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
```
wallet.BlockUntilSyncedToCurrentChain();
    LOCK(wallet.cs_wallet);
    const auto bal = wallet.GetBalance();
    UniValue balances{UniValue::VOBJ};
    {
        UniValue balances_mine{UniValue::VOBJ};
        balances_mine.pushKV("trusted", ValueFromAmount(bal.m_mine_trusted));
        balances_mine.pushKV("untrusted_pending", ValueFromAmount(bal.m_mine_untrusted_pending));
        balances_mine.pushKV("immature", ValueFromAmount(bal.m_mine_immature));
        if (wallet.IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE)) {
            
            
            const auto full_bal = wallet.GetBalance(0, false);
            balances_mine.pushKV("used", ValueFromAmount(full_bal.m_mine_trusted + full_bal.m_mine_untrusted_pending - bal.m_mine_trusted - bal.m_mine_untrusted_pending));
        }
        balances.pushKV("mine", balances_mine);
    }
    auto spk_man = wallet.GetLegacyScriptPubKeyMan();
    if (spk_man && spk_man->HaveWatchOnly()) {
        UniValue balances_watchonly{UniValue::VOBJ};
        balances_watchonly.pushKV("trusted", ValueFromAmount(bal.m_watchonly_trusted));
        balances_watchonly.pushKV("untrusted_pending", ValueFromAmount(bal.m_watchonly_untrusted_pending));
        balances_watchonly.pushKV("immature", ValueFromAmount(bal.m_watchonly_immature));
        balances.pushKV("watchonly", balances_watchonly);
    }
    return balances;
},
    };
}
static RPCHelpMan getwalletinfo()