diff options
Diffstat (limited to 'builtin/update-ref.c')
| -rw-r--r-- | builtin/update-ref.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/builtin/update-ref.c b/builtin/update-ref.c index 3d79a46b03..6763cf1837 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -408,14 +408,27 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix) die("%s: not a valid SHA1", value); } - hashclr(oldsha1); /* all-zero hash in case oldval is the empty string */ - if (oldval && *oldval && get_sha1(oldval, oldsha1)) - die("%s: not a valid old SHA1", oldval); + if (oldval) { + if (!*oldval) + /* + * The empty string implies that the reference + * must not already exist: + */ + hashclr(oldsha1); + else if (get_sha1(oldval, oldsha1)) + die("%s: not a valid old SHA1", oldval); + } if (no_deref) flags = REF_NODEREF; if (delete) - return delete_ref(refname, oldval ? oldsha1 : NULL, flags); + /* + * For purposes of backwards compatibility, we treat + * NULL_SHA1 as "don't care" here: + */ + return delete_ref(refname, + (oldval && !is_null_sha1(oldsha1)) ? oldsha1 : NULL, + flags); else return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL, flags, UPDATE_REFS_DIE_ON_ERR); |