Important: I do not know how reproducible this bug actually is as I did not have the items necessary to recreate it a second time, but I wanted to report it anyways as it seemed like it had potential to be exploited.

Description of Bug: Using a broken ironwood shield as an enchantment component (focus) repaired the shield from its broken state.
Reproduction Steps:

1.  Attempt to enchant an item, using gems and a broken ironwood shield as a focus.
   
2.  Close the enchanting table.
   
3.  Reopen the enchanting table.
4. The ironwood shield is now no longer broken, and has a small amount of durability.
   

Error message (if applicable): N/A

I am not fully sure if it was a specific combination of gems that caused this bug, as I attempted several combinations before closing the enchanting table and re-opening it. Upon viewing it again, the shield was no longer broken. No gems were consumed. The shield was also already enchanted with an enchantment I do not know the effects of at the time of it being broken.

Not able to reproduce this currently, may have already been fixed.