wallet: make CanGetAddresses() const

CWallet::CanGetAddresses() is used to check whether the wallet has available or is able to produce keys for addresses. It uses the ScriptPubKeyMan::CanGetAddresses(), which in turn uses the const KeypoolCountExternalKeys() method, all which do counting and no modifications.

src/interfaces/wallet.cpp

@@ -468,7 +468,7 @@ public:
     }
     unsigned int getConfirmTarget() override { return m_wallet->m_confirm_target; }
     bool hdEnabled() override { return m_wallet->IsHDEnabled(); }
-    bool canGetAddresses() override { return m_wallet->CanGetAddresses(); }
+    bool canGetAddresses() const override { return m_wallet->CanGetAddresses(); }
     bool IsWalletFlagSet(uint64_t flag) override { return m_wallet->IsWalletFlagSet(flag); }
     OutputType getDefaultAddressType() override { return m_wallet->m_default_address_type; }
     OutputType getDefaultChangeType() override { return m_wallet->m_default_change_type; }

src/interfaces/wallet.h

@@ -246,7 +246,7 @@ public:
     virtual bool hdEnabled() = 0;
 
     // Return whether the wallet is blank.
-    virtual bool canGetAddresses() = 0;
+    virtual bool canGetAddresses() const = 0;
 
     // check if a certain wallet flag is set.
     virtual bool IsWalletFlagSet(uint64_t flag) = 0;

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

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; }
@@ -344,7 +344,7 @@ public:
 
     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;
 

src/wallet/wallet.cpp

@@ -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;

src/wallet/wallet.h

@@ -1104,7 +1104,7 @@ public:
     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