Fix bug in bundled GNU readline library, based on similar report for

GNU bash (http://lists.gnu.org/archive/html/bug-bash/2002-08/msg00042.html)
and current code from GNU readline 5.0. (Bug #5672)

cmd-line-utils/readline/bind.c

@@ -311,7 +311,7 @@ rl_generic_bind (type, keyseq, data, map)
 	     mapped to something, `abc' to be mapped to something else,
 	     and the function bound  to `a' to be executed when the user
 	     types `abx', leaving `bx' in the input queue. */
-	  if (k.function /* && k.type == ISFUNC */)
+	  if (k.function && ((k.type == ISFUNC && k.function != rl_do_lowercase_version) || k.type == ISMACR))
 	    {
 	      map[ANYOTHERKEY] = k;
 	      k.function = 0;