bug(windows): backspace with selected text deletes an extra character in TSF only

[mcdurdin]

Describe the bug

Per Jeff Heath at https://community.software.sil.org/t/ios-and-android-undesirable-behaviour-with-selected-text/6986/2:

... unexpected behavior on Windows 11 (but I believe also on Windows 10 as well) when I have some text selected and I press backspace. It deletes the selected text, but also the previous character.

...

I can demonstrate the behavior right now in Word 2019. With my keyboard activated, type “A test”, select “test” and type backspace, and the space is deleted as well. It doesn’t do this in LibreOffice Writer.

I have seen this behavior for quite some time, maybe a year, but I don’t remember it happening before that. So I think it must have happened with some Keyman version change.

This looks like a regression, perhaps in Keyman 15? We should track down the exact release where this behaviour changed.

Reproduce the bug

No response

Expected behavior

No response

Related issues

• #7865
• #7866

Keyman apps

• [ ] Keyman for Android
• [ ] Keyman for iPhone and iPad
• [ ] Keyman for Linux
• [ ] Keyman for macOS
• [X] Keyman for Windows
• [ ] Keyman Developer
• [ ] KeymanWeb
• [ ] Other - give details at bottom of form

Keyman version

15.0.274

Operating system

Windows 11

Device

No response

Target application

No response

Browser

No response

Keyboard name

No response

Keyboard version

No response

Language name

No response

Additional context

No response