Await pending client authentication task before disposing (#66682)

Fixes #65455.

The assert was hit due to the SslStream being disposed during handshake, while `AuthenticateAsClientAsync` was still running. This removes a rare crash in test runs with debug libraries configuration.

diff --git a/src/libraries/System.Net.Security/tests/FunctionalTests/SslStreamNetworkStreamTest.cs b/src/libraries/System.Net.Security/tests/FunctionalTests/SslStreamNetworkStreamTest.cs
index 2f60715..b8c622e 100644 (file)
--- a/src/libraries/System.Net.Security/tests/FunctionalTests/SslStreamNetworkStreamTest.cs
+++ b/src/libraries/System.Net.Security/tests/FunctionalTests/SslStreamNetworkStreamTest.cs
@@ -123,6 +123,13 @@ namespace System.Net.Security.Tests
                     Assert.Contains("SSL_ERROR_SSL", e.InnerException.Message);
                     Assert.NotNull(e.InnerException.InnerException);
                     Assert.Contains("protocol", e.InnerException.InnerException.Message);
+
+                    e = await Assert.ThrowsAsync<AuthenticationException>(() => clientAuthenticationTask);
+
+                    Assert.NotNull(e.InnerException);
+                    Assert.Contains("SSL_ERROR_SSL", e.InnerException.Message);
+                    Assert.NotNull(e.InnerException.InnerException);
+                    Assert.Contains("protocol", e.InnerException.InnerException.Message);
                 }
             }