What I expected to happen was...:

When I started the game, I noticed that all my enchanted items like armor, sword, and pickaxe doesn't have any damage. Then I killed some mobs with an enchanted sword and it doesn't take any damage. Then, I rolled back to 13w39b and I found out that the tools are almost break.

What actually happened was...:

I found out that the break bar on enchanted tools are missing.

Steps to Reproduce:

Put any damage on enchanted tools like hitting a zombie with enchanted sword