fix poor server handling of double close frames fixes #259

Author: zaphoyd

changelog.md

@@ -1,4 +1,6 @@
 HEAD
+- Fixes a regression that caused servers being sent two close frames in a row
+  to end a connection uncleanly. #259
 - Fixes a regression that caused spurious frames following a legitimate close 
   frames to erroneously trigger handlers. #258
 - Changes default HTTP response error code when no http_handler is defined from

websocketpp/connection.hpp

@@ -193,6 +193,7 @@ class connection
       , m_rng(rng)
       , m_local_close_code(close::status::abnormal_close)
       , m_remote_close_code(close::status::abnormal_close)
+      , m_was_clean(false)
     {
         m_alog.write(log::alevel::devel,"connection constructor");
     }
@@ -1172,6 +1173,8 @@ class connection
     /// Detailed internal error code
     lib::error_code m_ec;
 
+    bool m_was_clean;
+    
     /// Whether or not this endpoint initiated the closing handshake.
     bool                    m_closed_by_me;
 

websocketpp/impl/connection_impl.hpp

@@ -1724,10 +1724,12 @@ void connection<config>::process_control_frame(typename
                 m_elog.write(log::elevel::devel,
                     "send_close_ack error: "+ec.message());
             }
-        } else if (m_state == session::state::closing) {
+        } else if (m_state == session::state::closing && !m_was_clean) {
             // ack of our close
             m_alog.write(log::alevel::devel,"Got acknowledgement of close");
 
+            m_was_clean = true;
+            
             // If we are a server terminate the connection now. Clients should
             // leave the connection open to give the server an opportunity to
             // initiate the TCP close. The client's timer will handle closing
@@ -1815,6 +1817,10 @@ lib::error_code connection<config>::send_close_frame(close::status::value code,
 
     m_state = session::state::closing;
 
+    if (ack) {
+        m_was_clean = true;
+    }
+    
     // Start a timer so we don't wait forever for the acknowledgement close 
     // frame
     m_handshake_timer = transport_con_type::set_timer(