[bitcoin/bitcoin] Add checks for settxfee reasonableness (#13988)

promag commented on this pull request.

Concept ACK, could add tests?

> @@ -2982,8 +2982,16 @@ static UniValue settxfee(const JSONRPCRequest& request)
LOCK2(cs_main, pwallet->cs_wallet);

CAmount nAmount = AmountFromValue(request.params[0]);
+ CFeeRate tx_fee_rate(nAmount, 1000);
+ if (tx_fee_rate == 0) {
+ // automatic selection
+ } else if (tx_fee_rate < ::minRelayTxFee) { + throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("txfee cannot be less than min relay tx fee (%s)", ::minRelayTxFee.ToString())); + } else if (tx_fee_rate < pwallet->m_min_fee) {

How about test this first?