[gtk/wip/on-the-fence-about-damage] fixup! wip! gdkglcontext-x11: freeze frame clock while driver finishes swapping buffers

[Ray Strode <halfline src gnome org>]

commit 7b32ee489ae81bbb426e8dcadc2635a24cc14089
Author: Ray Strode <rstrode redhat com>
Date:   Thu May 28 16:11:02 2020 -0400

    fixup! wip! gdkglcontext-x11: freeze frame clock while driver finishes swapping buffers
    
    Oops we're getting disposed more than once, handle that better.

 gdk/x11/gdkglcontext-x11.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/gdk/x11/gdkglcontext-x11.c b/gdk/x11/gdkglcontext-x11.c
index 75936d6b71..8c8fa50e81 100644
--- a/gdk/x11/gdkglcontext-x11.c
+++ b/gdk/x11/gdkglcontext-x11.c
@@ -825,7 +825,10 @@ gdk_x11_gl_context_dispose (GObject *gobject)
   GdkX11GLContext *context_x11 = GDK_X11_GL_CONTEXT (gobject);
   GdkGLContext *context = GDK_GL_CONTEXT (gobject);
   GdkDisplay *display = gdk_gl_context_get_display (context);
-  Display *dpy = gdk_x11_display_get_xdisplay (display);
+  Display *dpy = NULL;
+
+  if (display != NULL)
+    dpy = gdk_x11_display_get_xdisplay (display);
 
   if (context_x11->glx_context != NULL)
     {