Assign disallowed types to a region of a layout

Nice!

However I think it reverts a previous patch at

 // If no disallowed types, return.
-    if (empty($disallowed_types[$parent_layout])) {
+    if (!isset($disallowed_types[$parent_layout][$region])) {
      return;
    }

So likely as $disallowed_types[$parent_layout][$region] can be empty array we should have
if (empty($disallowed_types[$parent_layout][$region]))

Otherwise this should be ready to go.

Thanks!

Automatically closed - issue fixed for 2 weeks with no activity.