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