Get rid of the data socket completely when data transfer is finished.

net/ftp/ftp_network_transaction.cc

Index: net/ftp/ftp_network_transaction.cc
diff --git a/net/ftp/ftp_network_transaction.cc b/net/ftp/ftp_network_transaction.cc
index 212ec26476e38a7539181ff992ce7ee5ac5321bd..c5c9daf42787de5b79e86adeb4c17e9fa1df1a49 100644
--- a/net/ftp/ftp_network_transaction.cc
+++ b/net/ftp/ftp_network_transaction.cc
@@ -981,6 +981,10 @@ int FtpNetworkTransaction::DoDataRead() {
   DCHECK_GT(read_data_buf_len_, 0);
 
   if (data_socket_ == NULL || !data_socket_->IsConnected()) {
+    // If we don't destroy the data socket completely, some servers will wait

[wtc, 2009/09/09 20:20:42]

It would be nice to explain that a half-closed TCP connection
still needs to be closed on our side.

+    // for us (http://crbug.com/21127).
+    data_socket_.reset();
+
     // No more data so send QUIT Command now and wait for response.
     return Stop(OK);
   }