Built against `master` branch 801dd40666d1e6009920ad3ff755c7bb993b2a62:

If I have no wallet.dat file and run:

    bitcoind -usehd=0

A new wallet.dat file is created and an HD seed is assigned.

I see an error message in the source:

    "Error loading %s: You can't disable HD on an already existing HD wallet or create new non-HD wallets."

but that doesn't get shown because `fFirstRun` is true, and so the code which checks for `-usehd` values doesn't run.

If it's no longer possible to create non-HD wallets, specifying -usehd=0 when creating a wallet should be an error, and not get silently ignored.
txByTime.insert(std::make_pair(entry.nTime, TxPair(nullptr, &entry)));
    }
    nOrderPosNext = 0;
    std::vector<int64_t> nOrderPosOffsets;
    for (TxItems::iterator it = txByTime.begin(); it != txByTime.end(); ++it)
    {
        CWalletTx *const pwtx = (*it).second.first;
        CAccountingEntry *const pacentry = (*it).second.second;
        int64_t& nOrderPos = (pwtx != nullptr) ? pwtx->nOrderPos : pacentry->nOrderPos;
        if (nOrderPos == -1)
        {
            nOrderPos = nOrderPosNext++;
            nOrderPosOffsets.push_back(nOrderPos);
            if (pwtx)
            {
                if (!walletdb.WriteTx(*pwtx))
                    return DB_LOAD_FAIL;
            }
            else
                if (!walletdb.WriteAccountingEntry(pacentry->nEntryNo, *pacentry))
                    return DB_LOAD_FAIL;
        }
        else
        {
            int64_t nOrderPosOff = 0;
            for (const int64_t& nOffsetStart : nOrderPosOffsets)
            {
                if (nOrderPos >= nOffsetStart)
                    ++nOrderPosOff;
            }