- Linus Nielsen Feltzing reported and helped me repeat and fix a problem with

  FTP with the multi interface: when a transfer fails, like when aborted by a
  write callback, the control connection was wrongly closed and thus not
  re-used properly.

  This change is also an attempt to cleanup the code somewhat in this area, as
  now the FTP code attempts to keep (better) track on pending responses
  necessary to get read in ftp_done().

1 files changed, 17 insertions, 19 deletions

diff --git a/lib/multi.c b/lib/multi.c
index 15339a3d6..2ce023331 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -1237,14 +1237,6 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
       break;
 
     case CURLM_STATE_WAITPERFORM:
-#ifdef CURLDEBUG
-      infof(easy->easy_handle, "Conn %d recv pipe %d inuse %d athead %d\n",
-            easy->easy_conn->connectindex,
-            easy->easy_conn->recv_pipe->size,
-            easy->easy_conn->readchannel_inuse,
-            isHandleAtHead(easy->easy_handle,
-                           easy->easy_conn->recv_pipe));
-#endif
       /* Wait for our turn to PERFORM */
       if(!easy->easy_conn->readchannel_inuse &&
          isHandleAtHead(easy->easy_handle,
@@ -1254,6 +1246,16 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
         multistate(easy, CURLM_STATE_PERFORM);
         result = CURLM_CALL_MULTI_PERFORM;
       }
+#ifdef CURLDEBUG
+      else {
+        infof(easy->easy_handle, "Conn %d recv pipe %d inuse %d athead %d\n",
+              easy->easy_conn->connectindex,
+              easy->easy_conn->recv_pipe->size,
+              easy->easy_conn->readchannel_inuse,
+              isHandleAtHead(easy->easy_handle,
+                             easy->easy_conn->recv_pipe));
+      }
+#endif
       break;
 
     case CURLM_STATE_TOOFAST: /* limit-rate exceeded in either direction */
@@ -1302,18 +1304,14 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
 
       if(easy->result)  {
         /* The transfer phase returned error, we mark the connection to get
-         * closed to prevent being re-used. This is because we can't
-         * possibly know if the connection is in a good shape or not now. */
-        easy->easy_conn->bits.close = TRUE;
-        Curl_removeHandleFromPipeline(easy->easy_handle,
-                                      easy->easy_conn->recv_pipe);
+         * closed to prevent being re-used. This is because we can't possibly
+         * know if the connection is in a good shape or not now.  Unless it is
+         * a protocol which uses two "channels" like FTP, as then the error
+         * happened in the data connection.
+         */
+        if(!(easy->easy_conn->protocol & PROT_DUALCHANNEL))
+          easy->easy_conn->bits.close = TRUE;
 
-        if(CURL_SOCKET_BAD != easy->easy_conn->sock[SECONDARYSOCKET]) {
-          /* if we failed anywhere, we must clean up the secondary socket if
-             it was used */
-          sclose(easy->easy_conn->sock[SECONDARYSOCKET]);
-          easy->easy_conn->sock[SECONDARYSOCKET] = CURL_SOCKET_BAD;
-        }
         Curl_posttransfer(easy->easy_handle);
         Curl_done(&easy->easy_conn, easy->result, FALSE);
       }