Merge branch 'warning-rules-assistant' into 'pregmod-master'

Fix for null objects in read only

See merge request !5516

src/004-base/proxies.js

 window.createReadonlyProxy = function(target) {
+	if (target == null) return target; //intentionally ==
 	if (target.__isReadonlyProxy) { return target; }
 	if (_.isArray(target)) {
 		return new Proxy(target, {
@@ -39,6 +40,7 @@ window.createReadonlyProxy = function(target) {
 	return target;
 };
 window.createCheatProxy = function(target) {
+	if (target == null) return target; //intentionally ==
 	if (target.__isCheatProxy) { return target; }
 	if (_.isArray(target)) {
 		return new Proxy(target, {