Fixes hangup triggering several times

conference.js

  */
 let DSExternalInstallationInProgress = false;
 
+/**
+ * Indicates whether we have started a hangup process.
+ * @type {boolean}
+ */
+let _hangupInProgress = false;
+
 import {VIDEO_CONTAINER_TYPE} from "./modules/UI/videolayout/LargeVideo";
 
 /**
  * @param {boolean} [requestFeedback=false] if user feedback should be requested
  */
 function hangup (requestFeedback = false) {
+    if (_hangupInProgress) {
+        console.log("Hangup already in progress.");
+        return;
+    }
+
+    _hangupInProgress = true;
+
     const errCallback = (f, err) => {
         console.error('Error occurred during hanging up: ', err);
         return f();
     .catch(errCallback.bind(null, disconnect))
     .then(maybeRedirectToWelcomePage)
     .catch(errCallback.bind(null, maybeRedirectToWelcomePage));
+
+    _hangupInProgress = false;
 }
 
 /**

modules/UI/Feedback.js

     isEnabled: function() {
         return this.enabled && APP.conference.isCallstatsEnabled();
     },
+
+    /**
+     * Returns true if the feedback window is currently visible and false
+     * otherwise.
+     * @return {boolean} true if the feedback window is visible, false
+     * otherwise
+     */
+    isVisible: function() {
+        return $(".feedback").is(":visible");
+    },
+
     /**
      * Opens the feedback window.
      */

modules/UI/UI.js

  * @returns {Promise} when dialog is closed.
  */
 UI.requestFeedback = function () {
-    return new Promise(function (resolve, reject) {
-        if (Feedback.isEnabled()) {
-            // If the user has already entered feedback, we'll show the window and
-            // immidiately start the conference dispose timeout.
-            if (Feedback.feedbackScore > 0) {
-                Feedback.openFeedbackWindow();
+    if (Feedback.isVisible())
+        return Promise.resolve();
+    else
+        return new Promise(function (resolve, reject) {
+            if (Feedback.isEnabled()) {
+                // If the user has already entered feedback, we'll show the
+                // window and immidiately start the conference dispose timeout.
+                if (Feedback.feedbackScore > 0) {
+                    Feedback.openFeedbackWindow();
+                    resolve();
+
+                } else { // Otherwise we'll wait for user's feedback.
+                    Feedback.openFeedbackWindow(resolve);
+                }
+            } else {
+                // If the feedback functionality isn't enabled we show a thank
+                // you dialog.
+                messageHandler.openMessageDialog(
+                    null, null, null,
+                    APP.translation.translateString(
+                        "dialog.thankYou", {appName:interfaceConfig.APP_NAME}
+                    )
+                );
                 resolve();
-
-            } else { // Otherwise we'll wait for user's feedback.
-                Feedback.openFeedbackWindow(resolve);
             }
-        } else {
-            // If the feedback functionality isn't enabled we show a thank you
-            // dialog.
-            messageHandler.openMessageDialog(
-                null, null, null,
-                APP.translation.translateString(
-                    "dialog.thankYou", {appName:interfaceConfig.APP_NAME}
-                )
-            );
-            resolve();
-        }
-    });
+        });
 };
 
 UI.updateRecordingState = function (state) {