Themed buttons (Cocoa or WinXP) lose their theme when zoomed, and turn back into "plain" buttons.
Please URL, testcase, or something can help to reproduce your problem ...
In Firefox, open the error console and evaluate this: top.window.opener.getBrowser().markupDocumentViewer.fullZoom = 1.2 Watch as the "Commit" button on the bottom of this page looses its native theme (color and shape). These values work (natively styled buttons): 0.5, 1, 1.5, 2 2.4 and 2.5 (look the same!?), 3, ...
Created attachment 274177 [details] [diff] [review] Patch I'm not sure if this fix is completely appropriate, but it seems right; the issue is that IsWidgetStyled is failing because pixel rounding of the border leads to different results.
Comment on attachment 274177 [details] [diff] [review] Patch +#define NS_ROUND_BORDER_TO_PIXELS(l,tpp) \ + ((l) == 0) ? 0 : PR_MAX((tpp), ((l) + ((tpp) / 2)) / (tpp) * (tpp)) Why can't we use the one in nsStyleStruct.h?
Actually, we can; and actually, nsNativeTheme already includes it (indirectly). I thought it would complicate the includes or something like that, but I wasn't really thinking about it.
Comment on attachment 274177 [details] [diff] [review] Patch Patch fixes native theme style checks to check against the right standard border-width. Should only have a significant affect with page zoom.