Reinstalling style with broken CSL deletes the style, but does not throw an error

[fbennett]

Steps to reproduce (Zotero 2.1.5):

1. Install a valid CSL style.
2. Open empty document in OO (or Word) and add a citation.
3. Edit the style to call an undefined macro.
4. Reinstall the style.
5. Switch to another style in the word processor.
6. Switch back to the original (invalid) style.
7. Observe that the style remains as that switched to in step 5.
8. Restart word processor and confirm that the original style is selected.
9. Attempt to insert a citation.
10. "Style is undefined" error issues from Zotero.

No error issues when the style is reinstalled, and the style remains in the plugin style listing, so it appears that the revised style was installed successfully. The user might miss the failure if switching between similar styles, until the word processor is restarted and the error at step 10 occurs.

If Zotero threw an error at step 4 (or maybe step 6), it would be clear that something went wrong.

[simon]

Fixed by validation.