On Fri, Nov 09, 2007 at 12:40:42PM -0500, Greg Troxel wrote:
>   package is not installed
>   package is installed and does not match pkgsrc
>   package is installed and does match pkgsrc

So essentially:
(a) Check if the pattern is currently installed.
(b) If it isn't installed, check if a package from the same location
exists.

The second could also hit for multi-version packages.

Joerg