[Web][CanvasKit] SelectableText.rich selection highlighting is mis-positioned

[Fito989]

Hello, I am developing an app with a list of SelectableText.rich and when it's executed I can't select the text and when I try to copy the text it only copies the first TextSpan

Steps to Reproduce

I did upload an example to make it easy to recreate.
Run this GitHub project: Project

Expected results: Can select and copy text

Actual results: Text is not selected and if you try to copy it it only takes first TextSpan

Logs

Flutter analyze

Analyzing untitled...
No issues found! (ran in 5.4s)

Flutter doctor -v

[√] Flutter (Channel beta, 1.25.0-8.3.pre, on Microsoft Windows [Versión 10.0.19041.746], locale es-ES)
    • Flutter version 1.25.0-8.3.pre at C:\flutter
    • Framework revision 5d36f2e7f5 (11 days ago), 2021-01-14 15:57:49 -0800
    • Engine revision 7a8f8ca02c
    • Dart version 2.12.0 (build 2.12.0-133.7.beta)

[√] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at C:\Users\pol98\AppData\Local\Android\sdk
    • Platform android-30, build-tools 30.0.3
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)
    • All Android licenses accepted.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Android Studio (version 4.1.0)
    • Android Studio at C:\Program Files\Android\Android Studio
    • 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 1.8.0_242-release-1644-b01)

[√] IntelliJ IDEA Ultimate Edition (version 2020.3)
    • IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA 2020.3
    • Flutter plugin version 52.2.5
    • Dart plugin version 203.6912

[√] VS Code (version 1.52.1)
    • VS Code at C:\Users\pol98\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension can be installed from:
       https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter

[√] Connected device (2 available)
    • Chrome (web) • chrome • web-javascript • Google Chrome 87.0.4280.141
    • Edge (web)   • edge   • web-javascript • Microsoft Edge 88.0.705.50

• No issues found!

[ferhatb]

/cc @mdebbar

[mdebbar]

@Fito989 the fix has landed in master and you are on the beta channel. Could you try on master to see if it's still an issue?

[Fito989]

I switched to master and when i execute it, selection was below the word

[mdebbar]

@Fito989 Could you share a minimal code sample that reproduces the issue?