fix(combobox): fix binding to an old DataSource when both ItemsSource and SelectedItem are bound

[ramezgerges]

GitHub Issue (If applicable): closes #11956

PR Type

What kind of change does this PR introduce?

What is the current behavior?

What is the new behavior?

Copilot Summary

🤖 Generated by Copilot at 87d757c

This pull request enhances the ImmutableList<T> and DependencyProperty classes, and adds a new feature for synchronizing the selection of an items control with the current item of a collection view. It modifies the ImmutableList<T>.Insert method, the DependencyProperty.Register method, and the Selector.IsSynchronizedWithCurrentItemProperty field. It also fixes a bug in the ImmutableList<T> array copying logic and adds a custom comparer class for dependency property bindings.

PR Checklist

Please check if your PR fulfills the following requirements:

• Docs have been added/updated which fit documentation template (for bug fixes / features)
• Unit Tests and/or UI Tests for the changes have been added (for bug fixes / features) (if applicable)
• Validated PR Screenshots Compare Test Run results.
• Contains NO breaking changes
• Associated with an issue (GitHub or internal) and uses the automatic close keywords.
• Commits must be following the Conventional Commits specification.

Other information

Internal Issue (If applicable):

[jeromelaban]

This is likely going to have an impact on animations. Let's see what the CI says.

[ramezgerges]

Indeed. We need to make the AreDifferent check for a reason that so far eludes me, but I guess we can use the old Value, but I'm not sure if there are specific cases that should actually call the getter instead of using the old value. Let's see what tests fail after the small change I just did.

Edit: _value.Value is pretty much equivalent to _value.GetPrecedenceSpecificValue(), so we're back to square one

[Youssef1313]

This code is probably wrong. I think it should have been BindingPropertyHelper.GetPrecedenceSpecificValueGetter but I have no idea if that's the root cause.

[jeromelaban]

This is indeed interesting. Looking at 5fe335c, this was originally the case, and there this test:

uno/src/Uno.UI.Tests/BinderTests/Given_Binder.cs

Line 616 in ad7fe3d

public void When_PrivateProperty_And_Binding()

was added at that time and that specifying a precedence to GetValueGetter was enough to make it precedence specific.