quote directory, it might be an empty string

[[Imported from SVN: r4800]]

bin/wmlwrap.in

@@ -23,7 +23,7 @@ for OPT in $* ; do
 done
 
 # check if DUNEWEBDIR seems correct
-if test -d $DUNEWEBDIR && test -r $DUNEWEBDIR/layout/default.wml ; then
+if test -d "$DUNEWEBDIR" && test -r $DUNEWEBDIR/layout/default.wml ; then
     # call wml from within dune-web
     # --nocd lets wml use the .wmlrc from dune-web
     ( cd $DUNEWEBDIR && @WML@ --nocd -DROOT=$BASEDIR $ARGS )