diff -Nru autoconf-2.58.orig/configure autoconf-2.58/configure
--- autoconf-2.58.orig/configure 2003-11-04 09:47:21.000000000 +0100
-+++ autoconf-2.58/configure 2003-11-05 09:35:17.144712072 +0100
++++ autoconf-2.58/configure 2003-11-05 10:11:37.318275312 +0100
@@ -23,7 +23,7 @@
fi
as_unset=unset
else
as_unset=false
+diff -Nru autoconf-2.58.orig/tests/wrapper.in autoconf-2.58/tests/wrapper.in
+--- autoconf-2.58.orig/tests/wrapper.in 2003-09-25 11:25:02.000000000 +0200
++++ autoconf-2.58/tests/wrapper.in 2003-11-05 10:11:53.217858208 +0100
+@@ -15,7 +15,7 @@
+ fi
+
+ # Support unset when possible.
+-if ((MAIL=60; unset MAIL) || exit) >/dev/null 2>&1; then
++if ( (MAIL=60; unset MAIL) || exit) >/dev/null 2>&1; then
+ as_unset=unset
+ else
+ as_unset=false