He Junyan 1146a7e3a0 glbasefilter: Need to check the display before lock it.
In find_gl_context_unlocked(), the display of filter may be NULL
and can cause crash if we directly access and lock it.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/922>
2020-12-04 00:23:38 +08:00
..