wallet: option to merge destinations

With the change from the original transfer method to the new
algorithm, payments to the same destination were merged. It
seemed like a good idea, optimizing space. However, it is a
useful tool for people who want to split large outputs into
several smaller ones (ie, service providers making frequent
payments, and who do not like a large chunk of their balance
being locked for 10 blocks after each payment).

Default to off, which is a change from the previous behavior.

2 files changed, 15 insertions, 6 deletions

diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index 09df30e66..ed31f34a4 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -1927,6 +1927,9 @@ bool wallet2::store_keys(const std::string& keys_file_name, const std::string& p
   value2.SetInt(cryptonote::get_default_decimal_point());
   json.AddMember("default_decimal_point", value2, json.GetAllocator());
 
+  value2.SetInt(m_merge_destinations ? 1 :0);
+  json.AddMember("merge_destinations", value2, json.GetAllocator());
+
   // Serialize the JSON object
   rapidjson::StringBuffer buffer;
   rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
@@ -1997,6 +2000,7 @@ bool wallet2::load_keys(const std::string& keys_file_name, const std::string& pa
     m_ask_password = true;
     m_min_output_count = 0;
     m_min_output_value = 0;
+    m_merge_destinations = false;
   }
   else
   {
@@ -2065,6 +2069,8 @@ bool wallet2::load_keys(const std::string& keys_file_name, const std::string& pa
     m_min_output_count = field_min_output_count;
     GET_FIELD_FROM_JSON_RETURN_ON_ERROR(json, min_output_value, uint64_t, Uint64, false, 0);
     m_min_output_value = field_min_output_value;
+    GET_FIELD_FROM_JSON_RETURN_ON_ERROR(json, merge_destinations, int, Int, false, false);
+    m_merge_destinations = field_merge_destinations;
   }
 
   const cryptonote::account_keys& keys = m_account.get_keys();
@@ -4238,10 +4244,10 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
     pending_tx ptx;
     size_t bytes;
 
-    void add(const account_public_address &addr, uint64_t amount) {
+    void add(const account_public_address &addr, uint64_t amount, bool merge_destinations) {
       std::vector<cryptonote::tx_destination_entry>::iterator i;
       i = std::find_if(dsts.begin(), dsts.end(), [&](const cryptonote::tx_destination_entry &d) { return !memcmp (&d.addr, &addr, sizeof(addr)); });
-      if (i == dsts.end())
+      if (!merge_destinations || i == dsts.end())
         dsts.push_back(tx_destination_entry(amount,addr));
       else
         i->amount += amount;
@@ -4408,7 +4414,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
         // we can fully pay that destination
         LOG_PRINT_L2("We can fully pay " << get_account_address_as_str(m_testnet, dsts[0].addr) <<
           " for " << print_money(dsts[0].amount));
-        tx.add(dsts[0].addr, dsts[0].amount);
+        tx.add(dsts[0].addr, dsts[0].amount, m_merge_destinations);
         available_amount -= dsts[0].amount;
         dsts[0].amount = 0;
         pop_index(dsts, 0);
@@ -4418,7 +4424,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
         // we can partially fill that destination
         LOG_PRINT_L2("We can partially pay " << get_account_address_as_str(m_testnet, dsts[0].addr) <<
           " for " << print_money(available_amount) << "/" << print_money(dsts[0].amount));
-        tx.add(dsts[0].addr, available_amount);
+        tx.add(dsts[0].addr, available_amount, m_merge_destinations);
         dsts[0].amount -= available_amount;
         available_amount = 0;
       }
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index d0d2cda3c..6d7bca2a5 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -105,7 +105,7 @@ namespace tools
     };
 
   private:
-    wallet2(const wallet2&) : m_run(true), m_callback(0), m_testnet(false), m_always_confirm_transfers(true), m_print_ring_members(false), m_store_tx_info(true), m_default_mixin(0), m_default_priority(0), m_refresh_type(RefreshOptimizeCoinbase), m_auto_refresh(true), m_refresh_from_block_height(0), m_confirm_missing_payment_id(true), m_ask_password(true), m_min_output_count(0), m_min_output_value(0), m_node_rpc_proxy(m_http_client, m_daemon_rpc_mutex) {}
+    wallet2(const wallet2&) : m_run(true), m_callback(0), m_testnet(false), m_always_confirm_transfers(true), m_print_ring_members(false), m_store_tx_info(true), m_default_mixin(0), m_default_priority(0), m_refresh_type(RefreshOptimizeCoinbase), m_auto_refresh(true), m_refresh_from_block_height(0), m_confirm_missing_payment_id(true), m_ask_password(true), m_min_output_count(0), m_min_output_value(0), m_merge_destinations(false), m_node_rpc_proxy(m_http_client, m_daemon_rpc_mutex) {}
 
   public:
     static const char* tr(const char* str);
@@ -126,7 +126,7 @@ namespace tools
     //! Uses stdin and stdout. Returns a wallet2 and password for wallet with no file if no errors.
     static std::pair<std::unique_ptr<wallet2>, password_container> make_new(const boost::program_options::variables_map& vm);
 
-    wallet2(bool testnet = false, bool restricted = false) : m_run(true), m_callback(0), m_testnet(testnet), m_always_confirm_transfers(true), m_print_ring_members(false), m_store_tx_info(true), m_default_mixin(0), m_default_priority(0), m_refresh_type(RefreshOptimizeCoinbase), m_auto_refresh(true), m_refresh_from_block_height(0), m_confirm_missing_payment_id(true), m_ask_password(true), m_min_output_count(0), m_min_output_value(0), m_restricted(restricted), is_old_file_format(false), m_node_rpc_proxy(m_http_client, m_daemon_rpc_mutex) {}
+    wallet2(bool testnet = false, bool restricted = false) : m_run(true), m_callback(0), m_testnet(testnet), m_always_confirm_transfers(true), m_print_ring_members(false), m_store_tx_info(true), m_default_mixin(0), m_default_priority(0), m_refresh_type(RefreshOptimizeCoinbase), m_auto_refresh(true), m_refresh_from_block_height(0), m_confirm_missing_payment_id(true), m_ask_password(true), m_min_output_count(0), m_min_output_value(0), m_merge_destinations(false), m_restricted(restricted), is_old_file_format(false), m_node_rpc_proxy(m_http_client, m_daemon_rpc_mutex) {}
 
     struct transfer_details
     {
@@ -531,6 +531,8 @@ namespace tools
     uint32_t get_min_output_count() const { return m_min_output_count; }
     void set_min_output_value(uint64_t value) { m_min_output_value = value; }
     uint64_t get_min_output_value() const { return m_min_output_value; }
+    void merge_destinations(bool merge) { m_merge_destinations = merge; }
+    bool merge_destinations() const { return m_merge_destinations; }
 
     bool get_tx_key(const crypto::hash &txid, crypto::secret_key &tx_key) const;
 
@@ -689,6 +691,7 @@ namespace tools
     bool m_ask_password;
     uint32_t m_min_output_count;
     uint64_t m_min_output_value;
+    bool m_merge_destinations;
     NodeRPCProxy m_node_rpc_proxy;
     std::unordered_set<crypto::hash> m_scanned_pool_txs[2];
   };