From 156c6614bf2eb566bd6fd2e40802b00695a29d87 Mon Sep 17 00:00:00 2001
From: codiss <xuelongqy@qq.com>
Date: Thu, 23 Feb 2023 10:46:11 +0800
Subject: [PATCH] Fix Material3 TabBarTheme.dividerColor not working (#119690)

* Fixed Material3 TabBarTheme.dividerColor not working

* Add 'Material3 - TabBar inherits the dividerColor of TabBarTheme' test

---------

Co-authored-by: Kate Lovett <katelovett@google.com>
---
 packages/flutter/lib/src/material/tabs.dart   |  2 +-
 packages/flutter/test/material/tabs_test.dart | 30 +++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/packages/flutter/lib/src/material/tabs.dart b/packages/flutter/lib/src/material/tabs.dart
index c488a4ee753..8a8c1989515 100644
--- a/packages/flutter/lib/src/material/tabs.dart
+++ b/packages/flutter/lib/src/material/tabs.dart
@@ -1122,7 +1122,7 @@ class _TabBarState extends State<TabBar> {
       indicatorPadding: widget.indicatorPadding,
       tabKeys: _tabKeys,
       old: _indicatorPainter,
-      dividerColor: theme.useMaterial3 ? widget.dividerColor ?? defaults.dividerColor : null,
+      dividerColor: theme.useMaterial3 ? widget.dividerColor ?? tabBarTheme.dividerColor ?? defaults.dividerColor : null,
       labelPaddings: _labelPaddings,
     );
   }
diff --git a/packages/flutter/test/material/tabs_test.dart b/packages/flutter/test/material/tabs_test.dart
index e3689cd8c0a..ce47d897ab9 100644
--- a/packages/flutter/test/material/tabs_test.dart
+++ b/packages/flutter/test/material/tabs_test.dart
@@ -5614,6 +5614,36 @@ void main() {
         labelColor.withAlpha(0xB2) // 70% alpha,
       );
     });
+
+    testWidgets('Material3 - TabBar inherits the dividerColor of TabBarTheme', (WidgetTester tester) async {
+      const Color dividerColor = Colors.yellow;
+
+      await tester.pumpWidget(
+        MaterialApp(
+          theme: ThemeData(
+            useMaterial3: true,
+            tabBarTheme: const TabBarTheme(dividerColor: dividerColor),
+          ),
+          home: Scaffold(
+            appBar: AppBar(
+              bottom: TabBar(
+                controller: TabController(length: 3, vsync: const TestVSync()),
+                tabs: const <Widget>[
+                  Tab(text: 'Tab 1'),
+                  Tab(text: 'Tab 2'),
+                  Tab(text: 'Tab 3'),
+                ],
+              ),
+            ),
+          ),
+        ),
+      );
+
+      // Test painter's divider color.
+      final CustomPaint paint = tester.widget<CustomPaint>(find.byType(CustomPaint).last);
+      // ignore: avoid_dynamic_calls
+      expect((paint.painter as dynamic).dividerColor, dividerColor);
+    });
   });
 }