[leak-scan] PathFigure.Segments — shared collection strongly retains path figure #38718

using System;
using System.Linq;
using System.Runtime.CompilerServices;
using Microsoft.Maui.Controls.Shapes;
using Xunit;

public class LeakTest
{
	const int N = 30;

	[Fact]
	public void PathFigure_Segments_Leaks()
	{
		var shared = new PathSegmentCollection();
		var control = CreateMany(() => Create(null, false));
		var leaky = CreateMany(() => Create(shared, false));
		var mitigation = CreateMany(() => Create(shared, true));

		for (var i = 0; i < 7; i++)
		{
			GC.Collect();
			GC.WaitForPendingFinalizers();
			GC.Collect();
		}

		Assert.Equal(0, control.Count(x => x.IsAlive));
		Assert.Equal(N, leaky.Count(x => x.IsAlive));
		Assert.Equal(0, mitigation.Count(x => x.IsAlive));
		GC.KeepAlive(shared);
	}

	[MethodImpl(MethodImplOptions.NoInlining)]
	static WeakReference[] CreateMany(Func<WeakReference> factory) =>
		Enumerable.Range(0, N).Select(_ => factory()).ToArray();

	[MethodImpl(MethodImplOptions.NoInlining)]
	static WeakReference Create(PathSegmentCollection? shared, bool mitigate)
	{
		var payload = new Payload();
		var figure = new PathFigure { BindingContext = payload };
		if (shared is not null)
			figure.Segments = shared;
		if (mitigate)
			figure.Segments = new PathSegmentCollection();
		return new WeakReference(payload);
	}

	sealed class Payload
	{
		readonly byte[] _bytes = new byte[1024 * 1024];
	}
}