Fix a query issue in the diff comments resources with anonymous users.
Review Request #2930 — Created Feb. 28, 2012 and submitted
Fix a query issue in the diff comments resources with anonymous users. A query in BaseDiffCommentResource was assuming the user was logged in. The result was a broken query for anonymous users. Execute that part of the query only if the user is logged in.
Added a unit test. It failed before the fix, and worked after.