When I select two Job configurations in the History page, and click "Show Diffs", I get an empty page.
The generated URL looks like this:
Note that the slashes in the pathes are escaped twice (%252F). When I replace the %252F with %2F, it works:
On a side note: Why are internal absolute path names on the server exposed as url parameters? Why not simply give the two dates? The job name is already part of the url anyway.