f2506fa9762bd9d868076710f38dfc9137186828
   1#include "cache.h"
   2#include "refs.h"
   3#include "builtin.h"
   4
   5static const char git_update_ref_usage[] =
   6"git-update-ref [-m <reason>] (-d <refname> <value> | <refname> <value> [<oldval>])";
   7
   8int 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}