Request arguments are not merged correctly for single object actions
I try to update a single entity via PUT:
curl -i -H "Accept: application/xml" -H "Content-Type: application/xml" -X POST -d "<root><product><title>changed title</title></product></root>" http://localhost/products/2a7a6fd9-fa6f-47e2-8976-7c8308a96e4c
This won't merge the changed product title correctly, because in Router::route() the request & routing arguments are merged via Arrays::arrayMergeRecursiveOverrule(). the routing array with array('product' => array('title' => 'changed title')) is then overridden by array('product' => '<the product UUID>'));
This works, when using the "object routes" (IdentityRoutePart) because that returns an array in the form array('__identity' => '<UUID>') which can be merged.