+static void check_ref_valid(unsigned char object[20],
+ unsigned char prev[20],
+ char *ref,
+ int ref_size,
+ int force)
+{
+ if (snprintf(ref, ref_size,
+ "refs/replace/%s",
+ sha1_to_hex(object)) > ref_size - 1)
+ die("replace ref name too long: %.*s...", 50, ref);
+ if (check_refname_format(ref, 0))
+ die("'%s' is not a valid ref name.", ref);
+
+ if (read_ref(ref, prev))
+ hashclr(prev);
+ else if (!force)
+ die("replace ref '%s' already exists", ref);
+}
+