Water bug

Put the summary of the bug you're having here

What I expected to happen was...:
The water would be cut short by the sign.

What actually happened was...:
The extra water after the sign remained until a block update.

Steps to Reproduce:
1. Place a water source going in one direction.
2. Place a sign on any spot on the stream other than the source and the last of the stream remains.
3. ...