Reset dirty saved query on reload (#43927) (#44142)

* Clears changes a loaded saved query before loading another one

* Adds general functional test to ensure changes to a saved query are discarded on reloading it

* Moves resetting a dirty saved query to the app controllers in Discover, Visualize and Dashboard

src/legacy/core_plugins/kibana/public/dashboard/dashboard_app_controller.tsx

@@ -431,7 +431,7 @@ export class DashboardAppController {
     };
 
     $scope.onSavedQueryUpdated = savedQuery => {
-      $scope.savedQuery = savedQuery;
+      $scope.savedQuery = { ...savedQuery };
     };
 
     $scope.onClearSavedQuery = () => {

src/legacy/core_plugins/kibana/public/discover/controllers/discover.js

@@ -923,7 +923,7 @@ function discoverController(
   };
 
   $scope.onSavedQueryUpdated = savedQuery => {
-    $scope.savedQuery = savedQuery;
+    $scope.savedQuery = { ...savedQuery };
   };
 
   $scope.onClearSavedQuery = () => {

src/legacy/core_plugins/kibana/public/visualize/editor/editor.js

@@ -476,7 +476,7 @@ function VisEditor(
   };
 
   $scope.onSavedQueryUpdated = savedQuery => {
-    $scope.savedQuery = savedQuery;
+    $scope.savedQuery = { ...savedQuery };
   };
 
   $scope.onClearSavedQuery = () => {

test/functional/apps/discover/_saved_queries.js

@@ -123,6 +123,13 @@ export default function ({ getService, getPageObjects }) {
         await savedQueryManagementComponent.clearCurrentlyLoadedQuery();
         expect(await queryBar.getQueryString()).to.eql('');
       });
+
+      it('resets any changes to a loaded query on reloading the same saved query', async () => {
+        await savedQueryManagementComponent.loadSavedQuery('OkResponse');
+        await queryBar.setQuery('response:503');
+        await savedQueryManagementComponent.loadSavedQuery('OkResponse');
+        expect(await queryBar.getQueryString()).to.eql('response:404');
+      });
     });
   });
 }