Prevent text from overflowing in OutlineButton and OutlinedButton label. (#70872)

packages/flutter/lib/src/material/outline_button.dart

@@ -310,7 +310,7 @@ class _OutlineButtonWithIcon extends OutlineButton with MaterialButtonWithIconMi
            children: <Widget>[
              icon,
              const SizedBox(width: 8.0),
-             label,
+             Flexible(child: label),
            ],
          ),
        );

packages/flutter/lib/src/material/outlined_button.dart

@@ -345,7 +345,7 @@ class _OutlinedButtonWithIconChild extends StatelessWidget {
     final double gap = scale <= 1 ? 8 : lerpDouble(8, 4, math.min(scale - 1, 1))!;
     return Row(
       mainAxisSize: MainAxisSize.min,
-      children: <Widget>[icon, SizedBox(width: gap), label],
+      children: <Widget>[icon, SizedBox(width: gap), Flexible(child: label)],
     );
   }
 }

packages/flutter/test/material/outline_button_test.dart

@@ -1222,6 +1222,22 @@ void main() {
     expect(box.size, equals(const Size(76, 36)));
     expect(childRect, equals(const Rect.fromLTRB(372.0, 293.0, 428.0, 307.0)));
   });
+
+  testWidgets('Text does not overflow in OutlineButton label', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      Directionality(
+        textDirection: TextDirection.ltr,
+        child: MouseRegion(
+          cursor: SystemMouseCursors.forbidden,
+          child: OutlineButton.icon(
+            icon: const Icon(Icons.add),
+            label: const Text('this is a very long text used to check whether an overflow occurs or not'),
+            onPressed: () {},
+          ),
+        ),
+      ),
+    );
+  });
 }
 
 PhysicalModelLayer _findPhysicalLayer(Element element) {

packages/flutter/test/material/outlined_button_test.dart

@@ -1212,6 +1212,22 @@ void main() {
     );
     expect(paddingWidget.padding, const EdgeInsets.all(22));
   });
+
+  testWidgets('Text does not overflow in OutlinedButton label', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      Directionality(
+        textDirection: TextDirection.ltr,
+        child: MouseRegion(
+          cursor: SystemMouseCursors.forbidden,
+          child: OutlinedButton.icon(
+            icon: const Icon(Icons.add),
+            label: const Text('this is a very long text used to check whether an overflow occurs or not'),
+            onPressed: () {},
+          ),
+        ),
+      ),
+    );
+  });
 }
 
 PhysicalModelLayer _findPhysicalLayer(Element element) {