Fix forwarding of 'SERVER_SESSION_STATE_CHANGED' status to clients #4023

Right now server session state isn't tracked for backend connections,
so we don't include this information in the generated OK packet. Because
of this, we should never report of this status change to clients.

lib/MySQL_Protocol.cpp

@@ -533,6 +533,8 @@ bool MySQL_Protocol::generate_pkt_OK(bool send, void **ptr, unsigned int *len, u
 			internal_status |= SERVER_STATUS_NO_BACKSLASH_ESCAPES;
 		}
 	}
+	// Always remove 'SERVER_SESSION_STATE_CHANGED', since we don't track this information right now
+	internal_status &= ~SERVER_SESSION_STATE_CHANGED;
 	memcpy(_ptr+l, &internal_status, sizeof(uint16_t)); l+=sizeof(uint16_t);
 	memcpy(_ptr+l, &warnings, sizeof(uint16_t)); l+=sizeof(uint16_t);
 	if (msg && strlen(msg)) {