src/xvba_video.c: extra ASSERTS()

src/xvba_video_glx.c

@@ -1787,8 +1787,10 @@ glx_output_surface_destroy(
         obj_output->render_context = NULL;
     }
 
-    if (obj_output->parent)
+    if (obj_output->parent) {
+        ASSERT(obj_output->parent->children_count > 0);
         --obj_output->parent->children_count;
+    }
 
     if (obj_output->gl_surface) {
         if (!obj_output->parent)
@@ -1953,6 +1955,7 @@ glx_output_surface_create(
     gl_set_current_context_cache(1);
 
     /* XXX: check that we don't already have a valid GLX context */
+    ASSERT(obj_output->gl_context == NULL);
     obj_output->gl_context = gl_create_context(
         driver_data->x11_dpy,
         driver_data->x11_screen,