Resetting world to previous state.

On Minecraft Pocket edition 0.10.5 I was playing and at one point the world reverted back to a state from a previous time.

What I expected to happen was...:
The world to continue to stay how it was.

What actually happened was...:
The world reverted back to a state from a previous time.

Steps to Reproduce:
1. Make a minecraft world.
2. Wait for something to trigger the error.