+/*
+ * Check whether a ref is hidden. If no namespace is set, both the first and
+ * the second parameter point to the full ref name. If a namespace is set and
+ * the ref is inside that namespace, the first parameter is a pointer to the
+ * name of the ref with the namespace prefix removed. If a namespace is set and
+ * the ref is outside that namespace, the first parameter is NULL. The second
+ * parameter always points to the full ref name.
+ */
+extern int ref_is_hidden(const char *, const char *);