for attended transfer feature.
void
BasicClientCall::onNewSession(ServerInviteSessionHandle h, InviteSession::OfferAnswerType oat, const SipMessage& msg)
{
InfoLog(<< "onNewSession(ServerInviteSessionHandle): msg=" << msg.brief());
mInviteSessionHandle = h->getSessionHandle();
// First check if this INVITE is to replace an existing session
if(msg.exists(h_Replaces))
{
pair<InviteSessionHandle, int> presult;
presult = mDum.findInviteSession(msg.header(h_Replaces));
if(!(presult.first == InviteSessionHandle::NotValid()))
{
Here always fail to mDum.findInviteSession, the presult.first is equals to InviteSessionHandle::NotValid().