From 4aa6bdf72b53591f6b0e52d5561a2f7a77d6d85d Mon Sep 17 00:00:00 2001
From: jony89 <ariel@emath.co.il>
Date: Wed, 5 Feb 2020 13:47:32 +0200
Subject: [PATCH] fix: memory leak event error is not unsubscribing

the event listener to scene `renderError` is only subscribing. causing memory leak upon cesium `.destory()`
---
 Source/Widgets/CesiumWidget/CesiumWidget.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Source/Widgets/CesiumWidget/CesiumWidget.js b/Source/Widgets/CesiumWidget/CesiumWidget.js
index d7fb8d9e5f6b..575dbf357f54 100644
--- a/Source/Widgets/CesiumWidget/CesiumWidget.js
+++ b/Source/Widgets/CesiumWidget/CesiumWidget.js
@@ -333,14 +333,15 @@ import getElement from '../getElement.js';
             this.targetFrameRate = options.targetFrameRate;
 
             var that = this;
-            scene.renderError.addEventListener(function(scene, error) {
+            this._onRenderError = function(scene, error) {
                 that._useDefaultRenderLoop = false;
                 that._renderLoopRunning = false;
                 if (that._showRenderLoopErrors) {
                     var title = 'An error occurred while rendering.  Rendering has stopped.';
                     that.showErrorPanel(title, undefined, error);
                 }
-            });
+            }
+            scene.renderError.addEventListener(this._onRenderError);
         } catch (error) {
             if (showRenderLoopErrors) {
                 var title = 'Error constructing CesiumWidget.';
@@ -671,6 +672,9 @@ import getElement from '../getElement.js';
      * removing the widget from layout.
      */
     CesiumWidget.prototype.destroy = function() {
+        if (this._scene) {
+            this._scene.renderError.removeEventListener(this._onRenderError);   
+        }
         this._scene = this._scene && this._scene.destroy();
         this._container.removeChild(this._element);
         this._creditContainer.removeChild(this._innerCreditContainer);