Crash in qt_pixmapFromWinHICON

in qpixmap_win.cpp function qt_pixmapFromWinHICON calls qt_imageFromWinIconHBITMAP but doesn't check if returned QImage is null and starts reading its memory based on earlier set x and y.

This is in our experience often caused by getDiBits: GetDIBits(). The reason why getDiBits fails is the Windows error "User stopped resource enumeration" 15106 (0x3B02) ERROR_RESOURCE_ENUM_USER_STOP. Some details about the error http://www.pcrpr.com/error_resource_enum_user_stop.php.