Another zsh 3.1 bug -- localization?

[SL Baur <steve@xemacs.org>]

I've tested this now on zsh 3.1.2 and zsh 3.1.3 Linux libc5 and GNU
libc.  It does not occur in zsh 3.0.4 or zsh 3.0.5.  It reproduces
reliably for me in a new zsh-3.1.3 (without the `unset CDPATH'
bugfix).  The machine I'm running on is localizable to the extent that
`LANG=ja' is able to programs that need Japanese input and display
Japanese output.

$ Src/zsh
$ LC_ALL=C; export LC_ALL; LANC=C; export LANG; date
zsh: 30841 segmentation fault (core dumped)  Src/zsh

[The misspelling of LANC=C is deliberate and duplicates the typo in
the GNU Awk 3.0.3 package].

The stack backtrace is cryptic:

$ LC_ALL=C; export LC_ALL; LANC=C; export LANG
# the previous step requires me to be running zsh-3.0
$ gdb src/Zsh 
(gdb) run -c date
Starting program: /usr/local/src/bin/zsh-3.1.3/Src/zsh -c date
Program received signal SIGTRAP, Trace/breakpoint trap.
0x400009d0 in lastmailcheck ()
(gdb) where
#0  0x400009d0 in lastmailcheck ()
Cannot access memory at address 0x80ad2f0.