https://travis-ci.org/github/bitcoin/bitcoin/jobs/679885530#L8791
if (!input.non_witness_utxo) {
            const uint256& txhash = txin.prevout.hash;
            const auto it = mapWallet.find(txhash);
            if (it != mapWallet.end()) {
                const CWalletTx& wtx = it->second;
                
                
                input.non_witness_utxo = wtx.tx;
            }
        }
    }
    
    for (ScriptPubKeyMan* spk_man : GetAllScriptPubKeyMans()) {
        int n_signed_this_spkm = 0;
        TransactionError res = spk_man->FillPSBT(psbtx, sighash_type, sign, bip32derivs, &n_signed_this_spkm);
        if (res != TransactionError::OK) {
            return res;
        }
        if (n_signed) {
            (*n_signed) += n_signed_this_spkm;
        }
    }
    
    complete = true;
    for (const auto& input : psbtx.inputs) {
        complete &= PSBTInputSigned(input);
    }
    return TransactionError::OK;
}
SigningResult CWallet::SignMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) const