3e69c5546b
When the window is called, we properly destroy all surfaces, which effectively will unmap that surface and should make it disapear on screen, but we also destroy the wl_source, a GSource that is resposibble of dispatching and executing messages to/from the Wayland server. As a side effect, the server never gets the message and the surfaces are "leaked" on the server. We fix this using wl_display_flush() before destroying the wl_source. Fixes #815 Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/1226>