- Scott Barrett provided a test case for a segfault in the FTP code and the

fix for it. It occured when you did a FTP transfer using
  CURLFTPMETHOD_SINGLECWD and then did another one on the same easy handle but
  switched to CURLFTPMETHOD_NOCWD. Due to the "dir depth" variable not being
  cleared properly.  Scott's test case is now known as test 539 and it
  verifies the fix.

lib/ftp.c

@@ -279,6 +279,7 @@ static void freedirs(struct ftp_conn *ftpc)
     }
     free(ftpc->dirs);
     ftpc->dirs = NULL;
+    ftpc->dirdepth = 0;
   }
   if(ftpc->file) {
     free(ftpc->file);