Block "resets" when right clicked with a food item.
So i was playing a new survival and picked up an apple off the bat, i decided to walk up to a tree and get some logs with the apple in hand. I started to hit the tree i was half way done when i accidentally hit right, which reset the damage on the tree. Food was full so i could not eat the apple. i made a quick video showing this bug http://www.youtube.com/watch?v=v6-7eafAqJc