_CastError on Semantics copy in release mode (#91827)

packages/flutter/lib/src/widgets/editable_text.dart

@@ -2712,7 +2712,7 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
     if (hideHandles) {
       // Hide the handles and the toolbar.
       _selectionOverlay?.hide();
-    } else {
+    } else if (_selectionOverlay?.toolbarIsVisible ?? false) {
       // Hide only the toolbar but not the handles.
       _selectionOverlay?.hideToolbar();
     }

packages/flutter/lib/src/widgets/text_selection.dart

@@ -357,7 +357,7 @@ class TextSelectionOverlay {
   /// Controls the fade-in and fade-out animations for the toolbar and handles.
   static const Duration fadeDuration = Duration(milliseconds: 150);
 
-  late AnimationController _toolbarController;
+  late final AnimationController _toolbarController;
   Animation<double> get _toolbarOpacity => _toolbarController.view;
 
   /// Retrieve current value.
@@ -496,7 +496,7 @@ class TextSelectionOverlay {
   void hideToolbar() {
     assert(_toolbar != null);
     _toolbarController.stop();
-    _toolbar!.remove();
+    _toolbar?.remove();
     _toolbar = null;
   }
 

packages/flutter/test/widgets/editable_text_test.dart

@@ -3323,6 +3323,51 @@ void main() {
 
       semantics.dispose();
     });
+
+    // Regression test for b/201218542.
+    testWidgets('copying with a11y works even when toolbar is hidden', (WidgetTester tester) async {
+      Future<void> testByControls(TextSelectionControls controls) async {
+        final SemanticsTester semantics = SemanticsTester(tester);
+        final TextEditingController controller = TextEditingController(text: 'ABCDEFG');
+
+        await tester.pumpWidget(MaterialApp(
+          home: EditableText(
+            backgroundCursorColor: Colors.grey,
+            controller: controller,
+            focusNode: focusNode,
+            style: textStyle,
+            cursorColor: cursorColor,
+            selectionControls: controls,
+          ),
+        ));
+        await tester.tap(find.byType(EditableText));
+        await tester.pump();
+
+        final SemanticsOwner owner = tester.binding.pipelineOwner.semanticsOwner!;
+        const int expectedNodeId = 5;
+
+        expect(controller.value.selection.isCollapsed, isTrue);
+
+        controller.selection = TextSelection(
+          baseOffset: 0,
+          extentOffset: controller.value.text.length,
+        );
+        await tester.pump();
+
+        expect(find.text('Copy'), findsNothing);
+
+        owner.performAction(expectedNodeId, SemanticsAction.copy);
+        expect(tester.takeException(), isNull);
+        expect(
+          (await Clipboard.getData(Clipboard.kTextPlain))!.text,
+          equals('ABCDEFG'),
+        );
+
+        semantics.dispose();
+      }
+      await testByControls(materialTextSelectionControls);
+      await testByControls(cupertinoTextSelectionControls);
+    });
   });
 
   testWidgets('can set text with a11y', (WidgetTester tester) async {