file::source_exists installs for Link'd dirs

[Axel Hecht]

Hi,
I am trying to process some files into a staging area with cons.
I managed to trigger my own package by extension, but now I found out, 
that the source file is installed into the destination directory by 
file::source_exists.
Could I have a use case for this?
I use cons to have my output dir uncluttered, now it looks like it would 
need to have the source files there.
Any help? I may just fiddle around this in my local copy, but I'd prefer 
to know the reason why it's there.

Thanx

Axel