Lines 40 and 41 in the OddItemCommandExecutor for /odditem reset the damage value to 0 of the item held in the players hand, which will destroy the item if it's a spawn egg, potion, or other item for which the damage value matters. Removing these lines seemed to have no ill effects in my personal testing.

Since you seem to know exactly how to fix the problem, why not try fork it and fix it yourself?

Contributing patches to other people's projects is a great way to get started, and GitHub makes this especially easy to do.

Well, the primary reason was that I did not know to what purpose the code was originally intended to serve, so I was hoping for the author of them to point out some other bug which I had missed.

...That and this whole pull request workflow is new to me ^^;

I'll see if I can set up a pull request.

Made a pull request regarding this: #8