wallet: transfer_selected_rct now also selects fake outs

src/cryptonote_core/blockchain.cpp

@@ -1753,11 +1753,11 @@ bool Blockchain::get_outs(const COMMAND_RPC_GET_OUTPUTS::request& req, COMMAND_R
   for (const auto &i: req.outputs)
   {
     // get tx_hash, tx_out_index from DB
-    crypto::public_key key = m_db->get_output_key(i.amount, i.index).pubkey;
+    const output_data_t &od = m_db->get_output_key(i.amount, i.index);
     tx_out_index toi = m_db->get_output_tx_and_index(i.amount, i.index);
     bool unlocked = is_tx_spendtime_unlocked(m_db->get_tx_unlock_time(toi.first));
 
-    res.outs.push_back({key, unlocked});
+    res.outs.push_back({od.pubkey, od.commitment, unlocked});
   }
   return true;
 }

src/rpc/core_rpc_server_commands_defs.h

@@ -41,7 +41,7 @@ namespace cryptonote
 #define CORE_RPC_STATUS_BUSY   "BUSY"
 #define CORE_RPC_STATUS_NOT_MINING "NOT MINING"
 
-#define CORE_RPC_VERSION 2
+#define CORE_RPC_VERSION 3
 
   struct COMMAND_RPC_GET_HEIGHT
   {
@@ -316,10 +316,12 @@ namespace cryptonote
     struct outkey
     {
       crypto::public_key key;
+      rct::key mask;
       bool unlocked;
 
       BEGIN_KV_SERIALIZE_MAP()
         KV_SERIALIZE_VAL_POD_AS_BLOB(key)
+        KV_SERIALIZE_VAL_POD_AS_BLOB(mask)
         KV_SERIALIZE(unlocked)
       END_KV_SERIALIZE_MAP()
     };

src/wallet/wallet2.cpp

@@ -29,6 +29,7 @@
 // Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
 
 #include <random>
+#include <tuple>
 #include <boost/archive/binary_oarchive.hpp>
 #include <boost/archive/binary_iarchive.hpp>
 
@@ -2655,40 +2656,12 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions(std::vector<crypto
   }
 }
 
-template<typename T>
-void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_entry>& dsts, const std::list<transfer_container::iterator> selected_transfers, size_t fake_outputs_count,
-  uint64_t unlock_time, uint64_t fee, const std::vector<uint8_t>& extra, T destination_split_strategy, const tx_dust_policy& dust_policy, cryptonote::transaction& tx, pending_tx &ptx)
+template<typename entry>
+void wallet2::get_outs(std::vector<std::vector<entry>> &outs, const std::list<transfer_container::iterator> &selected_transfers, size_t fake_outputs_count)
 {
-  using namespace cryptonote;
-  // throw if attempting a transaction with no destinations
-  THROW_WALLET_EXCEPTION_IF(dsts.empty(), error::zero_destination);
-
-  uint64_t upper_transaction_size_limit = get_upper_tranaction_size_limit();
-  uint64_t needed_money = fee;
-  LOG_PRINT_L2("transfer: starting with fee " << print_money (needed_money));
-
-  // calculate total amount being sent to all destinations
-  // throw if total amount overflows uint64_t
-  BOOST_FOREACH(auto& dt, dsts)
-  {
-    THROW_WALLET_EXCEPTION_IF(0 == dt.amount, error::zero_destination);
-    needed_money += dt.amount;
-    LOG_PRINT_L2("transfer: adding " << print_money(dt.amount) << ", for a total of " << print_money (needed_money));
-    THROW_WALLET_EXCEPTION_IF(needed_money < dt.amount, error::tx_sum_overflow, dsts, fee, m_testnet);
-  }
-
-  uint64_t found_money = 0;
-  BOOST_FOREACH(auto it, selected_transfers)
-  {
-    found_money += it->amount();
-  }
-
-  LOG_PRINT_L2("wanted " << print_money(needed_money) << ", found " << print_money(found_money) << ", fee " << print_money(fee));
-  THROW_WALLET_EXCEPTION_IF(found_money < needed_money, error::not_enough_money, found_money, needed_money - fee, fee);
-
-  typedef std::pair<uint64_t, crypto::public_key> entry;
-  std::vector<std::vector<entry>> outs;
-  if (fake_outputs_count)
+  LOG_PRINT_L2("fake_outputs_count: " << fake_outputs_count);
+  outs.clear();
+  if (fake_outputs_count > 0)
   {
     // get histogram for the amounts we need
     epee::json_rpc::request<cryptonote::COMMAND_RPC_GET_OUTPUT_HISTOGRAM::request> req_t = AUTO_VAL_INIT(req_t);
@@ -2698,7 +2671,7 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
     req_t.id = epee::serialization::storage_entry(0);
     req_t.method = "get_output_histogram";
     for(auto it: selected_transfers)
-      req_t.params.amounts.push_back(it->amount());
+      req_t.params.amounts.push_back(it->is_rct() ? 0 : it->amount());
     req_t.params.unlocked = true;
     bool r = net_utils::invoke_http_json_remote_command2(m_daemon_address + "/json_rpc", req_t, resp_t, m_http_client);
     m_daemon_rpc_mutex.unlock();
@@ -2708,12 +2681,15 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
 
     // we ask for more, to have spares if some outputs are still locked
     size_t requested_outputs_count = (size_t)((fake_outputs_count + 1) * 1.5 + 1);
+    LOG_PRINT_L2("requested_outputs_count: " << requested_outputs_count);
 
     // generate output indices to request
     COMMAND_RPC_GET_OUTPUTS::request req = AUTO_VAL_INIT(req);
     COMMAND_RPC_GET_OUTPUTS::response daemon_resp = AUTO_VAL_INIT(daemon_resp);
+
     for(transfer_container::iterator it: selected_transfers)
     {
+      const uint64_t amount = it->is_rct() ? 0 : it->amount();
       std::unordered_set<uint64_t> seen_indices;
       size_t start = req.outputs.size();
 
@@ -2722,28 +2698,30 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
       uint64_t num_outs = 0;
       for (auto he: resp_t.result.histogram)
       {
-        if (he.amount == it->amount())
+        if (he.amount == amount)
         {
           num_outs = he.instances;
           break;
         }
       }
+      LOG_PRINT_L1("" << num_outs << " outputs of size " << print_money(amount));
+
       if (num_outs <= requested_outputs_count)
       {
         for (uint64_t i = 0; i < num_outs; i++)
-          req.outputs.push_back({it->amount(), i});
+          req.outputs.push_back({amount, i});
         // duplicate to make up shortfall: this will be caught after the RPC call,
         // so we can also output the amounts for which we can't reach the required
         // mixin after checking the actual unlockedness
         for (uint64_t i = num_outs; i < requested_outputs_count; ++i)
-          req.outputs.push_back({it->amount(), num_outs - 1});
+          req.outputs.push_back({amount, num_outs - 1});
       }
       else
       {
         // start with real one
         uint64_t num_found = 1;
         seen_indices.emplace(it->m_global_output_index);
-        req.outputs.push_back({it->amount(), it->m_global_output_index});
+        req.outputs.push_back({amount, it->m_global_output_index});
 
         // while we still need more mixins
         while (num_found < requested_outputs_count)
@@ -2768,7 +2746,7 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
             continue;
           seen_indices.emplace(i);
 
-          req.outputs.push_back({it->amount(), i});
+          req.outputs.push_back({amount, i});
           ++num_found;
         }
       }
@@ -2778,6 +2756,9 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
           [](const COMMAND_RPC_GET_OUTPUTS::out &a, const COMMAND_RPC_GET_OUTPUTS::out &b) { return a.index < b.index; });
     }
 
+    for (auto i: req.outputs)
+      LOG_PRINT_L1("asking for output " << i.index << " for " << print_money(i.amount));
+
     // get the keys for those
     m_daemon_rpc_mutex.lock();
     r = epee::net_utils::invoke_http_bin_remote_command2(m_daemon_address + "/get_outs.bin", req, daemon_resp, m_http_client, 200000);
@@ -2796,9 +2777,10 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
     {
       outs.push_back(std::vector<entry>());
       outs.back().reserve(fake_outputs_count + 1);
+      const rct::key mask = it->is_rct() ? rct::commit(it->amount(), it->m_mask) : rct::zeroCommit(it->amount());
 
       // pick real out first (it will be sorted when done)
-      outs.back().push_back({it->m_global_output_index, boost::get<txout_to_key>(it->m_tx.vout[it->m_internal_output_index].target).key});
+      outs.back().push_back(std::make_tuple(it->m_global_output_index, boost::get<txout_to_key>(it->m_tx.vout[it->m_internal_output_index].target).key, mask));
 
       // then pick others in random order till we reach the required number
       // since we use an equiprobable pick here, we don't upset the triangular distribution
@@ -2817,7 +2799,7 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
           continue;
         if (o > 0 && daemon_resp.outs[i].key == daemon_resp.outs[i - 1].key) // don't add duplicates
           continue;
-        outs.back().push_back({req.outputs[i].index, daemon_resp.outs[i].key});
+        outs.back().push_back(std::make_tuple(req.outputs[i].index, daemon_resp.outs[i].key, daemon_resp.outs[i].mask));
       }
       if (outs.back().size() < fake_outputs_count + 1)
       {
@@ -2826,14 +2808,14 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
       else
       {
         // sort the subsection, so any spares are reset in order
-        std::sort(outs.back().begin(), outs.back().end(), [](const entry &a, const entry &b) { return a.first < b.first; });
+        std::sort(outs.back().begin(), outs.back().end(), [](const entry &a, const entry &b) { return std::get<0>(a) < std::get<0>(b); });
 
         // sanity check
         for (size_t n = 1; n < outs.back().size(); ++n)
         {
-          THROW_WALLET_EXCEPTION_IF(outs.back()[n].first == outs.back()[n-1].first, error::wallet_internal_error,
+          THROW_WALLET_EXCEPTION_IF(std::get<0>(outs.back()[n]) == std::get<0>(outs.back()[n-1]), error::wallet_internal_error,
               "Duplicate indices though we did not ask for any");
-          THROW_WALLET_EXCEPTION_IF(outs.back()[n].second == outs.back()[n-1].second, error::wallet_internal_error,
+          THROW_WALLET_EXCEPTION_IF(std::get<1>(outs.back()[n]) == std::get<1>(outs.back()[n-1]), error::wallet_internal_error,
               "Duplicate keys after we have weeded them out");
         }
       }
@@ -2846,10 +2828,47 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
     for (transfer_container::iterator it: selected_transfers)
     {
       std::vector<entry> v;
-      v.push_back({it->m_global_output_index, boost::get<txout_to_key>(it->m_tx.vout[it->m_internal_output_index].target).key});
+      const rct::key mask = it->is_rct() ? rct::commit(it->amount(), it->m_mask) : rct::zeroCommit(it->amount());
+      v.push_back(std::make_tuple(it->m_global_output_index, boost::get<txout_to_key>(it->m_tx.vout[it->m_internal_output_index].target).key, mask));
       outs.push_back(v);
     }
   }
+}
+
+template<typename T>
+void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_entry>& dsts, const std::list<transfer_container::iterator> selected_transfers, size_t fake_outputs_count,
+  uint64_t unlock_time, uint64_t fee, const std::vector<uint8_t>& extra, T destination_split_strategy, const tx_dust_policy& dust_policy, cryptonote::transaction& tx, pending_tx &ptx)
+{
+  using namespace cryptonote;
+  // throw if attempting a transaction with no destinations
+  THROW_WALLET_EXCEPTION_IF(dsts.empty(), error::zero_destination);
+
+  uint64_t upper_transaction_size_limit = get_upper_tranaction_size_limit();
+  uint64_t needed_money = fee;
+  LOG_PRINT_L2("transfer: starting with fee " << print_money (needed_money));
+
+  // calculate total amount being sent to all destinations
+  // throw if total amount overflows uint64_t
+  BOOST_FOREACH(auto& dt, dsts)
+  {
+    THROW_WALLET_EXCEPTION_IF(0 == dt.amount, error::zero_destination);
+    needed_money += dt.amount;
+    LOG_PRINT_L2("transfer: adding " << print_money(dt.amount) << ", for a total of " << print_money (needed_money));
+    THROW_WALLET_EXCEPTION_IF(needed_money < dt.amount, error::tx_sum_overflow, dsts, fee, m_testnet);
+  }
+
+  uint64_t found_money = 0;
+  BOOST_FOREACH(auto it, selected_transfers)
+  {
+    found_money += it->amount();
+  }
+
+  LOG_PRINT_L2("wanted " << print_money(needed_money) << ", found " << print_money(found_money) << ", fee " << print_money(fee));
+  THROW_WALLET_EXCEPTION_IF(found_money < needed_money, error::not_enough_money, found_money, needed_money - fee, fee);
+
+  typedef std::tuple<uint64_t, crypto::public_key, rct::key> entry;
+  std::vector<std::vector<entry>> outs;
+  get_outs(outs, selected_transfers, fake_outputs_count); // may throw
 
   //prepare inputs
   typedef cryptonote::tx_source_entry::output_entry tx_output_entry;
@@ -2867,9 +2886,9 @@ void wallet2::transfer_selected(const std::vector<cryptonote::tx_destination_ent
     for (size_t n = 0; n < fake_outputs_count + 1; ++n)
     {
       tx_output_entry oe;
-      oe.first = outs[out_index][n].first;
-      oe.second.dest = rct::pk2rct(outs[out_index][n].second);
-      oe.second.mask = rct::zeroCommit(td.amount());
+      oe.first = std::get<0>(outs[out_index][n]);
+      oe.second.dest = rct::pk2rct(std::get<1>(outs[out_index][n]));
+      oe.second.mask = std::get<2>(outs[out_index][n]);
 
       src.outputs.push_back(oe);
       ++i;
@@ -2976,76 +2995,13 @@ void wallet2::transfer_selected_rct(std::vector<cryptonote::tx_destination_entry
   LOG_PRINT_L2("wanted " << print_money(needed_money) << ", found " << print_money(found_money) << ", fee " << print_money(fee));
   THROW_WALLET_EXCEPTION_IF(found_money < needed_money, error::not_enough_money, found_money, needed_money - fee, fee);
 
-  typedef cryptonote::tx_source_entry::output_entry tx_output_entry;
-
-  std::vector<size_t> selected_transfer_to_daemon_resp;
-  COMMAND_RPC_GET_RANDOM_RCT_OUTPUTS::request rct_req = AUTO_VAL_INIT(rct_req);
-  COMMAND_RPC_GET_RANDOM_RCT_OUTPUTS::response rct_daemon_resp = AUTO_VAL_INIT(rct_daemon_resp);
-  COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request daemon_req = AUTO_VAL_INIT(daemon_req);
-  COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response daemon_resp = AUTO_VAL_INIT(daemon_resp);
-  if(fake_outputs_count)
-  {
-    rct_req.outs_count = 0;
-    size_t n_rct_inputs = 0;
-    BOOST_FOREACH(transfer_container::iterator it, selected_transfers)
-    {
-      THROW_WALLET_EXCEPTION_IF(it->m_tx.vout.size() <= it->m_internal_output_index, error::wallet_internal_error,
-        "m_internal_output_index = " + std::to_string(it->m_internal_output_index) +
-        " is greater or equal to outputs count = " + std::to_string(it->m_tx.vout.size()));
-      if (it->is_rct())
-        ++n_rct_inputs;
-      else
-        daemon_req.amounts.push_back(it->amount());
-      selected_transfer_to_daemon_resp.push_back(daemon_req.amounts.size() - 1);
-    }
-    size_t n_amounts_requested = daemon_req.amounts.size();
-
-    rct_req.outs_count = n_rct_inputs * (fake_outputs_count + 1);
-    if (rct_req.outs_count > 0)
-    {
-      LOG_PRINT_L2("We need RCT fake outs for " << n_rct_inputs << " inputs");
-      rct_req.outs_count = n_rct_inputs * (fake_outputs_count + 1); // add one to make possible (if need) to skip real output key
-      m_daemon_rpc_mutex.lock();
-      bool r = epee::net_utils::invoke_http_bin_remote_command2(m_daemon_address + "/getrandom_rctouts.bin", rct_req, rct_daemon_resp, m_http_client, 200000);
-      m_daemon_rpc_mutex.unlock();
-      THROW_WALLET_EXCEPTION_IF(!r, error::no_connection_to_daemon, "getrandom_rctouts.bin");
-      THROW_WALLET_EXCEPTION_IF(rct_daemon_resp.status == CORE_RPC_STATUS_BUSY, error::daemon_busy, "getrandom_rctouts.bin");
-      THROW_WALLET_EXCEPTION_IF(rct_daemon_resp.status != CORE_RPC_STATUS_OK, error::get_random_outs_error, rct_daemon_resp.status);
-      THROW_WALLET_EXCEPTION_IF(rct_daemon_resp.outs.size() != n_rct_inputs * (fake_outputs_count + 1), error::wallet_internal_error,
-        "daemon returned wrong response for getrandom_rctouts.bin, wrong amounts count = " +
-        std::to_string(daemon_resp.outs.size()) + ", expected " +  std::to_string(n_rct_inputs * (fake_outputs_count + 1)));
-    }
-    if (!daemon_req.amounts.empty())
-    {
-      LOG_PRINT_L2("We need non-RCT fake outs for " << daemon_req.amounts.size() << " inputs");
-      daemon_req.outs_count = fake_outputs_count + 1; // add one to make possible (if need) to skip real output key
-      m_daemon_rpc_mutex.lock();
-      bool r = epee::net_utils::invoke_http_bin_remote_command2(m_daemon_address + "/getrandom_outs.bin", daemon_req, daemon_resp, m_http_client, 200000);
-      m_daemon_rpc_mutex.unlock();
-      THROW_WALLET_EXCEPTION_IF(!r, error::no_connection_to_daemon, "getrandom_outs.bin");
-      THROW_WALLET_EXCEPTION_IF(daemon_resp.status == CORE_RPC_STATUS_BUSY, error::daemon_busy, "getrandom_outs.bin");
-      THROW_WALLET_EXCEPTION_IF(daemon_resp.status != CORE_RPC_STATUS_OK, error::get_random_outs_error, daemon_resp.status);
-      THROW_WALLET_EXCEPTION_IF(daemon_resp.outs.size() != n_amounts_requested, error::wallet_internal_error,
-        "daemon returned wrong response for getrandom_outs.bin, wrong amounts count = " +
-        std::to_string(daemon_resp.outs.size()) + ", expected " +  std::to_string(n_amounts_requested));
-
-      std::unordered_map<uint64_t, uint64_t> scanty_outs;
-      BOOST_FOREACH(COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& amount_outs, daemon_resp.outs)
-      {
-        if (amount_outs.outs.size() < fake_outputs_count)
-        {
-          scanty_outs[amount_outs.amount] = amount_outs.outs.size();
-        }
-      }
-      THROW_WALLET_EXCEPTION_IF(!scanty_outs.empty(), error::not_enough_outs_to_mix, scanty_outs, fake_outputs_count);
-    }
-  }
+  typedef std::tuple<uint64_t, crypto::public_key, rct::key> entry;
+  std::vector<std::vector<entry>> outs;
+  get_outs(outs, selected_transfers, fake_outputs_count); // may throw
 
   //prepare inputs
-  size_t i = 0;
+  size_t i = 0, out_index = 0;
   std::vector<cryptonote::tx_source_entry> sources;
-  rct_daemon_resp.outs.sort([](const COMMAND_RPC_GET_RANDOM_RCT_OUTPUTS::out_entry& a, const COMMAND_RPC_GET_RANDOM_RCT_OUTPUTS::out_entry& b){return a.global_amount_index < b.global_amount_index;});
-  std::list<COMMAND_RPC_GET_RANDOM_RCT_OUTPUTS::out_entry>::const_iterator rctit = rct_daemon_resp.outs.begin();
   BOOST_FOREACH(transfer_container::iterator it, selected_transfers)
   {
     sources.resize(sources.size()+1);
@@ -3054,76 +3010,37 @@ void wallet2::transfer_selected_rct(std::vector<cryptonote::tx_destination_entry
     src.amount = td.amount();
     src.rct = td.is_rct();
     //paste mixin transaction
-    if(it->is_rct())
-    {
-      while (src.outputs.size() < fake_outputs_count)
-      {
-        THROW_WALLET_EXCEPTION_IF(rctit == rct_daemon_resp.outs.end(), error::wallet_internal_error, "Out of rct inputs");
-        // check if we have the daemon supplied output in our real ones
-        bool found = false;
-        BOOST_FOREACH(transfer_container::iterator checkit, selected_transfers)
-        {
-          if (checkit->m_global_output_index == rctit->global_amount_index && checkit->m_tx.vout[checkit->m_internal_output_index].amount == rctit->amount)
-          {
-            found = true;
-            break;
-          }
-        }
-        if(found)
-        {
-          ++rctit;
-          continue;
-        }
-        tx_output_entry oe;
-        oe.first = rctit->global_amount_index;
-        oe.second.dest = rct::pk2rct(rctit->out_key);
-        oe.second.mask = rctit->commitment;
-        ++rctit;
-        src.outputs.push_back(oe);
-      }
-    }
-    else
+
+    typedef cryptonote::tx_source_entry::output_entry tx_output_entry;
+    for (size_t n = 0; n < fake_outputs_count + 1; ++n)
     {
-      typedef COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::out_entry out_entry;
-      typedef cryptonote::tx_source_entry::output_entry tx_output_entry;
-
-      size_t idx = selected_transfer_to_daemon_resp[i];
-      THROW_WALLET_EXCEPTION_IF(daemon_req.amounts.size() != daemon_resp.outs.size(), error::wallet_internal_error, "Bad amounts/out size");
-      THROW_WALLET_EXCEPTION_IF(idx >= daemon_resp.outs.size(), error::wallet_internal_error, "Bad mapping to daemon_resp.outs");
-      THROW_WALLET_EXCEPTION_IF(td.amount() != daemon_req.amounts[idx], error::wallet_internal_error, "Bad mapping to daemon_resp.outs/amounts");
-      daemon_resp.outs[idx].outs.sort([](const out_entry& a, const out_entry& b){return a.global_amount_index < b.global_amount_index;});
-      BOOST_FOREACH(out_entry& daemon_oe, daemon_resp.outs[idx].outs)
-      {
-        if(td.m_global_output_index == daemon_oe.global_amount_index)
-          continue;
-        tx_output_entry oe;
-        oe.first = daemon_oe.global_amount_index;
-        oe.second.dest = rct::pk2rct(daemon_oe.out_key);
-        oe.second.mask = rct::zeroCommit(td.amount());
-        src.outputs.push_back(oe);
-        if(src.outputs.size() >= fake_outputs_count)
-          break;
-      }
+      tx_output_entry oe;
+      oe.first = std::get<0>(outs[out_index][n]);
+      oe.second.dest = rct::pk2rct(std::get<1>(outs[out_index][n]));
+      oe.second.mask = std::get<2>(outs[out_index][n]);
+      src.outputs.push_back(oe);
     }
+    ++i;
 
     //paste real transaction to the random index
-    auto it_to_insert = std::find_if(src.outputs.begin(), src.outputs.end(), [&](const tx_output_entry& a)
+    auto it_to_replace = std::find_if(src.outputs.begin(), src.outputs.end(), [&](const tx_output_entry& a)
     {
-      return a.first >= td.m_global_output_index;
+      return a.first == td.m_global_output_index;
     });
-    //size_t real_index = src.outputs.size() ? (rand() % src.outputs.size() ):0;
-// TODO: same index (for now)
+    THROW_WALLET_EXCEPTION_IF(it_to_replace == src.outputs.end(), error::wallet_internal_error,
+        "real output not found");
+
     tx_output_entry real_oe;
     real_oe.first = td.m_global_output_index;
     real_oe.second.dest = rct::pk2rct(boost::get<txout_to_key>(td.m_tx.vout[td.m_internal_output_index].target).key);
     real_oe.second.mask = rct::commit(td.amount(), td.m_mask);
-    auto interted_it = src.outputs.insert(it_to_insert, real_oe);
+    *it_to_replace = real_oe;
     src.real_out_tx_key = get_tx_pub_key_from_extra(td.m_tx);
-    src.real_output = interted_it - src.outputs.begin();
+    src.real_output = it_to_replace - src.outputs.begin();
     src.real_output_in_tx_index = td.m_internal_output_index;
     src.mask = td.m_mask;
     detail::print_source_entry(src);
-    ++i;
+    ++out_index;
   }
 
   cryptonote::tx_destination_entry change_dts = AUTO_VAL_INIT(change_dts);

src/wallet/wallet2.h

@@ -463,6 +463,8 @@ namespace tools
     std::vector<size_t> pick_prefered_rct_inputs(uint64_t needed_money) const;
     void set_spent(transfer_details &td, uint64_t height);
     void set_unspent(transfer_details &td);
+    template<typename entry>
+    void get_outs(std::vector<std::vector<entry>> &outs, const std::list<transfer_container::iterator> &selected_transfers, size_t fake_outputs_count);
 
     cryptonote::account_base m_account;
     std::string m_daemon_address;