Merge #16237: Have the wallet give out destinations instead of keys

8e7f930828a9f8f9be1c90ff45e3fdfef1980eaf Add GetNewChangeDestination for getting new change Destinations (Andrew Chow)
33d13edd2bda0af90660e275ea4fa96ca9896f2a Replace CReserveKey with ReserveDestinatoin (Andrew Chow)
172213be5b174243dc501c1103ad5fe2fee67a16 Add GetNewDestination to CWallet to fetch new destinations (Andrew Chow)

Pull request description:

  The wallet should give out destinations instead of keys. It should be the one that handles the conversion from key to destination and the setting of the label, not the caller. In order to do this, two new member functions are introduced `GetNewDestination()` and `GetNewChangeDestination()`. Additionally, `CReserveKey` is changed to be `ReserveDestination` and represents destinations whose keys can be returned to the keypool.

ACKs for top commit:
  instagibbs:
    re-utACK https://github.com/bitcoin/bitcoin/pull/16237/commits/8e7f930828a9f8f9be1c90ff45e3fdfef1980eaf
  sipa:
    ACK 8e7f930828a9f8f9be1c90ff45e3fdfef1980eaf. Concept ACK as this gives a much cleaner abstraction to work with, and light code review ACK.
  laanwj:
    ACK 8e7f930828a9f8f9be1c90ff45e3fdfef1980eaf

Tree-SHA512: 5be7051409232b71e0ef2c1fd1a3e76964ed2f5b14d47d06edc2ad3b3687abd0be2803a1adc45c0433aa2c3bed172e14f8a7e9f4a23bff70f86260b5a0497500

2 files changed, 10 insertions, 8 deletions

diff --git a/src/interfaces/wallet.cpp b/src/interfaces/wallet.cpp
index 34c982e1e6..c827658dbc 100644
--- a/src/interfaces/wallet.cpp
+++ b/src/interfaces/wallet.cpp
@@ -36,7 +36,7 @@ namespace {
 class PendingWalletTxImpl : public PendingWalletTx
 {
 public:
-    explicit PendingWalletTxImpl(CWallet& wallet) : m_wallet(wallet), m_key(&wallet) {}
+    explicit PendingWalletTxImpl(CWallet& wallet) : m_wallet(wallet), m_dest(&wallet) {}
 
     const CTransaction& get() override { return *m_tx; }
 
@@ -47,7 +47,7 @@ public:
         auto locked_chain = m_wallet.chain().lock();
         LOCK(m_wallet.cs_wallet);
         CValidationState state;
-        if (!m_wallet.CommitTransaction(m_tx, std::move(value_map), std::move(order_form), m_key, state)) {
+        if (!m_wallet.CommitTransaction(m_tx, std::move(value_map), std::move(order_form), m_dest, state)) {
             reject_reason = state.GetRejectReason();
             return false;
         }
@@ -56,7 +56,7 @@ public:
 
     CTransactionRef m_tx;
     CWallet& m_wallet;
-    CReserveKey m_key;
+    ReserveDestination m_dest;
 };
 
 //! Construct wallet tx struct.
@@ -140,9 +140,11 @@ public:
     void abortRescan() override { m_wallet->AbortRescan(); }
     bool backupWallet(const std::string& filename) override { return m_wallet->BackupWallet(filename); }
     std::string getWalletName() override { return m_wallet->GetName(); }
-    bool getKeyFromPool(bool internal, CPubKey& pub_key) override
+    bool getNewDestination(const OutputType type, const std::string label, CTxDestination& dest) override
     {
-        return m_wallet->GetKeyFromPool(pub_key, internal);
+        LOCK(m_wallet->cs_wallet);
+        std::string error;
+        return m_wallet->GetNewDestination(type, label, dest, error);
     }
     bool getPubKey(const CKeyID& address, CPubKey& pub_key) override { return m_wallet->GetPubKey(address, pub_key); }
     bool getPrivKey(const CKeyID& address, CKey& key) override { return m_wallet->GetKey(address, key); }
@@ -236,7 +238,7 @@ public:
         auto locked_chain = m_wallet->chain().lock();
         LOCK(m_wallet->cs_wallet);
         auto pending = MakeUnique<PendingWalletTxImpl>(*m_wallet);
-        if (!m_wallet->CreateTransaction(*locked_chain, recipients, pending->m_tx, pending->m_key, fee, change_pos,
+        if (!m_wallet->CreateTransaction(*locked_chain, recipients, pending->m_tx, pending->m_dest, fee, change_pos,
                 fail_reason, coin_control, sign)) {
             return {};
         }
diff --git a/src/interfaces/wallet.h b/src/interfaces/wallet.h
index 9c9b29a813..db47dbafaf 100644
--- a/src/interfaces/wallet.h
+++ b/src/interfaces/wallet.h
@@ -78,8 +78,8 @@ public:
     //! Get wallet name.
     virtual std::string getWalletName() = 0;
 
-    // Get key from pool.
-    virtual bool getKeyFromPool(bool internal, CPubKey& pub_key) = 0;
+    // Get a new address.
+    virtual bool getNewDestination(const OutputType type, const std::string label, CTxDestination& dest) = 0;
 
     //! Get public key.
     virtual bool getPubKey(const CKeyID& address, CPubKey& pub_key) = 0;