descriptors: Add PubkeyProvider::Clone

Author: achow101

src/script/descriptor.cpp

@@ -219,6 +219,9 @@ struct PubkeyProvider
     virtual std::optional<CPubKey> GetRootPubKey() const = 0;
     /** Return the extended public key for this PubkeyProvider, if it has one. */
     virtual std::optional<CExtPubKey> GetRootExtPubKey() const = 0;
+
+    /** Make a deep copy of this PubkeyProvider */
+    virtual std::unique_ptr<PubkeyProvider> Clone() const = 0;
 };
 
 class OriginPubkeyProvider final : public PubkeyProvider
@@ -280,6 +283,10 @@ class OriginPubkeyProvider final : public PubkeyProvider
     {
         return m_provider->GetRootExtPubKey();
     }
+    std::unique_ptr<PubkeyProvider> Clone() const override
+    {
+        return std::make_unique<OriginPubkeyProvider>(m_expr_index, m_origin, m_provider->Clone(), m_apostrophe);
+    }
 };
 
 /** An object representing a parsed constant public key in a descriptor. */
@@ -333,6 +340,10 @@ class ConstPubkeyProvider final : public PubkeyProvider
     {
         return std::nullopt;
     }
+    std::unique_ptr<PubkeyProvider> Clone() const override
+    {
+        return std::make_unique<ConstPubkeyProvider>(m_expr_index, m_pubkey, m_xonly);
+    }
 };
 
 enum class DeriveType {
@@ -556,6 +567,10 @@ class BIP32PubkeyProvider final : public PubkeyProvider
     {
         return m_root_extkey;
     }
+    std::unique_ptr<PubkeyProvider> Clone() const override
+    {
+        return std::make_unique<BIP32PubkeyProvider>(m_expr_index, m_root_extkey, m_path, m_derive, m_apostrophe);
+    }
 };
 
 /** Base class for all Descriptor implementations. */