This bug has been copied from bug #624450 and has been proposed to be backported to 5.5 z-stream (EUS).
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: Under certain circumstances, a null pointer may have been incorrectly dereferenced, causing the tcsh shell to terminate unexpectedly. With this update, the pointer is now checked properly and tcsh no longer crashes.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2010-0823.html