While checking #16661 I stumbled upon what seems to be a lifetime issue in `ReleaseWallet(CWallet* wallet)` (`wallet.cpp`).

https://github.com/bitcoin/bitcoin/blob/fa6431055abfacea4f72ef11d061c7c755de327a/src/wallet/wallet.cpp#L107-L111

After `delete wallet;` the pointer is invalid and shouldn't be used like in the call `g_unloading_wallet_set.erase(wallet)`.

The code was introduced in #14941 which was merged into `master` on January 15, 2019.

In addition to fixing this specific instance it might be worth thinking about how we can use static analysis to automatically catch this class of issues going forward :-)
{
    int64_t n = nTimeSmart;
    return n ? n : nTimeReceived;
}
bool CWallet::DummySignInput(CTxIn &tx_in, const CTxOut &txout, bool use_max_sig) const
{
    
    const CScript& scriptPubKey = txout.scriptPubKey;
    SignatureData sigdata;
    if (!ProduceSignature(*this, use_max_sig ? DUMMY_MAXIMUM_SIGNATURE_CREATOR : DUMMY_SIGNATURE_CREATOR, scriptPubKey, sigdata)) {
        return false;
    }
    UpdateInput(tx_in, sigdata);
    return true;
}
bool CWallet::DummySignTx(CMutableTransaction &txNew, const std::vector<CTxOut> &txouts, bool use_max_sig) const
{
    
    int nIn = 0;
    for (const auto& txout : txouts)
    {
        if (!DummySignInput(txNew.vin[nIn], txout, use_max_sig)) {
            return false;
        }
        nIn++;
    }
    return true;
}
bool CWallet::ImportScripts(const std::set<CScript> scripts, int64_t timestamp)