Have this warning while building current master (0bd4929cd00e91bf4137f43b097cd62f72f503e4) on one test machine.
```
wallet/rpcwallet.cpp: In function 'rescanblockchain()::<lambda(const RPCHelpMan&, const JSONRPCRequest&)>':
wallet/rpcwallet.cpp:3596:19: warning: '*((void*)& stop_height +4)' may be used uninitialized in this function [-Wmaybe-uninitialized]
 3596 |     Optional<int> stop_height;
      |                   ^~~~~~~~~~~
```
```
$ gcc --version
gcc (Gentoo 9.2.0-r2 p3) 9.2.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ uname -a
Linux red-box 4.19.72-gentoo #2 SMP Sun Sep 22 03:00:01 EEST 2019 x86_64 Intel(R) Pentium(R) CPU N3710 @ 1.60GHz GenuineIntel GNU/Linux
```
return NullUniValue;
},
    };
}
void ParseRecipients(const UniValue& address_amounts, const UniValue& subtract_fee_outputs, std::vector<CRecipient> &recipients) {
    std::set<CTxDestination> destinations;
    int i = 0;
    for (const std::string& address: address_amounts.getKeys()) {
        CTxDestination dest = DecodeDestination(address);
        if (!IsValidDestination(dest)) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, std::string("Invalid Bitcoin address: ") + address);
        }
        if (destinations.count(dest)) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid parameter, duplicated address: ") + address);
        }
        destinations.insert(dest);
        CScript script_pub_key = GetScriptForDestination(dest);
        CAmount amount = AmountFromValue(address_amounts[i++]);
        bool subtract_fee = false;
        for (unsigned int idx = 0; idx < subtract_fee_outputs.size(); idx++) {
            const UniValue& addr = subtract_fee_outputs[idx];
            if (addr.get_str() == address) {
                subtract_fee = true;
            }
        }
        CRecipient recipient = {script_pub_key, amount, subtract_fee};
        recipients.push_back(recipient);
    }
}
UniValue SendMoney(CWallet* const pwallet, const CCoinControl &coin_control, std::vector<CRecipient> &recipients, mapValue_t map_value, bool verbose)