I am developing a library which will be distributed as sources under a sane free license, probably MIT. The problem I face is that I depend on third party headers I have modified. The headers are not redistributable at all but are available in pristine form from their owner. As my library requires those headers to build, how legal would the following alternatives be:

1. Bundle the modified headers?
2. Bundle a set of patches the user must apply to the pristine headers?
3. Bundle a custom script to process pristine headers the user provides?

Alternative one feels like the safest of the above, as the only connection to the headers is that it's designed to mangle them into the form I require. Would alternative two be considered derivative work somehow, as the patches will contain part of the text of the pristine headers to establish context for applying the patch? Alternative three I assume will be right out, as I'm not even allowed to redistribute pristine headers. The headers in question are the C headers for DirectX, whose license explicitly says which headers may be redistributed (these are not among them).

A script that will make the required changes would probably be the safest option...

...but the real question is - why do you even need to modify DX headers in the first place? I'd be very, very weary of any library that asked me to make those kind of changes to my system. Even if it's a great library, those kind of requirements would make me view it as "hacky", and thus unreliable/unprofessional/unusable.

The headers are required to build my library, and will not be visible outside the build tree for my library.
The modifications are needed as I'm using a compiler that has a different idea about C standards than the Microsoft compiler.

[Edited by - Zao on January 29, 2010 7:59:45 PM]