https://bugs.winehq.org/show_bug.cgi?id=26379
--- Comment #11 from Rafał Mużyło galtgendo@o2.pl --- @comment 10: That patch is of little use on its own, as it moves the problem to a different function which currently is little but a stub.
Yet...
(for some reason, I doubt this is a coincidence) Close to the top of today's patch queue, there's a 5 patch series that uses the concept from that patch and seems to add just enough to D3DXComputeTangentFrameEx for it to actually work for this particular case.
Of course, being in the queue says nothing about actually getting accepted (nor about the quality of those patches)...