- Stefan Krause reported a busy-looping case when using the multi interface

and doing CONNECT to a proxy. The app would then busy-loop until the proxy
  completed its response.

lib/multi.c

@@ -722,6 +722,12 @@ static int waitconnect_getsock(struct connectdata *conn,
     return GETSOCK_BLANK;
 
   sock[0] = conn->sock[FIRSTSOCKET];
+
+  /* when we've sent a CONNECT to a proxy, we should rather wait for the
+     socket to become readable to be able to get the response headers */
+  if(conn->bits.tunnel_connecting)
+    return GETSOCK_READSOCK(0);
+
   return GETSOCK_WRITESOCK(0);
 }