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 :-)
{
    if (!IsCoinBase())
        return 0;
    int chain_depth = GetDepthInMainChain(locked_chain);
    assert(chain_depth >= 0); 
    return std::max(0, (COINBASE_MATURITY+1) - chain_depth);
}
bool CWalletTx::IsImmatureCoinBase(interfaces::Chain::Lock& locked_chain) const
{
    
    return GetBlocksToMaturity(locked_chain) > 0;
}
void CWallet::LearnRelatedScripts(const CPubKey& key, OutputType type)
{
    if (key.IsCompressed() && (type == OutputType::P2SH_SEGWIT || type == OutputType::BECH32)) {
        CTxDestination witdest = WitnessV0KeyHash(key.GetID());
        CScript witprog = GetScriptForDestination(witdest);
        
        assert(IsSolvable(*this, witprog));
        AddCScript(witprog);
    }
}
void CWallet::LearnAllRelatedScripts(const CPubKey& key)
{
    
    LearnRelatedScripts(key, OutputType::P2SH_SEGWIT);
}
std::vector<OutputGroup> CWallet::GroupOutputs(const std::vector<COutput>& outputs, bool single_coin) const {