[Bug 52301] Firefox installer shows black rectangles

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=52301

--- Comment #7 from Roman Pišl  ---
(In reply to Bernhard Übelacker from comment #6)
> (In reply to Roman Pišl from comment #5)
> > This fixes it.
>
> Confirming, this shows the bitmap instead of the black square.
> But one thing I noticed is that it shows it mirrored now,
> the yellow part is at the bottom, the red part at the top.

Yes, it's rather a hack that avoids nsis passing lpBits==NULL into
StretchDIBits.