@jonasschnelli wrote in #14979:
> #14573 broke < Qt5.6 compatibility due to calling the lambda version of `addAction` that was added in Qt5.6.

We currently [support](https://github.com/bitcoin/bitcoin/blob/master/doc/dependencies.md) QT >=5.2, but hardly anyone tests with that. If we make one of the Travis machines use it, we should have a better change of catching this.

See also discussion about minimum QT version in #13478 
{
    CMutableTransaction txNew(tx);
    if (!wallet->DummySignTx(txNew, txouts, use_max_sig)) {
        
        
        return -1;
    }
    return GetVirtualTransactionSize(CTransaction(txNew));
}
int CalculateMaximumSignedInputSize(const CTxOut& txout, const CWallet* wallet, bool use_max_sig)
{
    CMutableTransaction txn;
    txn.vin.push_back(CTxIn(COutPoint()));
    if (!wallet->DummySignInput(txn.vin[0], txout, use_max_sig)) {
        return -1;
    }
    return GetVirtualTransactionInputSize(txn.vin[0]);
}
void CWalletTx::GetAmounts(std::list<COutputEntry>& listReceived,