Patch #462122: add readline startup and pre_event hooks.
diff --git a/acconfig.h b/acconfig.h
index ded68bb..9e30ab5 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -87,6 +87,9 @@
 /* Define if you have GNU PTH threads */
 #undef HAVE_PTH
 
+/* Define if you have readline 4.0 */
+#undef HAVE_RL_PRE_INPUT_HOOK
+
 /* Define if you have readline 4.2 */
 #undef HAVE_RL_COMPLETION_MATCHES