As reported by @brianteeman if you enabled language debuggin, you will get a fatal error when trying to edit an article in backend.
This is because the getLayoutData method is run both for the getInput and getLabel methods and thus the value is processed twice. Now the first round works fine and leaves the value as **2016-12-15**, but the second round PHP can't work with that value anymore because it's no longer a valid date string.
Summary of Changes
This PR moves the value processing from the getLayoutData method to the getInput one so it is only run once.
Testing Instructions
Enable language debugging and edit an article in backend. See that the error occurs. (Form looks broken and there is a funny browser title).
Apply PR and the form works again.
Make sure the date eg in "Publish Up" is as expected, also taking also into account timezone settings.
Make sure the translate dateformat works. You need to add language strings to your second language as explained in #13158 (when you're at it, test that one as well :smile)
I have tested this item✅ successfully on 4826e6d
Works fine here.
This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/13233.