format-patch: preserve subject newlines with -k
[git] / builtin / symbolic-ref.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "refs.h"
4 #include "parse-options.h"
5
6 static const char * const git_symbolic_ref_usage[] = {
7         "git symbolic-ref [options] name [ref]",
8         NULL
9 };
10
11 static void check_symref(const char *HEAD, int quiet)
12 {
13         unsigned char sha1[20];
14         int flag;
15         const char *refs_heads_master = resolve_ref(HEAD, sha1, 0, &flag);
16
17         if (!refs_heads_master)
18                 die("No such ref: %s", HEAD);
19         else if (!(flag & REF_ISSYMREF)) {
20                 if (!quiet)
21                         die("ref %s is not a symbolic ref", HEAD);
22                 else
23                         exit(1);
24         }
25         puts(refs_heads_master);
26 }
27
28 int cmd_symbolic_ref(int argc, const char **argv, const char *prefix)
29 {
30         int quiet = 0;
31         const char *msg = NULL;
32         struct option options[] = {
33                 OPT__QUIET(&quiet,
34                         "suppress error message for non-symbolic (detached) refs"),
35                 OPT_STRING('m', NULL, &msg, "reason", "reason of the update"),
36                 OPT_END(),
37         };
38
39         git_config(git_default_config, NULL);
40         argc = parse_options(argc, argv, prefix, options,
41                              git_symbolic_ref_usage, 0);
42         if (msg &&!*msg)
43                 die("Refusing to perform update with empty message");
44         switch (argc) {
45         case 1:
46                 check_symref(argv[0], quiet);
47                 break;
48         case 2:
49                 if (!strcmp(argv[0], "HEAD") &&
50                     prefixcmp(argv[1], "refs/"))
51                         die("Refusing to point HEAD outside of refs/");
52                 create_symref(argv[0], argv[1], msg);
53                 break;
54         default:
55                 usage_with_options(git_symbolic_ref_usage, options);
56         }
57         return 0;
58 }