1 files changed, 4 insertions, 0 deletions
diff --git a/lib/net/imap.rb b/lib/net/imap.rb
index b2193dbf93..6e88fb96e4 100644
--- a/lib/net/imap.rb
+++ b/lib/net/imap.rb
@@ -1065,6 +1065,10 @@ module Net
       @exception = nil
 
       @greeting = get_response
+      if @greeting.nil?
+        @sock.close
+        raise Error, "connection closed"
+      end
       if @greeting.name == "BYE"
         @sock.close
         raise ByeResponseError, @greeting