[TYPO3-mvc] RFC #8973: DataMapper mapps FALSE into empty related property

[Felix Oertel]

This is an SVN patch request.

Type: Bugfix

Bugtracker references:
http://forge.typo3.org/issues/8973

Branches:
trunk, 1.2.0

Problem:
When you've got a model with a property holding an related object, 
extbase tries to find the corresponding row in the database (via 
DataMapper::fetchRelatedEager() and the query-object). If there is no 
such row (because it either does not exist or it is flagged hidden or 
deleted), the query-object will return an empty array.

The DataMapper will then give this empty array to 
DataMapper::mapResultToPropertyValue(). In line 451 current() is called 
on this empty array and the result is assigned as propertyValue. 
Unfortunately current() returns FALSE on an empty array. You end up with 
the property's value set to FALSE if the related object was not found.

Solution:
I would suggest to map NULL here, because it's an empty property 
(without the corresponding object).

Notes:
Mapping FALSE will get you in trouble when you try to give this property 
to another function using a typeHint. NULL will pass fine but FALSE will 
throw an exception like "PHP Catchable Fatal Error: Argument 1 passed to 
Tx_MyExt_Controller_BaseController::getSomeFancyStuff() must be an 
instance of Tx_MyExt_Domain_Model_RelatedObject, boolean given".
No core class depends on returning FALSE here.

regards, foertel