http-proxy: do the HTTP CONNECT process entirely non-blocking

Mentioned as a problem since 2007 (8f87c15) and of course it
existed even before that.

docs/libcurl/libcurl-multi.3

@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -173,7 +173,6 @@ the future, you should be aware of the following current restrictions:
 
 .nf
  - Name resolves unless the c-ares or threaded-resolver backends are used
- - HTTP proxy CONNECT operations
  - SOCKS proxy handshakes
  - file:// transfers
  - TELNET transfers

lib/ftp.c

@@ -272,7 +272,6 @@ static void close_secondarysocket(struct connectdata *conn)
     conn->sock[SECONDARYSOCKET] = CURL_SOCKET_BAD;
   }
   conn->bits.tcpconnect[SECONDARYSOCKET] = FALSE;
-  conn->tunnel_state[SECONDARYSOCKET] = TUNNEL_INIT;
 }
 
 /*
@@ -3585,7 +3584,7 @@ static CURLcode ftp_do_more(struct connectdata *conn, int *completep)
 
   /* if the second connection isn't done yet, wait for it */
   if(!conn->bits.tcpconnect[SECONDARYSOCKET]) {
-    if(conn->tunnel_state[SECONDARYSOCKET] == TUNNEL_CONNECT) {
+    if(Curl_connect_ongoing(conn)) {
       /* As we're in TUNNEL_CONNECT state now, we know the proxy name and port
          aren't used so we blank their arguments. TODO: make this nicer */
       result = Curl_proxyCONNECT(conn, SECONDARYSOCKET, NULL, 0);
@@ -3617,7 +3616,7 @@ static CURLcode ftp_do_more(struct connectdata *conn, int *completep)
     return result;
 
   if(conn->bits.tunnel_proxy && conn->bits.httpproxy &&
-     conn->tunnel_state[SECONDARYSOCKET] != TUNNEL_COMPLETE)
+     Curl_connect_ongoing(conn))
     return result;
 
 

lib/http.c

@@ -1369,7 +1369,7 @@ CURLcode Curl_http_connect(struct connectdata *conn, bool *done)
   if(CONNECT_FIRSTSOCKET_PROXY_SSL())
     return CURLE_OK; /* wait for HTTPS proxy SSL initialization to complete */
 
-  if(conn->tunnel_state[FIRSTSOCKET] == TUNNEL_CONNECT)
+  if(!Curl_connect_complete(conn))
     /* nothing else to do except wait right now - we're not done here. */
     return CURLE_OK;