While working on this PR https://github.com/bitcoin/bitcoin/pull/18570 I ran into a bit confusing situation where in one function a **CWallet reference** was expected while two others dealt with **CWallet pointers**. My initial reaction was: `let's harmonize them by making them references`. However, not being part of the PR itself I did't change anything and completed the PR first.

Now, after having analyzed the `rpcwallet.cpp` code I came to the conclusion that:

* converting them all into references is not the solution as they're originally **shared_ptr**s
* but also: there is no (visible) reason why every RPC function should begin like this:

```cpp
std::shared_ptr<CWallet> const pwallet = GetWalletForJSONRPCRequest(request);
const CWallet* const pwallet = wallet.get();
```

This clearly defeats the purpose of shared pointers for no obvious reason. *Maybe I am missing something?*

In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept their original names (that is, *pwallet*). In the end, they're pointers too, so the most of the original code remained untouched.

However, some of the helper functions couldn't be changed because external code is accessing them and I didn't want to make this task "virulent". So I introduced new ("Ref") variants that expect **shared_ptr** parameters, namely: 

```cpp
void EnsureWalletRefIsUnlocked(const std::shared_ptr<CWallet>);
bool EnsureWalletRefIsAvailable(const std::shared_ptr<CWallet>, bool avoidException);
```

I have tested the code, with python and boost-tests, and could not find any errors. 
But before opening a PR I would like to open a discussion about this. 

Is there any reason to keep on working with raw pointers when every function call actually begins with *shared_ptr*s?

Regards,
file.open(filepath);
    if (!file.is_open())
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot open wallet dump file");
    std::map<CKeyID, int64_t> mapKeyBirth;
    const std::map<CKeyID, int64_t>& mapKeyPool = spk_man.GetAllReserveKeys();
    wallet.GetKeyBirthTimes(mapKeyBirth);
    std::set<CScriptID> scripts = spk_man.GetCScripts();
    
    std::vector<std::pair<int64_t, CKeyID> > vKeyBirth;
    for (const auto& entry : mapKeyBirth) {
        vKeyBirth.push_back(std::make_pair(entry.second, entry.first));
    }
    mapKeyBirth.clear();
    std::sort(vKeyBirth.begin(), vKeyBirth.end());
    
    file << strprintf("# Wallet dump created by Bitcoin %s\n", CLIENT_BUILD);
    file << strprintf("# * Created on %s\n", FormatISO8601DateTime(GetTime()));
    file << strprintf("# * Best block at time of backup was %i (%s),\n", wallet.GetLastBlockHeight(), wallet.GetLastBlockHash().ToString());
    int64_t block_time = 0;
    CHECK_NONFATAL(wallet.chain().findBlock(wallet.GetLastBlockHash(), FoundBlock().time(block_time)));
    file << strprintf("#   mined on %s\n", FormatISO8601DateTime(block_time));
    file << "\n";
    
    CKeyID seed_id = spk_man.GetHDChain().seed_id;
    if (!seed_id.IsNull())
    {
        CKey seed;
        if (spk_man.GetKey(seed_id, seed)) {
            CExtKey masterKey;
            masterKey.SetSeed(seed.begin(), seed.size());