KTOR-4925 Fix CIO tunneling. (#3177)

Author: rsinukov1

ktor-client/ktor-client-cio/jvmAndNix/src/io/ktor/client/engine/cio/Endpoint.kt

@@ -177,9 +177,13 @@ internal class Endpoint(
                     if (proxy?.type == ProxyType.HTTP) {
                         startTunnel(requestData, connection.output, connection.input)
                     }
+                    val realAddress = when (proxy) {
+                        null -> address
+                        else -> InetSocketAddress(requestData.url.host, requestData.url.port)
+                    }
                     val tlsSocket = connection.tls(coroutineContext) {
                         takeFrom(config.https)
-                        serverName = serverName ?: address.hostname
+                        serverName = serverName ?: realAddress.hostname
                     }
                     return tlsSocket.connection()
                 } catch (cause: Throwable) {

ktor-client/ktor-client-cio/jvmAndNix/src/io/ktor/client/engine/cio/utils.kt

@@ -173,15 +173,9 @@ internal suspend fun startTunnel(
     val builder = RequestResponseBuilder()
 
     try {
-        builder.requestLine(HttpMethod("CONNECT"), request.url.hostWithPort, HttpProtocolVersion.HTTP_1_1.toString())
-        // this will only add the port to the host header if the port is non-standard for the protocol
-        val host = if (request.url.protocol.defaultPort == request.url.port) {
-            request.url.host
-        } else {
-            request.url.hostWithPort
-        }
-
-        builder.headerLine(HttpHeaders.Host, host)
+        val hostWithPort = request.url.hostWithPort
+        builder.requestLine(HttpMethod("CONNECT"), hostWithPort, HttpProtocolVersion.HTTP_1_1.toString())
+        builder.headerLine(HttpHeaders.Host, hostWithPort)
         builder.headerLine("Proxy-Connection", "Keep-Alive") // For HTTP/1.0 proxies like Squid.
         request.headers[HttpHeaders.UserAgent]?.let {
             builder.headerLine(HttpHeaders.UserAgent, it)