From 44ba6ab099a38cdf2174cee07a3aec49e5896fca Mon Sep 17 00:00:00 2001
From: Wilson Wilson <hello@wilsonwilson.dev>
Date: Fri, 18 Jun 2021 19:34:03 +0100
Subject: [PATCH] Added null check before NavigationRail.onDestinationSelected
 is called (#78032)

---
 .../flutter/lib/src/material/navigation_rail.dart |  3 ++-
 .../test/material/navigation_rail_test.dart       | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/packages/flutter/lib/src/material/navigation_rail.dart b/packages/flutter/lib/src/material/navigation_rail.dart
index 61e4e8c7c8..2c34bab2a2 100644
--- a/packages/flutter/lib/src/material/navigation_rail.dart
+++ b/packages/flutter/lib/src/material/navigation_rail.dart
@@ -498,7 +498,8 @@ class _NavigationRailState extends State<NavigationRail> with TickerProviderStat
                           labelTextStyle: widget.selectedIndex == i ? selectedLabelTextStyle : unselectedLabelTextStyle,
                           padding: widget.destinations[i].padding,
                           onTap: () {
-                            widget.onDestinationSelected!(i);
+                            if (widget.onDestinationSelected != null)
+                              widget.onDestinationSelected!(i);
                           },
                           indexLabel: localizations.tabLabel(
                             tabIndex: i + 1,
diff --git a/packages/flutter/test/material/navigation_rail_test.dart b/packages/flutter/test/material/navigation_rail_test.dart
index 1ac1438648..2eb79d234d 100644
--- a/packages/flutter/test/material/navigation_rail_test.dart
+++ b/packages/flutter/test/material/navigation_rail_test.dart
@@ -1918,6 +1918,21 @@ void main() {
     expect(selectedIndex, 2);
   });
 
+  testWidgets('onDestinationSelected is not called if null', (WidgetTester tester) async {
+    const int selectedIndex = 0;
+    await _pumpNavigationRail(
+      tester,
+      navigationRail: NavigationRail(
+        selectedIndex: selectedIndex,
+        destinations: _destinations(),
+        labelType: NavigationRailLabelType.all,
+      ),
+    );
+
+    await tester.tap(find.text('Def'));
+    expect(selectedIndex, 0);
+  });
+
   testWidgets('Changing destinations animate when [labelType]=selected', (WidgetTester tester) async {
     int selectedIndex = 0;