fix possible stale hashHistory.location in discover

src/plugins/discover/public/kibana_services.ts

@@ -59,10 +59,24 @@ export const [getDocViewsRegistry, setDocViewsRegistry] = createGetterSetter<Doc
   'DocViewsRegistry'
 );
 /**
- * Makes sure discover and context are using one instance of history
+ * Makes sure discover and context are using one instance of history.
  */
 export const getHistory = _.once(() => createHashHistory());
 
+/**
+ * Discover & context are using same hash history instance,
+ * When getting back to discover internal history.location could get out of sync with window.location
+ * This helper function syncs window.location state to internal hash history
+ *
+ * Using this on discover mount also workarounds possible issues with async hash event: https://github.com/elastic/kibana/pull/65163
+ * This helper is temp until: https://github.com/elastic/kibana/issues/65161 resolved
+ */
+export const ensureHashHistoryLocation = () => {
+  const h = getHistory();
+  Object.assign(h.location, createHashHistory().location);
+  return h;
+};
+
 export const [getScopedHistory, setScopedHistory] = createGetterSetter<ScopedHistory>(
   'scopedHistory'
 );

src/plugins/discover/public/plugin.ts

@@ -55,6 +55,7 @@ import {
   setServices,
   setScopedHistory,
   getScopedHistory,
+  ensureHashHistoryLocation,
 } from './kibana_services';
 import { createSavedSearchesLoader } from './saved_searches';
 import { registerFeature } from './register_feature';
@@ -242,6 +243,7 @@ export class DiscoverPlugin
           throw Error('Discover plugin method initializeInnerAngular is undefined');
         }
         setScopedHistory(params.history);
+        ensureHashHistoryLocation();
         appMounted();
         const {
           plugins: { data: dataStart },