GroupName Changes on radiobutton affect another usercontrol instance

[jismyname]

Description

a usercontrol has many radiobutton in the same groupName, while create a second instance of this usercontrol and set value to radiobutton binding before showing window, this chang will push to the first showed usercontrol instance. touch to me for more info.

Reproduction Steps

1. define a usercontrol with many radiobutton in the same groupname and bind ischecked to viewmodel.
2. create a instance of the usercontrol and set a new window and content to this usercontrol and show ,select any radiobutton.
3. creat a new instance of this usercontrol and set the binding viewmodel radiobutton ,and create a new window instance and set content to this second usercontrol and showdialog and close.

Expected behavior

1.open the firs window ,you should see your selected radiobutton just now,but it has been changed because of step 2.

Actual behavior

open the firs window, your selected radiobutton has been unselected.

Regression?

No response

Known Workarounds

No response

Impact

No response

Configuration

No response

Other information

No response

[miloush]

Which version are you using? Do you have a repro project?

This sounds quite like #2995

[jismyname]

Assembly PresentationFramework, Version=6.0.2.0
yes, quite like
even with different usercontrol with same groupname radiobuttons, this problem still exists!

[miloush]

That issue was fixed in .NET 8, can you try if you can still repro in 8 or 9?

[jismyname]

yes, in .net8.0,the problem exist ,when change to .net 9, it is fixed ,great! @miloush

[h3xds1nz]

@miloush It also got reverted in .NET 9, see #10087

[miloush]

Ah, good point, so the conclusion was this is by design? The issue in both cases seems to be that you end up with no radio button selected, while the issue with the fix was that you end up with multiple radiobuttons selected, am I reading it correctly? Sounds like there should be a fix that does neither.

[h3xds1nz]

@miloush For me, it is definitely a bug and it is not the only one.

The fix is needed because there are hanging GC refs that haven't been collected yet when e.g. a window is destroyed, so the code prevents you from selecting another radio button until that happens.

The fix that got reverted is wrong because it checks whether the visual root is not null, which of course breaks popups.

There's also another issue, that is (especially, major usercase) with shared two way bindings.

See the PR description and the relevant commit for a fix candidate - b18bc5a

I've attached repro playground, I'm happy for any inputs.

PR is #10252