wip: restrict external urls

Author: rajveermalviya

ios/Runner/AppDelegate.swift

@@ -28,6 +28,14 @@ import UserNotifications
     )
   }
 
+  // Allow only `zulip://login` external urls.
+  override func application(_ application: UIApplication, open url: URL, options: [UIApplication.OpenURLOptionsKey : Any] = [:]) -> Bool {
+     if url.scheme == "zulip" && url.host == "login" {
+       return super.application(application, open: url, options: options)
+     }
+     return false
+   }
+
   // Handle notification tap while the app is running.
   override func userNotificationCenter(
     _ center: UNUserNotificationCenter,

lib/widgets/app.dart

@@ -141,6 +141,7 @@ class ZulipApp extends StatefulWidget {
 class _ZulipAppState extends State<ZulipApp> with WidgetsBindingObserver {
   @override
   Future<bool> didPushRouteInformation(routeInformation) async {
+    print("didPushRouteInformation: ${routeInformation.uri}");
     switch (routeInformation.uri) {
       case Uri(scheme: 'zulip', host: 'login') && var url:
         await LoginPage.handleWebAuthUrl(url);
@@ -206,7 +207,8 @@ class _ZulipAppState extends State<ZulipApp> with WidgetsBindingObserver {
           // like [Navigator.push], never mere names as with [Navigator.pushNamed].
           onGenerateRoute: (_) => null,
 
-          onGenerateInitialRoutes: (_) {
+          onGenerateInitialRoutes: (String initialRoute) {
+            print("onGenerateInitialRoutes: $initialRoute");
             return [
               if (initialAccountId == null)
                 MaterialWidgetRoute(page: const ChooseAccountPage())