Fixed issue #2227 second part

- removed the previously added encryption_error, less changes less bug
 - handshake fail is now signaled when an error happen while the
   mechanism is still hanshaking

src/session_base.cpp

@@ -421,8 +421,7 @@ void zmq::session_base_t::engine_error (
     if (pipe)
         clean_pipes ();
 
-    zmq_assert (reason == stream_engine_t::encryption_error
-             || reason == stream_engine_t::connection_error
+    zmq_assert (reason == stream_engine_t::connection_error
              || reason == stream_engine_t::timeout_error
              || reason == stream_engine_t::protocol_error);
 
@@ -434,7 +433,6 @@ void zmq::session_base_t::engine_error (
             else
                 terminate ();
             break;
-        case stream_engine_t::encryption_error:
         case stream_engine_t::protocol_error:
             terminate ();
             break;

src/stream_engine.cpp

@@ -356,10 +356,7 @@ void zmq::stream_engine_t::in_event ()
     //  or the session has rejected the message.
     if (rc == -1) {
         if (errno != EAGAIN) {
-            if(this->process_msg == &stream_engine_t::process_handshake_command)
-                error(encryption_error);
-            else
-                error(protocol_error);
+            error(protocol_error);
             return;
         }
         input_stopped = true;
@@ -981,7 +978,7 @@ void zmq::stream_engine_t::error (error_reason_t reason)
     }
     zmq_assert (session);
 #ifdef ZMQ_BUILD_DRAFT_API
-    if(reason == encryption_error)
+    if(mechanism->status() == mechanism_t::handshaking)
         socket->event_handshake_failed(endpoint, (int) s);
 #endif
     socket->event_disconnected (endpoint, (int) s);

src/stream_engine.hpp

@@ -65,8 +65,7 @@ namespace zmq
         enum error_reason_t {
             protocol_error,
             connection_error,
-            timeout_error,
-            encryption_error
+            timeout_error
         };
 
         stream_engine_t (fd_t fd_, const options_t &options_,