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 10:11:37.318275312 +0100
@@ -23,7 +23,7 @@
 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
@@ -2180,7 +2180,7 @@
 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
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