Bug report #1759542 (http://curl.haxx.se/bug/view.cgi?id=1759542). A bad use

of a socket after it has been closed, when the FTP-SSL data connection is taken
down.

lib/urldata.h

@@ -166,7 +166,9 @@ typedef enum {
 
 /* struct for data related to each SSL connection */
 struct ssl_connect_data {
-  bool use;        /* use ssl encrypted communications TRUE/FALSE */
+  bool use;        /* use ssl encrypted communications TRUE/FALSE, not
+                      necessarily using it atm but at least asked to or
+                      meaning to use it */
 #ifdef USE_SSLEAY
   /* these ones requires specific SSL-types */
   SSL_CTX* ctx;