For all wine files that contain code written by others:
a) Just keep them "secret" until I get paid, at which point I send them in all together. Pros: Simple, Cons: people might duplicate my work.
Good idea
b) Notify the Wine community of what the patches do/are but keep their contents secret.
LGPL violation, if you give your customer a LGPL'ed binary of wine, you must give them (Or at least offer them) access to the source, and you can't legally stop him/them from sending the code to wine-patches (Even if he/they may not have any interest in doing so)
c) Post them all to wine-devel but under a license that prevents them being merged unless you get a special exception from me. That way people can see, peer review the patches etc but they don't get committed. Of course, as this is just supposed to be insurance anyway, that seems a bit worthless.
Obvious and explicit LGPL violation.
d) Say "screw it", submit as usual and just hope I'm dealing with trustworthy people (unfortunately no contract in this case, the job isn't really big enough to warrant one).
Probably in your interest to opt for A, you can never be sure.
Of course, if the code you've written is just say a dll that's linked to/by wine,and you're the only author of that file/dll/whatever, you can even keep if proprietary and choose options b or c or just keep the code totally secret(That's what Transgaming and Codeweavers do). Alternatively, you can ask the copyright holders of the files you've modified for a special license that allows commercial use, in this case you can keep the code closed, and opt for b or d, or keep the code totally secret. Have a good look at http://www.gnu.org/licenses/lgpl.txt