Re: Do I have to release the patch for a GPL software under GPL?

[Alfred M. Szmidt]

   If I distribute the modifications, then yes. In this example only
   *instructions* are provided. Saying "crop the photo so you see only
   the face, then put it in a red frame" is not a derivative work of
   that photo.

All of this is irrelevant.  The instructions to crop a photo can be
applied to millions of photos, your instructions on how to modify the
program can only be applied to a single program to have a useful
result.  The instructions are the modifications in this case.  A patch
by any means is a set of instructions on how to modify something, and
a patch is always a deriviate work since well, it is a patch...

   >  To create the patch you modified a GPLed work, so it is clearly
   > a modification in anyway of the word, how you represent these
   > modifications are once again completely irrelevant.  Then there
   > is the fact that your patch requires the GPLed work to be useful.

   That's not the copyright law criterion for a derivative work.  The
   derivative has to *contain* all or part of the pre-existing work.

And your list of instructions does contain that.  You simply choose to
represent the dervivate work in a different form.  How it is
represented is not relevant here since your modifications contain
specifc knowledge of the original work.