http://bugs.winehq.org/show_bug.cgi?id=7428
--- Comment #7 from Mikolaj Zalewski mikolaj.zalewski@gmail.com 2007-08-24 21:21:32 --- Photoshop have a problem with drawing the sample in the font face and regular/italic/bold comboboxes. Probably it tries to paint it using it's own engine and then AlphaBlend it on the combo. The GdiAlphaBlend should failed if the xSrc or ySrc is negative and Photoshop seems to be prepared for it as when we return FALSE is such a case the sample it never the less drawn. If we do nothing for an invalid xSrc but return TRUE, some samples will be missing.
A breakpoint in AlphaBlend in Photoshop on Windows shows that it is also called with negative parameters and Windows returns 0. So it looks like not a bug elsewhere but we need to validate the parameters.