Opening two of the same wallet (tested in v0.18.0 of bitcoin-qt 64 bit) will cause a database collision, and will crash the program.

`[marshall@likon] {21:21} [~] $ bitcoin-0.18.0/bin/bitcoin-qt `
`terminate called after throwing an instance of 'std::runtime_error'  what():  BerkeleyBatch: Can't open database 8204388-wallet.dat (duplicates fileid 8b1c090000000800e25686350000000000000000 from 1352491-wallet.dat)`
`Aborted (core dumped)`

I have been able to reproduce the issue by importing two of the same wallet (with different filenames).
{
    {
        LOCK(cs_wallet);
        for (const auto& spk_man_pair : m_spk_managers) {
            if (!spk_man_pair.second->CheckDecryptionKey(vMasterKeyIn, accept_no_keys)) {
                return false;
            }
        }
        vMasterKey = vMasterKeyIn;
    }
    NotifyStatusChanged(this);
    return true;
}
std::set<ScriptPubKeyMan*> CWallet::GetActiveScriptPubKeyMans() const
{
    std::set<ScriptPubKeyMan*> spk_mans;
    for (bool internal : {false, true}) {
        for (OutputType t : OUTPUT_TYPES) {
            auto spk_man = GetScriptPubKeyMan(t, internal);
            if (spk_man) {
                spk_mans.insert(spk_man);
            }
        }
    }
    return spk_mans;
}
std::set<ScriptPubKeyMan*> CWallet::GetAllScriptPubKeyMans() const