Merge branch 'js/completion-ctags-pattern-substitution-fix'
[git] / sha1_name.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "commit.h"
4 #include "tree.h"
5 #include "blob.h"
6 #include "tree-walk.h"
7 #include "refs.h"
8 #include "remote.h"
9
10 static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *);
11
12 typedef int (*disambiguate_hint_fn)(const unsigned char *, void *);
13
14 struct disambiguate_state {
15         disambiguate_hint_fn fn;
16         void *cb_data;
17         unsigned char candidate[20];
18         unsigned candidate_exists:1;
19         unsigned candidate_checked:1;
20         unsigned candidate_ok:1;
21         unsigned disambiguate_fn_used:1;
22         unsigned ambiguous:1;
23         unsigned always_call_fn:1;
24 };
25
26 static void update_candidates(struct disambiguate_state *ds, const unsigned char *current)
27 {
28         if (ds->always_call_fn) {
29                 ds->ambiguous = ds->fn(current, ds->cb_data) ? 1 : 0;
30                 return;
31         }
32         if (!ds->candidate_exists) {
33                 /* this is the first candidate */
34                 hashcpy(ds->candidate, current);
35                 ds->candidate_exists = 1;
36                 return;
37         } else if (!hashcmp(ds->candidate, current)) {
38                 /* the same as what we already have seen */
39                 return;
40         }
41
42         if (!ds->fn) {
43                 /* cannot disambiguate between ds->candidate and current */
44                 ds->ambiguous = 1;
45                 return;
46         }
47
48         if (!ds->candidate_checked) {
49                 ds->candidate_ok = ds->fn(ds->candidate, ds->cb_data);
50                 ds->disambiguate_fn_used = 1;
51                 ds->candidate_checked = 1;
52         }
53
54         if (!ds->candidate_ok) {
55                 /* discard the candidate; we know it does not satisfy fn */
56                 hashcpy(ds->candidate, current);
57                 ds->candidate_checked = 0;
58                 return;
59         }
60
61         /* if we reach this point, we know ds->candidate satisfies fn */
62         if (ds->fn(current, ds->cb_data)) {
63                 /*
64                  * if both current and candidate satisfy fn, we cannot
65                  * disambiguate.
66                  */
67                 ds->candidate_ok = 0;
68                 ds->ambiguous = 1;
69         }
70
71         /* otherwise, current can be discarded and candidate is still good */
72 }
73
74 static void find_short_object_filename(int len, const char *hex_pfx, struct disambiguate_state *ds)
75 {
76         struct alternate_object_database *alt;
77         char hex[40];
78         static struct alternate_object_database *fakeent;
79
80         if (!fakeent) {
81                 /*
82                  * Create a "fake" alternate object database that
83                  * points to our own object database, to make it
84                  * easier to get a temporary working space in
85                  * alt->name/alt->base while iterating over the
86                  * object databases including our own.
87                  */
88                 const char *objdir = get_object_directory();
89                 int objdir_len = strlen(objdir);
90                 int entlen = objdir_len + 43;
91                 fakeent = xmalloc(sizeof(*fakeent) + entlen);
92                 memcpy(fakeent->base, objdir, objdir_len);
93                 fakeent->name = fakeent->base + objdir_len + 1;
94                 fakeent->name[-1] = '/';
95         }
96         fakeent->next = alt_odb_list;
97
98         sprintf(hex, "%.2s", hex_pfx);
99         for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
100                 struct dirent *de;
101                 DIR *dir;
102                 sprintf(alt->name, "%.2s/", hex_pfx);
103                 dir = opendir(alt->base);
104                 if (!dir)
105                         continue;
106
107                 while (!ds->ambiguous && (de = readdir(dir)) != NULL) {
108                         unsigned char sha1[20];
109
110                         if (strlen(de->d_name) != 38)
111                                 continue;
112                         if (memcmp(de->d_name, hex_pfx + 2, len - 2))
113                                 continue;
114                         memcpy(hex + 2, de->d_name, 38);
115                         if (!get_sha1_hex(hex, sha1))
116                                 update_candidates(ds, sha1);
117                 }
118                 closedir(dir);
119         }
120 }
121
122 static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
123 {
124         do {
125                 if (*a != *b)
126                         return 0;
127                 a++;
128                 b++;
129                 len -= 2;
130         } while (len > 1);
131         if (len)
132                 if ((*a ^ *b) & 0xf0)
133                         return 0;
134         return 1;
135 }
136
137 static void unique_in_pack(int len,
138                           const unsigned char *bin_pfx,
139                            struct packed_git *p,
140                            struct disambiguate_state *ds)
141 {
142         uint32_t num, last, i, first = 0;
143         const unsigned char *current = NULL;
144
145         open_pack_index(p);
146         num = p->num_objects;
147         last = num;
148         while (first < last) {
149                 uint32_t mid = (first + last) / 2;
150                 const unsigned char *current;
151                 int cmp;
152
153                 current = nth_packed_object_sha1(p, mid);
154                 cmp = hashcmp(bin_pfx, current);
155                 if (!cmp) {
156                         first = mid;
157                         break;
158                 }
159                 if (cmp > 0) {
160                         first = mid+1;
161                         continue;
162                 }
163                 last = mid;
164         }
165
166         /*
167          * At this point, "first" is the location of the lowest object
168          * with an object name that could match "bin_pfx".  See if we have
169          * 0, 1 or more objects that actually match(es).
170          */
171         for (i = first; i < num && !ds->ambiguous; i++) {
172                 current = nth_packed_object_sha1(p, i);
173                 if (!match_sha(len, bin_pfx, current))
174                         break;
175                 update_candidates(ds, current);
176         }
177 }
178
179 static void find_short_packed_object(int len, const unsigned char *bin_pfx,
180                                      struct disambiguate_state *ds)
181 {
182         struct packed_git *p;
183
184         prepare_packed_git();
185         for (p = packed_git; p && !ds->ambiguous; p = p->next)
186                 unique_in_pack(len, bin_pfx, p, ds);
187 }
188
189 #define SHORT_NAME_NOT_FOUND (-1)
190 #define SHORT_NAME_AMBIGUOUS (-2)
191
192 static int finish_object_disambiguation(struct disambiguate_state *ds,
193                                         unsigned char *sha1)
194 {
195         if (ds->ambiguous)
196                 return SHORT_NAME_AMBIGUOUS;
197
198         if (!ds->candidate_exists)
199                 return SHORT_NAME_NOT_FOUND;
200
201         if (!ds->candidate_checked)
202                 /*
203                  * If this is the only candidate, there is no point
204                  * calling the disambiguation hint callback.
205                  *
206                  * On the other hand, if the current candidate
207                  * replaced an earlier candidate that did _not_ pass
208                  * the disambiguation hint callback, then we do have
209                  * more than one objects that match the short name
210                  * given, so we should make sure this one matches;
211                  * otherwise, if we discovered this one and the one
212                  * that we previously discarded in the reverse order,
213                  * we would end up showing different results in the
214                  * same repository!
215                  */
216                 ds->candidate_ok = (!ds->disambiguate_fn_used ||
217                                     ds->fn(ds->candidate, ds->cb_data));
218
219         if (!ds->candidate_ok)
220                 return SHORT_NAME_AMBIGUOUS;
221
222         hashcpy(sha1, ds->candidate);
223         return 0;
224 }
225
226 static int disambiguate_commit_only(const unsigned char *sha1, void *cb_data_unused)
227 {
228         int kind = sha1_object_info(sha1, NULL);
229         return kind == OBJ_COMMIT;
230 }
231
232 static int disambiguate_committish_only(const unsigned char *sha1, void *cb_data_unused)
233 {
234         struct object *obj;
235         int kind;
236
237         kind = sha1_object_info(sha1, NULL);
238         if (kind == OBJ_COMMIT)
239                 return 1;
240         if (kind != OBJ_TAG)
241                 return 0;
242
243         /* We need to do this the hard way... */
244         obj = deref_tag(parse_object(sha1), NULL, 0);
245         if (obj && obj->type == OBJ_COMMIT)
246                 return 1;
247         return 0;
248 }
249
250 static int disambiguate_tree_only(const unsigned char *sha1, void *cb_data_unused)
251 {
252         int kind = sha1_object_info(sha1, NULL);
253         return kind == OBJ_TREE;
254 }
255
256 static int disambiguate_treeish_only(const unsigned char *sha1, void *cb_data_unused)
257 {
258         struct object *obj;
259         int kind;
260
261         kind = sha1_object_info(sha1, NULL);
262         if (kind == OBJ_TREE || kind == OBJ_COMMIT)
263                 return 1;
264         if (kind != OBJ_TAG)
265                 return 0;
266
267         /* We need to do this the hard way... */
268         obj = deref_tag(lookup_object(sha1), NULL, 0);
269         if (obj && (obj->type == OBJ_TREE || obj->type == OBJ_COMMIT))
270                 return 1;
271         return 0;
272 }
273
274 static int disambiguate_blob_only(const unsigned char *sha1, void *cb_data_unused)
275 {
276         int kind = sha1_object_info(sha1, NULL);
277         return kind == OBJ_BLOB;
278 }
279
280 static int prepare_prefixes(const char *name, int len,
281                             unsigned char *bin_pfx,
282                             char *hex_pfx)
283 {
284         int i;
285
286         hashclr(bin_pfx);
287         memset(hex_pfx, 'x', 40);
288         for (i = 0; i < len ;i++) {
289                 unsigned char c = name[i];
290                 unsigned char val;
291                 if (c >= '0' && c <= '9')
292                         val = c - '0';
293                 else if (c >= 'a' && c <= 'f')
294                         val = c - 'a' + 10;
295                 else if (c >= 'A' && c <='F') {
296                         val = c - 'A' + 10;
297                         c -= 'A' - 'a';
298                 }
299                 else
300                         return -1;
301                 hex_pfx[i] = c;
302                 if (!(i & 1))
303                         val <<= 4;
304                 bin_pfx[i >> 1] |= val;
305         }
306         return 0;
307 }
308
309 static int get_short_sha1(const char *name, int len, unsigned char *sha1,
310                           unsigned flags)
311 {
312         int status;
313         char hex_pfx[40];
314         unsigned char bin_pfx[20];
315         struct disambiguate_state ds;
316         int quietly = !!(flags & GET_SHA1_QUIETLY);
317
318         if (len < MINIMUM_ABBREV || len > 40)
319                 return -1;
320         if (prepare_prefixes(name, len, bin_pfx, hex_pfx) < 0)
321                 return -1;
322
323         prepare_alt_odb();
324
325         memset(&ds, 0, sizeof(ds));
326         if (flags & GET_SHA1_COMMIT)
327                 ds.fn = disambiguate_commit_only;
328         else if (flags & GET_SHA1_COMMITTISH)
329                 ds.fn = disambiguate_committish_only;
330         else if (flags & GET_SHA1_TREE)
331                 ds.fn = disambiguate_tree_only;
332         else if (flags & GET_SHA1_TREEISH)
333                 ds.fn = disambiguate_treeish_only;
334         else if (flags & GET_SHA1_BLOB)
335                 ds.fn = disambiguate_blob_only;
336
337         find_short_object_filename(len, hex_pfx, &ds);
338         find_short_packed_object(len, bin_pfx, &ds);
339         status = finish_object_disambiguation(&ds, sha1);
340
341         if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
342                 return error("short SHA1 %.*s is ambiguous.", len, hex_pfx);
343         return status;
344 }
345
346 int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data)
347 {
348         char hex_pfx[40];
349         unsigned char bin_pfx[20];
350         struct disambiguate_state ds;
351         int len = strlen(prefix);
352
353         if (len < MINIMUM_ABBREV || len > 40)
354                 return -1;
355         if (prepare_prefixes(prefix, len, bin_pfx, hex_pfx) < 0)
356                 return -1;
357
358         prepare_alt_odb();
359
360         memset(&ds, 0, sizeof(ds));
361         ds.always_call_fn = 1;
362         ds.cb_data = cb_data;
363         ds.fn = fn;
364
365         find_short_object_filename(len, hex_pfx, &ds);
366         find_short_packed_object(len, bin_pfx, &ds);
367         return ds.ambiguous;
368 }
369
370 const char *find_unique_abbrev(const unsigned char *sha1, int len)
371 {
372         int status, exists;
373         static char hex[41];
374
375         memcpy(hex, sha1_to_hex(sha1), 40);
376         if (len == 40 || !len)
377                 return hex;
378         exists = has_sha1_file(sha1);
379         while (len < 40) {
380                 unsigned char sha1_ret[20];
381                 status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);
382                 if (exists
383                     ? !status
384                     : status == SHORT_NAME_NOT_FOUND) {
385                         hex[len] = 0;
386                         return hex;
387                 }
388                 len++;
389         }
390         return hex;
391 }
392
393 static int ambiguous_path(const char *path, int len)
394 {
395         int slash = 1;
396         int cnt;
397
398         for (cnt = 0; cnt < len; cnt++) {
399                 switch (*path++) {
400                 case '\0':
401                         break;
402                 case '/':
403                         if (slash)
404                                 break;
405                         slash = 1;
406                         continue;
407                 case '.':
408                         continue;
409                 default:
410                         slash = 0;
411                         continue;
412                 }
413                 break;
414         }
415         return slash;
416 }
417
418 static inline int upstream_mark(const char *string, int len)
419 {
420         const char *suffix[] = { "@{upstream}", "@{u}" };
421         int i;
422
423         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
424                 int suffix_len = strlen(suffix[i]);
425                 if (suffix_len <= len
426                     && !memcmp(string, suffix[i], suffix_len))
427                         return suffix_len;
428         }
429         return 0;
430 }
431
432 static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
433 static int interpret_nth_prior_checkout(const char *name, int namelen, struct strbuf *buf);
434
435 static int get_sha1_basic(const char *str, int len, unsigned char *sha1,
436                           unsigned int flags)
437 {
438         static const char *warn_msg = "refname '%.*s' is ambiguous.";
439         static const char *object_name_msg = N_(
440         "Git normally never creates a ref that ends with 40 hex characters\n"
441         "because it will be ignored when you just specify 40-hex. These refs\n"
442         "may be created by mistake. For example,\n"
443         "\n"
444         "  git checkout -b $br $(git rev-parse ...)\n"
445         "\n"
446         "where \"$br\" is somehow empty and a 40-hex ref is created. Please\n"
447         "examine these refs and maybe delete them. Turn this message off by\n"
448         "running \"git config advice.objectNameWarning false\"");
449         unsigned char tmp_sha1[20];
450         char *real_ref = NULL;
451         int refs_found = 0;
452         int at, reflog_len, nth_prior = 0;
453
454         if (len == 40 && !get_sha1_hex(str, sha1)) {
455                 if (warn_ambiguous_refs && warn_on_object_refname_ambiguity) {
456                         refs_found = dwim_ref(str, len, tmp_sha1, &real_ref);
457                         if (refs_found > 0) {
458                                 warning(warn_msg, len, str);
459                                 if (advice_object_name_warning)
460                                         fprintf(stderr, "%s\n", _(object_name_msg));
461                         }
462                         free(real_ref);
463                 }
464                 return 0;
465         }
466
467         /* basic@{time or number or -number} format to query ref-log */
468         reflog_len = at = 0;
469         if (len && str[len-1] == '}') {
470                 for (at = len-4; at >= 0; at--) {
471                         if (str[at] == '@' && str[at+1] == '{') {
472                                 if (str[at+2] == '-') {
473                                         if (at != 0)
474                                                 /* @{-N} not at start */
475                                                 return -1;
476                                         nth_prior = 1;
477                                         continue;
478                                 }
479                                 if (!upstream_mark(str + at, len - at)) {
480                                         reflog_len = (len-1) - (at+2);
481                                         len = at;
482                                 }
483                                 break;
484                         }
485                 }
486         }
487
488         /* Accept only unambiguous ref paths. */
489         if (len && ambiguous_path(str, len))
490                 return -1;
491
492         if (nth_prior) {
493                 struct strbuf buf = STRBUF_INIT;
494                 int detached;
495
496                 if (interpret_nth_prior_checkout(str, len, &buf) > 0) {
497                         detached = (buf.len == 40 && !get_sha1_hex(buf.buf, sha1));
498                         strbuf_release(&buf);
499                         if (detached)
500                                 return 0;
501                 }
502         }
503
504         if (!len && reflog_len)
505                 /* allow "@{...}" to mean the current branch reflog */
506                 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
507         else if (reflog_len)
508                 refs_found = dwim_log(str, len, sha1, &real_ref);
509         else
510                 refs_found = dwim_ref(str, len, sha1, &real_ref);
511
512         if (!refs_found)
513                 return -1;
514
515         if (warn_ambiguous_refs && !(flags & GET_SHA1_QUIETLY) &&
516             (refs_found > 1 ||
517              !get_short_sha1(str, len, tmp_sha1, GET_SHA1_QUIETLY)))
518                 warning(warn_msg, len, str);
519
520         if (reflog_len) {
521                 int nth, i;
522                 unsigned long at_time;
523                 unsigned long co_time;
524                 int co_tz, co_cnt;
525
526                 /* Is it asking for N-th entry, or approxidate? */
527                 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
528                         char ch = str[at+2+i];
529                         if ('0' <= ch && ch <= '9')
530                                 nth = nth * 10 + ch - '0';
531                         else
532                                 nth = -1;
533                 }
534                 if (100000000 <= nth) {
535                         at_time = nth;
536                         nth = -1;
537                 } else if (0 <= nth)
538                         at_time = 0;
539                 else {
540                         int errors = 0;
541                         char *tmp = xstrndup(str + at + 2, reflog_len);
542                         at_time = approxidate_careful(tmp, &errors);
543                         free(tmp);
544                         if (errors) {
545                                 free(real_ref);
546                                 return -1;
547                         }
548                 }
549                 if (read_ref_at(real_ref, flags, at_time, nth, sha1, NULL,
550                                 &co_time, &co_tz, &co_cnt)) {
551                         if (!len) {
552                                 if (starts_with(real_ref, "refs/heads/")) {
553                                         str = real_ref + 11;
554                                         len = strlen(real_ref + 11);
555                                 } else {
556                                         /* detached HEAD */
557                                         str = "HEAD";
558                                         len = 4;
559                                 }
560                         }
561                         if (at_time) {
562                                 if (!(flags & GET_SHA1_QUIETLY)) {
563                                         warning("Log for '%.*s' only goes "
564                                                 "back to %s.", len, str,
565                                                 show_date(co_time, co_tz, DATE_RFC2822));
566                                 }
567                         } else {
568                                 if (flags & GET_SHA1_QUIETLY) {
569                                         exit(128);
570                                 }
571                                 die("Log for '%.*s' only has %d entries.",
572                                     len, str, co_cnt);
573                         }
574                 }
575         }
576
577         free(real_ref);
578         return 0;
579 }
580
581 static int get_parent(const char *name, int len,
582                       unsigned char *result, int idx)
583 {
584         unsigned char sha1[20];
585         int ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
586         struct commit *commit;
587         struct commit_list *p;
588
589         if (ret)
590                 return ret;
591         commit = lookup_commit_reference(sha1);
592         if (parse_commit(commit))
593                 return -1;
594         if (!idx) {
595                 hashcpy(result, commit->object.sha1);
596                 return 0;
597         }
598         p = commit->parents;
599         while (p) {
600                 if (!--idx) {
601                         hashcpy(result, p->item->object.sha1);
602                         return 0;
603                 }
604                 p = p->next;
605         }
606         return -1;
607 }
608
609 static int get_nth_ancestor(const char *name, int len,
610                             unsigned char *result, int generation)
611 {
612         unsigned char sha1[20];
613         struct commit *commit;
614         int ret;
615
616         ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
617         if (ret)
618                 return ret;
619         commit = lookup_commit_reference(sha1);
620         if (!commit)
621                 return -1;
622
623         while (generation--) {
624                 if (parse_commit(commit) || !commit->parents)
625                         return -1;
626                 commit = commit->parents->item;
627         }
628         hashcpy(result, commit->object.sha1);
629         return 0;
630 }
631
632 struct object *peel_to_type(const char *name, int namelen,
633                             struct object *o, enum object_type expected_type)
634 {
635         if (name && !namelen)
636                 namelen = strlen(name);
637         while (1) {
638                 if (!o || (!o->parsed && !parse_object(o->sha1)))
639                         return NULL;
640                 if (expected_type == OBJ_ANY || o->type == expected_type)
641                         return o;
642                 if (o->type == OBJ_TAG)
643                         o = ((struct tag*) o)->tagged;
644                 else if (o->type == OBJ_COMMIT)
645                         o = &(((struct commit *) o)->tree->object);
646                 else {
647                         if (name)
648                                 error("%.*s: expected %s type, but the object "
649                                       "dereferences to %s type",
650                                       namelen, name, typename(expected_type),
651                                       typename(o->type));
652                         return NULL;
653                 }
654         }
655 }
656
657 static int peel_onion(const char *name, int len, unsigned char *sha1)
658 {
659         unsigned char outer[20];
660         const char *sp;
661         unsigned int expected_type = 0;
662         unsigned lookup_flags = 0;
663         struct object *o;
664
665         /*
666          * "ref^{type}" dereferences ref repeatedly until you cannot
667          * dereference anymore, or you get an object of given type,
668          * whichever comes first.  "ref^{}" means just dereference
669          * tags until you get a non-tag.  "ref^0" is a shorthand for
670          * "ref^{commit}".  "commit^{tree}" could be used to find the
671          * top-level tree of the given commit.
672          */
673         if (len < 4 || name[len-1] != '}')
674                 return -1;
675
676         for (sp = name + len - 1; name <= sp; sp--) {
677                 int ch = *sp;
678                 if (ch == '{' && name < sp && sp[-1] == '^')
679                         break;
680         }
681         if (sp <= name)
682                 return -1;
683
684         sp++; /* beginning of type name, or closing brace for empty */
685         if (starts_with(sp, "commit}"))
686                 expected_type = OBJ_COMMIT;
687         else if (starts_with(sp, "tag}"))
688                 expected_type = OBJ_TAG;
689         else if (starts_with(sp, "tree}"))
690                 expected_type = OBJ_TREE;
691         else if (starts_with(sp, "blob}"))
692                 expected_type = OBJ_BLOB;
693         else if (starts_with(sp, "object}"))
694                 expected_type = OBJ_ANY;
695         else if (sp[0] == '}')
696                 expected_type = OBJ_NONE;
697         else if (sp[0] == '/')
698                 expected_type = OBJ_COMMIT;
699         else
700                 return -1;
701
702         if (expected_type == OBJ_COMMIT)
703                 lookup_flags = GET_SHA1_COMMITTISH;
704         else if (expected_type == OBJ_TREE)
705                 lookup_flags = GET_SHA1_TREEISH;
706
707         if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
708                 return -1;
709
710         o = parse_object(outer);
711         if (!o)
712                 return -1;
713         if (!expected_type) {
714                 o = deref_tag(o, name, sp - name - 2);
715                 if (!o || (!o->parsed && !parse_object(o->sha1)))
716                         return -1;
717                 hashcpy(sha1, o->sha1);
718                 return 0;
719         }
720
721         /*
722          * At this point, the syntax look correct, so
723          * if we do not get the needed object, we should
724          * barf.
725          */
726         o = peel_to_type(name, len, o, expected_type);
727         if (!o)
728                 return -1;
729
730         hashcpy(sha1, o->sha1);
731         if (sp[0] == '/') {
732                 /* "$commit^{/foo}" */
733                 char *prefix;
734                 int ret;
735                 struct commit_list *list = NULL;
736
737                 /*
738                  * $commit^{/}. Some regex implementation may reject.
739                  * We don't need regex anyway. '' pattern always matches.
740                  */
741                 if (sp[1] == '}')
742                         return 0;
743
744                 prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
745                 commit_list_insert((struct commit *)o, &list);
746                 ret = get_sha1_oneline(prefix, sha1, list);
747                 free(prefix);
748                 return ret;
749         }
750         return 0;
751 }
752
753 static int get_describe_name(const char *name, int len, unsigned char *sha1)
754 {
755         const char *cp;
756         unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
757
758         for (cp = name + len - 1; name + 2 <= cp; cp--) {
759                 char ch = *cp;
760                 if (!isxdigit(ch)) {
761                         /* We must be looking at g in "SOMETHING-g"
762                          * for it to be describe output.
763                          */
764                         if (ch == 'g' && cp[-1] == '-') {
765                                 cp++;
766                                 len -= cp - name;
767                                 return get_short_sha1(cp, len, sha1, flags);
768                         }
769                 }
770         }
771         return -1;
772 }
773
774 static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags)
775 {
776         int ret, has_suffix;
777         const char *cp;
778
779         /*
780          * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
781          */
782         has_suffix = 0;
783         for (cp = name + len - 1; name <= cp; cp--) {
784                 int ch = *cp;
785                 if ('0' <= ch && ch <= '9')
786                         continue;
787                 if (ch == '~' || ch == '^')
788                         has_suffix = ch;
789                 break;
790         }
791
792         if (has_suffix) {
793                 int num = 0;
794                 int len1 = cp - name;
795                 cp++;
796                 while (cp < name + len)
797                         num = num * 10 + *cp++ - '0';
798                 if (!num && len1 == len - 1)
799                         num = 1;
800                 if (has_suffix == '^')
801                         return get_parent(name, len1, sha1, num);
802                 /* else if (has_suffix == '~') -- goes without saying */
803                 return get_nth_ancestor(name, len1, sha1, num);
804         }
805
806         ret = peel_onion(name, len, sha1);
807         if (!ret)
808                 return 0;
809
810         ret = get_sha1_basic(name, len, sha1, lookup_flags);
811         if (!ret)
812                 return 0;
813
814         /* It could be describe output that is "SOMETHING-gXXXX" */
815         ret = get_describe_name(name, len, sha1);
816         if (!ret)
817                 return 0;
818
819         return get_short_sha1(name, len, sha1, lookup_flags);
820 }
821
822 /*
823  * This interprets names like ':/Initial revision of "git"' by searching
824  * through history and returning the first commit whose message starts
825  * the given regular expression.
826  *
827  * For future extension, ':/!' is reserved. If you want to match a message
828  * beginning with a '!', you have to repeat the exclamation mark.
829  */
830
831 /* Remember to update object flag allocation in object.h */
832 #define ONELINE_SEEN (1u<<20)
833
834 static int handle_one_ref(const char *path,
835                 const unsigned char *sha1, int flag, void *cb_data)
836 {
837         struct commit_list **list = cb_data;
838         struct object *object = parse_object(sha1);
839         if (!object)
840                 return 0;
841         if (object->type == OBJ_TAG) {
842                 object = deref_tag(object, path, strlen(path));
843                 if (!object)
844                         return 0;
845         }
846         if (object->type != OBJ_COMMIT)
847                 return 0;
848         commit_list_insert((struct commit *)object, list);
849         return 0;
850 }
851
852 static int get_sha1_oneline(const char *prefix, unsigned char *sha1,
853                             struct commit_list *list)
854 {
855         struct commit_list *backup = NULL, *l;
856         int found = 0;
857         regex_t regex;
858
859         if (prefix[0] == '!') {
860                 if (prefix[1] != '!')
861                         die ("Invalid search pattern: %s", prefix);
862                 prefix++;
863         }
864
865         if (regcomp(&regex, prefix, REG_EXTENDED))
866                 die("Invalid search pattern: %s", prefix);
867
868         for (l = list; l; l = l->next) {
869                 l->item->object.flags |= ONELINE_SEEN;
870                 commit_list_insert(l->item, &backup);
871         }
872         while (list) {
873                 const char *p, *buf;
874                 struct commit *commit;
875                 int matches;
876
877                 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
878                 if (!parse_object(commit->object.sha1))
879                         continue;
880                 buf = get_commit_buffer(commit, NULL);
881                 p = strstr(buf, "\n\n");
882                 matches = p && !regexec(&regex, p + 2, 0, NULL, 0);
883                 unuse_commit_buffer(commit, buf);
884
885                 if (matches) {
886                         hashcpy(sha1, commit->object.sha1);
887                         found = 1;
888                         break;
889                 }
890         }
891         regfree(&regex);
892         free_commit_list(list);
893         for (l = backup; l; l = l->next)
894                 clear_commit_marks(l->item, ONELINE_SEEN);
895         free_commit_list(backup);
896         return found ? 0 : -1;
897 }
898
899 struct grab_nth_branch_switch_cbdata {
900         int remaining;
901         struct strbuf buf;
902 };
903
904 static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
905                                   const char *email, unsigned long timestamp, int tz,
906                                   const char *message, void *cb_data)
907 {
908         struct grab_nth_branch_switch_cbdata *cb = cb_data;
909         const char *match = NULL, *target = NULL;
910         size_t len;
911
912         if (skip_prefix(message, "checkout: moving from ", &match))
913                 target = strstr(match, " to ");
914
915         if (!match || !target)
916                 return 0;
917         if (--(cb->remaining) == 0) {
918                 len = target - match;
919                 strbuf_reset(&cb->buf);
920                 strbuf_add(&cb->buf, match, len);
921                 return 1; /* we are done */
922         }
923         return 0;
924 }
925
926 /*
927  * Parse @{-N} syntax, return the number of characters parsed
928  * if successful; otherwise signal an error with negative value.
929  */
930 static int interpret_nth_prior_checkout(const char *name, int namelen,
931                                         struct strbuf *buf)
932 {
933         long nth;
934         int retval;
935         struct grab_nth_branch_switch_cbdata cb;
936         const char *brace;
937         char *num_end;
938
939         if (namelen < 4)
940                 return -1;
941         if (name[0] != '@' || name[1] != '{' || name[2] != '-')
942                 return -1;
943         brace = memchr(name, '}', namelen);
944         if (!brace)
945                 return -1;
946         nth = strtol(name + 3, &num_end, 10);
947         if (num_end != brace)
948                 return -1;
949         if (nth <= 0)
950                 return -1;
951         cb.remaining = nth;
952         strbuf_init(&cb.buf, 20);
953
954         retval = 0;
955         if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
956                 strbuf_reset(buf);
957                 strbuf_addbuf(buf, &cb.buf);
958                 retval = brace - name + 1;
959         }
960
961         strbuf_release(&cb.buf);
962         return retval;
963 }
964
965 int get_sha1_mb(const char *name, unsigned char *sha1)
966 {
967         struct commit *one, *two;
968         struct commit_list *mbs;
969         unsigned char sha1_tmp[20];
970         const char *dots;
971         int st;
972
973         dots = strstr(name, "...");
974         if (!dots)
975                 return get_sha1(name, sha1);
976         if (dots == name)
977                 st = get_sha1("HEAD", sha1_tmp);
978         else {
979                 struct strbuf sb;
980                 strbuf_init(&sb, dots - name);
981                 strbuf_add(&sb, name, dots - name);
982                 st = get_sha1_committish(sb.buf, sha1_tmp);
983                 strbuf_release(&sb);
984         }
985         if (st)
986                 return st;
987         one = lookup_commit_reference_gently(sha1_tmp, 0);
988         if (!one)
989                 return -1;
990
991         if (get_sha1_committish(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
992                 return -1;
993         two = lookup_commit_reference_gently(sha1_tmp, 0);
994         if (!two)
995                 return -1;
996         mbs = get_merge_bases(one, two);
997         if (!mbs || mbs->next)
998                 st = -1;
999         else {
1000                 st = 0;
1001                 hashcpy(sha1, mbs->item->object.sha1);
1002         }
1003         free_commit_list(mbs);
1004         return st;
1005 }
1006
1007 /* parse @something syntax, when 'something' is not {.*} */
1008 static int interpret_empty_at(const char *name, int namelen, int len, struct strbuf *buf)
1009 {
1010         const char *next;
1011
1012         if (len || name[1] == '{')
1013                 return -1;
1014
1015         /* make sure it's a single @, or @@{.*}, not @foo */
1016         next = memchr(name + len + 1, '@', namelen - len - 1);
1017         if (next && next[1] != '{')
1018                 return -1;
1019         if (!next)
1020                 next = name + namelen;
1021         if (next != name + 1)
1022                 return -1;
1023
1024         strbuf_reset(buf);
1025         strbuf_add(buf, "HEAD", 4);
1026         return 1;
1027 }
1028
1029 static int reinterpret(const char *name, int namelen, int len, struct strbuf *buf)
1030 {
1031         /* we have extra data, which might need further processing */
1032         struct strbuf tmp = STRBUF_INIT;
1033         int used = buf->len;
1034         int ret;
1035
1036         strbuf_add(buf, name + len, namelen - len);
1037         ret = interpret_branch_name(buf->buf, buf->len, &tmp);
1038         /* that data was not interpreted, remove our cruft */
1039         if (ret < 0) {
1040                 strbuf_setlen(buf, used);
1041                 return len;
1042         }
1043         strbuf_reset(buf);
1044         strbuf_addbuf(buf, &tmp);
1045         strbuf_release(&tmp);
1046         /* tweak for size of {-N} versus expanded ref name */
1047         return ret - used + len;
1048 }
1049
1050 static void set_shortened_ref(struct strbuf *buf, const char *ref)
1051 {
1052         char *s = shorten_unambiguous_ref(ref, 0);
1053         strbuf_reset(buf);
1054         strbuf_addstr(buf, s);
1055         free(s);
1056 }
1057
1058 static const char *get_upstream_branch(const char *branch_buf, int len)
1059 {
1060         char *branch = xstrndup(branch_buf, len);
1061         struct branch *upstream = branch_get(*branch ? branch : NULL);
1062
1063         /*
1064          * Upstream can be NULL only if branch refers to HEAD and HEAD
1065          * points to something different than a branch.
1066          */
1067         if (!upstream)
1068                 die(_("HEAD does not point to a branch"));
1069         if (!upstream->merge || !upstream->merge[0]->dst) {
1070                 if (!ref_exists(upstream->refname))
1071                         die(_("No such branch: '%s'"), branch);
1072                 if (!upstream->merge) {
1073                         die(_("No upstream configured for branch '%s'"),
1074                                 upstream->name);
1075                 }
1076                 die(
1077                         _("Upstream branch '%s' not stored as a remote-tracking branch"),
1078                         upstream->merge[0]->src);
1079         }
1080         free(branch);
1081
1082         return upstream->merge[0]->dst;
1083 }
1084
1085 static int interpret_upstream_mark(const char *name, int namelen,
1086                                    int at, struct strbuf *buf)
1087 {
1088         int len;
1089
1090         len = upstream_mark(name + at, namelen - at);
1091         if (!len)
1092                 return -1;
1093
1094         if (memchr(name, ':', at))
1095                 return -1;
1096
1097         set_shortened_ref(buf, get_upstream_branch(name, at));
1098         return len + at;
1099 }
1100
1101 /*
1102  * This reads short-hand syntax that not only evaluates to a commit
1103  * object name, but also can act as if the end user spelled the name
1104  * of the branch from the command line.
1105  *
1106  * - "@{-N}" finds the name of the Nth previous branch we were on, and
1107  *   places the name of the branch in the given buf and returns the
1108  *   number of characters parsed if successful.
1109  *
1110  * - "<branch>@{upstream}" finds the name of the other ref that
1111  *   <branch> is configured to merge with (missing <branch> defaults
1112  *   to the current branch), and places the name of the branch in the
1113  *   given buf and returns the number of characters parsed if
1114  *   successful.
1115  *
1116  * If the input is not of the accepted format, it returns a negative
1117  * number to signal an error.
1118  *
1119  * If the input was ok but there are not N branch switches in the
1120  * reflog, it returns 0.
1121  */
1122 int interpret_branch_name(const char *name, int namelen, struct strbuf *buf)
1123 {
1124         char *at;
1125         const char *start;
1126         int len = interpret_nth_prior_checkout(name, namelen, buf);
1127
1128         if (!namelen)
1129                 namelen = strlen(name);
1130
1131         if (!len) {
1132                 return len; /* syntax Ok, not enough switches */
1133         } else if (len > 0) {
1134                 if (len == namelen)
1135                         return len; /* consumed all */
1136                 else
1137                         return reinterpret(name, namelen, len, buf);
1138         }
1139
1140         for (start = name;
1141              (at = memchr(start, '@', namelen - (start - name)));
1142              start = at + 1) {
1143
1144                 len = interpret_empty_at(name, namelen, at - name, buf);
1145                 if (len > 0)
1146                         return reinterpret(name, namelen, len, buf);
1147
1148                 len = interpret_upstream_mark(name, namelen, at - name, buf);
1149                 if (len > 0)
1150                         return len;
1151         }
1152
1153         return -1;
1154 }
1155
1156 int strbuf_branchname(struct strbuf *sb, const char *name)
1157 {
1158         int len = strlen(name);
1159         int used = interpret_branch_name(name, len, sb);
1160
1161         if (used == len)
1162                 return 0;
1163         if (used < 0)
1164                 used = 0;
1165         strbuf_add(sb, name + used, len - used);
1166         return len;
1167 }
1168
1169 int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
1170 {
1171         strbuf_branchname(sb, name);
1172         if (name[0] == '-')
1173                 return -1;
1174         strbuf_splice(sb, 0, 0, "refs/heads/", 11);
1175         return check_refname_format(sb->buf, 0);
1176 }
1177
1178 /*
1179  * This is like "get_sha1_basic()", except it allows "sha1 expressions",
1180  * notably "xyz^" for "parent of xyz"
1181  */
1182 int get_sha1(const char *name, unsigned char *sha1)
1183 {
1184         struct object_context unused;
1185         return get_sha1_with_context(name, 0, sha1, &unused);
1186 }
1187
1188 /*
1189  * Many callers know that the user meant to name a commit-ish by
1190  * syntactical positions where the object name appears.  Calling this
1191  * function allows the machinery to disambiguate shorter-than-unique
1192  * abbreviated object names between commit-ish and others.
1193  *
1194  * Note that this does NOT error out when the named object is not a
1195  * commit-ish. It is merely to give a hint to the disambiguation
1196  * machinery.
1197  */
1198 int get_sha1_committish(const char *name, unsigned char *sha1)
1199 {
1200         struct object_context unused;
1201         return get_sha1_with_context(name, GET_SHA1_COMMITTISH,
1202                                      sha1, &unused);
1203 }
1204
1205 int get_sha1_treeish(const char *name, unsigned char *sha1)
1206 {
1207         struct object_context unused;
1208         return get_sha1_with_context(name, GET_SHA1_TREEISH,
1209                                      sha1, &unused);
1210 }
1211
1212 int get_sha1_commit(const char *name, unsigned char *sha1)
1213 {
1214         struct object_context unused;
1215         return get_sha1_with_context(name, GET_SHA1_COMMIT,
1216                                      sha1, &unused);
1217 }
1218
1219 int get_sha1_tree(const char *name, unsigned char *sha1)
1220 {
1221         struct object_context unused;
1222         return get_sha1_with_context(name, GET_SHA1_TREE,
1223                                      sha1, &unused);
1224 }
1225
1226 int get_sha1_blob(const char *name, unsigned char *sha1)
1227 {
1228         struct object_context unused;
1229         return get_sha1_with_context(name, GET_SHA1_BLOB,
1230                                      sha1, &unused);
1231 }
1232
1233 /* Must be called only when object_name:filename doesn't exist. */
1234 static void diagnose_invalid_sha1_path(const char *prefix,
1235                                        const char *filename,
1236                                        const unsigned char *tree_sha1,
1237                                        const char *object_name,
1238                                        int object_name_len)
1239 {
1240         struct stat st;
1241         unsigned char sha1[20];
1242         unsigned mode;
1243
1244         if (!prefix)
1245                 prefix = "";
1246
1247         if (!lstat(filename, &st))
1248                 die("Path '%s' exists on disk, but not in '%.*s'.",
1249                     filename, object_name_len, object_name);
1250         if (errno == ENOENT || errno == ENOTDIR) {
1251                 char *fullname = xstrfmt("%s%s", prefix, filename);
1252
1253                 if (!get_tree_entry(tree_sha1, fullname,
1254                                     sha1, &mode)) {
1255                         die("Path '%s' exists, but not '%s'.\n"
1256                             "Did you mean '%.*s:%s' aka '%.*s:./%s'?",
1257                             fullname,
1258                             filename,
1259                             object_name_len, object_name,
1260                             fullname,
1261                             object_name_len, object_name,
1262                             filename);
1263                 }
1264                 die("Path '%s' does not exist in '%.*s'",
1265                     filename, object_name_len, object_name);
1266         }
1267 }
1268
1269 /* Must be called only when :stage:filename doesn't exist. */
1270 static void diagnose_invalid_index_path(int stage,
1271                                         const char *prefix,
1272                                         const char *filename)
1273 {
1274         struct stat st;
1275         const struct cache_entry *ce;
1276         int pos;
1277         unsigned namelen = strlen(filename);
1278         unsigned fullnamelen;
1279         char *fullname;
1280
1281         if (!prefix)
1282                 prefix = "";
1283
1284         /* Wrong stage number? */
1285         pos = cache_name_pos(filename, namelen);
1286         if (pos < 0)
1287                 pos = -pos - 1;
1288         if (pos < active_nr) {
1289                 ce = active_cache[pos];
1290                 if (ce_namelen(ce) == namelen &&
1291                     !memcmp(ce->name, filename, namelen))
1292                         die("Path '%s' is in the index, but not at stage %d.\n"
1293                             "Did you mean ':%d:%s'?",
1294                             filename, stage,
1295                             ce_stage(ce), filename);
1296         }
1297
1298         /* Confusion between relative and absolute filenames? */
1299         fullnamelen = namelen + strlen(prefix);
1300         fullname = xmalloc(fullnamelen + 1);
1301         strcpy(fullname, prefix);
1302         strcat(fullname, filename);
1303         pos = cache_name_pos(fullname, fullnamelen);
1304         if (pos < 0)
1305                 pos = -pos - 1;
1306         if (pos < active_nr) {
1307                 ce = active_cache[pos];
1308                 if (ce_namelen(ce) == fullnamelen &&
1309                     !memcmp(ce->name, fullname, fullnamelen))
1310                         die("Path '%s' is in the index, but not '%s'.\n"
1311                             "Did you mean ':%d:%s' aka ':%d:./%s'?",
1312                             fullname, filename,
1313                             ce_stage(ce), fullname,
1314                             ce_stage(ce), filename);
1315         }
1316
1317         if (!lstat(filename, &st))
1318                 die("Path '%s' exists on disk, but not in the index.", filename);
1319         if (errno == ENOENT || errno == ENOTDIR)
1320                 die("Path '%s' does not exist (neither on disk nor in the index).",
1321                     filename);
1322
1323         free(fullname);
1324 }
1325
1326
1327 static char *resolve_relative_path(const char *rel)
1328 {
1329         if (!starts_with(rel, "./") && !starts_with(rel, "../"))
1330                 return NULL;
1331
1332         if (!startup_info)
1333                 die("BUG: startup_info struct is not initialized.");
1334
1335         if (!is_inside_work_tree())
1336                 die("relative path syntax can't be used outside working tree.");
1337
1338         /* die() inside prefix_path() if resolved path is outside worktree */
1339         return prefix_path(startup_info->prefix,
1340                            startup_info->prefix ? strlen(startup_info->prefix) : 0,
1341                            rel);
1342 }
1343
1344 static int get_sha1_with_context_1(const char *name,
1345                                    unsigned flags,
1346                                    const char *prefix,
1347                                    unsigned char *sha1,
1348                                    struct object_context *oc)
1349 {
1350         int ret, bracket_depth;
1351         int namelen = strlen(name);
1352         const char *cp;
1353         int only_to_die = flags & GET_SHA1_ONLY_TO_DIE;
1354
1355         memset(oc, 0, sizeof(*oc));
1356         oc->mode = S_IFINVALID;
1357         ret = get_sha1_1(name, namelen, sha1, flags);
1358         if (!ret)
1359                 return ret;
1360         /*
1361          * sha1:path --> object name of path in ent sha1
1362          * :path -> object name of absolute path in index
1363          * :./path -> object name of path relative to cwd in index
1364          * :[0-3]:path -> object name of path in index at stage
1365          * :/foo -> recent commit matching foo
1366          */
1367         if (name[0] == ':') {
1368                 int stage = 0;
1369                 const struct cache_entry *ce;
1370                 char *new_path = NULL;
1371                 int pos;
1372                 if (!only_to_die && namelen > 2 && name[1] == '/') {
1373                         struct commit_list *list = NULL;
1374                         for_each_ref(handle_one_ref, &list);
1375                         commit_list_sort_by_date(&list);
1376                         return get_sha1_oneline(name + 2, sha1, list);
1377                 }
1378                 if (namelen < 3 ||
1379                     name[2] != ':' ||
1380                     name[1] < '0' || '3' < name[1])
1381                         cp = name + 1;
1382                 else {
1383                         stage = name[1] - '0';
1384                         cp = name + 3;
1385                 }
1386                 new_path = resolve_relative_path(cp);
1387                 if (!new_path) {
1388                         namelen = namelen - (cp - name);
1389                 } else {
1390                         cp = new_path;
1391                         namelen = strlen(cp);
1392                 }
1393
1394                 strlcpy(oc->path, cp, sizeof(oc->path));
1395
1396                 if (!active_cache)
1397                         read_cache();
1398                 pos = cache_name_pos(cp, namelen);
1399                 if (pos < 0)
1400                         pos = -pos - 1;
1401                 while (pos < active_nr) {
1402                         ce = active_cache[pos];
1403                         if (ce_namelen(ce) != namelen ||
1404                             memcmp(ce->name, cp, namelen))
1405                                 break;
1406                         if (ce_stage(ce) == stage) {
1407                                 hashcpy(sha1, ce->sha1);
1408                                 oc->mode = ce->ce_mode;
1409                                 free(new_path);
1410                                 return 0;
1411                         }
1412                         pos++;
1413                 }
1414                 if (only_to_die && name[1] && name[1] != '/')
1415                         diagnose_invalid_index_path(stage, prefix, cp);
1416                 free(new_path);
1417                 return -1;
1418         }
1419         for (cp = name, bracket_depth = 0; *cp; cp++) {
1420                 if (*cp == '{')
1421                         bracket_depth++;
1422                 else if (bracket_depth && *cp == '}')
1423                         bracket_depth--;
1424                 else if (!bracket_depth && *cp == ':')
1425                         break;
1426         }
1427         if (*cp == ':') {
1428                 unsigned char tree_sha1[20];
1429                 int len = cp - name;
1430                 if (!get_sha1_1(name, len, tree_sha1, GET_SHA1_TREEISH)) {
1431                         const char *filename = cp+1;
1432                         char *new_filename = NULL;
1433
1434                         new_filename = resolve_relative_path(filename);
1435                         if (new_filename)
1436                                 filename = new_filename;
1437                         ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
1438                         if (ret && only_to_die) {
1439                                 diagnose_invalid_sha1_path(prefix, filename,
1440                                                            tree_sha1,
1441                                                            name, len);
1442                         }
1443                         hashcpy(oc->tree, tree_sha1);
1444                         strlcpy(oc->path, filename, sizeof(oc->path));
1445
1446                         free(new_filename);
1447                         return ret;
1448                 } else {
1449                         if (only_to_die)
1450                                 die("Invalid object name '%.*s'.", len, name);
1451                 }
1452         }
1453         return ret;
1454 }
1455
1456 /*
1457  * Call this function when you know "name" given by the end user must
1458  * name an object but it doesn't; the function _may_ die with a better
1459  * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
1460  * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
1461  * you have a chance to diagnose the error further.
1462  */
1463 void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
1464 {
1465         struct object_context oc;
1466         unsigned char sha1[20];
1467         get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
1468 }
1469
1470 int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
1471 {
1472         return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
1473 }