tls: fix flaky handshake cancellation test

p2p/security/tls/transport_test.go

@@ -188,7 +188,7 @@ func (c *delayedConn) Read(b []byte) (int, error) {
 	return c.Conn.Read(b)
 }
 
-func TestHandshakeConnectionCancelations(t *testing.T) {
+func TestHandshakeConnectionCancellations(t *testing.T) {
 	_, clientKey := createPeer(t)
 	serverID, serverKey := createPeer(t)
 
@@ -202,7 +202,13 @@ func TestHandshakeConnectionCancelations(t *testing.T) {
 
 		errChan := make(chan error)
 		go func() {
-			_, err := serverTransport.SecureInbound(context.Background(), serverInsecureConn, "")
+			conn, err := serverTransport.SecureInbound(context.Background(), serverInsecureConn, "")
+			// crypto/tls' context handling works by spinning up a separate Go routine that watches the context,
+			// and closes the underlying connection when that context is canceled.
+			// It is therefore not guaranteed (but very likely) that this happens _during_ the TLS handshake.
+			if err == nil {
+				_, err = conn.Read([]byte{0})
+			}
 			errChan <- err
 		}()
 		ctx, cancel := context.WithCancel(context.Background())