} else if addr != firstAddr {
			t.Fatalf("On request %d, addr %q != original addr %q", i+1, addr, firstAddr)
		}
		res.Body.Close()
	}
}

// Issue 13839
func TestNoCrashReturningTransportAltConn(t *testing.T) {
	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
	if err != nil {
		t.Fatal(err)
	}
	ln := newLocalListener(t)
	defer ln.Close()