2005-10-01  Tor Lillqvist  <tml@novell.com>

	* gdk/win32/gdkdrawable-win32.c (blit_from_pixmap): In case
	BitBlt() fails with ERROR_INVALID_HANDLE, the most probable cause
	is that the the desktop isn't visible because the session has been
	switched, the screen is locked, or a terminal server session
	disconnected, so no error message necessary. (#137796)

	It is of course remotely possible that BitBlt() failing with
	ERROR_INVALID_HANDLE might also be caused by some other
	problem. We could strive for perfection and track whether the
	desktop is visible by using WTSRegisterSessionNotification() and
	handling WM_WTSESSION_CHANGE. I think that's overdoing it just for
	this issue, though. If we would track desktop visibility, we
	should then avoid even trying to update the display at all while
	the desktop isn't visible.