Fix reloading of index pattern

Author: kertal

src/plugins/discover/public/application/angular/discover.js

@@ -264,7 +264,8 @@ function discoverController($element, $route, $scope, $timeout, $window, Promise
     if (!_.isEqual(newStatePartial, oldStatePartial)) {
       $scope.$evalAsync(async () => {
         if (oldStatePartial.index !== newStatePartial.index) {
-          //in case of index switch the route has currently to be reloaded, legacy
+          //in case of index pattern switch the route has currently to be reloaded, legacy
+          $route.reload();
           return;
         }
 
@@ -302,7 +303,6 @@ function discoverController($element, $route, $scope, $timeout, $window, Promise
         config.get(MODIFY_COLUMNS_ON_SWITCH)
       );
       await setAppState(nextAppState);
-      $route.reload();
     }
   };
 

test/functional/apps/discover/_indexpattern_without_timefield.ts

@@ -51,7 +51,16 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
         throw new Error('Expected timepicker to exist');
       }
     });
-    it('should not display a timepicker after using history.back()', async () => {
+    it('should switch between with and without timefield using the browser back button', async () => {
+      await PageObjects.discover.selectIndexPattern('without-timefield');
+      if (await PageObjects.timePicker.timePickerExists()) {
+        throw new Error('Expected timepicker not to exist');
+      }
+
+      await PageObjects.discover.selectIndexPattern('with-timefield');
+      if (!(await PageObjects.timePicker.timePickerExists())) {
+        throw new Error('Expected timepicker to exist');
+      }
       // Navigating back to discover
       await browser.goBack();
       if (await PageObjects.timePicker.timePickerExists()) {