rename a DISTFILE at download time?

["Mark E. Perkins" <perkinsm%bway.net@localhost>]

Is there a way in pkgsrc to rename a DISTFILE when it is downloaded?  The
reason I'm asking is that x11/xpmicons downloads both KDEicons.tgz and
kdeicons.tgz, which results in breakage on case insensitive file systems.  My
thought is that an easy fix would be to save (remote file) KDEicons.tgz as
(local file) KDEicons_.tgz (say).  I don't see a way to do this with a pre-*
or post-* target.

Is this possible?  Or is there a better pkgsrc solution for something like this?

Thanks,
Mark