I was messing around with min relay policies and found that under certain circumstances the mempool will accept things, then not relay to any peers.

Example made using wallet:
Transaction of size 6195, fee of 619 satoshis, minrelay of 100 satoshis per kvB. Mempool logic allows it:

```
        // No transactions are allowed below minRelayTxFee except from disconnected blocks
        if (!bypass_limits && nModifiedFees < ::minRelayTxFee.GetFee(nSize)) {
            return state.DoS(0, false, REJECT_INSUFFICIENTFEE, "min relay fee not met", false, strprintf("%d < %d", nModifiedFees, ::minRelayTxFee.GetFee(nSize)));
        }
```
and lets it into mempool

but in net_processing.cpp:

```
                    if (filterrate && txinfo.feeRate.GetFeePerK() < filterrate) {
                        continue;
                    }
```
this gets hit because the computed feerate is insufficient(printing I added):
```
0.00000099 BTC/kB
```

I'm not super at arithmetic so I'm opening this up in case someone has an easy fix. 

let me also get a reproducible test failure with this...
{
    mapLinks.clear();
    mapTx.clear();
    mapNextTx.clear();
    totalTxSize = 0;
    cachedInnerUsage = 0;
    lastRollingFeeUpdate = GetTime();
    blockSinceLastRollingFeeBump = false;
    rollingMinimumFeeRate = 0;
    ++nTransactionsUpdated;
}
void CTxMemPool::clear()
{
    LOCK(cs);
    _clear();
}
static void CheckInputsAndUpdateCoins(const CTransaction& tx, CCoinsViewCache& mempoolDuplicate, const int64_t spendheight)
{
    CValidationState state;
    CAmount txfee = 0;
    bool fCheckResult = tx.IsCoinBase() || Consensus::CheckTxInputs(tx, state, mempoolDuplicate, spendheight, txfee);
    assert(fCheckResult);
    UpdateCoins(tx, mempoolDuplicate, std::numeric_limits<int>::max());
}
void CTxMemPool::check(const CCoinsViewCache *pcoins) const