For the apropo PW32 have just introduced the DLL and API versioning..
If I develop a commercial application then stability rules and I would use a
choosen version of pthread (or any other external) library which I link
against, usually lagging some versions (to be real-life tested). So, even if
I provide the object files I cannot accept any claims if you link it with
eg. a newer version of the library either statically or dynamically.
Moreover, I usually use more than one external library with some licenses so
then I must provide those too to really enable you to relink..
I think this would be not a real case if the application is not something
simple and you provide good support which is generally your business..
Otherwise ask lawers who play that game ;)