fix missing 'test'

build/branch.sh

@@ -31,7 +31,7 @@ case $child in
   *) child="b_$child"
 esac
 
-if test "$parent" != "HEAD" && test -f $dir/CVS/Tag && "`cat $dir/CVS/Tag`" != "T$parent"; then
+if test "$parent" != "HEAD" -a -f $dir/CVS/Tag -a "`cat $dir/CVS/Tag`" != "T$parent"; then
 	echo "This script must be run within the $parent branch"
 	exit 1
 fi