For software that interfaces with Bitcoin Core via RPC, it can be useful to know whether the fRelayTxes flag is set. It could be added to `getnetworkinfo`.

if (pool.exists(hash))
        return state.Invalid(false, REJECT_ALREADY_KNOWN, "txn-already-in-mempool");
    
    set<uint256> setConflicts;
    {
    LOCK(pool.cs); 
    BOOST_FOREACH(const CTxIn &txin, tx.vin)
    {
        if (pool.mapNextTx.count(txin.prevout))
        {
            const CTransaction *ptxConflicting = pool.mapNextTx[txin.prevout].ptx;
            if (!setConflicts.count(ptxConflicting->GetHash()))
            {
                
                
                
                
                
                
                
                
                
                
                
                
                bool fReplacementOptOut = true;
                if (fEnableReplacement)
                {
                    BOOST_FOREACH(const CTxIn &txin, ptxConflicting->vin)