Modifying a port and keeping the mods across updates

[Paul Hoffman]

Greetings again. I have a two-part question that may be a ports FAQ, 
but I couldn't find such a beast.

(1) For a particular port, I need to change the the MAKE_ENV to make 
it build the way I want. What is the proper way to do this that will 
live beyond the next time I do a cvsup? That is, editing the Makefile 
works just fine, but I want something that will live if the Makefile 
gets reverted.

(2) For a particular port, I need to patch a particular source file. 
This is a patch that will probably be in a future release. Same 
question as above: what's the proper way to do this that will live 
beyond the next cvsup? I know how to use 'patch' to apply patches, 
but not yet to create them.

--Paul Hoffman