Removing this made me realize that calling the renderers' FakeFlat functions from the automap is inherently unsafe with the recent refactorings because there is absolutely no guarantee that the data may actually still be defined when the automap is being drawn.
So the best approach here is to give the automap its own FakeFlat function that runs independently of render data and assumptions of data preservation. This one can also be a lot simpler because it only needs the floor, not the ceiling info.
This was done to clean up the license and to ensure that any commercial fork of the engine has to obey the far stricter requirements concerning source distribution. The old license was compatible with GPLv2 whereas combining GPLv2 and LGPLv3 force a license upgrade to GPLv3. The license of code that originates from ZDoomGL has not been changed.
