git-revert: Revert revert message to old behaviour
[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> | <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;
14
15         delete = 0;
16         git_config(git_default_config);
17
18         for (i = 1; i < argc; i++) {
19                 if (!strcmp("-m", argv[i])) {
20                         if (i+1 >= argc)
21                                 usage(git_update_ref_usage);
22                         msg = argv[++i];
23                         if (!*msg)
24                                 die("Refusing to perform update with empty message.");
25                         if (strchr(msg, '\n'))
26                                 die("Refusing to perform update with \\n in message.");
27                         continue;
28                 }
29                 if (!strcmp("-d", argv[i])) {
30                         delete = 1;
31                         continue;
32                 }
33                 if (!refname) {
34                         refname = argv[i];
35                         continue;
36                 }
37                 if (!value) {
38                         value = argv[i];
39                         continue;
40                 }
41                 if (!oldval) {
42                         oldval = argv[i];
43                         continue;
44                 }
45         }
46         if (!refname || !value)
47                 usage(git_update_ref_usage);
48
49         if (get_sha1(value, sha1))
50                 die("%s: not a valid SHA1", value);
51
52         if (delete) {
53                 if (oldval)
54                         usage(git_update_ref_usage);
55                 return delete_ref(refname, sha1);
56         }
57
58         hashclr(oldsha1);
59         if (oldval && *oldval && get_sha1(oldval, oldsha1))
60                 die("%s: not a valid old SHA1", oldval);
61
62         lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL);
63         if (!lock)
64                 die("%s: cannot lock the ref", refname);
65         if (write_ref_sha1(lock, sha1, msg) < 0)
66                 die("%s: cannot update the ref", refname);
67         return 0;
68 }