Sticky piston do not put arrov up when its oppened, so its impossible to create eye detector now
What I expected to happen was...:
sticky piston will put arrow up
What actually happened was...:
arrow stayed down
Steps to Reproduce:
1. put sticky piston with sticky-side up
2. shoot arrov to sticky-side
3. arrow will stay down (in 1.2.5, it goes up and it made possibility to build an "eye detector" http://www.youtube.com/watch?v=iNLuOGKbuEo)
The previous functionality was a bug. A very strange one, with some useful properties. They've kept some "buggy" behavior in the past, when it was useful, and didn't negatively affect other things, but this appears to be something they either weren't aware was being used, or was changed to fix some other issue.