Add check for Bison. A recent version is required when in ZTS mode.

makedist

@@ -27,6 +27,15 @@
 # $Id$
 #
 
+old_IFS="$IFS"
+IFS=.
+eval set `bison -V|sed "s/GNU Bison version //"`
+if test "$1" = "1" && test "28" -gt "$2"; then
+  echo "Please use Bison 1.28 or higher"
+  exit 10
+fi
+IFS="$old_IFS"
+
 PHPROOT=:pserver:cvsread@cvs.php.net:/repository
 ZENDROOT=:pserver:cvsread@cvs.zend.com:/repository
 PHPMOD=php4