[Bug]: TargetClosedException thrown after clicking "Yes" on MS OAuth prompt in 1.60 (Regression from 1.58) #41348

public static async Task MSLogin(this IPage page, string eMail, string password)
{
    await page.GetByLabel("someone@example.com").FillAsync(eMail);
    await page.GetByText("Next").ClickAsync();
    await page.GetByLabel("Password").FillAsync(password);
    await page.GetByText("Sign In").ClickAsync();

    // Wait for the "Stay signed in?" prompt
    var yesButton = page.GetByText("Yes");
    await yesButton.WaitForAsync(new() { State = WaitForSelectorState.Visible, Timeout = 10000 });
    
    // Clicking "Yes" triggers the final cross-origin redirect back to the app
    await yesButton.ClickAsync(); 

    // BUG: In 1.60, this line (or the click itself) throws TargetClosedException.
    // In 1.58, this successfully waits for the dashboard to load.
    await page.WaitForLoadStateAsync(LoadState.NetworkIdle); 
}

using System.Net;
using System.Net.Sockets;
using System.Text;
using Microsoft.Playwright;

class Program
{
    static async Task Main(string[] args)
    {
        var server = new MockOAuthServer();
        await server.StartAsync();
        Console.WriteLine($"[Mock] App: http://localhost:{server.AppPort} | IdP: http://localhost:{server.IdpPort}");

        try
        {
            var playwright = await Playwright.CreateAsync();
            await using var browser = await playwright.Chromium.LaunchAsync(new()
            {
                Headless = false,
                Channel = "msedge",
                Args = new[] { "--auth-server-allowlist=\"_\"" }
            });
            var page = await browser.NewPageAsync();

            await page.GotoAsync($"http://localhost:{server.AppPort}/");
            await page.ClickAsync("text=Login"); // Redirects to IdP

            // Simulate the MS Login flow
            await page.GetByLabel("someone@example.com").FillAsync("test@example.com");
            await page.GetByText("Next").ClickAsync();
            await page.GetByLabel("Password").FillAsync("password");
            await page.GetByText("Sign In").ClickAsync();

            var yesButton = page.GetByText("Yes");
            await yesButton.WaitForAsync(new() { State = WaitForSelectorState.Visible });

            // BUG TRIGGER: Clicking "Yes" triggers a cross-origin 302 redirect to an external site (Bing/Yahoo).
            // In Playwright 1.60, this cross-origin navigation from a mocked server can throw TargetClosedException.

            // We wait for the URL to change to Bing.com or yahoo.com to ensure the navigation actually started and completed
            var navTask = page.WaitForURLAsync("**/*yahoo.com*");

            await yesButton.ClickAsync();
            await navTask;

            Console.WriteLine("[V] SUCCESS: Page survived the cross-origin redirect to Bing/Yahoo!");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[X] FAILED: {ex.GetType().Name} - {ex.Message}");
        }
        finally
        {
            server.Stop();
        }
    }
}

public class MockOAuthServer
{
    private TcpListener _appListener, _idpListener;
    private CancellationTokenSource _cts = new();
    public int AppPort { get; private set; }
    public int IdpPort { get; private set; }

    public async Task StartAsync()
    {
        _appListener = new TcpListener(IPAddress.Loopback, 0); _appListener.Start();
        AppPort = ((IPEndPoint)_appListener.LocalEndpoint).Port;
        _idpListener = new TcpListener(IPAddress.Loopback, 0); _idpListener.Start();
        IdpPort = ((IPEndPoint)_idpListener.LocalEndpoint).Port;

        _ = Task.Run(() => AcceptClients(_appListener, true));
        _ = Task.Run(() => AcceptClients(_idpListener, false));
        await Task.Delay(200);
    }

    private async Task AcceptClients(TcpListener listener, bool isApp)
    {
        while (!_cts.Token.IsCancellationRequested)
        {
            try { var client = await listener.AcceptTcpClientAsync(); _ = Task.Run(() => HandleClient(client, isApp)); }
            catch { break; }
        }
    }

    private async Task HandleClient(TcpClient client, bool isApp)
    {
        using (client) using (var stream = client.GetStream())
        {
            var buffer = new byte[8192];
            var bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
            if (bytesRead == 0) return;

            var request = Encoding.UTF8.GetString(buffer, 0, bytesRead);
            var path = request.Split('\n')[0].Split(' ')[1];

            string headers = "HTTP/1.1 200 OK\r\nContent-Type: text/html; charset=utf-8\r\nConnection: close\r\n\r\n";
            string body = "";

            if (isApp)
            {
                if (path == "/dashboard") body = "<html><body><h1>Dashboard</h1></body></html>";
                else body = $"<html><body><a href='http://localhost:{IdpPort}/login'>Login</a></body></html>";
            }
            else
            {
                if (path.StartsWith("/login") && !request.Contains("POST"))
                    body = "<html><body><form action='/login' method='POST'><input name='email' aria-label='someone@example.com'/><button>Next</button></form></body></html>";
                else if (path.StartsWith("/login") && request.Contains("POST"))
                    body = "<html><body><form action='/password' method='POST'><input type='password' name='password' aria-label='Password'/><button>Sign In</button></form></body></html>";
                else if (path.StartsWith("/password"))
                    body = "<html><body><div>Stay signed in?</div><form action='/redirect' method='POST'><button name='choice' value='yes'>Yes</button></form></body></html>";
                else if (path.StartsWith("/redirect"))
                {
                    // Redirect to Bing.com/Yahoo.com to force a true cross-origin navigation
                    headers = "HTTP/1.1 302 Found\r\nLocation: https://www.yahoo.com/\r\nConnection: close\r\n\r\n";
                    body = "";
                }
            }

            var responseBytes = Encoding.UTF8.GetBytes(headers + body);
            await stream.WriteAsync(responseBytes, 0, responseBytes.Length);
        }
    }

    public void Stop() { _cts.Cancel(); _appListener?.Stop(); _idpListener?.Stop(); }
}