Merge #18241: wallet/refactor: refer to CWallet immutably when possible

79facb11e92f8b61063f301027dee7c7344eb1be wallet: use constant CWallets in rpcwallet.cpp (Karl-Johan Alm)
d9b0ebc1da8758645f6de24a4a557511ef9b5e36 wallet: make ReserveDestination pwallet ivar const (Karl-Johan Alm)
57c569e4d9779e2263848770e0ba7eab3054a1bf wallet: make BackupWallet() const (Karl-Johan Alm)
df3a818d2a9fe48e656a8ad2da18fab8a1bfd6e3 wallet: make getters const (Karl-Johan Alm)
227b9dd2d6e1914edfec108af6bec5f12d9f6f39 wallet/spkm: make GetOldestKeyPoolTime() const (Karl-Johan Alm)
22d329ad0ed3ed501bd811720be6a2876d1afe4d wallet: use constant CWallets in rpcdump.cpp (Karl-Johan Alm)
7b3587b29db9eaf11718fc09d48817a45a0a429a wallet/db: make IsDummy() const (Karl-Johan Alm)
d366795d180bc52ba750f71f201a6e5e0c40f1b6 wallet/db: make Backup() const (Karl-Johan Alm)
8cd0b86340870d8f359e4ae26880e03ea36818ab wallet: make CanGetAddresses() const (Karl-Johan Alm)
037fa770eb1ed5152b3ef2c5d3fb2a812d3ef944 wallet: make KeypoolCountExternalKeys() const (Karl-Johan Alm)
ddc93557ad0cf8e433df850d38710828ccd99c16 wallet: make CanGenerateKeys() const (Karl-Johan Alm)
dc2d0650fdb69d27fe1b0092555b7841d542a635 make BlockUntilSyncedToCurrentChain() const (Karl-Johan Alm)

Pull request description:

  A lot of places refer to `CWallet*`'s as `CWallet * const`, which translates to *"an immutable pointer to a mutable `CWallet` instance"*; this is

  1. often not what the author meant, especially as a lot of these places do not at all modify the wallet object, and
  2. confusing, as it tends to suggest that this is a proper way to refer to a constant `CWallet` instance.

  This PR changes references to wallets to `const CWallet* const` whenever immutability is expected. This should result in no behavioral changes at all, and improved compile-time error checking.

  Note from irc:

  > <sipa> sounds good to me; this is the sort of change that as long as it compiles, the behavior shouldn't change
  > <sipa> though in general it may lead to introducing automatic copying of objects sometimes (e.g. trying to std::move a const object will work, but generally result in a copy rather than an efficient move)
  > <sipa> CWallet objects aren't copied or moved though

ACKs for top commit:
  laanwj:
    ACK 79facb11e92f8b61063f301027dee7c7344eb1be
  Empact:
    ACK https://github.com/bitcoin/bitcoin/pull/18241/commits/79facb11e92f8b61063f301027dee7c7344eb1be
  promag:
    ACK 79facb11e92f8b61063f301027dee7c7344eb1be.
  fjahr:
    ACK 79facb11e92f8b61063f301027dee7c7344eb1be

Tree-SHA512: 80a80c1a52f0f788d0ccb268b53bc0f46c796643a3c5a22b55bbbde4ffa6c7e347784e5e53b1e488a3b4e14399e31d5be9417ad5b6319c74a462609e9b1a98e8

8 files changed, 64 insertions, 64 deletions

diff --git a/src/wallet/db.cpp b/src/wallet/db.cpp
index aa6e91c05e..67be4d85d2 100644
--- a/src/wallet/db.cpp
+++ b/src/wallet/db.cpp
@@ -850,7 +850,7 @@ bool BerkeleyDatabase::Rewrite(const char* pszSkip)
     return BerkeleyBatch::Rewrite(*this, pszSkip);
 }
 
-bool BerkeleyDatabase::Backup(const std::string& strDest)
+bool BerkeleyDatabase::Backup(const std::string& strDest) const
 {
     if (IsDummy()) {
         return false;
diff --git a/src/wallet/db.h b/src/wallet/db.h
index abec3ae4e2..bebaa55d05 100644
--- a/src/wallet/db.h
+++ b/src/wallet/db.h
@@ -157,7 +157,7 @@ public:
 
     /** Back up the entire database to a file.
      */
-    bool Backup(const std::string& strDest);
+    bool Backup(const std::string& strDest) const;
 
     /** Make sure all changes are flushed to disk.
      */
@@ -193,7 +193,7 @@ private:
      * Only to be used at a low level, application should ideally not care
      * about this.
      */
-    bool IsDummy() { return env == nullptr; }
+    bool IsDummy() const { return env == nullptr; }
 };
 
 /** RAII class that provides access to a Berkeley database */
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 4253038090..8df3491060 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -54,7 +54,7 @@ static std::string DecodeDumpString(const std::string &str) {
     return ret.str();
 }
 
-static bool GetWalletAddressesForKey(LegacyScriptPubKeyMan* spk_man, CWallet* const pwallet, const CKeyID& keyid, std::string& strAddr, std::string& strLabel) EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)
+static bool GetWalletAddressesForKey(LegacyScriptPubKeyMan* spk_man, const CWallet* const pwallet, const CKeyID& keyid, std::string& strAddr, std::string& strLabel) EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)
 {
     bool fLabelFound = false;
     CKey key;
@@ -65,7 +65,7 @@ static bool GetWalletAddressesForKey(LegacyScriptPubKeyMan* spk_man, CWallet* co
                 strAddr += ",";
             }
             strAddr += EncodeDestination(dest);
-            strLabel = EncodeDumpString(pwallet->mapAddressBook[dest].name);
+            strLabel = EncodeDumpString(pwallet->mapAddressBook.at(dest).name);
             fLabelFound = true;
         }
     }
@@ -676,7 +676,7 @@ UniValue importwallet(const JSONRPCRequest& request)
 UniValue dumpprivkey(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
@@ -724,7 +724,7 @@ UniValue dumpprivkey(const JSONRPCRequest& request)
 UniValue dumpwallet(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
     }
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index d9d92f8984..a390050f9a 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -40,7 +40,7 @@
 
 static const std::string WALLET_ENDPOINT_BASE = "/wallet/";
 
-static inline bool GetAvoidReuseFlag(CWallet * const pwallet, const UniValue& param) {
+static inline bool GetAvoidReuseFlag(const CWallet* const pwallet, const UniValue& param) {
     bool can_avoid_reuse = pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
     bool avoid_reuse = param.isNull() ? can_avoid_reuse : param.get_bool();
 
@@ -458,7 +458,7 @@ static UniValue sendtoaddress(const JSONRPCRequest& request)
 static UniValue listaddressgroupings(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -520,7 +520,7 @@ static UniValue listaddressgroupings(const JSONRPCRequest& request)
 static UniValue signmessage(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -590,7 +590,7 @@ static UniValue signmessage(const JSONRPCRequest& request)
 static UniValue getreceivedbyaddress(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -660,7 +660,7 @@ static UniValue getreceivedbyaddress(const JSONRPCRequest& request)
 static UniValue getreceivedbylabel(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -728,7 +728,7 @@ static UniValue getreceivedbylabel(const JSONRPCRequest& request)
 static UniValue getbalance(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -786,7 +786,7 @@ static UniValue getbalance(const JSONRPCRequest& request)
 static UniValue getunconfirmedbalance(const JSONRPCRequest &request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -1041,7 +1041,7 @@ struct tallyitem
     }
 };
 
-static UniValue ListReceived(interfaces::Chain::Lock& locked_chain, CWallet * const pwallet, const UniValue& params, bool by_label) EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)
+static UniValue ListReceived(interfaces::Chain::Lock& locked_chain, const CWallet* const pwallet, const UniValue& params, bool by_label) EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)
 {
     // Minimum confirmations
     int nMinDepth = 1;
@@ -1190,7 +1190,7 @@ static UniValue ListReceived(interfaces::Chain::Lock& locked_chain, CWallet * co
 static UniValue listreceivedbyaddress(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -1242,7 +1242,7 @@ static UniValue listreceivedbyaddress(const JSONRPCRequest& request)
 static UniValue listreceivedbylabel(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -1302,7 +1302,7 @@ static void MaybePushAddress(UniValue & entry, const CTxDestination &dest)
  * @param  filter_ismine  The "is mine" filter flags.
  * @param  filter_label   Optional label string to filter incoming transactions.
  */
-static void ListTransactions(interfaces::Chain::Lock& locked_chain, CWallet* const pwallet, const CWalletTx& wtx, int nMinDepth, bool fLong, UniValue& ret, const isminefilter& filter_ismine, const std::string* filter_label) EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)
+static void ListTransactions(interfaces::Chain::Lock& locked_chain, const CWallet* const pwallet, const CWalletTx& wtx, int nMinDepth, bool fLong, UniValue& ret, const isminefilter& filter_ismine, const std::string* filter_label) EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)
 {
     CAmount nFee;
     std::list<COutputEntry> listReceived;
@@ -1325,7 +1325,7 @@ static void ListTransactions(interfaces::Chain::Lock& locked_chain, CWallet* con
             entry.pushKV("category", "send");
             entry.pushKV("amount", ValueFromAmount(-s.amount));
             if (pwallet->mapAddressBook.count(s.destination)) {
-                entry.pushKV("label", pwallet->mapAddressBook[s.destination].name);
+                entry.pushKV("label", pwallet->mapAddressBook.at(s.destination).name);
             }
             entry.pushKV("vout", s.vout);
             entry.pushKV("fee", ValueFromAmount(-nFee));
@@ -1342,7 +1342,7 @@ static void ListTransactions(interfaces::Chain::Lock& locked_chain, CWallet* con
         {
             std::string label;
             if (pwallet->mapAddressBook.count(r.destination)) {
-                label = pwallet->mapAddressBook[r.destination].name;
+                label = pwallet->mapAddressBook.at(r.destination).name;
             }
             if (filter_label && label != *filter_label) {
                 continue;
@@ -1402,7 +1402,7 @@ static const std::vector<RPCResult> TransactionDescriptionString()
 UniValue listtransactions(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -1516,7 +1516,7 @@ UniValue listtransactions(const JSONRPCRequest& request)
 static UniValue listsinceblock(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -1658,7 +1658,7 @@ static UniValue listsinceblock(const JSONRPCRequest& request)
 static UniValue gettransaction(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -1817,7 +1817,7 @@ static UniValue abandontransaction(const JSONRPCRequest& request)
 static UniValue backupwallet(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -2266,7 +2266,7 @@ static UniValue lockunspent(const JSONRPCRequest& request)
 static UniValue listlockunspent(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -2432,7 +2432,7 @@ static UniValue getbalances(const JSONRPCRequest& request)
 static UniValue getwalletinfo(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -2814,7 +2814,7 @@ static UniValue unloadwallet(const JSONRPCRequest& request)
 static UniValue listunspent(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -3248,7 +3248,7 @@ static UniValue fundrawtransaction(const JSONRPCRequest& request)
 UniValue signrawtransactionwithwallet(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -3728,7 +3728,7 @@ public:
     UniValue operator()(const WitnessUnknown& id) const { return UniValue(UniValue::VOBJ); }
 };
 
-static UniValue DescribeWalletAddress(CWallet* pwallet, const CTxDestination& dest)
+static UniValue DescribeWalletAddress(const CWallet* const pwallet, const CTxDestination& dest)
 {
     UniValue ret(UniValue::VOBJ);
     UniValue detail = DescribeAddress(dest);
@@ -3756,7 +3756,7 @@ static UniValue AddressBookDataToJSON(const CAddressBookData& data, const bool v
 UniValue getaddressinfo(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -3858,7 +3858,7 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
     // be associated with an address, so the label should be equivalent to the
     // value of the name key/value pair in the labels array below.
     if ((pwallet->chain().rpcEnableDeprecated("label")) && (pwallet->mapAddressBook.count(dest))) {
-        ret.pushKV("label", pwallet->mapAddressBook[dest].name);
+        ret.pushKV("label", pwallet->mapAddressBook.at(dest).name);
     }
 
     ret.pushKV("ischange", pwallet->IsChange(scriptPubKey));
@@ -3881,7 +3881,7 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
     // stable if we allow multiple labels to be associated with an address in
     // the future.
     UniValue labels(UniValue::VARR);
-    std::map<CTxDestination, CAddressBookData>::iterator mi = pwallet->mapAddressBook.find(dest);
+    std::map<CTxDestination, CAddressBookData>::const_iterator mi = pwallet->mapAddressBook.find(dest);
     if (mi != pwallet->mapAddressBook.end()) {
         // DEPRECATED: The previous behavior of returning an array containing a
         // JSON object of `name` and `purpose` key/value pairs is deprecated.
@@ -3899,7 +3899,7 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
 static UniValue getaddressesbylabel(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -3958,7 +3958,7 @@ static UniValue getaddressesbylabel(const JSONRPCRequest& request)
 static UniValue listlabels(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
@@ -4091,7 +4091,7 @@ UniValue sethdseed(const JSONRPCRequest& request)
 UniValue walletprocesspsbt(const JSONRPCRequest& request)
 {
     std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
-    CWallet* const pwallet = wallet.get();
+    const CWallet* const pwallet = wallet.get();
 
     if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
         return NullUniValue;
diff --git a/src/wallet/scriptpubkeyman.cpp b/src/wallet/scriptpubkeyman.cpp
index 0c95ab29b1..8851d0af31 100644
--- a/src/wallet/scriptpubkeyman.cpp
+++ b/src/wallet/scriptpubkeyman.cpp
@@ -358,7 +358,7 @@ bool LegacyScriptPubKeyMan::IsHDEnabled() const
     return !hdChain.seed_id.IsNull();
 }
 
-bool LegacyScriptPubKeyMan::CanGetAddresses(bool internal)
+bool LegacyScriptPubKeyMan::CanGetAddresses(bool internal) const
 {
     LOCK(cs_KeyStore);
     // Check if the keypool has keys
@@ -441,7 +441,7 @@ static int64_t GetOldestKeyTimeInPool(const std::set<int64_t>& setKeyPool, Walle
     return keypool.nTime;
 }
 
-int64_t LegacyScriptPubKeyMan::GetOldestKeyPoolTime()
+int64_t LegacyScriptPubKeyMan::GetOldestKeyPoolTime() const
 {
     LOCK(cs_KeyStore);
 
@@ -459,7 +459,7 @@ int64_t LegacyScriptPubKeyMan::GetOldestKeyPoolTime()
     return oldestKey;
 }
 
-size_t LegacyScriptPubKeyMan::KeypoolCountExternalKeys()
+size_t LegacyScriptPubKeyMan::KeypoolCountExternalKeys() const
 {
     LOCK(cs_KeyStore);
     return setExternalKeyPool.size() + set_pre_split_keypool.size();
@@ -973,7 +973,7 @@ void LegacyScriptPubKeyMan::LoadKeyPool(int64_t nIndex, const CKeyPool &keypool)
         mapKeyMetadata[keyid] = CKeyMetadata(keypool.nTime);
 }
 
-bool LegacyScriptPubKeyMan::CanGenerateKeys()
+bool LegacyScriptPubKeyMan::CanGenerateKeys() const
 {
     // A wallet can generate keys if it has an HD seed (IsHDEnabled) or it is a non-HD wallet (pre FEATURE_HD)
     LOCK(cs_KeyStore);
diff --git a/src/wallet/scriptpubkeyman.h b/src/wallet/scriptpubkeyman.h
index 7b1c023bc9..1a0d34a445 100644
--- a/src/wallet/scriptpubkeyman.h
+++ b/src/wallet/scriptpubkeyman.h
@@ -184,7 +184,7 @@ public:
     virtual bool IsHDEnabled() const { return false; }
 
     /* Returns true if the wallet can give out new addresses. This means it has keys in the keypool or can generate new keys */
-    virtual bool CanGetAddresses(bool internal = false) { return false; }
+    virtual bool CanGetAddresses(bool internal = false) const { return false; }
 
     /** Upgrades the wallet to the specified version */
     virtual bool Upgrade(int prev_version, std::string& error) { return false; }
@@ -194,9 +194,9 @@ public:
     //! The action to do when the DB needs rewrite
     virtual void RewriteDB() {}
 
-    virtual int64_t GetOldestKeyPoolTime() { return GetTime(); }
+    virtual int64_t GetOldestKeyPoolTime() const { return GetTime(); }
 
-    virtual size_t KeypoolCountExternalKeys() { return 0; }
+    virtual size_t KeypoolCountExternalKeys() const { return 0; }
     virtual unsigned int GetKeyPoolSize() const { return 0; }
 
     virtual int64_t GetTimeFirstKey() const { return 0; }
@@ -336,15 +336,15 @@ public:
 
     void RewriteDB() override;
 
-    int64_t GetOldestKeyPoolTime() override;
-    size_t KeypoolCountExternalKeys() override;
+    int64_t GetOldestKeyPoolTime() const override;
+    size_t KeypoolCountExternalKeys() const override;
     unsigned int GetKeyPoolSize() const override;
 
     int64_t GetTimeFirstKey() const override;
 
     const CKeyMetadata* GetMetadata(const CTxDestination& dest) const override;
 
-    bool CanGetAddresses(bool internal = false) override;
+    bool CanGetAddresses(bool internal = false) const override;
 
     std::unique_ptr<SigningProvider> GetSigningProvider(const CScript& script) const override;
 
@@ -410,7 +410,7 @@ public:
     bool ImportScriptPubKeys(const std::set<CScript>& script_pub_keys, const bool have_solving_data, const int64_t timestamp) EXCLUSIVE_LOCKS_REQUIRED(cs_KeyStore);
 
     /* Returns true if the wallet can generate new keys */
-    bool CanGenerateKeys();
+    bool CanGenerateKeys() const;
 
     /* Generates a new HD seed (will not be activated) */
     CPubKey GenerateNewSeed();
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 5a97f62b71..9d2e5598e8 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1150,7 +1150,7 @@ void CWallet::UpdatedBlockTip()
 }
 
 
-void CWallet::BlockUntilSyncedToCurrentChain() {
+void CWallet::BlockUntilSyncedToCurrentChain() const {
     AssertLockNotHeld(cs_wallet);
     // Skip the queue-draining stuff if we know we're caught up with
     // ::ChainActive().Tip(), otherwise put a callback in the validation interface queue and wait
@@ -1333,7 +1333,7 @@ bool CWallet::IsHDEnabled() const
     return result;
 }
 
-bool CWallet::CanGetAddresses(bool internal)
+bool CWallet::CanGetAddresses(bool internal) const
 {
     LOCK(cs_wallet);
     if (m_spk_managers.empty()) return false;
@@ -3112,7 +3112,7 @@ bool CWallet::DelAddressBook(const CTxDestination& address)
     return WalletBatch(*database).EraseName(EncodeDestination(address));
 }
 
-size_t CWallet::KeypoolCountExternalKeys()
+size_t CWallet::KeypoolCountExternalKeys() const
 {
     AssertLockHeld(cs_wallet);
 
@@ -3177,7 +3177,7 @@ bool CWallet::GetNewChangeDestination(const OutputType type, CTxDestination& des
     return true;
 }
 
-int64_t CWallet::GetOldestKeyPoolTime()
+int64_t CWallet::GetOldestKeyPoolTime() const
 {
     LOCK(cs_wallet);
     int64_t oldestKey = std::numeric_limits<int64_t>::max();
@@ -3201,7 +3201,7 @@ void CWallet::MarkDestinationsDirty(const std::set<CTxDestination>& destinations
     }
 }
 
-std::map<CTxDestination, CAmount> CWallet::GetAddressBalances(interfaces::Chain::Lock& locked_chain)
+std::map<CTxDestination, CAmount> CWallet::GetAddressBalances(interfaces::Chain::Lock& locked_chain) const
 {
     std::map<CTxDestination, CAmount> balances;
 
@@ -3242,7 +3242,7 @@ std::map<CTxDestination, CAmount> CWallet::GetAddressBalances(interfaces::Chain:
     return balances;
 }
 
-std::set< std::set<CTxDestination> > CWallet::GetAddressGroupings()
+std::set< std::set<CTxDestination> > CWallet::GetAddressGroupings() const
 {
     AssertLockHeld(cs_wallet);
     std::set< std::set<CTxDestination> > groupings;
@@ -4004,7 +4004,7 @@ void CWallet::postInitProcess()
     chain().requestMempoolTransactions(*this);
 }
 
-bool CWallet::BackupWallet(const std::string& strDest)
+bool CWallet::BackupWallet(const std::string& strDest) const
 {
     return database->Backup(strDest);
 }
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 6c1c3040c2..3664a6787c 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -141,7 +141,7 @@ class ReserveDestination
 {
 protected:
     //! The wallet to reserve from
-    CWallet* const pwallet;
+    const CWallet* const pwallet;
     //! The ScriptPubKeyMan to reserve from. Based on type when GetReservedDestination is called
     ScriptPubKeyMan* m_spk_man{nullptr};
     OutputType const type;
@@ -832,8 +832,8 @@ public:
      * Rescan abort properties
      */
     void AbortRescan() { fAbortRescan = true; }
-    bool IsAbortingRescan() { return fAbortRescan; }
-    bool IsScanning() { return fScanningWallet; }
+    bool IsAbortingRescan() const { return fAbortRescan; }
+    bool IsScanning() const { return fScanningWallet; }
     int64_t ScanningDuration() const { return fScanningWallet ? GetTimeMillis() - m_scanning_start : 0; }
     double ScanningProgress() const { return fScanningWallet ? (double) m_scanning_progress : 0; }
 
@@ -968,13 +968,13 @@ public:
     /** Absolute maximum transaction fee (in satoshis) used by default for the wallet */
     CAmount m_default_max_tx_fee{DEFAULT_TRANSACTION_MAXFEE};
 
-    size_t KeypoolCountExternalKeys() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    size_t KeypoolCountExternalKeys() const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool TopUpKeyPool(unsigned int kpSize = 0);
 
-    int64_t GetOldestKeyPoolTime();
+    int64_t GetOldestKeyPoolTime() const;
 
-    std::set<std::set<CTxDestination>> GetAddressGroupings() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
-    std::map<CTxDestination, CAmount> GetAddressBalances(interfaces::Chain::Lock& locked_chain);
+    std::set<std::set<CTxDestination>> GetAddressGroupings() const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
+    std::map<CTxDestination, CAmount> GetAddressBalances(interfaces::Chain::Lock& locked_chain) const;
 
     std::set<CTxDestination> GetLabelAddresses(const std::string& label) const;
 
@@ -1027,7 +1027,7 @@ public:
     bool SetMaxVersion(int nVersion);
 
     //! get the current wallet format (the oldest client version guaranteed to understand this wallet)
-    int GetVersion() { LOCK(cs_wallet); return nWalletVersion; }
+    int GetVersion() const { LOCK(cs_wallet); return nWalletVersion; }
 
     //! Get wallet transactions that conflict with given transaction (spend same outputs)
     std::set<uint256> GetConflicts(const uint256& txid) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
@@ -1098,13 +1098,13 @@ public:
      */
     void postInitProcess();
 
-    bool BackupWallet(const std::string& strDest);
+    bool BackupWallet(const std::string& strDest) const;
 
     /* Returns true if HD is enabled */
     bool IsHDEnabled() const;
 
     /* Returns true if the wallet can give out new addresses. This means it has keys in the keypool or can generate new keys */
-    bool CanGetAddresses(bool internal = false);
+    bool CanGetAddresses(bool internal = false) const;
 
     /**
      * Blocks until the wallet state is up-to-date to /at least/ the current
@@ -1112,7 +1112,7 @@ public:
      * Obviously holding cs_main/cs_wallet when going into this call may cause
      * deadlock
      */
-    void BlockUntilSyncedToCurrentChain() LOCKS_EXCLUDED(cs_main, cs_wallet);
+    void BlockUntilSyncedToCurrentChain() const LOCKS_EXCLUDED(cs_main, cs_wallet);
 
     /** set a single wallet flag */
     void SetWalletFlag(uint64_t flags);