--- lib/readline/input.c
+++ lib/readline/input.c	2007-05-11 10:42:11.000000000 +0200
@@ -151,7 +151,7 @@
     {
       pop_index--;
       if (pop_index < 0)
-	pop_index = ibuffer_len - 1;
+	pop_index = ibuffer_len;
       ibuffer[pop_index] = key;
       return (1);
     }