crash when just about to place a train station

[db48x]

My bots were building rails and junctions from blueprints, and I had manually placed some of the track. I was just about to install the station stop when the game crashed.

Edit: by "about to place" I mean that I hack picked up the station and was attempting to place it. It had drawn the directional indicators on the track, but I had not yet moved it into the correct location to actually place it. The relevant portion of the stack trace fingers this as the proximate cause:

c:\factorio\src\entity\rail.cpp (452): Rail::length
c:\factorio\src\entity\rail.cpp (934): Rail::drawRailPath
c:\factorio\src\entity\trainstop.cpp (80): TrainStop::drawSelectionInfo
c:\factorio\src\graphics\buildingrenderer.cpp (228): BuildingRenderer::drawEntityToBeBuilt

[Rseding91]

I wasn't able to reproduce this issue in 0.12 and there have been changes to this section of the code reported in the crash so I believe it to be resolved. If it happens again please post with the new log.

Thanks.