Index: zdiff.in
===================================================================
--- zdiff.in.orig	2012-01-01 09:53:58.000000000 +0100
+++ zdiff.in	2012-10-16 13:40:46.854905141 +0200
@@ -105,9 +105,9 @@ elif test $# -eq 2; then
                                 5<&0
                     then
                         gzip_status=$(
-                          exec 4>&1
-                          (gzip -cdfq -- "$1" 4>&-; echo $? >&4) 3>&- |
-                            ( (gzip -cdfq -- "$2" 4>&-; echo $? >&4) 3>&- 5<&- </dev/null |
+			  exec 4>&1 6<&0
+			  (gzip -cdfq -- "$1" 4>&-; echo $? >&4) 3>&- 6<&- |
+			    ( (gzip -cdfq -- "$2" 4>&- 0<&6 6<&-; echo $? >&4) 3>&- 5<&- </dev/null |
                                eval "$cmp" /dev/fd/5 - >&3) 5<&0
                         )
                         cmp_status=$?