In /kernel/content/action.php for "CurrentAction" == AddAssignment the array "$assignedIDArray" is filled with the wrong nodes.

Currently this array contains the nodeIDs of the nodes of the object already has. This is wrong as it should contain the nodeIDs the current object is already placed on.

This is easy to resolve by just changing this line in /kernel/content/action.php

$assignedNodeID = $assignedNode->attribute( 'node_id' );

to this:

$assignedNodeID = $assignedNode->attribute( 'parent_node_id' );

In current trunk rev. 17263 the affected line# is 705.

Steps to reproduce

Simply try to add an object in the admin interface twice to a new node. This will lead to something like you can see in the attached screenshot.