net/ftp.rb: NullSocket#closed?

* net/ftp.rb: add NullSocket#closed? to fix closing not opened
  connection.  [Fix GH-1232]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53810 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/net/ftp.rb b/lib/net/ftp.rb
index 26bca1a54a..cfd8cf7945 100644
--- a/lib/net/ftp.rb
+++ b/lib/net/ftp.rb
@@ -1270,6 +1270,10 @@ module Net
       def read_timeout=(sec)
       end
 
+      def closed?
+        true
+      end
+
       def close
       end