[TYPO3-mvc] Extending another extensions sub-models (single table inheritance)

[Thomas "Thasmo" Deinhamer]

Hello all!

Imagine the following model structure:

	Extension 1
	
	Model: Contact
	  * Model: Person (extends Contact)
	  * Model: Corporation (extends Contact)
	
	Extension 2
	
	Model: Client extends Contact (from Extension)
	  * Model: Person (?)
	  * Model: Corporation (?)

The problem "(?)" is now, that I don't know how to extend
the models 'Person' and 'Corporation' of Extension 2
while _not_ losing any functionality.

If I do it like this:

	Extension 2
	
	Model: Person extends Client
	Model: Corporation extends Client

then I will lose methods of the models
'Person' and 'Corporation' from Extension 1

And if I do it like this:

	Extension 2
	
	Model: Person extends Person (from Extension 1)
	Model: Corporation extends Corporation (from Extension 1)

then I will lose methods of the model 'Client' from Extension 2.

Is there any solution to this or is this still a weak point of Extbase?

Thanks a lot for your response,
Thomas