Fatal error when used with metatag in certain cases

Problem/Motivation

I am using this module as part of COD along with the Metatag module. On one of the views in COD package (My Presentations view) causes a fatal error for an unprivileged user.

I ran a debug session and found the problem with how metatag module figured out entity types. It constructs a mock entity object and calls the uri callback for all entities to check if it gets a valid URI. The fatal error occurs when it calls og_vocab_uri. Now, this could be an issue with the metatag module but it seems that og_vocab could use some defensive coding anyway.

Proposed resolution

Check if the object and id's are valid before actually using them.

Remaining tasks

- Write a patch.
- Review
- Commit

User interface changes

None

API changes

None