next/prev navigation links incorrect when comparing to current (moderated)

Issue Summary

Diff and Revisioning are the only third party modules installed.

Created a post, made some revisions, published a revision, then created a new moderated revision. Then I used the revisioning block to view the moderated revision. Finally I clicked on the compare to current tab. (recall that current is older than the revision I was viewing.)

When that comparison came up, the previous diff and next diff links both pointed to the same url. And it was wrong!

On the left of this grab, you see the newest (unpublished) revision. On the right is the current (the published revision.) If you click either link, you see the same two revisions compared, just with left and right sides switched!