[BUG] Diff on revision range for branch in repository without working trees is not possible

[Nicholas Allen]

> At present, diffs can only be performed in working trees, so this is
> more of a known limitation than an actual bug.
But then you can't examine any of the diffs on the server as the server 
will not have working tree as it does not need one. Isn't that a major 
limitation? When I specify a revision range there is no need for the 
working copy so isn't this really a bug anyway? If I just specify one 
revision then it needs to compare the working tree to the revision 
specified but for a range all info is held in the repository so I don't 
think this should be necessary and to me at least it is a bug...

Nick