If a window didn't have a WM_STATE set, xwindow_get_state_reply() returned 0
which just happened to be XCB_WM_STATE_WITHDRAWN. This caused issues in scan().
Instead, we now assume a window is in state normal if no state is explicitly
set, which makes a lot more sense and fixes actual bugs.
Signed-off-by: Uli Schlachter <psychon@znc.in>
Signed-off-by: Julien Danjou <julien@danjou.info>