From 03dfa59acb1765f3e1cc49305903da4e10009acd Mon Sep 17 00:00:00 2001
From: Dave Smith <getdavemail@gmail.com>
Date: Fri, 28 May 2021 10:15:44 +0100
Subject: [PATCH 1/2] Reset the persisted selected menu ID if there are no
 longer any menus

---
 packages/edit-navigation/src/hooks/use-navigation-editor.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/packages/edit-navigation/src/hooks/use-navigation-editor.js b/packages/edit-navigation/src/hooks/use-navigation-editor.js
index cec78cf3a59dc2..7d7e9d15c1e5fa 100644
--- a/packages/edit-navigation/src/hooks/use-navigation-editor.js
+++ b/packages/edit-navigation/src/hooks/use-navigation-editor.js
@@ -47,6 +47,10 @@ export default function useNavigationEditor() {
 	useEffect( () => {
 		if ( hasLoadedMenus ) {
 			setHasFinishedInitialLoad( true );
+
+			if ( ! menus?.length ) {
+				setSelectedMenuId( 0 );
+			}
 		}
 	}, [ hasLoadedMenus ] );
 

From 718f0662eb948c144b8bb9d5a22daf6aabfc2936 Mon Sep 17 00:00:00 2001
From: Dave Smith <getdavemail@gmail.com>
Date: Fri, 28 May 2021 10:34:41 +0100
Subject: [PATCH 2/2] Test for menus and selected menu availability otherwise
 reset selected menu ID

---
 .../src/hooks/use-navigation-editor.js         | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/packages/edit-navigation/src/hooks/use-navigation-editor.js b/packages/edit-navigation/src/hooks/use-navigation-editor.js
index 7d7e9d15c1e5fa..b5baf9a236cc66 100644
--- a/packages/edit-navigation/src/hooks/use-navigation-editor.js
+++ b/packages/edit-navigation/src/hooks/use-navigation-editor.js
@@ -47,13 +47,23 @@ export default function useNavigationEditor() {
 	useEffect( () => {
 		if ( hasLoadedMenus ) {
 			setHasFinishedInitialLoad( true );
-
-			if ( ! menus?.length ) {
-				setSelectedMenuId( 0 );
-			}
 		}
 	}, [ hasLoadedMenus ] );
 
+	useEffect( () => {
+		// Don't reset selected menu before we can check whether
+		// it is still available.
+		if ( ! hasLoadedMenus ) {
+			return;
+		}
+
+		const selectedMenu = menus?.find( ( { id } ) => id === selectedMenuId );
+
+		if ( ! menus?.length || ! selectedMenu ) {
+			setSelectedMenuId( 0 );
+		}
+	}, [ hasLoadedMenus, menus, selectedMenuId ] );
+
 	const navigationPost = useSelect(
 		( select ) => {
 			if ( ! selectedMenuId ) {