@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 
{
    if (IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
        return false;
    }
    CKeyPool keypool;
    {
        LOCK(cs_wallet);
        int64_t nIndex;
        if (!ReserveKeyFromKeyPool(nIndex, keypool, internal)) {
            if (IsLocked()) return false;
            WalletBatch batch(*database);
            result = GenerateNewKey(batch, internal);
            return true;
        }
        KeepKey(nIndex);
        result = keypool.vchPubKey;
    }
    return true;
}
static int64_t GetOldestKeyTimeInPool(const std::set<int64_t>& setKeyPool, WalletBatch& batch) {