aboutsummaryrefslogtreecommitdiff
path: root/remote.c
blob: d8a4671e68b4b59611ca4826dc88586f044210d5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
#include "cache.h"
#include "remote.h"
#include "refs.h"

static struct remote **remotes;
static int allocated_remotes;

static struct branch **branches;
static int allocated_branches;

static struct branch *current_branch;
static const char *default_remote_name;

#define BUF_SIZE (2048)
static char buffer[BUF_SIZE];

static void add_push_refspec(struct remote *remote, const char *ref)
{
	int nr = remote->push_refspec_nr + 1;
	remote->push_refspec =
		xrealloc(remote->push_refspec, nr * sizeof(char *));
	remote->push_refspec[nr-1] = ref;
	remote->push_refspec_nr = nr;
}

static void add_fetch_refspec(struct remote *remote, const char *ref)
{
	int nr = remote->fetch_refspec_nr + 1;
	remote->fetch_refspec =
		xrealloc(remote->fetch_refspec, nr * sizeof(char *));
	remote->fetch_refspec[nr-1] = ref;
	remote->fetch_refspec_nr = nr;
}

static void add_url(struct remote *remote, const char *url)
{
	int nr = remote->url_nr + 1;
	remote->url =
		xrealloc(remote->url, nr * sizeof(char *));
	remote->url[nr-1] = url;
	remote->url_nr = nr;
}

static struct remote *make_remote(const char *name, int len)
{
	int i, empty = -1;

	for (i = 0; i < allocated_remotes; i++) {
		if (!remotes[i]) {
			if (empty < 0)
				empty = i;
		} else {
			if (len ? (!strncmp(name, remotes[i]->name, len) &&
				   !remotes[i]->name[len]) :
			    !strcmp(name, remotes[i]->name))
				return remotes[i];
		}
	}

	if (empty < 0) {
		empty = allocated_remotes;
		allocated_remotes += allocated_remotes ? allocated_remotes : 1;
		remotes = xrealloc(remotes,
				   sizeof(*remotes) * allocated_remotes);
		memset(remotes + empty, 0,
		       (allocated_remotes - empty) * sizeof(*remotes));
	}
	remotes[empty] = xcalloc(1, sizeof(struct remote));
	if (len)
		remotes[empty]->name = xstrndup(name, len);
	else
		remotes[empty]->name = xstrdup(name);
	return remotes[empty];
}

static void add_merge(struct branch *branch, const char *name)
{
	int nr = branch->merge_nr + 1;
	branch->merge_name =
		xrealloc(branch->merge_name, nr * sizeof(char *));
	branch->merge_name[nr-1] = name;
	branch->merge_nr = nr;
}

static struct branch *make_branch(const char *name, int len)
{
	int i, empty = -1;
	char *refname;

	for (i = 0; i < allocated_branches; i++) {
		if (!branches[i]) {
			if (empty < 0)
				empty = i;
		} else {
			if (len ? (!strncmp(name, branches[i]->name, len) &&
				   !branches[i]->name[len]) :
			    !strcmp(name, branches[i]->name))
				return branches[i];
		}
	}

	if (empty < 0) {
		empty = allocated_branches;
		allocated_branches += allocated_branches ? allocated_branches : 1;
		branches = xrealloc(branches,
				   sizeof(*branches) * allocated_branches);
		memset(branches + empty, 0,
		       (allocated_branches - empty) * sizeof(*branches));
	}
	branches[empty] = xcalloc(1, sizeof(struct branch));
	if (len)
		branches[empty]->name = xstrndup(name, len);
	else
		branches[empty]->name = xstrdup(name);
	refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
	strcpy(refname, "refs/heads/");
	strcpy(refname + strlen("refs/heads/"),
	       branches[empty]->name);
	branches[empty]->refname = refname;

	return branches[empty];
}

static void read_remotes_file(struct remote *remote)
{
	FILE *f = fopen(git_path("remotes/%s", remote->name), "r");

	if (!f)
		return;
	while (fgets(buffer, BUF_SIZE, f)) {
		int value_list;
		char *s, *p;

		if (!prefixcmp(buffer, "URL:")) {
			value_list = 0;
			s = buffer + 4;
		} else if (!prefixcmp(buffer, "Push:")) {
			value_list = 1;
			s = buffer + 5;
		} else if (!prefixcmp(buffer, "Pull:")) {
			value_list = 2;
			s = buffer + 5;
		} else
			continue;

		while (isspace(*s))
			s++;
		if (!*s)
			continue;

		p = s + strlen(s);
		while (isspace(p[-1]))
			*--p = 0;

		switch (value_list) {
		case 0:
			add_url(remote, xstrdup(s));
			break;
		case 1:
			add_push_refspec(remote, xstrdup(s));
			break;
		case 2:
			add_fetch_refspec(remote, xstrdup(s));
			break;
		}
	}
	fclose(f);
}

static void read_branches_file(struct remote *remote)
{
	const char *slash = strchr(remote->name, '/');
	char *frag;
	struct strbuf branch;
	int n = slash ? slash - remote->name : 1000;
	FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
	char *s, *p;
	int len;

	if (!f)
		return;
	s = fgets(buffer, BUF_SIZE, f);
	fclose(f);
	if (!s)
		return;
	while (isspace(*s))
		s++;
	if (!*s)
		return;
	p = s + strlen(s);
	while (isspace(p[-1]))
		*--p = 0;
	len = p - s;
	if (slash)
		len += strlen(slash);
	p = xmalloc(len + 1);
	strcpy(p, s);
	if (slash)
		strcat(p, slash);

	/*
	 * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
	 * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
	 * the partial URL obtained from the branches file plus
	 * "/netdev-2.6" and does not store it in any tracking ref.
	 * #branch specifier in the file is ignored.
	 *
	 * Otherwise, the branches file would have URL and optionally
	 * #branch specified.  The "master" (or specified) branch is
	 * fetched and stored in the local branch of the same name.
	 */
	strbuf_init(&branch, 0);
	frag = strchr(p, '#');
	if (frag) {
		*(frag++) = '\0';
		strbuf_addf(&branch, "refs/heads/%s", frag);
	} else
		strbuf_addstr(&branch, "refs/heads/master");
	if (!slash) {
		strbuf_addf(&branch, ":refs/heads/%s", remote->name);
	} else {
		strbuf_reset(&branch);
		strbuf_addstr(&branch, "HEAD:");
	}
	add_url(remote, p);
	add_fetch_refspec(remote, strbuf_detach(&branch, 0));
	remote->fetch_tags = 1; /* always auto-follow */
}

static int handle_config(const char *key, const char *value)
{
	const char *name;
	const char *subkey;
	struct remote *remote;
	struct branch *branch;
	if (!prefixcmp(key, "branch.")) {
		name = key + 7;
		subkey = strrchr(name, '.');
		if (!subkey)
			return 0;
		branch = make_branch(name, subkey - name);
		if (!strcmp(subkey, ".remote")) {
			if (!value)
				return config_error_nonbool(key);
			branch->remote_name = xstrdup(value);
			if (branch == current_branch)
				default_remote_name = branch->remote_name;
		} else if (!strcmp(subkey, ".merge")) {
			if (!value)
				return config_error_nonbool(key);
			add_merge(branch, xstrdup(value));
		}
		return 0;
	}
	if (prefixcmp(key,  "remote."))
		return 0;
	name = key + 7;
	subkey = strrchr(name, '.');
	if (!subkey)
		return error("Config with no key for remote %s", name);
	if (*subkey == '/') {
		warning("Config remote shorthand cannot begin with '/': %s", name);
		return 0;
	}
	remote = make_remote(name, subkey - name);
	if (!value) {
		/* if we ever have a boolean variable, e.g. "remote.*.disabled"
		 * [remote "frotz"]
		 *      disabled
		 * is a valid way to set it to true; we get NULL in value so
		 * we need to handle it here.
		 *
		 * if (!strcmp(subkey, ".disabled")) {
		 *      val = git_config_bool(key, value);
		 *      return 0;
		 * } else
		 *
		 */
		return 0; /* ignore unknown booleans */
	}
	if (!strcmp(subkey, ".url")) {
		add_url(remote, xstrdup(value));
	} else if (!strcmp(subkey, ".push")) {
		add_push_refspec(remote, xstrdup(value));
	} else if (!strcmp(subkey, ".fetch")) {
		add_fetch_refspec(remote, xstrdup(value));
	} else if (!strcmp(subkey, ".receivepack")) {
		if (!remote->receivepack)
			remote->receivepack = xstrdup(value);
		else
			error("more than one receivepack given, using the first");
	} else if (!strcmp(subkey, ".uploadpack")) {
		if (!remote->uploadpack)
			remote->uploadpack = xstrdup(value);
		else
			error("more than one uploadpack given, using the first");
	} else if (!strcmp(subkey, ".tagopt")) {
		if (!strcmp(value, "--no-tags"))
			remote->fetch_tags = -1;
	} else if (!strcmp(subkey, ".proxy")) {
		remote->http_proxy = xstrdup(value);
	}
	return 0;
}

static void read_config(void)
{
	unsigned char sha1[20];
	const char *head_ref;
	int flag;
	if (default_remote_name) // did this already
		return;
	default_remote_name = xstrdup("origin");
	current_branch = NULL;
	head_ref = resolve_ref("HEAD", sha1, 0, &flag);
	if (head_ref && (flag & REF_ISSYMREF) &&
	    !prefixcmp(head_ref, "refs/heads/")) {
		current_branch =
			make_branch(head_ref + strlen("refs/heads/"), 0);
	}
	git_config(handle_config);
}

static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch)
{
	int i;
	int st;
	struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);

	for (i = 0; i < nr_refspec; i++) {
		size_t llen, rlen;
		int is_glob;
		const char *lhs, *rhs;

		llen = rlen = is_glob = 0;

		lhs = refspec[i];
		if (*lhs == '+') {
			rs[i].force = 1;
			lhs++;
		}

		rhs = strrchr(lhs, ':');
		if (rhs) {
			rhs++;
			rlen = strlen(rhs);
			is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
			if (is_glob)
				rlen -= 2;
			rs[i].dst = xstrndup(rhs, rlen);
		}

		llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
		if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
			if ((rhs && !is_glob) || (!rhs && fetch))
				goto invalid;
			is_glob = 1;
			llen -= 2;
		} else if (rhs && is_glob) {
			goto invalid;
		}

		rs[i].pattern = is_glob;
		rs[i].src = xstrndup(lhs, llen);

		if (fetch) {
			/*
			 * LHS
			 * - empty is allowed; it means HEAD.
			 * - otherwise it must be a valid looking ref.
			 */
			if (!*rs[i].src)
				; /* empty is ok */
			else {
				st = check_ref_format(rs[i].src);
				if (st && st != CHECK_REF_FORMAT_ONELEVEL)
					goto invalid;
			}
			/*
			 * RHS
			 * - missing is ok, and is same as empty.
			 * - empty is ok; it means not to store.
			 * - otherwise it must be a valid looking ref.
			 */
			if (!rs[i].dst) {
				; /* ok */
			} else if (!*rs[i].dst) {
				; /* ok */
			} else {
				st = check_ref_format(rs[i].dst);
				if (st && st != CHECK_REF_FORMAT_ONELEVEL)
					goto invalid;
			}
		} else {
			/*
			 * LHS
			 * - empty is allowed; it means delete.
			 * - when wildcarded, it must be a valid looking ref.
			 * - otherwise, it must be an extended SHA-1, but
			 *   there is no existing way to validate this.
			 */
			if (!*rs[i].src)
				; /* empty is ok */
			else if (is_glob) {
				st = check_ref_format(rs[i].src);
				if (st && st != CHECK_REF_FORMAT_ONELEVEL)
					goto invalid;
			}
			else
				; /* anything goes, for now */
			/*
			 * RHS
			 * - missing is allowed, but LHS then must be a
			 *   valid looking ref.
			 * - empty is not allowed.
			 * - otherwise it must be a valid looking ref.
			 */
			if (!rs[i].dst) {
				st = check_ref_format(rs[i].src);
				if (st && st != CHECK_REF_FORMAT_ONELEVEL)
					goto invalid;
			} else if (!*rs[i].dst) {
				goto invalid;
			} else {
				st = check_ref_format(rs[i].dst);
				if (st && st != CHECK_REF_FORMAT_ONELEVEL)
					goto invalid;
			}
		}
	}
	return rs;

 invalid:
	die("Invalid refspec '%s'", refspec[i]);
}

struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
{
	return parse_refspec_internal(nr_refspec, refspec, 1);
}

struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
{
	return parse_refspec_internal(nr_refspec, refspec, 0);
}

static int valid_remote_nick(const char *name)
{
	if (!name[0] || /* not empty */
	    (name[0] == '.' && /* not "." */
	     (!name[1] || /* not ".." */
	      (name[1] == '.' && !name[2]))))
		return 0;
	return !strchr(name, '/'); /* no slash */
}

struct remote *remote_get(const char *name)
{
	struct remote *ret;

	read_config();
	if (!name)
		name = default_remote_name;
	ret = make_remote(name, 0);
	if (valid_remote_nick(name)) {
		if (!ret->url)
			read_remotes_file(ret);
		if (!ret->url)
			read_branches_file(ret);
	}
	if (!ret->url)
		add_url(ret, name);
	if (!ret->url)
		return NULL;
	ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
	ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
	return ret;
}

int for_each_remote(each_remote_fn fn, void *priv)
{
	int i, result = 0;
	read_config();
	for (i = 0; i < allocated_remotes && !result; i++) {
		struct remote *r = remotes[i];
		if (!r)
			continue;
		if (!r->fetch)
			r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
						       r->fetch_refspec);
		if (!r->push)
			r->push = parse_push_refspec(r->push_refspec_nr,
						     r->push_refspec);
		result = fn(r, priv);
	}
	return result;
}

void ref_remove_duplicates(struct ref *ref_map)
{
	struct ref **posn;
	struct ref *next;
	for (; ref_map; ref_map = ref_map->next) {
		if (!ref_map->peer_ref)
			continue;
		posn = &ref_map->next;
		while (*posn) {
			if ((*posn)->peer_ref &&
			    !strcmp((*posn)->peer_ref->name,
				    ref_map->peer_ref->name)) {
				if (strcmp((*posn)->name, ref_map->name))
					die("%s tracks both %s and %s",
					    ref_map->peer_ref->name,
					    (*posn)->name, ref_map->name);
				next = (*posn)->next;
				free((*posn)->peer_ref);
				free(*posn);
				*posn = next;
			} else {
				posn = &(*posn)->next;
			}
		}
	}
}

int remote_has_url(struct remote *remote, const char *url)
{
	int i;
	for (i = 0; i < remote->url_nr; i++) {
		if (!strcmp(remote->url[i], url))
			return 1;
	}
	return 0;
}

int remote_find_tracking(struct remote *remote, struct refspec *refspec)
{
	int find_src = refspec->src == NULL;
	char *needle, **result;
	int i;

	if (find_src) {
		if (!refspec->dst)
			return error("find_tracking: need either src or dst");
		needle = refspec->dst;
		result = &refspec->src;
	} else {
		needle = refspec->src;
		result = &refspec->dst;
	}

	for (i = 0; i < remote->fetch_refspec_nr; i++) {
		struct refspec *fetch = &remote->fetch[i];
		const char *key = find_src ? fetch->dst : fetch->src;
		const char *value = find_src ? fetch->src : fetch->dst;
		if (!fetch->dst)
			continue;
		if (fetch->pattern) {
			if (!prefixcmp(needle, key) &&
			    needle[strlen(key)] == '/') {
				*result = xmalloc(strlen(value) +
						  strlen(needle) -
						  strlen(key) + 1);
				strcpy(*result, value);
				strcpy(*result + strlen(value),
				       needle + strlen(key));
				refspec->force = fetch->force;
				return 0;
			}
		} else if (!strcmp(needle, key)) {
			*result = xstrdup(value);
			refspec->force = fetch->force;
			return 0;
		}
	}
	return -1;
}

struct ref *alloc_ref(unsigned namelen)
{
	struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
	memset(ret, 0, sizeof(struct ref) + namelen);
	return ret;
}

static struct ref *copy_ref(const struct ref *ref)
{
	struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
	memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
	ret->next = NULL;
	return ret;
}

struct ref *copy_ref_list(const struct ref *ref)
{
	struct ref *ret = NULL;
	struct ref **tail = &ret;
	while (ref) {
		*tail = copy_ref(ref);
		ref = ref->next;
		tail = &((*tail)->next);
	}
	return ret;
}

void free_refs(struct ref *ref)
{
	struct ref *next;
	while (ref) {
		next = ref->next;
		if (ref->peer_ref)
			free(ref->peer_ref);
		free(ref);
		ref = next;
	}
}

static int count_refspec_match(const char *pattern,
			       struct ref *refs,
			       struct ref **matched_ref)
{
	int patlen = strlen(pattern);
	struct ref *matched_weak = NULL;
	struct ref *matched = NULL;
	int weak_match = 0;
	int match = 0;

	for (weak_match = match = 0; refs; refs = refs->next) {
		char *name = refs->name;
		int namelen = strlen(name);

		if (!refname_match(pattern, name, ref_rev_parse_rules))
			continue;

		/* A match is "weak" if it is with refs outside
		 * heads or tags, and did not specify the pattern
		 * in full (e.g. "refs/remotes/origin/master") or at
		 * least from the toplevel (e.g. "remotes/origin/master");
		 * otherwise "git push $URL master" would result in
		 * ambiguity between remotes/origin/master and heads/master
		 * at the remote site.
		 */
		if (namelen != patlen &&
		    patlen != namelen - 5 &&
		    prefixcmp(name, "refs/heads/") &&
		    prefixcmp(name, "refs/tags/")) {
			/* We want to catch the case where only weak
			 * matches are found and there are multiple
			 * matches, and where more than one strong
			 * matches are found, as ambiguous.  One
			 * strong match with zero or more weak matches
			 * are acceptable as a unique match.
			 */
			matched_weak = refs;
			weak_match++;
		}
		else {
			matched = refs;
			match++;
		}
	}
	if (!matched) {
		*matched_ref = matched_weak;
		return weak_match;
	}
	else {
		*matched_ref = matched;
		return match;
	}
}

static void tail_link_ref(struct ref *ref, struct ref ***tail)
{
	**tail = ref;
	while (ref->next)
		ref = ref->next;
	*tail = &ref->next;
}

static struct ref *try_explicit_object_name(const char *name)
{
	unsigned char sha1[20];
	struct ref *ref;
	int len;

	if (!*name) {
		ref = alloc_ref(20);
		strcpy(ref->name, "(delete)");
		hashclr(ref->new_sha1);
		return ref;
	}
	if (get_sha1(name, sha1))
		return NULL;
	len = strlen(name) + 1;
	ref = alloc_ref(len);
	memcpy(ref->name, name, len);
	hashcpy(ref->new_sha1, sha1);
	return ref;
}

static struct ref *make_linked_ref(const char *name, struct ref ***tail)
{
	struct ref *ret;
	size_t len;

	len = strlen(name) + 1;
	ret = alloc_ref(len);
	memcpy(ret->name, name, len);
	tail_link_ref(ret, tail);
	return ret;
}

static int match_explicit(struct ref *src, struct ref *dst,
			  struct ref ***dst_tail,
			  struct refspec *rs,
			  int errs)
{
	struct ref *matched_src, *matched_dst;

	const char *dst_value = rs->dst;

	if (rs->pattern)
		return errs;

	matched_src = matched_dst = NULL;
	switch (count_refspec_match(rs->src, src, &matched_src)) {
	case 1:
		break;
	case 0:
		/* The source could be in the get_sha1() format
		 * not a reference name.  :refs/other is a
		 * way to delete 'other' ref at the remote end.
		 */
		matched_src = try_explicit_object_name(rs->src);
		if (!matched_src)
			error("src refspec %s does not match any.", rs->src);
		break;
	default:
		matched_src = NULL;
		error("src refspec %s matches more than one.", rs->src);
		break;
	}

	if (!matched_src)
		errs = 1;

	if (!dst_value) {
		if (!matched_src)
			return errs;
		dst_value = matched_src->name;
	}

	switch (count_refspec_match(dst_value, dst, &matched_dst)) {
	case 1:
		break;
	case 0:
		if (!memcmp(dst_value, "refs/", 5))
			matched_dst = make_linked_ref(dst_value, dst_tail);
		else
			error("dst refspec %s does not match any "
			      "existing ref on the remote and does "
			      "not start with refs/.", dst_value);
		break;
	default:
		matched_dst = NULL;
		error("dst refspec %s matches more than one.",
		      dst_value);
		break;
	}
	if (errs || !matched_dst)
		return 1;
	if (matched_dst->peer_ref) {
		errs = 1;
		error("dst ref %s receives from more than one src.",
		      matched_dst->name);
	}
	else {
		matched_dst->peer_ref = matched_src;
		matched_dst->force = rs->force;
	}
	return errs;
}

static int match_explicit_refs(struct ref *src, struct ref *dst,
			       struct ref ***dst_tail, struct refspec *rs,
			       int rs_nr)
{
	int i, errs;
	for (i = errs = 0; i < rs_nr; i++)
		errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
	return -errs;
}

static const struct refspec *check_pattern_match(const struct refspec *rs,
						 int rs_nr,
						 const struct ref *src)
{
	int i;
	for (i = 0; i < rs_nr; i++) {
		if (rs[i].pattern &&
		    !prefixcmp(src->name, rs[i].src) &&
		    src->name[strlen(rs[i].src)] == '/')
			return rs + i;
	}
	return NULL;
}

/*
 * Note. This is used only by "push"; refspec matching rules for
 * push and fetch are subtly different, so do not try to reuse it
 * without thinking.
 */
int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
	       int nr_refspec, const char **refspec, int flags)
{
	struct refspec *rs =
		parse_push_refspec(nr_refspec, (const char **) refspec);
	int send_all = flags & MATCH_REFS_ALL;
	int send_mirror = flags & MATCH_REFS_MIRROR;

	if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
		return -1;

	/* pick the remainder */
	for ( ; src; src = src->next) {
		struct ref *dst_peer;
		const struct refspec *pat = NULL;
		char *dst_name;
		if (src->peer_ref)
			continue;
		if (nr_refspec) {
			pat = check_pattern_match(rs, nr_refspec, src);
			if (!pat)
				continue;
		}
		else if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
			/*
			 * "matching refs"; traditionally we pushed everything
			 * including refs outside refs/heads/ hierarchy, but
			 * that does not make much sense these days.
			 */
			continue;

		if (pat) {
			const char *dst_side = pat->dst ? pat->dst : pat->src;
			dst_name = xmalloc(strlen(dst_side) +
					   strlen(src->name) -
					   strlen(pat->src) + 2);
			strcpy(dst_name, dst_side);
			strcat(dst_name, src->name + strlen(pat->src));
		} else
			dst_name = xstrdup(src->name);
		dst_peer = find_ref_by_name(dst, dst_name);
		if (dst_peer && dst_peer->peer_ref)
			/* We're already sending something to this ref. */
			goto free_name;

		if (!dst_peer && !nr_refspec && !(send_all || send_mirror))
			/*
			 * Remote doesn't have it, and we have no
			 * explicit pattern, and we don't have
			 * --all nor --mirror.
			 */
			goto free_name;
		if (!dst_peer) {
			/* Create a new one and link it */
			dst_peer = make_linked_ref(dst_name, dst_tail);
			hashcpy(dst_peer->new_sha1, src->new_sha1);
		}
		dst_peer->peer_ref = src;
		if (pat)
			dst_peer->force = pat->force;
	free_name:
		free(dst_name);
	}
	return 0;
}

struct branch *branch_get(const char *name)
{
	struct branch *ret;

	read_config();
	if (!name || !*name || !strcmp(name, "HEAD"))
		ret = current_branch;
	else
		ret = make_branch(name, 0);
	if (ret && ret->remote_name) {
		ret->remote = remote_get(ret->remote_name);
		if (ret->merge_nr) {
			int i;
			ret->merge = xcalloc(sizeof(*ret->merge),
					     ret->merge_nr);
			for (i = 0; i < ret->merge_nr; i++) {
				ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
				ret->merge[i]->src = xstrdup(ret->merge_name[i]);
				remote_find_tracking(ret->remote,
						     ret->merge[i]);
			}
		}
	}
	return ret;
}

int branch_has_merge_config(struct branch *branch)
{
	return branch && !!branch->merge;
}

int branch_merge_matches(struct branch *branch,
		                 int i,
		                 const char *refname)
{
	if (!branch || i < 0 || i >= branch->merge_nr)
		return 0;
	return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
}

static struct ref *get_expanded_map(const struct ref *remote_refs,
				    const struct refspec *refspec)
{
	const struct ref *ref;
	struct ref *ret = NULL;
	struct ref **tail = &ret;

	int remote_prefix_len = strlen(refspec->src);
	int local_prefix_len = strlen(refspec->dst);

	for (ref = remote_refs; ref; ref = ref->next) {
		if (strchr(ref->name, '^'))
			continue; /* a dereference item */
		if (!prefixcmp(ref->name, refspec->src)) {
			const char *match;
			struct ref *cpy = copy_ref(ref);
			match = ref->name + remote_prefix_len;

			cpy->peer_ref = alloc_ref(local_prefix_len +
						  strlen(match) + 1);
			sprintf(cpy->peer_ref->name, "%s%s",
				refspec->dst, match);
			if (refspec->force)
				cpy->peer_ref->force = 1;
			*tail = cpy;
			tail = &cpy->next;
		}
	}

	return ret;
}

static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
{
	const struct ref *ref;
	for (ref = refs; ref; ref = ref->next) {
		if (refname_match(name, ref->name, ref_fetch_rules))
			return ref;
	}
	return NULL;
}

struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
{
	const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);

	if (!ref)
		return NULL;

	return copy_ref(ref);
}

static struct ref *get_local_ref(const char *name)
{
	struct ref *ret;
	if (!name)
		return NULL;

	if (!prefixcmp(name, "refs/")) {
		ret = alloc_ref(strlen(name) + 1);
		strcpy(ret->name, name);
		return ret;
	}

	if (!prefixcmp(name, "heads/") ||
	    !prefixcmp(name, "tags/") ||
	    !prefixcmp(name, "remotes/")) {
		ret = alloc_ref(strlen(name) + 6);
		sprintf(ret->name, "refs/%s", name);
		return ret;
	}

	ret = alloc_ref(strlen(name) + 12);
	sprintf(ret->name, "refs/heads/%s", name);
	return ret;
}

int get_fetch_map(const struct ref *remote_refs,
		  const struct refspec *refspec,
		  struct ref ***tail,
		  int missing_ok)
{
	struct ref *ref_map, **rmp;

	if (refspec->pattern) {
		ref_map = get_expanded_map(remote_refs, refspec);
	} else {
		const char *name = refspec->src[0] ? refspec->src : "HEAD";

		ref_map = get_remote_ref(remote_refs, name);
		if (!missing_ok && !ref_map)
			die("Couldn't find remote ref %s", name);
		if (ref_map) {
			ref_map->peer_ref = get_local_ref(refspec->dst);
			if (ref_map->peer_ref && refspec->force)
				ref_map->peer_ref->force = 1;
		}
	}

	for (rmp = &ref_map; *rmp; ) {
		if ((*rmp)->peer_ref) {
			int st = check_ref_format((*rmp)->peer_ref->name + 5);
			if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
				struct ref *ignore = *rmp;
				error("* Ignoring funny ref '%s' locally",
				      (*rmp)->peer_ref->name);
				*rmp = (*rmp)->next;
				free(ignore->peer_ref);
				free(ignore);
				continue;
			}
		}
		rmp = &((*rmp)->next);
	}

	if (ref_map)
		tail_link_ref(ref_map, tail);

	return 0;
}