Currently, the code which handles support of the new depth stuffs (--depth,
sparse directories, etc.) when talking to a pre-1.5 (non-depth-aware) server
does so by simply throwing away information retrieved from the server that falls
outside the scope of the requested depth. This is an accurate way to deal with
the problem, but isn't optimal for RA layers which use multiple requests to get
the job done. For example, ra_serf requests a skeletal tree delta report from
the server, then subsequently (and somewhat simultaneously) fetches file
contents and such as necessary. Today, ra_serf behaves exactly the same with
the depth-filtering code in place as without. But ideally, it wouldn't even do
those extra file content fetches for files that fall outside the depth scope --
those file contents are today immediately discarded anyway.
Improvement
Major