Re: segmentation fault on 'unset MAIL' for bash 2.01.1(1)-release

[Paul Eggert]

Brian Gough <address@hidden> writes:

> The comment in the autoconf source is "work around bugs in pre-3.0
> UWIN ksh".  If this is the only reason I'd suggest removing the unset
> command, since it seems to benefit a proprietary OS at the expense of
> GNU.

Better would be to support both systems.

Does this patch to Autoconf fix things for you?  If not, can you
suggest a simple test that would let us know whether the shell has the
bug?

2003-07-30  Paul Eggert  <address@hidden>

        * lib/m4sugar/m4sh.m4 (_AS_UNSET_PREPARE): Try to unset MAIL,
        since Bash 2.01 dumps core in that case.

--- m4sh.m4.~1.98.~     Thu May 22 14:39:45 2003
+++ m4sh.m4     Wed Jul 30 14:11:41 2003
@@ -278,7 +278,7 @@ fi
 # AS_UNSET depends upon $as_unset: compute it.
 m4_defun([_AS_UNSET_PREPARE],
 [# Support unset when possible.
-if (as_foo=foo; unset as_foo) >/dev/null 2>&1; then
+if (MAIL=60; unset MAIL) >/dev/null 2>&1; then
   as_unset=unset
 else
   as_unset=false