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In my (unpublished) [code changes](https://github.com/brakmic/bitcoin/commit/0b3ee615491edf6f542631bf6ae6f72eac406550) all raw pointers got replaced with **shared_ptr**s but kept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,
if (!error.empty()) {
            warnings.push_back("Importing as non-solvable: " + error + ". If this is intentional, don't provide any keys, pubkeys, witnessscript, or redeemscript.");
            import_data = ImportData();
            pubkey_map.clear();
            privkey_map.clear();
            have_solving_data = false;
        } else {
            
            if (import_data.redeemscript) warnings.push_back("Ignoring redeemscript as this is not a P2SH script.");
            if (import_data.witnessscript) warnings.push_back("Ignoring witnessscript as this is not a (P2SH-)P2WSH script.");
            for (auto it = privkey_map.begin(); it != privkey_map.end(); ) {
                auto oldit = it++;
                if (import_data.used_keys.count(oldit->first) == 0) {
                    warnings.push_back("Ignoring irrelevant private key.");
                    privkey_map.erase(oldit);
                }
            }
            for (auto it = pubkey_map.begin(); it != pubkey_map.end(); ) {
                auto oldit = it++;
                auto key_data_it = import_data.used_keys.find(oldit->first);
                if (key_data_it == import_data.used_keys.end() || !key_data_it->second) {
                    warnings.push_back("Ignoring public key \"" + HexStr(oldit->first) + "\" as it doesn't appear inside P2PKH or P2WPKH.");
                    pubkey_map.erase(oldit);
                }
            }
        }
    }
    return warnings;
}
static UniValue ProcessImportDescriptor(ImportData& import_data, std::map<CKeyID, CPubKey>& pubkey_map, std::map<CKeyID, CKey>& privkey_map, std::set<CScript>& script_pub_keys, bool& have_solving_data, const UniValue& data, std::vector<CKeyID>& ordered_pubkeys)