xterm segfaults when typing "set"

[Scott.Ellis@firstunion.com]

When running an xterm (from phase2v7), typing the command "set" (perhaps
only when using zsh as a shell) causes the xterm to experience a segfault
(and when not sgid, to dump core).  This is not reproducable with a 3.3.6
xterm, but is universal with the 4.0.1 xterm.  The set builtin in zsh
appears to output special characters when printing the value of IFS (the ^@
[null?] character).  I can produce an strace and/or coredump if necessary.

P.S. I'm not on the list, please CC me with any response.