1 files changed, 30 insertions, 8 deletions

diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index ae4321eef8..ccede60097 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -86,6 +86,9 @@ enum WalletFeature
     FEATURE_COMPRPUBKEY = 60000, // compressed public keys
 
     FEATURE_HD = 130000, // Hierarchical key derivation after BIP32 (HD Wallet)
+
+    FEATURE_HD_SPLIT = 139900, // Wallet with HD chain split (change outputs will use m/0'/1'/k)
+
     FEATURE_LATEST = FEATURE_COMPRPUBKEY // HD is optional, use FEATURE_COMPRPUBKEY as latest version
 };
 
@@ -96,9 +99,10 @@ class CKeyPool
 public:
     int64_t nTime;
     CPubKey vchPubKey;
+    bool fInternal; // for change outputs
 
     CKeyPool();
-    CKeyPool(const CPubKey& vchPubKeyIn);
+    CKeyPool(const CPubKey& vchPubKeyIn, bool internalIn);
 
     ADD_SERIALIZE_METHODS;
 
@@ -109,6 +113,19 @@ public:
             READWRITE(nVersion);
         READWRITE(nTime);
         READWRITE(vchPubKey);
+        if (ser_action.ForRead()) {
+            try {
+                READWRITE(fInternal);
+            }
+            catch (std::ios_base::failure&) {
+                /* flag as external address if we can't read the internal boolean
+                   (this will be the case for any wallet before the HD chain split version) */
+                fInternal = false;
+            }
+        }
+        else {
+            READWRITE(fInternal);
+        }
     }
 };
 
@@ -647,6 +664,9 @@ private:
     /* the HD chain data model (external chain counters) */
     CHDChain hdChain;
 
+    /* HD derive new child key (on internal or external chain) */
+    void DeriveNewChildKey(CKeyMetadata& metadata, CKey& secret, bool internal = false);
+
     bool fFileBacked;
 
     std::set<int64_t> setKeyPool;
@@ -774,8 +794,7 @@ public:
      * keystore implementation
      * Generate a new key
      */
-    CPubKey GenerateNewKey();
-    void DeriveNewChildKey(CKeyMetadata& metadata, CKey& secret);
+    CPubKey GenerateNewKey(bool internal = false);
     //! Adds a key to the store, and saves it to disk.
     bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey) override;
     //! Adds a key to the store, without saving it to disk (used by LoadWallet)
@@ -883,11 +902,12 @@ public:
     static CAmount GetRequiredFee(unsigned int nTxBytes);
 
     bool NewKeyPool();
+    size_t KeypoolCountExternalKeys();
     bool TopUpKeyPool(unsigned int kpSize = 0);
-    void ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool);
+    void ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool internal);
     void KeepKey(int64_t nIndex);
     void ReturnKey(int64_t nIndex);
-    bool GetKeyFromPool(CPubKey &key);
+    bool GetKeyFromPool(CPubKey &key, bool internal = false);
     int64_t GetOldestKeyPoolTime();
     void GetAllReserveKeys(std::set<CKeyID>& setAddress) const;
 
@@ -1035,8 +1055,10 @@ public:
     /* Generates a new HD master key (will not be activated) */
     CPubKey GenerateNewHDMasterKey();
     
-    /* Set the current HD master key (will reset the chain child index counters) */
-    bool SetHDMasterKey(const CPubKey& key);
+    /* Set the current HD master key (will reset the chain child index counters)
+       If possibleOldChain is provided, the parameters from the old chain (version)
+       will be preserved. */
+    bool SetHDMasterKey(const CPubKey& key, CHDChain *possibleOldChain = nullptr);
 };
 
 /** A key allocated from the key pool. */
@@ -1063,7 +1085,7 @@ public:
     }
 
     void ReturnKey();
-    bool GetReservedKey(CPubKey &pubkey);
+    bool GetReservedKey(CPubKey &pubkey, bool internal = false);
     void KeepKey();
     void KeepScript() { KeepKey(); }
 };