Repository: flutter
Issue: Empty space on TextField bug when using Chinese Keyboard (iOS)
Labels: a: text input,platform-ios,engine,a: internationalization,has reproducible steps,P2,found in release: 2.0,found in release: 2.1,team-ios,triaged-ios

I encountered this bug when developing the login screen for an app. Where `myemail@email.com` will changed to `myemail@email.co m` when using a Chinese keyboard. This issue is not found on vanilla iOS application. This can be solved temporarily via setting the `FilteringTextInputFormatter.deny(RegExp('[\\s]'))`. 

## Steps to Reproduce

<!-- You must include full steps to reproduce so that we can reproduce the problem. -->

1. Run `flutter create bug`.
2. Update the `main.dart` to include the follow: 
    ```
    Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            TextField(
              keyboardType: TextInputType.text,
            ),
            TextField(
              keyboardType: TextInputType.emailAddress,
            ),
          ],
        )
    ```
3. Change to Chinese Keyboard via iOS settings
4. Type text with Chinese shorthand. Example, p g => 苹果. Before the Chinese character is selected. Click on the other textfield

**Expected results:**
Created with a sample Swift UI project with 2 TextFields

https://user-images.githubusercontent.com/4220976/112440478-54ee4400-8d85-11eb-89f1-2ad5c6c002cb.MP4



**Actual results:** 

https://user-images.githubusercontent.com/4220976/112440513-5f104280-8d85-11eb-8920-02601a71c339.MP4



<details>
  <summary>Logs</summary>

<!--
      Run your application with `flutter run --verbose` and attach all the
      log output below between the lines with the backticks. If there is an
      exception, please see if the error message includes enough information
      to explain how to solve the issue.
-->

```
```

<!--
     Run `flutter analyze` and attach any output of that command below.
     If there are any analysis errors, try resolving them before filing this issue.
-->

```
```

<!-- Finally, paste the output of running `flutter doctor -v` here. -->

```
[✓] Flutter (Channel stable, 2.0.3, on macOS 11.1 20C69 darwin-arm, locale en-GB)
    • Flutter version 2.0.3 at /Users/liewjuntung/Applications/flutter
    • Framework revision 4d7946a68d (6 days ago), 2021-03-18 17:24:33 -0700
    • Engine revision 3459eb2436
    • Dart version 2.12.2

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at /Users/liewjuntung/Library/Android/sdk
    • Platform android-30, build-tools 30.0.3
    • Java binary at: /Users/liewjuntung/Library/Application
      Support/JetBrains/Toolbox/apps/AndroidStudio/ch-0/203.7185775/Android Studio
      Preview.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.8+10-b944.6842174)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.4, Build version 12D4e
    • CocoaPods version 1.10.1

[✗] Chrome - develop for the web (Cannot find Chrome executable at
    /Applications/Google Chrome.app/Contents/MacOS/Google Chrome)
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.

[✓] Android Studio
    • Android Studio at /Users/liewjuntung/Library/Application
      Support/JetBrains/Toolbox/apps/AndroidStudio/ch-0/203.7185775/Android Studio
      Preview.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.8+10-b944.6842174)

[✓] VS Code (version 1.54.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.20.0

[✓] Connected device (1 available)
    • USiPh11P1 (mobile) • 00008030-000579010C78802E • ios • iOS 14.2

! Doctor found issues in 1 category.
```

</details>