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
@@ -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