checked for existence of messages before committing to

db store in genexhange (sql error drB noted in tests)

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@7324 b45a01b8-16f6-495d-af2f-9b41ad6348cc

libretroshare/src/gxs/rsgenexchange.h

@@ -771,7 +771,7 @@ private:
 
     /*!
      * Checks validation of recently received groups to be
-     * updated
+     * updated (and updates them, a bit of a misnomer)
      */
     void performUpdateValidation();
 
@@ -790,6 +790,14 @@ private:
      */
     bool checkKeys(const RsTlvSecurityKeySet& keySet);
 
+    /*!
+     * Message and notification map passed to method
+     * are cleansed of msgs and ids that already exist in database
+     * @param msgs messages to be filtered
+     * @param msgIdsNotify message notification map to be filtered
+     */
+    void removeDeleteExistingMessages(RsGeneralDataService::MsgStoreMap& msgs, GxsMsgReq& msgIdsNotify);
+
 private:
 
     RsMutex mGenMtx;