and `www.squareup.com`. If a server refuses such sharing it will return HTTP 421 and OkHttp will
    automatically retry on an unshared connection.
 *  Fix: Don't crash if a TLS tunnel's response body is truncated.
 *  Fix: Don't track unusable routes beyond their usefulness. We had a bug where we could track
    certain bad routes indefinitely; now we only track the ones that could be necessary.

    // Make an SSL Tunnel on the first message pair of each SSL + proxy connection.
    val url = route.address.url
    val requestLine = "CONNECT ${url.toHostHeader(includeDefaultPort = true)} HTTP/1.1"
    while (true) {
      val source = this.source!!
      val sink = this.sink!!
      val tunnelCodec =
        Http1ExchangeCodec(
          // No client for CONNECT tunnels:
          client = null,

    assertThat(get2.headers["Proxy-Authorization"]).isEqualTo("password")
  }

  /**
   * OkHttp has a bug where a `Connection: close` response header is not honored when establishing a
   * TLS tunnel. https://github.com/square/okhttp/issues/2426
   */
  @Test
  fun proxyAuthenticateOnConnectWithConnectionClose() {
    server.useHttps(handshakeCertificates.sslSocketFactory())

   * connections are requested concurrently OkHttp will pessimistically connect multiple times, then
   * close any unnecessary connections. This test confirms that behavior works as intended.
   *
   * This test uses proxy tunnels to get a hook while a connection is being established.
   */
  @ParameterizedTest
  @ArgumentsSource(ProtocolParamProvider::class)
  fun concurrentHttp2ConnectionsDeduplicated(
    protocol: Protocol,

      connectionSpecIndex = -1,
      isTlsFallback = false,
    )
  }

  /**
   * Returns a request that creates a TLS tunnel via an HTTP proxy. Everything in the tunnel request
   * is sent unencrypted to the proxy server, so tunnels include only the minimum set of headers.
   * This avoids sending potentially sensitive data like HTTP cookies to the proxy unencrypted.
   *

_2022-06-08_

 *  Fix: Change how `H2_PRIOR_KNOWLEDGE` works with HTTP proxies. Previously OkHttp assumed the
    proxy itself was a prior knowledge HTTP/2 server. With this update, OkHttp attempts a `CONNECT`
    tunnel just as it would with HTTPS. For prior knowledge with proxies OkHttp's is now consistent
    with these curl arguments:

    ```
    curl \
      --http2-prior-knowledge \
      --proxy localhost:8888 \

    }

    /**
     * Respond to `CONNECT` requests until a non-tunnel response is peeked. Returns true if further
     * calls should be attempted on the socket.
     */
    @Throws(IOException::class, InterruptedException::class)
    private fun processTunnelRequests(): Boolean {
      if (!dispatcher.peek().inTunnel) return true // No tunnel requests.

      val source = raw.source().buffer()