Repository: flutter
Issue: [Linux Desktop - TextField] Cant input text with iBus/fcitx enabled 
Labels: a: text input,framework,engine,a: desktop,P2,team-text-input,triaged-text-input

It works good when running on Chrome and using virtual keyboard on Linux Desktop.
But doesnt work using physical keyboard on Linux Desktop.

|     | Virtual Keyboard  |  Physical Keyboard  |
|  ----  | ----  | ----  |
| Chrome  | Pass | Pass |
| Linux Desktop  | Pass | Cant type words |
| Linux Desktop(ctrl+v add content) | Pass | Pass |
| Linux Desktop(delete words) | Pass | Pass |

## flutter doctor -v
```
(base) ➜  bug flutter doctor -v
[✓] Flutter (Channel master, 2.6.0-12.0.pre.340, on Ubuntu 21.04
    5.11.0-37-generic, locale en_US.UTF-8)
    • Flutter version 2.6.0-12.0.pre.340 at
      /home/xxxxx/snap/flutter/common/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision a6f375abdc (86 minutes ago), 2021-10-14 03:08:05
      -0400
    • Engine revision c432592e04
    • Dart version 2.15.0 (build 2.15.0-211.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version
    31.0.0)
    • Android SDK at /home/xxxxx/Android/Sdk
    • Platform android-31, build-tools 31.0.0
    • Java binary at: /opt/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build
      11.0.8+0-b944-P17168821)
    • All Android licenses accepted.

[✓] Chrome - develop for the web
    • Chrome at google-chrome

[✓] Linux toolchain - develop for Linux desktop
    • clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
    • cmake version 3.10.2
    • ninja version 1.8.2
    • pkg-config version 0.29.1

[✓] Android Studio (version 4.2)
    • Android Studio at /opt/android-studio
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin version 202.8531
    • Java version OpenJDK Runtime Environment (build
      11.0.8+0-b944-P17168821)

[✓] VS Code (version 1.60.2)
    • VS Code at /usr/share/code
    • Flutter extension version 3.27.0

[✓] Connected device (2 available)
    • Linux (desktop) • linux  • linux-x64      • Ubuntu 21.04
      5.11.0-37-generic
    • Chrome (web)    • chrome • web-javascript • Google Chrome 94.0.4606.54

• No issues found!
```
## Here is a minimal reproduction

``` dart
import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  TextEditingController controller = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            TextField(
              decoration: InputDecoration(
                border: UnderlineInputBorder(),
                hintText: 'Enter something',
              ),
              controller: controller,
            ),
          ],
        ),
      ),
    );
  }
}
```