fixing callSuper (#3844)

* fixing callSuper

* fixing lint

* fixed unexpected alias for this

src/mixins/itext_behavior.mixin.js

@@ -18,6 +18,7 @@
     onDeselect: function() {
       this.isEditing && this.exitEditing();
       this.selected = false;
+      this.callSuper('onDeselect');
     },
 
     /**

src/mixins/object_origin.mixin.js

@@ -250,6 +250,13 @@
      */
     _getLeftTopCoords: function() {
       return this.translateToOriginPoint(this.getCenterPoint(), 'left', 'top');
+    },
+
+    /**
+    * Callback; invoked right before object is about to go from active to inactive
+    */
+    onDeselect: function() {
+      /* NOOP */
     }
   });
 

src/util/lang_class.js

@@ -51,10 +51,26 @@
   function Subclass() { }
 
   function callSuper(methodName) {
-    var fn = this.constructor.superclass.prototype[methodName];
+    var parentMethod = null,
+        _this = this;
+
+    // climb prototype chain to find method not equal to callee's method
+    while (_this.constructor.superclass) {
+      var superClassMethod = _this.constructor.superclass.prototype[methodName];
+      if (_this[methodName] !== superClassMethod) {
+        parentMethod = superClassMethod;
+        break;
+      }
+      _this = _this.constructor.superclass.prototype;
+    }
+
+    if (!parentMethod) {
+      return console.log('tried to callSuper ' + methodName + ', method not found in prototype chain', this);
+    }
+
     return (arguments.length > 1)
-      ? fn.apply(this, slice.call(arguments, 1))
-      : fn.call(this);
+      ? parentMethod.apply(this, slice.call(arguments, 1))
+      : parentMethod.call(this);
   }
 
   /**