Merge bitcoin/bitcoin#20191: wallet, refactor: make DescriptorScriptPubKeyMan agnostic of internal flag

181181019c5baa3e2d5b675d1843a45aa028781c refactor: remove m_internal from DescriptorSPKman (S3RK)

Pull request description:

  Rationale: improve consistency between `CWallet` and `DescriptorScriptPubKeyMan`; simplify `ScriptPubKeyMan` interface.

  Descriptor in itself is neither internal or external. It's responsibility of a wallet to assign and manage descriptors for a specific purpose. Duplicating information about internalness of a descriptor could lead to inconsistencies and unexpected behaviour (for example misreporting keypool size).

ACKs for top commit:
  instagibbs:
    reACK https://github.com/bitcoin/bitcoin/pull/20191/commits/181181019c5baa3e2d5b675d1843a45aa028781c
  achow101:
    reACK 181181019c5baa3e2d5b675d1843a45aa028781c

Tree-SHA512: d5613b7f6795b290bfa0fd8cb0536de1714d0cf72cba402266bd06d550758ebad690b54fc0a336a1c7414b5814aa4a37c90a6ae89926474a97d30956d7e034ff

4 files changed, 19 insertions, 40 deletions

diff --git a/src/wallet/external_signer_scriptpubkeyman.h b/src/wallet/external_signer_scriptpubkeyman.h
index 8eed947b7b..61df3d0015 100644
--- a/src/wallet/external_signer_scriptpubkeyman.h
+++ b/src/wallet/external_signer_scriptpubkeyman.h
@@ -15,8 +15,8 @@ class ExternalSignerScriptPubKeyMan : public DescriptorScriptPubKeyMan
   ExternalSignerScriptPubKeyMan(WalletStorage& storage, WalletDescriptor& descriptor)
       :   DescriptorScriptPubKeyMan(storage, descriptor)
       {}
-  ExternalSignerScriptPubKeyMan(WalletStorage& storage, bool internal)
-      :   DescriptorScriptPubKeyMan(storage, internal)
+  ExternalSignerScriptPubKeyMan(WalletStorage& storage)
+      :   DescriptorScriptPubKeyMan(storage)
       {}
 
   /** Provide a descriptor at setup time
diff --git a/src/wallet/scriptpubkeyman.cpp b/src/wallet/scriptpubkeyman.cpp
index c20950e999..73433214f1 100644
--- a/src/wallet/scriptpubkeyman.cpp
+++ b/src/wallet/scriptpubkeyman.cpp
@@ -1613,12 +1613,10 @@ std::set<CKeyID> LegacyScriptPubKeyMan::GetKeys() const
     return set_address;
 }
 
-void LegacyScriptPubKeyMan::SetInternal(bool internal) {}
-
 bool DescriptorScriptPubKeyMan::GetNewDestination(const OutputType type, CTxDestination& dest, std::string& error)
 {
     // Returns true if this descriptor supports getting new addresses. Conditions where we may be unable to fetch them (e.g. locked) are caught later
-    if (!CanGetAddresses(m_internal)) {
+    if (!CanGetAddresses()) {
         error = "No addresses available";
         return false;
     }
@@ -1876,7 +1874,7 @@ bool DescriptorScriptPubKeyMan::AddDescriptorKeyWithDB(WalletBatch& batch, const
     }
 }
 
-bool DescriptorScriptPubKeyMan::SetupDescriptorGeneration(const CExtKey& master_key, OutputType addr_type)
+bool DescriptorScriptPubKeyMan::SetupDescriptorGeneration(const CExtKey& master_key, OutputType addr_type, bool internal)
 {
     if (addr_type == OutputType::BECH32M) {
         // Don't allow setting up taproot descriptors yet
@@ -1924,7 +1922,7 @@ bool DescriptorScriptPubKeyMan::SetupDescriptorGeneration(const CExtKey& master_
         desc_prefix += "/0'";
     }
 
-    std::string internal_path = m_internal ? "/1" : "/0";
+    std::string internal_path = internal ? "/1" : "/0";
     std::string desc_str = desc_prefix + "/0'" + internal_path + desc_suffix;
 
     // Make the descriptor
@@ -1979,13 +1977,6 @@ int64_t DescriptorScriptPubKeyMan::GetOldestKeyPoolTime() const
     return 0;
 }
 
-size_t DescriptorScriptPubKeyMan::KeypoolCountExternalKeys() const
-{
-    if (m_internal) {
-        return 0;
-    }
-    return GetKeyPoolSize();
-}
 
 unsigned int DescriptorScriptPubKeyMan::GetKeyPoolSize() const
 {
@@ -2187,11 +2178,6 @@ uint256 DescriptorScriptPubKeyMan::GetID() const
     return id;
 }
 
-void DescriptorScriptPubKeyMan::SetInternal(bool internal)
-{
-    this->m_internal = internal;
-}
-
 void DescriptorScriptPubKeyMan::SetCache(const DescriptorCache& cache)
 {
     LOCK(cs_desc_man);
diff --git a/src/wallet/scriptpubkeyman.h b/src/wallet/scriptpubkeyman.h
index 6ed4a7a541..572a695662 100644
--- a/src/wallet/scriptpubkeyman.h
+++ b/src/wallet/scriptpubkeyman.h
@@ -216,7 +216,6 @@ public:
 
     virtual int64_t GetOldestKeyPoolTime() const { return GetTime(); }
 
-    virtual size_t KeypoolCountExternalKeys() const { return 0; }
     virtual unsigned int GetKeyPoolSize() const { return 0; }
 
     virtual int64_t GetTimeFirstKey() const { return 0; }
@@ -239,8 +238,6 @@ public:
 
     virtual uint256 GetID() const { return uint256(); }
 
-    virtual void SetInternal(bool internal) {}
-
     /** Prepends the wallet name in logging output to ease debugging in multi-wallet use cases */
     template<typename... Params>
     void WalletLogPrintf(std::string fmt, Params... parameters) const {
@@ -386,7 +383,7 @@ public:
     void RewriteDB() override;
 
     int64_t GetOldestKeyPoolTime() const override;
-    size_t KeypoolCountExternalKeys() const override;
+    size_t KeypoolCountExternalKeys() const;
     unsigned int GetKeyPoolSize() const override;
 
     int64_t GetTimeFirstKey() const override;
@@ -405,8 +402,6 @@ public:
 
     uint256 GetID() const override;
 
-    void SetInternal(bool internal) override;
-
     // Map from Key ID to key metadata.
     std::map<CKeyID, CKeyMetadata> mapKeyMetadata GUARDED_BY(cs_KeyStore);
 
@@ -533,8 +528,6 @@ private:
     PubKeyMap m_map_pubkeys GUARDED_BY(cs_desc_man);
     int32_t m_max_cached_index = -1;
 
-    bool m_internal = false;
-
     KeyMap m_map_keys GUARDED_BY(cs_desc_man);
     CryptedKeyMap m_map_crypted_keys GUARDED_BY(cs_desc_man);
 
@@ -560,9 +553,8 @@ public:
         :   ScriptPubKeyMan(storage),
             m_wallet_descriptor(descriptor)
         {}
-    DescriptorScriptPubKeyMan(WalletStorage& storage, bool internal)
-        :   ScriptPubKeyMan(storage),
-            m_internal(internal)
+    DescriptorScriptPubKeyMan(WalletStorage& storage)
+        :   ScriptPubKeyMan(storage)
         {}
 
     mutable RecursiveMutex cs_desc_man;
@@ -587,7 +579,7 @@ public:
     bool IsHDEnabled() const override;
 
     //! Setup descriptors based on the given CExtkey
-    bool SetupDescriptorGeneration(const CExtKey& master_key, OutputType addr_type);
+    bool SetupDescriptorGeneration(const CExtKey& master_key, OutputType addr_type, bool internal);
 
     /** Provide a descriptor at setup time
     * Returns false if already setup or setup fails, true if setup is successful
@@ -597,7 +589,6 @@ public:
     bool HavePrivateKeys() const override;
 
     int64_t GetOldestKeyPoolTime() const override;
-    size_t KeypoolCountExternalKeys() const override;
     unsigned int GetKeyPoolSize() const override;
 
     int64_t GetTimeFirstKey() const override;
@@ -616,8 +607,6 @@ public:
 
     uint256 GetID() const override;
 
-    void SetInternal(bool internal) override;
-
     void SetCache(const DescriptorCache& cache);
 
     bool AddKey(const CKeyID& key_id, const CKey& key);
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index c506bc6255..1f736f8baf 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2094,9 +2094,14 @@ size_t CWallet::KeypoolCountExternalKeys() const
 {
     AssertLockHeld(cs_wallet);
 
+    auto legacy_spk_man = GetLegacyScriptPubKeyMan();
+    if (legacy_spk_man) {
+        return legacy_spk_man->KeypoolCountExternalKeys();
+    }
+
     unsigned int count = 0;
-    for (auto spk_man : GetActiveScriptPubKeyMans()) {
-        count += spk_man->KeypoolCountExternalKeys();
+    for (auto spk_man : m_external_spk_managers) {
+        count += spk_man.second->GetKeyPoolSize();
     }
 
     return count;
@@ -3112,7 +3117,7 @@ void CWallet::SetupDescriptorScriptPubKeyMans()
                     // TODO: Setup taproot (bech32m) descriptors by default
                     continue;
                 }
-                auto spk_manager = std::unique_ptr<DescriptorScriptPubKeyMan>(new DescriptorScriptPubKeyMan(*this, internal));
+                auto spk_manager = std::unique_ptr<DescriptorScriptPubKeyMan>(new DescriptorScriptPubKeyMan(*this));
                 if (IsCrypted()) {
                     if (IsLocked()) {
                         throw std::runtime_error(std::string(__func__) + ": Wallet is locked, cannot setup new descriptors");
@@ -3121,7 +3126,7 @@ void CWallet::SetupDescriptorScriptPubKeyMans()
                         throw std::runtime_error(std::string(__func__) + ": Could not encrypt new descriptors");
                     }
                 }
-                spk_manager->SetupDescriptorGeneration(master_key, t);
+                spk_manager->SetupDescriptorGeneration(master_key, t, internal);
                 uint256 id = spk_manager->GetID();
                 m_spk_managers[id] = std::move(spk_manager);
                 AddActiveScriptPubKeyMan(id, t, internal);
@@ -3147,7 +3152,7 @@ void CWallet::SetupDescriptorScriptPubKeyMans()
                     continue;
                 }
                 OutputType t =  *desc->GetOutputType();
-                auto spk_manager = std::unique_ptr<ExternalSignerScriptPubKeyMan>(new ExternalSignerScriptPubKeyMan(*this, internal));
+                auto spk_manager = std::unique_ptr<ExternalSignerScriptPubKeyMan>(new ExternalSignerScriptPubKeyMan(*this));
                 spk_manager->SetupDescriptor(std::move(desc));
                 uint256 id = spk_manager->GetID();
                 m_spk_managers[id] = std::move(spk_manager);
@@ -3176,7 +3181,6 @@ void CWallet::LoadActiveScriptPubKeyMan(uint256 id, OutputType type, bool intern
     auto& spk_mans = internal ? m_internal_spk_managers : m_external_spk_managers;
     auto& spk_mans_other = internal ? m_external_spk_managers : m_internal_spk_managers;
     auto spk_man = m_spk_managers.at(id).get();
-    spk_man->SetInternal(internal);
     spk_mans[type] = spk_man;
 
     if (spk_mans_other[type] == spk_man) {