https://bugs.winehq.org/show_bug.cgi?id=37689
--- Comment #2 from zippy gohabsgo60@yahoo.ca --- Michael, thanks for looking into this.
are you sure GdipCreateBitmapFromScan0 isn't supposed to make a copy of the data ?
on an unrelated note, it looks like the nested 'for' loops in alpha_blend_bmp_pixels are in the wrong order - the pixels are fetched by column which is very inefficient.
one last thing, i forgot to mention that the program is open source and available on github https://github.com/sumatrapdfreader/sumatrapdf