Package node loses position when last child node unlinked

[prmr]

Description
The position of package nodes is a function of the position of their children nodes. However, when all nodes are deleted, the package node should retain its last position. This occurs correctly when children nodes are deleted, but not when they are unlinked from the parent node.

Steps to reproduce

1. Create new class diagram
2. Create a new package node
3. Add some children nodes to the package node
4. Move the children around
5. Unlink all the children from the package node
6. The package node jumps to the position where it was initially created

Configuration

• JetUML Release: 3.5