Use dedicated hostname_resolve

lib/url.c

@@ -708,6 +708,7 @@ static void conn_free(struct connectdata *conn)
   Curl_safefree(conn->trailer);
   Curl_safefree(conn->host.rawalloc); /* host name buffer */
   Curl_safefree(conn->conn_to_host.rawalloc); /* host name buffer */
+  Curl_safefree(conn->hostname_resolve);
   Curl_safefree(conn->secondaryhostname);
   Curl_safefree(conn->http_proxy.host.rawalloc); /* http proxy name buffer */
   Curl_safefree(conn->socks_proxy.host.rawalloc); /* socks proxy name buffer */
@@ -3434,7 +3435,10 @@ static CURLcode resolve_server(struct Curl_easy *data,
         conn->port = conn->remote_port;
 
       /* Resolve target host right on */
-      rc = Curl_resolv_timeout(conn, connhost->name, (int)conn->port,
+      conn->hostname_resolve = strdup(connhost->name);
+      if(!conn->hostname_resolve)
+        return CURLE_OUT_OF_MEMORY;
+      rc = Curl_resolv_timeout(conn, conn->hostname_resolve, (int)conn->port,
                                &hostaddr, timeout_ms);
       if(rc == CURLRESOLV_PENDING)
         *async = TRUE;
@@ -3455,7 +3459,10 @@ static CURLcode resolve_server(struct Curl_easy *data,
         &conn->socks_proxy.host : &conn->http_proxy.host;
 
       /* resolve proxy */
-      rc = Curl_resolv_timeout(conn, host->name, (int)conn->port,
+      conn->hostname_resolve = strdup(host->name);
+      if(!conn->hostname_resolve)
+        return CURLE_OUT_OF_MEMORY;
+      rc = Curl_resolv_timeout(conn, conn->hostname_resolve, (int)conn->port,
                                &hostaddr, timeout_ms);
 
       if(rc == CURLRESOLV_PENDING)
@@ -3538,6 +3545,10 @@ static void reuse_conn(struct connectdata *old_conn,
   conn->conn_to_host = old_conn->conn_to_host;
   conn->conn_to_port = old_conn->conn_to_port;
   conn->remote_port = old_conn->remote_port;
+  Curl_safefree(conn->hostname_resolve);
+
+  conn->hostname_resolve = old_conn->hostname_resolve;
+  old_conn->hostname_resolve = NULL;
 
   /* persist connection info in session handle */
   Curl_persistconninfo(conn);

lib/urldata.h

@@ -828,6 +828,7 @@ struct connectdata {
   int socktype;  /* SOCK_STREAM or SOCK_DGRAM */
 
   struct hostname host;
+  char *hostname_resolve; /* host name to resolve to address, allocated */
   char *secondaryhostname; /* secondary socket host name (ftp) */
   struct hostname conn_to_host; /* the host to connect to. valid only if
                                    bits.conn_to_host is set */