If I create an RBF transaction using the Qt GUI but specify my own custom change address, bumpfee doesn't work because it claims it can't find the change address:

    "Transaction does not have a change output"

This is because none of the outputs satisfy

    pWallet->IsChange(...)

I see there's a "TODO" commented in `CWallet::IsChange()` in `src/wallet/wallet.cpp`:

    // TODO: fix handling of 'change' outputs. The assumption is that any
    // payment to a script that is ours, but is not in the address book
    // is change.

I tend to put all my addresses in the address book whether I'm going to use them as change or not. I guess if the wallet was capable of creating its own SegWit change addresses I'd stop using custom change addresses, but currently it always seems to send change to a legacy address if I don't manually specify a change address.
{
    
    
    
    int64_t txSize = GetVirtualTransactionSize(*(wtx.tx));
    CFeeRate feerate(old_fee, txSize);
    feerate += CFeeRate(1);
    
    
    
    
    
    
    
    CFeeRate node_incremental_relay_fee = wallet.chain().relayIncrementalFee();
    CFeeRate wallet_incremental_relay_fee = CFeeRate(WALLET_INCREMENTAL_RELAY_FEE);
    feerate += std::max(node_incremental_relay_fee, wallet_incremental_relay_fee);
    
    CFeeRate min_feerate(GetMinimumFeeRate(wallet, coin_control, nullptr));
    
    return std::max(feerate, min_feerate);
}
namespace feebumper {
bool TransactionCanBeBumped(const CWallet& wallet, const uint256& txid)