Fixing concurrent super() calls

luci.js.diff

diff --git a/modules/luci-base/htdocs/luci-static/resources/luci.js b/modules/luci-base/htdocs/luci-static/resources/luci.js
index 7c1831376..3433da396 100644
--- a/modules/luci-base/htdocs/luci-static/resources/luci.js
+++ b/modules/luci-base/htdocs/luci-static/resources/luci.js
@@ -67,7 +67,7 @@
 	 * It provides simple means to create subclasses of given classes and
 	 * implements prototypal inheritance.
 	 */
-	var superContext = null, Class = Object.assign(function() {}, {
+	var superContext = {}, Class = Object.assign(function() {}, {
 		/**
 		 * Extends this base class with the properties described in
 		 * `properties` and returns a new subclassed Class instance
@@ -265,19 +265,26 @@
 			 * superclass method returned `null`.
 			 */
 			super: function(key, callArgs) {
-				for (superContext = Object.getPrototypeOf(superContext ||
+				if (key == null)
+					return null;
+
+				for (superContext[key] = Object.getPrototypeOf(superContext[key] ||
 				                                          Object.getPrototypeOf(this));
-				     superContext && !superContext.hasOwnProperty(key);
-				     superContext = Object.getPrototypeOf(superContext)) { }
+				     superContext[key] && !superContext[key].hasOwnProperty(key);
+				     superContext[key] = Object.getPrototypeOf(superContext[key])) {}
 
-				if (!superContext)
+				if (!superContext[key]) {
+					delete superContext[key];
 					return null;
+				}
 
-				var res = superContext[key];
+				var res = superContext[key][key];
 
 				if (arguments.length > 1) {
-					if (typeof(res) != 'function')
+					if (typeof(res) != 'function') {
+						delete superContext[key];
 						throw new ReferenceError(key + ' is not a function in base class');
+					}
 
 					if (typeof(callArgs) != 'object')
 						callArgs = this.varargs(arguments, 1);
@@ -285,8 +292,7 @@
 					res = res.apply(this, callArgs);
 				}
 
-				superContext = null;
-
+				delete superContext[key];
 				return res;
 			},