- Based on bug report #2723219 (http://curl.haxx.se/bug/view.cgi?id=2723219)

I've now made TFTP "connections" not being kept for re-use within libcurl.
  TFTP is UDP-based so the benefit was really low (if even existing) to begin
  with so instead of tracking down to fix this problem we instead removed the
  re-use. I also enabled test case 1099 that I wrote a few days ago to verify
  that this change fixes the reported problem.

lib/tftp.c

@@ -863,7 +863,9 @@ static CURLcode tftp_connect(struct connectdata *conn, bool *done)
       return CURLE_OUT_OF_MEMORY;
   }
 
-  conn->bits.close = FALSE; /* keep it open if possible */
+  conn->bits.close = TRUE; /* we don't keep TFTP connections up bascially
+                              because there's none or very little gain for UDP
+                           */
 
   state->conn = conn;
   state->sockfd = state->conn->sock[FIRSTSOCKET];