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         setup_ident();
  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                         if (strchr(msg, '\n'))
  27                                 die("Refusing to perform update with \\n in message.");
  28                         continue;
  29                 }
  30                 if (!strcmp("-d", argv[i])) {
  31                         delete = 1;
  32                         continue;
  33                 }
  34                 if (!refname) {
  35                         refname = argv[i];
  36                         continue;
  37                 }
  38                 if (!value) {
  39                         value = argv[i];
  40                         continue;
  41                 }
  42                 if (!oldval) {
  43                         oldval = argv[i];
  44                         continue;
  45                 }
  46         }
  47         if (!refname || !value)
  48                 usage(git_update_ref_usage);
  49
  50         if (get_sha1(value, sha1))
  51                 die("%s: not a valid SHA1", value);
  52
  53         if (delete) {
  54                 if (oldval)
  55                         usage(git_update_ref_usage);
  56                 return delete_ref(refname, sha1);
  57         }
  58
  59         hashclr(oldsha1);
  60         if (oldval && *oldval && get_sha1(oldval, oldsha1))
  61                 die("%s: not a valid old SHA1", oldval);
  62
  63         lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL);
  64         if (!lock)
  65                 return 1;
  66         if (write_ref_sha1(lock, sha1, msg) < 0)
  67                 return 1;
  68
  69         /* write_ref_sha1 always unlocks the ref, no need to do it explicitly */
  70         return 0;
  71 }