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                 return 1;
  65         if (write_ref_sha1(lock, sha1, msg) < 0)
  66                 return 1;
  67
  68         /* write_ref_sha1 always unlocks the ref, no need to do it explicitly */
  69         return 0;
  70 }