This morning, I found a problem with my Zimbra installation that had appeared since a recent server upgrade that turned out to actually be a fixable bug with an open entry in Bugzilla.
So, I went ahead and made up a patch and submitted it with some comments about the bug, not knowing that Zimbra developers are unable to accept patches without the submitter having signed a contributor agreement. It turns out that Zimbra developers may not even be allowed to LOOK at these patches unless the submitter has a signed agreement.
I understand that the CA is a necessary legal device for Zimbra and its customers. It's Zimbra's responsibility to ensure that the code it distributes is legally distributable, and I can't hold a grudge against anyone for simply being responsible.
However, I think it's also incumbent upon Zimbra to warn people about the legal requirements when submitting a bug or attachment, right there in Bugzilla, before submitters waste their time creating patches that developers aren't allowed to look at, hence wasting the developers' valuable time as well.
Anyway, no hard feelings. It turns out that submitting a patch is a good way to get a developer to look at a bug, even if they're not allowed to use the patch in the end.
With ZCS 6 just recently becoming GA, it would be my guess that this issue will come up again in the near future, so maybe now would be a good time to raise this issue with your Bugzilla admin.