What I expected to happen was...:
I expected to turn on the minecart rail inside the minecart.

What actually happened was...:
My game crashed and closed on the turn.

Steps to Reproduce:
1. Place some rails so that your minecart can change direction 90 degrees.
2. Place fire down so the fire would be in the turn and touching the rails.(Fire may need to be on netherrack)
3. Place your minecart and ride through the rail.

P.S. Picture is in the pc version of minecraft. It is an example of my rail. (I wasn't quite sure how to screenshot in minecraft pe.) BUG ONLY APPEARS IN MINECRAFT POCKET EDITION!