Merge branch 'maint'
[git] / builtin-update-ref.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "builtin.h"
4
5 static const char git_update_ref_usage[] =
6 "git-update-ref [-m <reason>] (-d <refname> <value> | [--no-deref] <refname> <value> [<oldval>])";
7
8 int cmd_update_ref(int argc, const char **argv, const char *prefix)
9 {
10         const char *refname=NULL, *value=NULL, *oldval=NULL, *msg=NULL;
11         struct ref_lock *lock;
12         unsigned char sha1[20], oldsha1[20];
13         int i, delete, ref_flags;
14
15         delete = 0;
16         ref_flags = 0;
17         git_config(git_default_config);
18
19         for (i = 1; i < argc; i++) {
20                 if (!strcmp("-m", argv[i])) {
21                         if (i+1 >= argc)
22                                 usage(git_update_ref_usage);
23                         msg = argv[++i];
24                         if (!*msg)
25                                 die("Refusing to perform update with empty message.");
26                         continue;
27                 }
28                 if (!strcmp("-d", argv[i])) {
29                         delete = 1;
30                         continue;
31                 }
32                 if (!strcmp("--no-deref", argv[i])) {
33                         ref_flags |= REF_NODEREF;
34                         continue;
35                 }
36                 if (!refname) {
37                         refname = argv[i];
38                         continue;
39                 }
40                 if (!value) {
41                         value = argv[i];
42                         continue;
43                 }
44                 if (!oldval) {
45                         oldval = argv[i];
46                         continue;
47                 }
48         }
49         if (!refname || !value)
50                 usage(git_update_ref_usage);
51
52         if (get_sha1(value, sha1))
53                 die("%s: not a valid SHA1", value);
54
55         if (delete) {
56                 if (oldval)
57                         usage(git_update_ref_usage);
58                 return delete_ref(refname, sha1);
59         }
60
61         hashclr(oldsha1);
62         if (oldval && *oldval && get_sha1(oldval, oldsha1))
63                 die("%s: not a valid old SHA1", oldval);
64
65         lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL, ref_flags);
66         if (!lock)
67                 die("%s: cannot lock the ref", refname);
68         if (write_ref_sha1(lock, sha1, msg) < 0)
69                 die("%s: cannot update the ref", refname);
70         return 0;
71 }