Blazor nested [SupplyParameterFromQuery] causes exception on navigation

[ben-farrant]

There was an issue discovered in NET 8, but still exists in NET 10, despite it supposedly being fixed.

The original (incorrectly closed) issue:
#57746

The problem is with OnLocationChanged() in SupplyParameterFromQueryValueProvider. The list of subscribers can be updated in the middle of a foreach loop. A similar issue was fixed in CascadingValueSource.NotifyChangedAsync() released in NET 9, which is why some thought this issue was fixed.

aspnetcore/src/Components/Components/src/Routing/SupplyParameterFromQueryValueProvider.cs

Line 124 in da2e7e1

private void OnLocationChanged(object? sender, LocationChangedEventArgs args)

aspnetcore/src/Components/Components/src/CascadingValueSource.cs

Line 85 in da2e7e1

public Task NotifyChangedAsync()