[Bug 57306] Multiple programs crash due to memory corruption since 5924ab4c515 (Nikon NX studio, Profit, Falcosoft's Soundfont Midi Player, IBExpert)

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=57306

--- Comment #66 from Fabian Maurer  ---
Created attachment 77533
  --> https://bugs.winehq.org/attachment.cgi?id=77533
Test that crashes Wine

So, I found an issue. Not sure if it's the same as yours, but it might have the
same roots.

In generate_ellipse_top_half we do as follows:
> const double a = (hsq * xform->eM11 * xform->eM11) + (wsq * xform->eM12 * xform->eM12);
> ...
> const double d = (hsq * wsq);
> ...
> pt.x = -sqrt(d / a);
> ...
>     while (pt.y > 0 || (pt.y == 0 && pt.x != -start_x))

When pt.x is 0, the functions returns a count of 0, leading to the assertion
and crash. No idea how to fix this though...

@Zeb, do you have an idea?