OpenSubdiv: Fix crash toggling edit mode with new depsgraph

source/blender/blenkernel/intern/scene.c

@@ -1804,6 +1804,11 @@ void BKE_scene_update_tagged(EvaluationContext *eval_ctx, Main *bmain, Scene *sc
 	else
 #endif
 	{
+#ifdef OPENSUBDIV_GL_WORKAROUND
+		if (DEG_needs_eval(scene->depsgraph)) {
+			scene_free_unused_opensubdiv_cache(scene);
+		}
+#endif
 		DEG_evaluate_on_refresh(eval_ctx, scene->depsgraph, scene);
 		/* TODO(sergey): This is to beocme a node in new depsgraph. */
 		BKE_mask_update_scene(bmain, scene);

source/blender/depsgraph/DEG_depsgraph.h

@@ -193,6 +193,8 @@ void DEG_evaluate_on_refresh(struct EvaluationContext *eval_ctx,
                              Depsgraph *graph,
                              struct Scene *scene);
 
+bool DEG_needs_eval(Depsgraph *graph);
+
 /* Editors Integration  -------------------------- */
 
 /* Mechanism to allow editors to be informed of depsgraph updates,

source/blender/depsgraph/intern/depsgraph_eval.cc

@@ -392,3 +392,8 @@ void DEG_evaluate_on_framechange(EvaluationContext *eval_ctx,
 	/* Perform recalculation updates. */
 	DEG_evaluate_on_refresh_ex(eval_ctx, graph, layers);
 }
+
+bool DEG_needs_eval(Depsgraph *graph)
+{
+	return graph->entry_tags.size() != 0;
+}