CupertinoTextField should not accept requestFocus when disabled (#65235)

packages/flutter/lib/src/cupertino/text_field.dart

@@ -653,6 +653,7 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with Restoratio
     if (widget.controller == null) {
       _createLocalController();
     }
+    _effectiveFocusNode.canRequestFocus = widget.enabled ?? true;
   }
 
   @override
@@ -665,11 +666,7 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with Restoratio
       _controller!.dispose();
       _controller = null;
     }
-    final bool isEnabled = widget.enabled ?? true;
-    final bool wasEnabled = oldWidget.enabled ?? true;
-    if (wasEnabled && !isEnabled) {
-      _effectiveFocusNode.unfocus();
-    }
+    _effectiveFocusNode.canRequestFocus = widget.enabled ?? true;
   }
 
   @override

packages/flutter/test/cupertino/text_field_test.dart

@@ -2707,6 +2707,43 @@ void main() {
       expect(tapCount, 1);
   });
 
+  testWidgets('Focus test when the text field is disabled', (WidgetTester tester) async {
+    final FocusNode focusNode = FocusNode();
+    await tester.pumpWidget(
+      CupertinoApp(
+        home: Center(
+          child: CupertinoTextField(
+            focusNode: focusNode,
+          ),
+        ),
+      ),
+    );
+
+    expect(focusNode.hasFocus, false); // initial status
+
+    // Should accept requestFocus.
+    focusNode.requestFocus();
+    await tester.pump();
+    expect(focusNode.hasFocus, true);
+
+    // Disable the text field, now it should not accept requestFocus.
+    await tester.pumpWidget(
+      CupertinoApp(
+        home: Center(
+          child: CupertinoTextField(
+            enabled: false,
+            focusNode: focusNode,
+          ),
+        ),
+      ),
+    );
+
+    // Should not accept requestFocus.
+    focusNode.requestFocus();
+    await tester.pump();
+    expect(focusNode.hasFocus, false);
+  });
+
   testWidgets(
     'text field respects theme',
     (WidgetTester tester) async {