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.
{
    return ::IsMine(*this, txout.scriptPubKey);
}
CAmount CWallet::GetCredit(const CTxOut& txout, const isminefilter& filter) const
{
    if (!MoneyRange(txout.nValue))
        throw std::runtime_error(std::string(__func__) + ": value out of range");
    return ((IsMine(txout) & filter) ? txout.nValue : 0);
}
bool CWallet::IsChange(const CTxOut& txout) const
{
    
    
    
    
    
    
    
    if (::IsMine(*this, txout.scriptPubKey))
    {
        CTxDestination address;
        if (!ExtractDestination(txout.scriptPubKey, address))
            return true;
        LOCK(cs_wallet);
        if (!mapAddressBook.count(address))
            return true;
    }
    return false;
}
CAmount CWallet::GetChange(const CTxOut& txout) const