A' - 'a';
178 }
179 else
180 return -1;
181 canonical[i] = c;
182 if (!(i & 1))
183 val <<= 4;
184 res[i >> 1] |= val;
185 }
99a19b43 186
013f276e
JH
187 status = find_unique_short_object(i, canonical, res, sha1);
188 if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
189 return error("short SHA1 %.*s is ambiguous.", len, canonical);
190 return status;
191}
192
193const char *find_unique_abbrev(const unsigned char *sha1, int len)
194{
b66fde9a 195 int status, exists;
013f276e 196 static char hex[41];
47dd0d59 197
b66fde9a 198 exists = has_sha1_file(sha1);
013f276e 199 memcpy(hex, sha1_to_hex(sha1), 40);
02c5cba2 200 if (len == 40 || !len)
47dd0d59 201 return hex;
013f276e
JH
202 while (len < 40) {
203 unsigned char sha1_ret[20];
204 status = get_short_sha1(hex, len, sha1_ret, 1);
b66fde9a
JH
205 if (exists
206 ? !status
207 : status == SHORT_NAME_NOT_FOUND) {
013f276e
JH
208 hex[len] = 0;
209 return hex;
210 }
013f276e
JH
211 len++;
212 }
b66fde9a 213 return hex;
9938af6a
JH
214}
215
6677c466 216static int ambiguous_path(const char *path, int len)
af13cdf2
LT
217{
218 int slash = 1;
6677c466 219 int cnt;
af13cdf2 220
6677c466 221 for (cnt = 0; cnt < len; cnt++) {
af13cdf2
LT
222 switch (*path++) {
223 case '\0':
224 break;
225 case '/':
226 if (slash)
227 break;
228 slash = 1;
229 continue;
230 case '.':
231 continue;
232 default:
233 slash = 0;
234 continue;
235 }
c054d64e 236 break;
af13cdf2 237 }
6677c466 238 return slash;
af13cdf2
LT
239}
240
aa9c55b6
JS
241/*
242 * *string and *len will only be substituted, and *string returned (for
243 * later free()ing) if the string passed in is of the form @{-<n>}.
244 */
245static char *substitute_nth_last_branch(const char **string, int *len)
246{
247 struct strbuf buf = STRBUF_INIT;
248 int ret = interpret_nth_last_branch(*string, &buf);
249
250 if (ret == *len) {
251 size_t size;
252 *string = strbuf_detach(&buf, &size);
253 *len = size;
254 return (char *)*string;
255 }
256
257 return NULL;
258}
259
e86eb666 260int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
9938af6a 261{
aa9c55b6 262 char *last_branch = substitute_nth_last_branch(&str, &len);
e86eb666
JH
263 const char **p, *r;
264 int refs_found = 0;
265
266 *ref = NULL;
79803322 267 for (p = ref_rev_parse_rules; *p; p++) {
94cc3552 268 char fullref[PATH_MAX];
e86eb666
JH
269 unsigned char sha1_from_ref[20];
270 unsigned char *this_result;
271
272 this_result = refs_found ? sha1_from_ref : sha1;
94cc3552
AR
273 mksnpath(fullref, sizeof(fullref), *p, len, str);
274 r = resolve_ref(fullref, this_result, 1, NULL);
e86eb666
JH
275 if (r) {
276 if (!refs_found++)
277 *ref = xstrdup(r);
278 if (!warn_ambiguous_refs)
279 break;
280 }
281 }
aa9c55b6 282 free(last_branch);
e86eb666
JH
283 return refs_found;
284}
285
eb3a4822 286int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
f2eba66d 287{
aa9c55b6 288 char *last_branch = substitute_nth_last_branch(&str, &len);
f2eba66d
NP
289 const char **p;
290 int logs_found = 0;
291
292 *log = NULL;
79803322 293 for (p = ref_rev_parse_rules; *p; p++) {
f2eba66d 294 struct stat st;
40facde0
JH
295 unsigned char hash[20];
296 char path[PATH_MAX];
297 const char *ref, *it;
298
94cc3552 299 mksnpath(path, sizeof(path), *p, len, str);
0c4cd7f4 300 ref = resolve_ref(path, hash, 1, NULL);
40facde0
JH
301 if (!ref)
302 continue;
f2eba66d 303 if (!stat(git_path("logs/%s", path), &st) &&
40facde0
JH
304 S_ISREG(st.st_mode))
305 it = path;
306 else if (strcmp(ref, path) &&
307 !stat(git_path("logs/%s", ref), &st) &&
308 S_ISREG(st.st_mode))
309 it = ref;
310 else
311 continue;
312 if (!logs_found++) {
313 *log = xstrdup(it);
314 hashcpy(sha1, hash);
f2eba66d 315 }
40facde0
JH
316 if (!warn_ambiguous_refs)
317 break;
f2eba66d 318 }
aa9c55b6 319 free(last_branch);
f2eba66d
NP
320 return logs_found;
321}
322
d18ba221
TR
323static int get_sha1_1(const char *name, int len, unsigned char *sha1);
324
e86eb666
JH
325static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
326{
d556fae2 327 static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
ed378ec7 328 char *real_ref = NULL;
ab2a1a32
JH
329 int refs_found = 0;
330 int at, reflog_len;
9938af6a 331
3c3852e3 332 if (len == 40 && !get_sha1_hex(str, sha1))
9938af6a
JH
333 return 0;
334
d18ba221 335 /* basic@{time or number or -number} format to query ref-log */
694500ed 336 reflog_len = at = 0;
ab2a1a32 337 if (str[len-1] == '}') {
aa9c55b6 338 for (at = len-2; at >= 0; at--) {
ab2a1a32
JH
339 if (str[at] == '@' && str[at+1] == '{') {
340 reflog_len = (len-1) - (at+2);
341 len = at;
342 break;
343 }
d556fae2
SP
344 }
345 }
346
af13cdf2 347 /* Accept only unambiguous ref paths. */
11cf8801 348 if (len && ambiguous_path(str, len))
af13cdf2
LT
349 return -1;
350
11cf8801 351 if (!len && reflog_len) {
d18ba221
TR
352 struct strbuf buf = STRBUF_INIT;
353 int ret;
354 /* try the @{-N} syntax for n-th checkout */
355 ret = interpret_nth_last_branch(str+at, &buf);
356 if (ret > 0) {
357 /* substitute this branch name and restart */
358 return get_sha1_1(buf.buf, buf.len, sha1);
359 } else if (ret == 0) {
360 return -1;
361 }
11cf8801
NP
362 /* allow "@{...}" to mean the current branch reflog */
363 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
f2eba66d
NP
364 } else if (reflog_len)
365 refs_found = dwim_log(str, len, sha1, &real_ref);
366 else
11cf8801 367 refs_found = dwim_ref(str, len, sha1, &real_ref);
d556fae2
SP
368
369 if (!refs_found)
370 return -1;
371
372 if (warn_ambiguous_refs && refs_found > 1)
373 fprintf(stderr, warning, len, str);
374
ab2a1a32 375 if (reflog_len) {
ab2a1a32
JH
376 int nth, i;
377 unsigned long at_time;
16d7cc90
JH
378 unsigned long co_time;
379 int co_tz, co_cnt;
380
fe558516 381 /* Is it asking for N-th entry, or approxidate? */
ab2a1a32
JH
382 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
383 char ch = str[at+2+i];
384 if ('0' <= ch && ch <= '9')
385 nth = nth * 10 + ch - '0';
386 else
387 nth = -1;
388 }
ea360dd0
SP
389 if (100000000 <= nth) {
390 at_time = nth;
391 nth = -1;
392 } else if (0 <= nth)
ab2a1a32 393 at_time = 0;
861f00e3
JK
394 else {
395 char *tmp = xstrndup(str + at + 2, reflog_len);
396 at_time = approxidate(tmp);
397 free(tmp);
398 }
16d7cc90
JH
399 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
400 &co_time, &co_tz, &co_cnt)) {
401 if (at_time)
402 fprintf(stderr,
403 "warning: Log for '%.*s' only goes "
404 "back to %s.\n", len, str,
73013afd 405 show_date(co_time, co_tz, DATE_RFC2822));
16d7cc90
JH
406 else
407 fprintf(stderr,
408 "warning: Log for '%.*s' only has "
409 "%d entries.\n", len, str, co_cnt);
410 }
d556fae2
SP
411 }
412
ed378ec7 413 free(real_ref);
d556fae2 414 return 0;
9938af6a
JH
415}
416
9938af6a
JH
417static int get_parent(const char *name, int len,
418 unsigned char *result, int idx)
419{
420 unsigned char sha1[20];
421 int ret = get_sha1_1(name, len, sha1);
422 struct commit *commit;
423 struct commit_list *p;
424
425 if (ret)
426 return ret;
427 commit = lookup_commit_reference(sha1);
428 if (!commit)
429 return -1;
430 if (parse_commit(commit))
431 return -1;
432 if (!idx) {
e702496e 433 hashcpy(result, commit->object.sha1);
9938af6a
JH
434 return 0;
435 }
436 p = commit->parents;
437 while (p) {
438 if (!--idx) {
e702496e 439 hashcpy(result, p->item->object.sha1);
9938af6a
JH
440 return 0;
441 }
442 p = p->next;
443 }
444 return -1;
445}
446
4f7599ac
JH
447static int get_nth_ancestor(const char *name, int len,
448 unsigned char *result, int generation)
449{
450 unsigned char sha1[20];
621ff675
LT
451 struct commit *commit;
452 int ret;
453
454 ret = get_sha1_1(name, len, sha1);
4f7599ac
JH
455 if (ret)
456 return ret;
621ff675
LT
457 commit = lookup_commit_reference(sha1);
458 if (!commit)
459 return -1;
4f7599ac
JH
460
461 while (generation--) {
621ff675 462 if (parse_commit(commit) || !commit->parents)
4f7599ac 463 return -1;
621ff675 464 commit = commit->parents->item;
4f7599ac 465 }
621ff675 466 hashcpy(result, commit->object.sha1);
4f7599ac
JH
467 return 0;
468}
469
81776315
JH
470struct object *peel_to_type(const char *name, int namelen,
471 struct object *o, enum object_type expected_type)
472{
473 if (name && !namelen)
474 namelen = strlen(name);
475 if (!o) {
476 unsigned char sha1[20];
477 if (get_sha1_1(name, namelen, sha1))
478 return NULL;
479 o = parse_object(sha1);
480 }
481 while (1) {
482 if (!o || (!o->parsed && !parse_object(o->sha1)))
483 return NULL;
484 if (o->type == expected_type)
485 return o;
486 if (o->type == OBJ_TAG)
487 o = ((struct tag*) o)->tagged;
488 else if (o->type == OBJ_COMMIT)
489 o = &(((struct commit *) o)->tree->object);
490 else {
491 if (name)
492 error("%.*s: expected %s type, but the object "
493 "dereferences to %s type",
494 namelen, name, typename(expected_type),
495 typename(o->type));
496 return NULL;
497 }
498 }
499}
500
5385f52d
JH
501static int peel_onion(const char *name, int len, unsigned char *sha1)
502{
503 unsigned char outer[20];
504 const char *sp;
885a86ab 505 unsigned int expected_type = 0;
5385f52d
JH
506 struct object *o;
507
508 /*
509 * "ref^{type}" dereferences ref repeatedly until you cannot
510 * dereference anymore, or you get an object of given type,
511 * whichever comes first. "ref^{}" means just dereference
512 * tags until you get a non-tag. "ref^0" is a shorthand for
513 * "ref^{commit}". "commit^{tree}" could be used to find the
514 * top-level tree of the given commit.
515 */
516 if (len < 4 || name[len-1] != '}')
517 return -1;
518
519 for (sp = name + len - 1; name <= sp; sp--) {
520 int ch = *sp;
521 if (ch == '{' && name < sp && sp[-1] == '^')
522 break;
523 }
524 if (sp <= name)
525 return -1;
526
527 sp++; /* beginning of type name, or closing brace for empty */
528 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
1974632c 529 expected_type = OBJ_COMMIT;
5385f52d 530 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
1974632c 531 expected_type = OBJ_TREE;
5385f52d 532 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
1974632c 533 expected_type = OBJ_BLOB;
5385f52d 534 else if (sp[0] == '}')
1974632c 535 expected_type = OBJ_NONE;
5385f52d
JH
536 else
537 return -1;
538
539 if (get_sha1_1(name, sp - name - 2, outer))
540 return -1;
541
542 o = parse_object(outer);
543 if (!o)
544 return -1;
885a86ab 545 if (!expected_type) {
9534f40b 546 o = deref_tag(o, name, sp - name - 2);
6e1c6c10
JH
547 if (!o || (!o->parsed && !parse_object(o->sha1)))
548 return -1;
e702496e 549 hashcpy(sha1, o->sha1);
5385f52d
JH
550 }
551 else {
81776315
JH
552 /*
553 * At this point, the syntax look correct, so
5385f52d
JH
554 * if we do not get the needed object, we should
555 * barf.
556 */
81776315
JH
557 o = peel_to_type(name, len, o, expected_type);
558 if (o) {
559 hashcpy(sha1, o->sha1);
560 return 0;
5385f52d 561 }
81776315 562 return -1;
5385f52d
JH
563 }
564 return 0;
565}
566
7dd45e15
JH
567static int get_describe_name(const char *name, int len, unsigned char *sha1)
568{
569 const char *cp;
570
571 for (cp = name + len - 1; name + 2 <= cp; cp--) {
572 char ch = *cp;
573 if (hexval(ch) & ~0377) {
574 /* We must be looking at g in "SOMETHING-g"
575 * for it to be describe output.
576 */
577 if (ch == 'g' && cp[-1] == '-') {
578 cp++;
579 len -= cp - name;
580 return get_short_sha1(cp, len, sha1, 1);
581 }
582 }
583 }
584 return -1;
585}
586
9938af6a
JH
587static int get_sha1_1(const char *name, int len, unsigned char *sha1)
588{
0601dbe1 589 int ret, has_suffix;
4f7599ac 590 const char *cp;
9938af6a 591
621ff675
LT
592 /*
593 * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
4f7599ac 594 */
0601dbe1 595 has_suffix = 0;
4f7599ac
JH
596 for (cp = name + len - 1; name <= cp; cp--) {
597 int ch = *cp;
598 if ('0' <= ch && ch <= '9')
599 continue;
0601dbe1
JH
600 if (ch == '~' || ch == '^')
601 has_suffix = ch;
4f7599ac
JH
602 break;
603 }
0601dbe1
JH
604
605 if (has_suffix) {
606 int num = 0;
4f7599ac
JH
607 int len1 = cp - name;
608 cp++;
609 while (cp < name + len)
0601dbe1 610 num = num * 10 + *cp++ - '0';
621ff675
LT
611 if (!num && len1 == len - 1)
612 num = 1;
613 if (has_suffix == '^')
0601dbe1 614 return get_parent(name, len1, sha1, num);
0601dbe1
JH
615 /* else if (has_suffix == '~') -- goes without saying */
616 return get_nth_ancestor(name, len1, sha1, num);
4f7599ac
JH
617 }
618
5385f52d
JH
619 ret = peel_onion(name, len, sha1);
620 if (!ret)
621 return 0;
622
9938af6a
JH
623 ret = get_sha1_basic(name, len, sha1);
624 if (!ret)
625 return 0;
7dd45e15
JH
626
627 /* It could be describe output that is "SOMETHING-gXXXX" */
628 ret = get_describe_name(name, len, sha1);
629 if (!ret)
630 return 0;
631
013f276e 632 return get_short_sha1(name, len, sha1, 0);
9938af6a
JH
633}
634
28a4d940
JS
635static int handle_one_ref(const char *path,
636 const unsigned char *sha1, int flag, void *cb_data)
637{
638 struct commit_list **list = cb_data;
639 struct object *object = parse_object(sha1);
640 if (!object)
641 return 0;
affeef12 642 if (object->type == OBJ_TAG) {
28a4d940 643 object = deref_tag(object, path, strlen(path));
affeef12
MK
644 if (!object)
645 return 0;
646 }
28a4d940
JS
647 if (object->type != OBJ_COMMIT)
648 return 0;
649 insert_by_date((struct commit *)object, list);
650 return 0;
651}
652
653/*
654 * This interprets names like ':/Initial revision of "git"' by searching
655 * through history and returning the first commit whose message starts
656 * with the given string.
657 *
658 * For future extension, ':/!' is reserved. If you want to match a message
659 * beginning with a '!', you have to repeat the exclamation mark.
660 */
661
662#define ONELINE_SEEN (1u<<20)
1358e7d6 663static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
28a4d940
JS
664{
665 struct commit_list *list = NULL, *backup = NULL, *l;
1358e7d6 666 int retval = -1;
364d3e65 667 char *temp_commit_buffer = NULL;
28a4d940
JS
668
669 if (prefix[0] == '!') {
670 if (prefix[1] != '!')
671 die ("Invalid search pattern: %s", prefix);
672 prefix++;
673 }
28a4d940
JS
674 for_each_ref(handle_one_ref, &list);
675 for (l = list; l; l = l->next)
676 commit_list_insert(l->item, &backup);
ed8ad7e2 677 while (list) {
28a4d940 678 char *p;
1358e7d6 679 struct commit *commit;
364d3e65
JS
680 enum object_type type;
681 unsigned long size;
ed8ad7e2
JM
682
683 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
283cdbcf
MK
684 if (!parse_object(commit->object.sha1))
685 continue;
8e0f7003 686 free(temp_commit_buffer);
364d3e65
JS
687 if (commit->buffer)
688 p = commit->buffer;
689 else {
690 p = read_sha1_file(commit->object.sha1, &type, &size);
691 if (!p)
692 continue;
693 temp_commit_buffer = p;
694 }
695 if (!(p = strstr(p, "\n\n")))
28a4d940
JS
696 continue;
697 if (!prefixcmp(p + 2, prefix)) {
698 hashcpy(sha1, commit->object.sha1);
1358e7d6 699 retval = 0;
28a4d940
JS
700 break;
701 }
702 }
8e0f7003 703 free(temp_commit_buffer);
28a4d940
JS
704 free_commit_list(list);
705 for (l = backup; l; l = l->next)
706 clear_commit_marks(l->item, ONELINE_SEEN);
1358e7d6 707 return retval;
28a4d940
JS
708}
709
ae5a6c36 710struct grab_nth_branch_switch_cbdata {
c2883e62 711 long cnt, alloc;
ae5a6c36
JH
712 struct strbuf *buf;
713};
714
715static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
716 const char *email, unsigned long timestamp, int tz,
717 const char *message, void *cb_data)
718{
719 struct grab_nth_branch_switch_cbdata *cb = cb_data;
a884d0cb
TR
720 const char *match = NULL, *target = NULL;
721 size_t len;
c2883e62 722 int nth;
a884d0cb
TR
723
724 if (!prefixcmp(message, "checkout: moving from ")) {
725 match = message + strlen("checkout: moving from ");
726 if ((target = strstr(match, " to ")) != NULL)
727 target += 4;
ae5a6c36
JH
728 }
729
730 if (!match)
731 return 0;
732
a884d0cb
TR
733 len = target - match - 4;
734 if (target[len] == '\n' && !strncmp(match, target, len))
735 return 0;
736
c2883e62
JH
737 nth = cb->cnt++ % cb->alloc;
738 strbuf_reset(&cb->buf[nth]);
739 strbuf_add(&cb->buf[nth], match, len);
ae5a6c36
JH
740 return 0;
741}
742
743/*
744 * This reads "@{-N}" syntax, finds the name of the Nth previous
745 * branch we were on, and places the name of the branch in the given
a884d0cb 746 * buf and returns the number of characters parsed if successful.
ae5a6c36
JH
747 *
748 * If the input is not of the accepted format, it returns a negative
749 * number to signal an error.
a884d0cb
TR
750 *
751 * If the input was ok but there are not N branch switches in the
752 * reflog, it returns 0.
ae5a6c36
JH
753 */
754int interpret_nth_last_branch(const char *name, struct strbuf *buf)
755{
c2883e62
JH
756 long nth;
757 int i;
ae5a6c36 758 struct grab_nth_branch_switch_cbdata cb;
a884d0cb
TR
759 const char *brace;
760 char *num_end;
ae5a6c36
JH
761
762 if (name[0] != '@' || name[1] != '{' || name[2] != '-')
763 return -1;
a884d0cb
TR
764 brace = strchr(name, '}');
765 if (!brace)
766 return -1;
767 nth = strtol(name+3, &num_end, 10);
768 if (num_end != brace)
ae5a6c36 769 return -1;
c2883e62
JH
770 if (nth <= 0)
771 return -1;
772 cb.alloc = nth;
773 cb.buf = xmalloc(nth * sizeof(struct strbuf));
774 for (i = 0; i < nth; i++)
775 strbuf_init(&cb.buf[i], 20);
776 cb.cnt = 0;
ae5a6c36 777 for_each_reflog_ent("HEAD", grab_nth_branch_switch, &cb);
c2883e62 778 if (cb.cnt < nth)
a884d0cb 779 return 0;
c2883e62
JH
780 i = cb.cnt % nth;
781 strbuf_reset(buf);
782 strbuf_add(buf, cb.buf[i].buf, cb.buf[i].len);
783 for (i = 0; i < nth; i++)
784 strbuf_release(&cb.buf[i]);
785 free(cb.buf);
a884d0cb
TR
786
787 return brace-name+1;
ae5a6c36
JH
788}
789
9938af6a
JH
790/*
791 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
792 * notably "xyz^" for "parent of xyz"
793 */
794int get_sha1(const char *name, unsigned char *sha1)
795{
041a7308 796 unsigned unused;
a0cd87a5
MK
797 return get_sha1_with_mode(name, sha1, &unused);
798}
799
800int get_sha1_with_mode(const char *name, unsigned char *sha1, unsigned *mode)
801{
802 int ret, bracket_depth;
73b0e5af
JH
803 int namelen = strlen(name);
804 const char *cp;
5119602a 805
a0cd87a5 806 *mode = S_IFINVALID;
73b0e5af
JH
807 ret = get_sha1_1(name, namelen, sha1);
808 if (!ret)
809 return ret;
810 /* sha1:path --> object name of path in ent sha1
811 * :path -> object name of path in index
812 * :[0-3]:path -> object name of path in index at stage
813 */
814 if (name[0] == ':') {
815 int stage = 0;
816 struct cache_entry *ce;
817 int pos;
28a4d940
JS
818 if (namelen > 2 && name[1] == '/')
819 return get_sha1_oneline(name + 2, sha1);
73b0e5af
JH
820 if (namelen < 3 ||
821 name[2] != ':' ||
822 name[1] < '0' || '3' < name[1])
823 cp = name + 1;
824 else {
825 stage = name[1] - '0';
826 cp = name + 3;
5119602a 827 }
73b0e5af
JH
828 namelen = namelen - (cp - name);
829 if (!active_cache)
830 read_cache();
73b0e5af
JH
831 pos = cache_name_pos(cp, namelen);
832 if (pos < 0)
833 pos = -pos - 1;
834 while (pos < active_nr) {
835 ce = active_cache[pos];
836 if (ce_namelen(ce) != namelen ||
837 memcmp(ce->name, cp, namelen))
838 break;
839 if (ce_stage(ce) == stage) {
e702496e 840 hashcpy(sha1, ce->sha1);
7a51ed66 841 *mode = ce->ce_mode;
73b0e5af
JH
842 return 0;
843 }
e7cef45f 844 pos++;
73b0e5af
JH
845 }
846 return -1;
847 }
cce91a2c
SP
848 for (cp = name, bracket_depth = 0; *cp; cp++) {
849 if (*cp == '{')
850 bracket_depth++;
851 else if (bracket_depth && *cp == '}')
852 bracket_depth--;
853 else if (!bracket_depth && *cp == ':')
854 break;
855 }
856 if (*cp == ':') {
73b0e5af
JH
857 unsigned char tree_sha1[20];
858 if (!get_sha1_1(name, cp-name, tree_sha1))
859 return get_tree_entry(tree_sha1, cp+1, sha1,
a0cd87a5 860 mode);
5119602a
LT
861 }
862 return ret;
9938af6a 863}