Two unit tests are adapted to test the correct merge behavior
with both situations "value in overlay is blank" and
"value in overlay is not blank".

Resolves: #68592
Releases: master
Change-Id: Iba6d648aa9f4ce21badef1667a63806fde36af3c
Reviewed-on: http://review.typo3.org/42065


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>