From http://ftp.gnu.org/pub/gnu/readline/readline-6.3-patches/readline63-002

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>

			   READLINE PATCH REPORT
			   =====================

Readline-Release: 6.3
Patch-ID: readline63-002

Bug-Reported-by:	Anatol Pomozov <anatol.pomozov@gmail.com>
Bug-Reference-ID:	<CAOMFOmXy3mT2So5GQ5F-smCVArQuAeBwZ2QKzgCtMeXJoDeYOQ@mail.gmail.com>
Bug-Reference-URL:	http://lists.gnu.org/archive/html/bug-readline/2014-03/msg00010.html

Bug-Description:

When in callback mode, some readline commands can cause readline to seg
fault by passing invalid contexts to callback functions.

Patch (apply with `patch -p0'):

*** a/readline-6.3/readline.c	2013-10-28 14:58:06.000000000 -0400
--- b/readline.c	2014-03-10 14:15:02.000000000 -0400
***************
*** 745,749 ****
  
    RL_CHECK_SIGNALS ();
!   if (r == 0)			/* success! */
      {
        _rl_keyseq_chain_dispose ();
--- 745,750 ----
  
    RL_CHECK_SIGNALS ();
!   /* We only treat values < 0 specially to simulate recursion. */
!   if (r >= 0 || (r == -1 && (cxt->flags & KSEQ_SUBSEQ) == 0))	/* success! or failure! */
      {
        _rl_keyseq_chain_dispose ();
*** a/readline-6.3/patchlevel	2013-11-15 08:11:11.000000000 -0500
--- b/patchlevel	2014-03-21 08:28:40.000000000 -0400
***************
*** 1,3 ****
  # Do not edit -- exists only for use by patch
  
! 1
--- 1,3 ----
  # Do not edit -- exists only for use by patch
  
! 2