If client A has an xdg_popup open and the user moves the cursor over a
surface of client B and waits for the cursor to be hidden after a
timeout, the cursor will not be shown on movement until the (invisible)
cursor is moved back into a surface of client A or somewhere the
compositor is responsible for rendering the cursor.
This is due to the (flawed) xdg popup grab interface of wlroots which
prevents wlr_seat_pointer_notify_enter() from sending events to clients
other than the one with the active xdg popup.
Closes: https://codeberg.org/river/river/issues/1192
8490558b8b