@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 
{
    AssertLockHeld(cs_wallet);
    auto iter = mapTxSpends.lower_bound(COutPoint(txid, 0));
    return (iter != mapTxSpends.end() && iter->first.hash == txid);
}
void CWallet::Flush(bool shutdown)
{
    database->Flush(shutdown);
}
void CWallet::SyncMetaData(std::pair<TxSpends::iterator, TxSpends::iterator> range)
{
    
    
    
    int nMinOrderPos = std::numeric_limits<int>::max();
    const CWalletTx* copyFrom = nullptr;
    for (TxSpends::iterator it = range.first; it != range.second; ++it) {
        const CWalletTx* wtx = &mapWallet.at(it->second);
        if (wtx->nOrderPos < nMinOrderPos) {