Fix the disabling of the Welcome page

react/features/welcome/route.js

-/* global APP */
+/* @flow */
 
 import { RouteRegistry } from '../base/react';
 
 import { WelcomePage } from './components';
 import { generateRoomWithoutSeparator } from './roomnameGenerator';
 
+declare var APP: Object;
+declare var config: Object;
+
 /**
  * Register route for WelcomePage.
  */
  * @returns {void}
  */
 function onEnter(nextState, replace) {
-    if (typeof APP !== 'undefined' && !APP.settings.isWelcomePageEnabled()) {
+    // The disabling of the Welcome page by redirecting to a random room name is
+    // a feature (1) we have on Web/React and (2) we do not want on mobile/React
+    // Native (at the time of this writing).
+    if (typeof APP === 'object'
+
+            // TODO Technically, there is features/base/config now so it is
+            // preferable to read config(uration) values from there and not rely
+            // on a global variable. However, the redux store is not available
+            // here at the time of this writing. Given the current (1) Web
+            // exclusivity of the feature and (2) the reliance on other global
+            // variables (e.g. APP), go with the global variable for now in
+            // order to minimize the effort involved.
+            && !(config.enableWelcomePage
+                && APP.settings.isWelcomePageEnabled())) {
         const room = generateRoomWithoutSeparator();
 
         replace(`/${room}`);