Convert memset(hash,0,20) to hashclr(hash).
[git/git.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 <refname> <value> [<oldval>] [-m <reason>]";
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;
14
15 setup_ident();
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 (!refname) {
30 refname = argv[i];
31 continue;
32 }
33 if (!value) {
34 value = argv[i];
35 continue;
36 }
37 if (!oldval) {
38 oldval = argv[i];
39 continue;
40 }
41 }
42 if (!refname || !value)
43 usage(git_update_ref_usage);
44
45 if (get_sha1(value, sha1))
46 die("%s: not a valid SHA1", value);
47 hashclr(oldsha1);
48 if (oldval && get_sha1(oldval, oldsha1))
49 die("%s: not a valid old SHA1", oldval);
50
51 lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL, 0);
52 if (!lock)
53 return 1;
54 if (write_ref_sha1(lock, sha1, msg) < 0)
55 return 1;
56
57 /* write_ref_sha1 always unlocks the ref, no need to do it explicitly */
58 return 0;
59 }