svn_client_patch() should have a 'filter' parameter, specifiying one (or more?)
paths that will get patched. Other paths that are in the svnpatch file would not
get used if those paths don't match that filter.
This allows the user to select which parts of the svnpatch file to apply and
which ones not.
And it would be great if svn_client_patch() could have a parameter specifying
the target path, either the original path (like now) or a path to a temp file.
The result would be written to that file.
That way, svn_client_patch() could produce patched files in a different location
than the target working copy.
Improvement
Major