Optional patching?

[Paul Schmehl]

I have an interesting situation.  I maintain the security/barnyard port. 
It's used for several things, one of which is sguil.  (I'm working on new 
ports for that as well.)  Barnyard includes a plugin for sguil, named 
op_sguil.plugin.

The sguil developers have changed the way they gather data for the newest 
release, 0.6.x.  The new release requires that you patch barnyard to update 
the op_sguil.plugin.  However, people who are still running the older 
versions of sguil; 0.5.x cannot use the new, patched version of the 
op_sguil.plugin.

My question is, is it possible to make a patch optional?  Offer the user 
the choice of patching or not based upon what version of sguil they intend 
to install?  If it is, how would the sguil port (which requires barnyard) 
patch barnyard if barnyard had been previously installed without the patch? 
Is this something that can be done within the port?  Or should it just be 
in pkg-message and let the user deinstall and reinstall and patch barnyard?

Paul Schmehl (pauls at utdallas.edu)
Adjunct Information Security Officer
University of Texas at Dallas
AVIEN Founding Member
http://www.utdallas.edu/