16 files changed, 216 insertions, 62 deletions
diff --git a/src/blockchain_db/blockchain_db.h b/src/blockchain_db/blockchain_db.h
index 838385e8a..ca097fad2 100644
--- a/src/blockchain_db/blockchain_db.h
+++ b/src/blockchain_db/blockchain_db.h
@@ -147,8 +147,9 @@ struct txpool_tx_meta_t
   uint8_t kept_by_block;
   uint8_t relayed;
   uint8_t do_not_relay;
+  uint8_t double_spend_seen: 1;
 
-  uint8_t padding[77]; // till 192 bytes
+  uint8_t padding[76]; // till 192 bytes
 };
 
 #define DBF_SAFE       1
diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 9d89c6280..0296b4908 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -3166,9 +3166,9 @@ bool Blockchain::flush_txes_from_pool(const std::list<crypto::hash> &txids)
     cryptonote::transaction tx;
     size_t blob_size;
     uint64_t fee;
-    bool relayed, do_not_relay;
+    bool relayed, do_not_relay, double_spend_seen;
     MINFO("Removing txid " << txid << " from the pool");
-    if(m_tx_pool.have_tx(txid) && !m_tx_pool.take_tx(txid, tx, blob_size, fee, relayed, do_not_relay))
+    if(m_tx_pool.have_tx(txid) && !m_tx_pool.take_tx(txid, tx, blob_size, fee, relayed, do_not_relay, double_spend_seen))
     {
       MERROR("Failed to remove txid " << txid << " from the pool");
       res = false;
@@ -3351,7 +3351,7 @@ leave:
     transaction tx;
     size_t blob_size = 0;
     uint64_t fee = 0;
-    bool relayed = false, do_not_relay = false;
+    bool relayed = false, do_not_relay = false, double_spend_seen = false;
     TIME_MEASURE_START(aa);
 
 // XXX old code does not check whether tx exists
@@ -3368,7 +3368,7 @@ leave:
     TIME_MEASURE_START(bb);
 
     // get transaction with hash <tx_id> from tx_pool
-    if(!m_tx_pool.take_tx(tx_id, tx, blob_size, fee, relayed, do_not_relay))
+    if(!m_tx_pool.take_tx(tx_id, tx, blob_size, fee, relayed, do_not_relay, double_spend_seen))
     {
       MERROR_VER("Block with id: " << id  << " has at least one unknown transaction with id: " << tx_id);
       bvc.m_verifivation_failed = true;
@@ -4381,12 +4381,12 @@ void Blockchain::load_compiled_in_block_hashes()
 
         size_t blob_size;
         uint64_t fee;
-        bool relayed, do_not_relay;
+        bool relayed, do_not_relay, double_spend_seen;
         transaction pool_tx;
         for(const transaction &tx : txs)
         {
           crypto::hash tx_hash = get_transaction_hash(tx);
-          m_tx_pool.take_tx(tx_hash, pool_tx, blob_size, fee, relayed, do_not_relay);
+          m_tx_pool.take_tx(tx_hash, pool_tx, blob_size, fee, relayed, do_not_relay, double_spend_seen);
         }
       }
     }
diff --git a/src/cryptonote_core/tx_pool.cpp b/src/cryptonote_core/tx_pool.cpp
index 9071c330c..40691f6a3 100644
--- a/src/cryptonote_core/tx_pool.cpp
+++ b/src/cryptonote_core/tx_pool.cpp
@@ -187,6 +187,7 @@ namespace cryptonote
     {
       if(have_tx_keyimges_as_spent(tx))
       {
+        mark_double_spend(tx);
         LOG_PRINT_L1("Transaction with id= "<< id << " used already spent key images");
         tvc.m_verifivation_failed = true;
         tvc.m_double_spend = true;
@@ -228,6 +229,7 @@ namespace cryptonote
         meta.last_relayed_time = time(NULL);
         meta.relayed = relayed;
         meta.do_not_relay = do_not_relay;
+        meta.double_spend_seen = have_tx_keyimges_as_spent(tx);
         memset(meta.padding, 0, sizeof(meta.padding));
         try
         {
@@ -266,6 +268,7 @@ namespace cryptonote
       meta.last_relayed_time = time(NULL);
       meta.relayed = relayed;
       meta.do_not_relay = do_not_relay;
+      meta.double_spend_seen = false;
       memset(meta.padding, 0, sizeof(meta.padding));
 
       try
@@ -354,7 +357,7 @@ namespace cryptonote
     return true;
   }
   //---------------------------------------------------------------------------------
-  bool tx_memory_pool::take_tx(const crypto::hash &id, transaction &tx, size_t& blob_size, uint64_t& fee, bool &relayed, bool &do_not_relay)
+  bool tx_memory_pool::take_tx(const crypto::hash &id, transaction &tx, size_t& blob_size, uint64_t& fee, bool &relayed, bool &do_not_relay, bool &double_spend_seen)
   {
     CRITICAL_REGION_LOCAL(m_transactions_lock);
     CRITICAL_REGION_LOCAL1(m_blockchain);
@@ -377,6 +380,7 @@ namespace cryptonote
       fee = meta.fee;
       relayed = meta.relayed;
       do_not_relay = meta.do_not_relay;
+      double_spend_seen = meta.double_spend_seen;
 
       // remove first, in case this throws, so key images aren't removed
       m_blockchain.remove_txpool_tx(id);
@@ -594,6 +598,8 @@ namespace cryptonote
       uint64_t age = now - meta.receive_time + (now == meta.receive_time);
       agebytes[age].txs++;
       agebytes[age].bytes += meta.blob_size;
+      if (meta.double_spend_seen)
+        ++stats.num_double_spends;
       return true;
     });
     stats.bytes_med = epee::misc_utils::median(sizes);
@@ -649,6 +655,7 @@ namespace cryptonote
     m_blockchain.for_all_txpool_txes([&tx_infos, key_image_infos](const crypto::hash &txid, const txpool_tx_meta_t &meta, const cryptonote::blobdata *bd){
       tx_info txi;
       txi.id_hash = epee::string_tools::pod_to_hex(txid);
+      txi.tx_blob = *bd;
       transaction tx;
       if (!parse_and_validate_tx_from_blob(*bd, tx))
       {
@@ -668,6 +675,7 @@ namespace cryptonote
       txi.relayed = meta.relayed;
       txi.last_relayed_time = meta.last_relayed_time;
       txi.do_not_relay = meta.do_not_relay;
+      txi.double_spend_seen = meta.double_spend_seen;
       tx_infos.push_back(txi);
       return true;
     }, true);
@@ -712,6 +720,7 @@ namespace cryptonote
       txi.relayed = meta.relayed;
       txi.last_relayed_time = meta.last_relayed_time;
       txi.do_not_relay = meta.do_not_relay;
+      txi.double_spend_seen = meta.double_spend_seen;
       tx_infos.push_back(txi);
       return true;
     }, true);
@@ -843,7 +852,10 @@ namespace cryptonote
     }
     //if we here, transaction seems valid, but, anyway, check for key_images collisions with blockchain, just to be sure
     if(m_blockchain.have_tx_keyimges_as_spent(tx))
+    {
+      txd.double_spend_seen = true;
       return false;
+    }
 
     //transaction is ok.
     return true;
@@ -871,6 +883,39 @@ namespace cryptonote
     return true;
   }
   //---------------------------------------------------------------------------------
+  void tx_memory_pool::mark_double_spend(const transaction &tx)
+  {
+    CRITICAL_REGION_LOCAL(m_transactions_lock);
+    CRITICAL_REGION_LOCAL1(m_blockchain);
+    LockedTXN lock(m_blockchain);
+    for(size_t i = 0; i!= tx.vin.size(); i++)
+    {
+      CHECKED_GET_SPECIFIC_VARIANT(tx.vin[i], const txin_to_key, itk, void());
+      const key_images_container::const_iterator it = m_spent_key_images.find(itk.k_image);
+      if (it != m_spent_key_images.end())
+      {
+        for (const crypto::hash &txid: it->second)
+        {
+          txpool_tx_meta_t meta = m_blockchain.get_txpool_tx_meta(txid);
+          if (!meta.double_spend_seen)
+          {
+            MDEBUG("Marking " << txid << " as double spending " << itk.k_image);
+            meta.double_spend_seen = true;
+            try
+            {
+              m_blockchain.update_txpool_tx(txid, meta);
+            }
+            catch (const std::exception &e)
+            {
+              MERROR("Failed to update tx meta: " << e.what());
+              // continue, not fatal
+            }
+          }
+        }
+      }
+    }
+  }
+  //---------------------------------------------------------------------------------
   std::string tx_memory_pool::print_pool(bool short_format) const
   {
     std::stringstream ss;
@@ -890,6 +935,7 @@ namespace cryptonote
       ss << "blob_size: " << meta.blob_size << std::endl
         << "fee: " << print_money(meta.fee) << std::endl
         << "kept_by_block: " << (meta.kept_by_block ? 'T' : 'F') << std::endl
+        << "double_spend_seen: " << (meta.double_spend_seen ? 'T' : 'F') << std::endl
         << "max_used_block_height: " << meta.max_used_block_height << std::endl
         << "max_used_block_id: " << meta.max_used_block_id << std::endl
         << "last_failed_height: " << meta.last_failed_height << std::endl
diff --git a/src/cryptonote_core/tx_pool.h b/src/cryptonote_core/tx_pool.h
index 3e4ccb338..8a0106638 100644
--- a/src/cryptonote_core/tx_pool.h
+++ b/src/cryptonote_core/tx_pool.h
@@ -137,10 +137,11 @@ namespace cryptonote
      * @param fee the transaction fee
      * @param relayed return-by-reference was transaction relayed to us by the network?
      * @param do_not_relay return-by-reference is transaction not to be relayed to the network?
+     * @param double_spend_seen return-by-reference was a double spend seen for that transaction?
      *
      * @return true unless the transaction cannot be found in the pool
      */
-    bool take_tx(const crypto::hash &id, transaction &tx, size_t& blob_size, uint64_t& fee, bool &relayed, bool &do_not_relay);
+    bool take_tx(const crypto::hash &id, transaction &tx, size_t& blob_size, uint64_t& fee, bool &relayed, bool &do_not_relay, bool &double_spend_seen);
 
     /**
      * @brief checks if the pool has a transaction with the given hash
@@ -391,6 +392,8 @@ namespace cryptonote
       time_t last_relayed_time;  //!< the last time the transaction was relayed to the network
       bool relayed;  //!< whether or not the transaction has been relayed to the network
       bool do_not_relay; //!< to avoid relay this transaction to the network
+
+      bool double_spend_seen; //!< true iff another tx was seen double spending this one
     };
 
   private:
@@ -478,6 +481,11 @@ namespace cryptonote
      */
     bool is_transaction_ready_to_go(txpool_tx_meta_t& txd, transaction &tx) const;
 
+    /**
+     * @brief mark all transactions double spending the one passed
+     */
+    void mark_double_spend(const transaction &tx);
+
     //TODO: confirm the below comments and investigate whether or not this
     //      is the desired behavior
     //! map key images to transactions which spent them
diff --git a/src/daemon/rpc_command_executor.cpp b/src/daemon/rpc_command_executor.cpp
index 2c11dcb31..6733d66c2 100644
--- a/src/daemon/rpc_command_executor.cpp
+++ b/src/daemon/rpc_command_executor.cpp
@@ -840,6 +840,7 @@ bool t_rpc_command_executor::print_transaction_pool_long() {
                           << "relayed: " << [&](const cryptonote::tx_info &tx_info)->std::string { if (!tx_info.relayed) return "no"; return boost::lexical_cast<std::string>(tx_info.last_relayed_time) + " (" + get_human_time_ago(tx_info.last_relayed_time, now) + ")"; } (tx_info) << std::endl
                           << "do_not_relay: " << (tx_info.do_not_relay ? 'T' : 'F')  << std::endl
                           << "kept_by_block: " << (tx_info.kept_by_block ? 'T' : 'F') << std::endl
+                          << "double_spend_seen: " << (tx_info.double_spend_seen ? 'T' : 'F')  << std::endl
                           << "max_used_block_height: " << tx_info.max_used_block_height << std::endl
                           << "max_used_block_id: " << tx_info.max_used_block_id_hash << std::endl
                           << "last_failed_height: " << tx_info.last_failed_height << std::endl
@@ -922,6 +923,7 @@ bool t_rpc_command_executor::print_transaction_pool_short() {
                           << "relayed: " << [&](const cryptonote::tx_info &tx_info)->std::string { if (!tx_info.relayed) return "no"; return boost::lexical_cast<std::string>(tx_info.last_relayed_time) + " (" + get_human_time_ago(tx_info.last_relayed_time, now) + ")"; } (tx_info) << std::endl
                           << "do_not_relay: " << (tx_info.do_not_relay ? 'T' : 'F')  << std::endl
                           << "kept_by_block: " << (tx_info.kept_by_block ? 'T' : 'F') << std::endl
+                          << "double_spend_seen: " << (tx_info.double_spend_seen ? 'T' : 'F') << std::endl
                           << "max_used_block_height: " << tx_info.max_used_block_height << std::endl
                           << "max_used_block_id: " << tx_info.max_used_block_id_hash << std::endl
                           << "last_failed_height: " << tx_info.last_failed_height << std::endl
@@ -984,7 +986,7 @@ bool t_rpc_command_executor::print_transaction_pool_stats() {
 
   tools::msg_writer() << n_transactions << " tx(es), " << res.pool_stats.bytes_total << " bytes total (min " << res.pool_stats.bytes_min << ", max " << res.pool_stats.bytes_max << ", avg " << avg_bytes << ", median " << res.pool_stats.bytes_med << ")" << std::endl
       << "fees " << cryptonote::print_money(res.pool_stats.fee_total) << " (avg " << cryptonote::print_money(n_transactions ? res.pool_stats.fee_total / n_transactions : 0) << " per tx" << ", " << cryptonote::print_money(res.pool_stats.bytes_total ? res.pool_stats.fee_total / res.pool_stats.bytes_total : 0) << " per byte)" << std::endl
-      << res.pool_stats.num_not_relayed << " not relayed, " << res.pool_stats.num_failing << " failing, " << res.pool_stats.num_10m << " older than 10 minutes (oldest " << (res.pool_stats.oldest == 0 ? "-" : get_human_time_ago(res.pool_stats.oldest, now)) << "), " << backlog_message;
+      << res.pool_stats.num_double_spends << " double spends, " << res.pool_stats.num_not_relayed << " not relayed, " << res.pool_stats.num_failing << " failing, " << res.pool_stats.num_10m << " older than 10 minutes (oldest " << (res.pool_stats.oldest == 0 ? "-" : get_human_time_ago(res.pool_stats.oldest, now)) << "), " << backlog_message;
 
   if (n_transactions > 1 && res.pool_stats.histo.size())
   {
diff --git a/src/rpc/core_rpc_server.cpp b/src/rpc/core_rpc_server.cpp
index b3ce30d0c..e653b9520 100755
--- a/src/rpc/core_rpc_server.cpp
+++ b/src/rpc/core_rpc_server.cpp
@@ -478,15 +478,17 @@ namespace cryptonote
     // try the pool for any missing txes
     size_t found_in_pool = 0;
     std::unordered_set<crypto::hash> pool_tx_hashes;
+    std::unordered_map<crypto::hash, bool> double_spend_seen;
     if (!missed_txs.empty())
     {
-      std::list<transaction> pool_txs;
-      bool r = m_core.get_pool_transactions(pool_txs);
+      std::vector<tx_info> pool_tx_info;
+      std::vector<spent_key_image_info> pool_key_image_info;
+      bool r = m_core.get_pool_transactions_and_spent_keys_info(pool_tx_info, pool_key_image_info);
       if(r)
       {
         // sort to match original request
         std::list<transaction> sorted_txs;
-        std::list<cryptonote::transaction>::const_iterator i;
+        std::vector<tx_info>::const_iterator i;
         for (const crypto::hash &h: vh)
         {
           if (std::find(missed_txs.begin(), missed_txs.end(), h) == missed_txs.end())
@@ -500,11 +502,26 @@ namespace cryptonote
             sorted_txs.push_back(std::move(txs.front()));
             txs.pop_front();
           }
-          else if ((i = std::find_if(pool_txs.begin(), pool_txs.end(), [h](cryptonote::transaction &tx) { return h == cryptonote::get_transaction_hash(tx); })) != pool_txs.end())
+          else if ((i = std::find_if(pool_tx_info.begin(), pool_tx_info.end(), [h](const tx_info &txi) { return epee::string_tools::pod_to_hex(h) == txi.id_hash; })) != pool_tx_info.end())
           {
-            sorted_txs.push_back(*i);
+            cryptonote::transaction tx;
+            if (!cryptonote::parse_and_validate_tx_from_blob(i->tx_blob, tx))
+            {
+              res.status = "Failed to parse and validate tx from blob";
+              return true;
+            }
+            sorted_txs.push_back(tx);
             missed_txs.remove(h);
             pool_tx_hashes.insert(h);
+            const std::string hash_string = epee::string_tools::pod_to_hex(h);
+            for (const auto &ti: pool_tx_info)
+            {
+              if (ti.id_hash == hash_string)
+              {
+                double_spend_seen.insert(std::make_pair(h, ti.double_spend_seen));
+                break;
+              }
+            }
             ++found_in_pool;
           }
         }
@@ -530,11 +547,21 @@ namespace cryptonote
       if (e.in_pool)
       {
         e.block_height = e.block_timestamp = std::numeric_limits<uint64_t>::max();
+        if (double_spend_seen.find(tx_hash) != double_spend_seen.end())
+        {
+          e.double_spend_seen = double_spend_seen[tx_hash];
+        }
+        else
+        {
+          MERROR("Failed to determine double spend status for " << tx_hash);
+          e.double_spend_seen = false;
+        }
       }
       else
       {
         e.block_height = m_core.get_blockchain_storage().get_db().get_tx_block_height(tx_hash);
         e.block_timestamp = m_core.get_blockchain_storage().get_db().get_block_timestamp(e.block_height);
+        e.double_spend_seen = false;
       }
 
       // fill up old style responses too, in case an old wallet asks
diff --git a/src/rpc/core_rpc_server_commands_defs.h b/src/rpc/core_rpc_server_commands_defs.h
index ee2a79eb4..57799bb81 100644
--- a/src/rpc/core_rpc_server_commands_defs.h
+++ b/src/rpc/core_rpc_server_commands_defs.h
@@ -566,6 +566,7 @@ namespace cryptonote
       std::string as_hex;
       std::string as_json;
       bool in_pool;
+      bool double_spend_seen;
       uint64_t block_height;
       uint64_t block_timestamp;
       std::vector<uint64_t> output_indices;
@@ -575,6 +576,7 @@ namespace cryptonote
         KV_SERIALIZE(as_hex)
         KV_SERIALIZE(as_json)
         KV_SERIALIZE(in_pool)
+        KV_SERIALIZE(double_spend_seen)
         KV_SERIALIZE(block_height)
         KV_SERIALIZE(block_timestamp)
         KV_SERIALIZE(output_indices)
@@ -1357,6 +1359,8 @@ namespace cryptonote
     bool relayed;
     uint64_t last_relayed_time;
     bool do_not_relay;
+    bool double_spend_seen;
+    std::string tx_blob;
 
     BEGIN_KV_SERIALIZE_MAP()
       KV_SERIALIZE(id_hash)
@@ -1372,6 +1376,8 @@ namespace cryptonote
       KV_SERIALIZE(relayed)
       KV_SERIALIZE(last_relayed_time)
       KV_SERIALIZE(do_not_relay)
+      KV_SERIALIZE(double_spend_seen)
+      KV_SERIALIZE(tx_blob)
     END_KV_SERIALIZE_MAP()
   };
 
@@ -1480,6 +1486,7 @@ namespace cryptonote
     uint32_t num_not_relayed;
     uint64_t histo_98pc;
     std::vector<txpool_histo> histo;
+    uint32_t num_double_spends;
 
     BEGIN_KV_SERIALIZE_MAP()
       KV_SERIALIZE(bytes_total)
@@ -1494,6 +1501,7 @@ namespace cryptonote
       KV_SERIALIZE(num_not_relayed)
       KV_SERIALIZE(histo_98pc)
       KV_SERIALIZE_CONTAINER_POD_AS_BLOB(histo)
+      KV_SERIALIZE(num_double_spends)
     END_KV_SERIALIZE_MAP()
   };
 
diff --git a/src/rpc/message_data_structs.h b/src/rpc/message_data_structs.h
index 00f1e0caa..581048eaf 100644
--- a/src/rpc/message_data_structs.h
+++ b/src/rpc/message_data_structs.h
@@ -95,6 +95,7 @@ namespace rpc
     uint64_t last_relayed_time;
     bool relayed;
     bool do_not_relay;
+    bool double_spend_seen;
   };
 
   typedef std::unordered_map<crypto::key_image, std::vector<crypto::hash> > key_images_with_tx_hashes;
diff --git a/src/serialization/json_object.cpp b/src/serialization/json_object.cpp
index a40821d19..6e6e51528 100644
--- a/src/serialization/json_object.cpp
+++ b/src/serialization/json_object.cpp
@@ -755,6 +755,7 @@ void toJsonValue(rapidjson::Document& doc, const cryptonote::rpc::tx_in_pool& tx
   INSERT_INTO_JSON_OBJECT(val, doc, last_relayed_time, tx.last_relayed_time);
   INSERT_INTO_JSON_OBJECT(val, doc, relayed, tx.relayed);
   INSERT_INTO_JSON_OBJECT(val, doc, do_not_relay, tx.do_not_relay);
+  INSERT_INTO_JSON_OBJECT(val, doc, double_spend_seen, tx.double_spend_seen);
 }
 
 
@@ -777,6 +778,7 @@ void fromJsonValue(const rapidjson::Value& val, cryptonote::rpc::tx_in_pool& tx)
   GET_FROM_JSON_OBJECT(val, tx.last_relayed_time, last_relayed_time);
   GET_FROM_JSON_OBJECT(val, tx.relayed, relayed);
   GET_FROM_JSON_OBJECT(val, tx.do_not_relay, do_not_relay);
+  GET_FROM_JSON_OBJECT(val, tx.double_spend_seen, double_spend_seen);
 }
 
 void toJsonValue(rapidjson::Document& doc, const cryptonote::rpc::hard_fork_info& info, rapidjson::Value& val)
diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index c936f481e..d099d22e7 100644
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -4415,15 +4415,18 @@ bool simple_wallet::show_transfers(const std::vector<std::string> &args_)
     try
     {
       m_wallet->update_pool_state();
-      std::list<std::pair<crypto::hash, tools::wallet2::payment_details>> payments;
+      std::list<std::pair<crypto::hash, tools::wallet2::pool_payment_details>> payments;
       m_wallet->get_unconfirmed_payments(payments, m_current_subaddress_account, subaddr_indices);
-      for (std::list<std::pair<crypto::hash, tools::wallet2::payment_details>>::const_iterator i = payments.begin(); i != payments.end(); ++i) {
-        const tools::wallet2::payment_details &pd = i->second;
+      for (std::list<std::pair<crypto::hash, tools::wallet2::pool_payment_details>>::const_iterator i = payments.begin(); i != payments.end(); ++i) {
+        const tools::wallet2::payment_details &pd = i->second.m_pd;
         std::string payment_id = string_tools::pod_to_hex(i->first);
         if (payment_id.substr(16).find_first_not_of('0') == std::string::npos)
           payment_id = payment_id.substr(0,16);
         std::string note = m_wallet->get_tx_note(pd.m_tx_hash);
-        message_writer() << (boost::format("%8.8s %6.6s %16.16s %20.20s %s %s %d %s %s") % "pool" % "in" % get_human_readable_timestamp(pd.m_timestamp) % print_money(pd.m_amount) % string_tools::pod_to_hex(pd.m_tx_hash) % payment_id % pd.m_subaddr_index.minor % "-" % note).str();
+        std::string double_spend_note;
+        if (i->second.m_double_spend_seen)
+          double_spend_note = tr("[Double spend seen on the network: this transaction may or may not end up being mined] ");
+        message_writer() << (boost::format("%8.8s %6.6s %16.16s %20.20s %s %s %d %s %s%s") % "pool" % "in" % get_human_readable_timestamp(pd.m_timestamp) % print_money(pd.m_amount) % string_tools::pod_to_hex(pd.m_tx_hash) % payment_id % pd.m_subaddr_index.minor % "-" % note % double_spend_note).str();
       }
     }
     catch (const std::exception& e)
@@ -5439,10 +5442,10 @@ bool simple_wallet::show_transfer(const std::vector<std::string> &args)
   try
   {
     m_wallet->update_pool_state();
-    std::list<std::pair<crypto::hash, tools::wallet2::payment_details>> pool_payments;
+    std::list<std::pair<crypto::hash, tools::wallet2::pool_payment_details>> pool_payments;
     m_wallet->get_unconfirmed_payments(pool_payments);
-    for (std::list<std::pair<crypto::hash, tools::wallet2::payment_details>>::const_iterator i = pool_payments.begin(); i != pool_payments.end(); ++i) {
-      const tools::wallet2::payment_details &pd = i->second;
+    for (std::list<std::pair<crypto::hash, tools::wallet2::pool_payment_details>>::const_iterator i = pool_payments.begin(); i != pool_payments.end(); ++i) {
+      const tools::wallet2::payment_details &pd = i->second.m_pd;
       if (pd.m_tx_hash == txid)
       {
         std::string payment_id = string_tools::pod_to_hex(i->first);
@@ -5455,6 +5458,8 @@ bool simple_wallet::show_transfer(const std::vector<std::string> &args)
         success_msg_writer() << "Payment ID: " << payment_id;
         success_msg_writer() << "Address index: " << pd.m_subaddr_index.minor;
         success_msg_writer() << "Note: " << m_wallet->get_tx_note(txid);
+        if (i->second.m_double_spend_seen)
+          success_msg_writer() << tr("Double spend seen on the network: this transaction may or may not end up being mined");
         return true;
       }
     }
diff --git a/src/wallet/api/transaction_history.cpp b/src/wallet/api/transaction_history.cpp
index 59eca3dd7..8a8243047 100644
--- a/src/wallet/api/transaction_history.cpp
+++ b/src/wallet/api/transaction_history.cpp
@@ -217,10 +217,10 @@ void TransactionHistoryImpl::refresh()
     
     
     // unconfirmed payments (tx pool)
-    std::list<std::pair<crypto::hash, tools::wallet2::payment_details>> upayments;
+    std::list<std::pair<crypto::hash, tools::wallet2::pool_payment_details>> upayments;
     m_wallet->m_wallet->get_unconfirmed_payments(upayments);
-    for (std::list<std::pair<crypto::hash, tools::wallet2::payment_details>>::const_iterator i = upayments.begin(); i != upayments.end(); ++i) {  
-        const tools::wallet2::payment_details &pd = i->second;
+    for (std::list<std::pair<crypto::hash, tools::wallet2::pool_payment_details>>::const_iterator i = upayments.begin(); i != upayments.end(); ++i) {
+        const tools::wallet2::payment_details &pd = i->second.m_pd;
         std::string payment_id = string_tools::pod_to_hex(i->first);
         if (payment_id.substr(16).find_first_not_of('0') == std::string::npos)
             payment_id = payment_id.substr(0,16);
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index f0eaf2331..25e48daac 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -444,6 +444,21 @@ std::string strjoin(const std::vector<size_t> &V, const char *sep)
   return ss.str();
 }
 
+static void emplace_or_replace(std::unordered_multimap<crypto::hash, tools::wallet2::pool_payment_details> &container,
+  const crypto::hash &key, const tools::wallet2::pool_payment_details &pd)
+{
+  auto range = container.equal_range(key);
+  for (auto i = range.first; i != range.second; ++i)
+  {
+    if (i->second.m_pd.m_tx_hash == pd.m_pd.m_tx_hash)
+    {
+      i->second = pd;
+      return;
+    }
+  }
+  container.emplace(key, pd);
+}
+
 } //namespace
 
 namespace tools
@@ -793,7 +808,7 @@ void wallet2::scan_output(const cryptonote::account_keys &keys, const cryptonote
   ++num_vouts_received;
 }
 //----------------------------------------------------------------------------------------------------
-void wallet2::process_new_transaction(const crypto::hash &txid, const cryptonote::transaction& tx, const std::vector<uint64_t> &o_indices, uint64_t height, uint64_t ts, bool miner_tx, bool pool)
+void wallet2::process_new_transaction(const crypto::hash &txid, const cryptonote::transaction& tx, const std::vector<uint64_t> &o_indices, uint64_t height, uint64_t ts, bool miner_tx, bool pool, bool double_spend_seen)
 {
   // In this function, tx (probably) only contains the base information
   // (that is, the prunable stuff may or may not be included)
@@ -1163,7 +1178,7 @@ void wallet2::process_new_transaction(const crypto::hash &txid, const cryptonote
       payment.m_timestamp    = ts;
       payment.m_subaddr_index = i.first;
       if (pool) {
-        m_unconfirmed_payments.emplace(payment_id, payment);
+        emplace_or_replace(m_unconfirmed_payments, payment_id, pool_payment_details{payment, double_spend_seen});
         if (0 != m_callback)
           m_callback->on_unconfirmed_money_received(height, txid, tx, payment.m_amount, payment.m_subaddr_index);
       }
@@ -1241,7 +1256,7 @@ void wallet2::process_new_blockchain_entry(const cryptonote::block& b, const cry
   if(b.timestamp + 60*60*24 > m_account.get_createtime() && height >= m_refresh_from_block_height)
   {
     TIME_MEASURE_START(miner_tx_handle_time);
-    process_new_transaction(get_transaction_hash(b.miner_tx), b.miner_tx, o_indices.indices[txidx++].indices, height, b.timestamp, true, false);
+    process_new_transaction(get_transaction_hash(b.miner_tx), b.miner_tx, o_indices.indices[txidx++].indices, height, b.timestamp, true, false, false);
     TIME_MEASURE_FINISH(miner_tx_handle_time);
 
     TIME_MEASURE_START(txs_handle_time);
@@ -1252,7 +1267,7 @@ void wallet2::process_new_blockchain_entry(const cryptonote::block& b, const cry
       cryptonote::transaction tx;
       bool r = parse_and_validate_tx_base_from_blob(txblob, tx);
       THROW_WALLET_EXCEPTION_IF(!r, error::tx_parse_error, txblob);
-      process_new_transaction(b.tx_hashes[idx], tx, o_indices.indices[txidx++].indices, height, b.timestamp, false, false);
+      process_new_transaction(b.tx_hashes[idx], tx, o_indices.indices[txidx++].indices, height, b.timestamp, false, false, false);
       ++idx;
     }
     TIME_MEASURE_FINISH(txs_handle_time);
@@ -1520,10 +1535,10 @@ void wallet2::pull_next_blocks(uint64_t start_height, uint64_t &blocks_start_hei
 void wallet2::remove_obsolete_pool_txs(const std::vector<crypto::hash> &tx_hashes)
 {
   // remove pool txes to us that aren't in the pool anymore
-  std::unordered_multimap<crypto::hash, wallet2::payment_details>::iterator uit = m_unconfirmed_payments.begin();
+  std::unordered_multimap<crypto::hash, wallet2::pool_payment_details>::iterator uit = m_unconfirmed_payments.begin();
   while (uit != m_unconfirmed_payments.end())
   {
-    const crypto::hash &txid = uit->second.m_tx_hash;
+    const crypto::hash &txid = uit->second.m_pd.m_tx_hash;
     bool found = false;
     for (const auto &it2: tx_hashes)
     {
@@ -1626,23 +1641,27 @@ void wallet2::update_pool_state(bool refreshed)
   MDEBUG("update_pool_state done second loop");
 
   // gather txids of new pool txes to us
-  std::vector<crypto::hash> txids;
+  std::vector<std::pair<crypto::hash, bool>> txids;
   for (const auto &txid: res.tx_hashes)
   {
-    if (m_scanned_pool_txs[0].find(txid) != m_scanned_pool_txs[0].end() || m_scanned_pool_txs[1].find(txid) != m_scanned_pool_txs[1].end())
-    {
-      LOG_PRINT_L2("Already seen " << txid << ", skipped");
-      continue;
-    }
     bool txid_found_in_up = false;
     for (const auto &up: m_unconfirmed_payments)
     {
-      if (up.second.m_tx_hash == txid)
+      if (up.second.m_pd.m_tx_hash == txid)
       {
         txid_found_in_up = true;
         break;
       }
     }
+    if (m_scanned_pool_txs[0].find(txid) != m_scanned_pool_txs[0].end() || m_scanned_pool_txs[1].find(txid) != m_scanned_pool_txs[1].end())
+    {
+      // if it's for us, we want to keep track of whether we saw a double spend, so don't bail out
+      if (!txid_found_in_up)
+      {
+        LOG_PRINT_L2("Already seen " << txid << ", and not for us, skipped");
+        continue;
+      }
+    }
     if (!txid_found_in_up)
     {
       LOG_PRINT_L1("Found new pool tx: " << txid);
@@ -1670,7 +1689,7 @@ void wallet2::update_pool_state(bool refreshed)
       if (!found)
       {
         // not one of those we sent ourselves
-        txids.push_back(txid);
+        txids.push_back({txid, false});
       }
       else
       {
@@ -1680,6 +1699,7 @@ void wallet2::update_pool_state(bool refreshed)
     else
     {
       LOG_PRINT_L1("Already saw that one, it's for us");
+      txids.push_back({txid, true});
     }
   }
 
@@ -1688,8 +1708,8 @@ void wallet2::update_pool_state(bool refreshed)
   {
     cryptonote::COMMAND_RPC_GET_TRANSACTIONS::request req;
     cryptonote::COMMAND_RPC_GET_TRANSACTIONS::response res;
-    for (const auto &txid: txids)
-      req.txs_hashes.push_back(epee::string_tools::pod_to_hex(txid));
+    for (const auto &p: txids)
+      req.txs_hashes.push_back(epee::string_tools::pod_to_hex(p.first));
     MDEBUG("asking for " << txids.size() << " transactions");
     req.decode_as_json = false;
     m_daemon_rpc_mutex.lock();
@@ -1711,10 +1731,11 @@ void wallet2::update_pool_state(bool refreshed)
             {
               if (cryptonote::parse_and_validate_tx_from_blob(bd, tx, tx_hash, tx_prefix_hash))
               {
-                const std::vector<crypto::hash>::const_iterator i = std::find(txids.begin(), txids.end(), tx_hash);
+                const std::vector<std::pair<crypto::hash, bool>>::const_iterator i = std::find_if(txids.begin(), txids.end(),
+                    [tx_hash](const std::pair<crypto::hash, bool> &e) { return e.first == tx_hash; });
                 if (i != txids.end())
                 {
-                  process_new_transaction(tx_hash, tx, std::vector<uint64_t>(), 0, time(NULL), false, true);
+                  process_new_transaction(tx_hash, tx, std::vector<uint64_t>(), 0, time(NULL), false, true, tx_entry.double_spend_seen);
                   m_scanned_pool_txs[0].insert(tx_hash);
                   if (m_scanned_pool_txs[0].size() > 5000)
                   {
@@ -3073,11 +3094,11 @@ void wallet2::get_unconfirmed_payments_out(std::list<std::pair<crypto::hash,wall
   }
 }
 //----------------------------------------------------------------------------------------------------
-void wallet2::get_unconfirmed_payments(std::list<std::pair<crypto::hash,wallet2::payment_details>>& unconfirmed_payments, const boost::optional<uint32_t>& subaddr_account, const std::set<uint32_t>& subaddr_indices) const
+void wallet2::get_unconfirmed_payments(std::list<std::pair<crypto::hash,wallet2::pool_payment_details>>& unconfirmed_payments, const boost::optional<uint32_t>& subaddr_account, const std::set<uint32_t>& subaddr_indices) const
 {
   for (auto i = m_unconfirmed_payments.begin(); i != m_unconfirmed_payments.end(); ++i) {
-    if ((!subaddr_account || *subaddr_account == i->second.m_subaddr_index.major) &&
-      (subaddr_indices.empty() || subaddr_indices.count(i->second.m_subaddr_index.minor) == 1))
+    if ((!subaddr_account || *subaddr_account == i->second.m_pd.m_subaddr_index.major) &&
+      (subaddr_indices.empty() || subaddr_indices.count(i->second.m_pd.m_subaddr_index.minor) == 1))
     unconfirmed_payments.push_back(*i);
   }
 }
@@ -5129,7 +5150,7 @@ void wallet2::light_wallet_get_address_txs()
     payments_txs.push_back(p.second.m_tx_hash);
   std::vector<crypto::hash> unconfirmed_payments_txs;
   for(const auto &up: m_unconfirmed_payments)
-    unconfirmed_payments_txs.push_back(up.second.m_tx_hash);
+    unconfirmed_payments_txs.push_back(up.second.m_pd.m_tx_hash);
 
   // for balance calculation
   uint64_t wallet_total_sent = 0;
@@ -5195,7 +5216,11 @@ void wallet2::light_wallet_get_address_txs()
       if (t.mempool) {   
         if (std::find(unconfirmed_payments_txs.begin(), unconfirmed_payments_txs.end(), tx_hash) == unconfirmed_payments_txs.end()) {
           pool_txs.push_back(tx_hash);
-          m_unconfirmed_payments.emplace(tx_hash, payment);
+          // assume false as we don't get that info from the light wallet server
+          crypto::hash payment_id;
+          THROW_WALLET_EXCEPTION_IF(!epee::string_tools::hex_to_pod(t.payment_id, payment_id),
+              error::wallet_internal_error, "Failed to parse payment id");
+          emplace_or_replace(m_unconfirmed_payments, payment_id, pool_payment_details{payment, false});
           if (0 != m_callback) {
             m_callback->on_lw_unconfirmed_money_received(t.height, payment.m_tx_hash, payment.m_amount);
           }
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index f1e12a700..ba2fc567d 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -244,6 +244,12 @@ namespace tools
       bool m_incoming;
     };
 
+    struct pool_payment_details
+    {
+      payment_details m_pd;
+      bool m_double_spend_seen;
+    };
+
     struct unconfirmed_transfer_details
     {
       cryptonote::transaction_prefix m_tx;
@@ -530,7 +536,7 @@ namespace tools
     void get_payments_out(std::list<std::pair<crypto::hash,wallet2::confirmed_transfer_details>>& confirmed_payments,
       uint64_t min_height, uint64_t max_height = (uint64_t)-1, const boost::optional<uint32_t>& subaddr_account = boost::none, const std::set<uint32_t>& subaddr_indices = {}) const;
     void get_unconfirmed_payments_out(std::list<std::pair<crypto::hash,wallet2::unconfirmed_transfer_details>>& unconfirmed_payments, const boost::optional<uint32_t>& subaddr_account = boost::none, const std::set<uint32_t>& subaddr_indices = {}) const;
-    void get_unconfirmed_payments(std::list<std::pair<crypto::hash,wallet2::payment_details>>& unconfirmed_payments, const boost::optional<uint32_t>& subaddr_account = boost::none, const std::set<uint32_t>& subaddr_indices = {}) const;
+    void get_unconfirmed_payments(std::list<std::pair<crypto::hash,wallet2::pool_payment_details>>& unconfirmed_payments, const boost::optional<uint32_t>& subaddr_account = boost::none, const std::set<uint32_t>& subaddr_indices = {}) const;
 
     uint64_t get_blockchain_current_height() const { return m_local_bc_height; }
     void rescan_spent();
@@ -585,7 +591,7 @@ namespace tools
         std::unordered_map<crypto::hash, payment_details> m;
         a & m;
         for (std::unordered_map<crypto::hash, payment_details>::const_iterator i = m.begin(); i != m.end(); ++i)
-          m_unconfirmed_payments.insert(*i);
+          m_unconfirmed_payments.insert(std::make_pair(i->first, pool_payment_details{i->second, false}));
       }
       if(ver < 14)
         return;
@@ -607,7 +613,15 @@ namespace tools
       a & m_address_book;
       if(ver < 17)
         return;
-      a & m_unconfirmed_payments;
+      if (ver < 21)
+      {
+        // we're loading an old version, where m_unconfirmed_payments payload was payment_details
+        std::unordered_map<crypto::hash, payment_details> m;
+        a & m;
+        for (const auto &i: m)
+          m_unconfirmed_payments.insert(std::make_pair(i.first, pool_payment_details{i.second, false}));
+        return;
+      }
       if(ver < 18)
         return;
       a & m_scanned_pool_txs[0];
@@ -621,6 +635,9 @@ namespace tools
       if(ver < 21)
         return;
       a & m_attributes;
+      if(ver < 22)
+        return;
+      a & m_unconfirmed_payments;
     }
 
     /*!
@@ -797,7 +814,7 @@ namespace tools
      * \param password       Password of wallet file
      */
     bool load_keys(const std::string& keys_file_name, const std::string& password);
-    void process_new_transaction(const crypto::hash &txid, const cryptonote::transaction& tx, const std::vector<uint64_t> &o_indices, uint64_t height, uint64_t ts, bool miner_tx, bool pool);
+    void process_new_transaction(const crypto::hash &txid, const cryptonote::transaction& tx, const std::vector<uint64_t> &o_indices, uint64_t height, uint64_t ts, bool miner_tx, bool pool, bool double_spend_seen);
     void process_new_blockchain_entry(const cryptonote::block& b, const cryptonote::block_complete_entry& bche, const crypto::hash& bl_id, uint64_t height, const cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::block_output_indices &o_indices);
     void detach_blockchain(uint64_t height);
     void get_short_chain_history(std::list<crypto::hash>& ids) const;
@@ -846,7 +863,7 @@ namespace tools
     std::atomic<uint64_t> m_local_bc_height; //temporary workaround
     std::unordered_map<crypto::hash, unconfirmed_transfer_details> m_unconfirmed_txs;
     std::unordered_map<crypto::hash, confirmed_transfer_details> m_confirmed_txs;
-    std::unordered_multimap<crypto::hash, payment_details> m_unconfirmed_payments;
+    std::unordered_multimap<crypto::hash, pool_payment_details> m_unconfirmed_payments;
     std::unordered_map<crypto::hash, crypto::secret_key> m_tx_keys;
     cryptonote::checkpoints m_checkpoints;
     std::unordered_map<crypto::hash, std::vector<crypto::secret_key>> m_additional_tx_keys;
@@ -908,9 +925,10 @@ namespace tools
     std::unordered_map<crypto::public_key, std::map<uint64_t, crypto::key_image> > m_key_image_cache;
   };
 }
-BOOST_CLASS_VERSION(tools::wallet2, 21)
+BOOST_CLASS_VERSION(tools::wallet2, 22)
 BOOST_CLASS_VERSION(tools::wallet2::transfer_details, 8)
 BOOST_CLASS_VERSION(tools::wallet2::payment_details, 2)
+BOOST_CLASS_VERSION(tools::wallet2::pool_payment_details, 1)
 BOOST_CLASS_VERSION(tools::wallet2::unconfirmed_transfer_details, 7)
 BOOST_CLASS_VERSION(tools::wallet2::confirmed_transfer_details, 5)
 BOOST_CLASS_VERSION(tools::wallet2::address_book_row, 17)
@@ -1137,7 +1155,14 @@ namespace boost
       }
       a & x.m_subaddr_index;
     }
-    
+
+    template <class Archive>
+    inline void serialize(Archive& a, tools::wallet2::pool_payment_details& x, const boost::serialization::version_type ver)
+    {
+      a & x.m_pd;
+      a & x.m_double_spend_seen;
+    }
+
     template <class Archive>
     inline void serialize(Archive& a, tools::wallet2::address_book_row& x, const boost::serialization::version_type ver)
     {
diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index 9e6a97bdc..5dbf30419 100755
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -299,8 +299,9 @@ namespace tools
     entry.subaddr_index = { pd.m_subaddr_account, 0 };
   }
   //------------------------------------------------------------------------------------------------------------------------------
-  void wallet_rpc_server::fill_transfer_entry(tools::wallet_rpc::transfer_entry &entry, const crypto::hash &payment_id, const tools::wallet2::payment_details &pd)
+  void wallet_rpc_server::fill_transfer_entry(tools::wallet_rpc::transfer_entry &entry, const crypto::hash &payment_id, const tools::wallet2::pool_payment_details &ppd)
   {
+    const tools::wallet2::payment_details &pd = ppd.m_pd;
     entry.txid = string_tools::pod_to_hex(pd.m_tx_hash);
     entry.payment_id = string_tools::pod_to_hex(payment_id);
     if (entry.payment_id.substr(16).find_first_not_of('0') == std::string::npos)
@@ -311,6 +312,7 @@ namespace tools
     entry.unlock_time = pd.m_unlock_time;
     entry.fee = 0; // TODO
     entry.note = m_wallet->get_tx_note(pd.m_tx_hash);
+    entry.double_spend_seen = ppd.m_double_spend_seen;
     entry.type = "pool";
     entry.subaddr_index = pd.m_subaddr_index;
   }
@@ -1357,9 +1359,9 @@ namespace tools
     {
       m_wallet->update_pool_state();
 
-      std::list<std::pair<crypto::hash, tools::wallet2::payment_details>> payments;
+      std::list<std::pair<crypto::hash, tools::wallet2::pool_payment_details>> payments;
       m_wallet->get_unconfirmed_payments(payments, req.account_index, req.subaddr_indices);
-      for (std::list<std::pair<crypto::hash, tools::wallet2::payment_details>>::const_iterator i = payments.begin(); i != payments.end(); ++i) {
+      for (std::list<std::pair<crypto::hash, tools::wallet2::pool_payment_details>>::const_iterator i = payments.begin(); i != payments.end(); ++i) {
         res.pool.push_back(wallet_rpc::transfer_entry());
         fill_transfer_entry(res.pool.back(), i->first, i->second);
       }
@@ -1430,10 +1432,10 @@ namespace tools
 
     m_wallet->update_pool_state();
 
-    std::list<std::pair<crypto::hash, tools::wallet2::payment_details>> pool_payments;
+    std::list<std::pair<crypto::hash, tools::wallet2::pool_payment_details>> pool_payments;
     m_wallet->get_unconfirmed_payments(pool_payments);
-    for (std::list<std::pair<crypto::hash, tools::wallet2::payment_details>>::const_iterator i = pool_payments.begin(); i != pool_payments.end(); ++i) {
-      if (i->second.m_tx_hash == txid)
+    for (std::list<std::pair<crypto::hash, tools::wallet2::pool_payment_details>>::const_iterator i = pool_payments.begin(); i != pool_payments.end(); ++i) {
+      if (i->second.m_pd.m_tx_hash == txid)
       {
         fill_transfer_entry(res.transfer, i->first, i->second);
         return true;
diff --git a/src/wallet/wallet_rpc_server.h b/src/wallet/wallet_rpc_server.h
index b38726cb7..a2677ef1b 100644
--- a/src/wallet/wallet_rpc_server.h
+++ b/src/wallet/wallet_rpc_server.h
@@ -163,7 +163,7 @@ namespace tools
       void fill_transfer_entry(tools::wallet_rpc::transfer_entry &entry, const crypto::hash &txid, const crypto::hash &payment_id, const tools::wallet2::payment_details &pd);
       void fill_transfer_entry(tools::wallet_rpc::transfer_entry &entry, const crypto::hash &txid, const tools::wallet2::confirmed_transfer_details &pd);
       void fill_transfer_entry(tools::wallet_rpc::transfer_entry &entry, const crypto::hash &txid, const tools::wallet2::unconfirmed_transfer_details &pd);
-      void fill_transfer_entry(tools::wallet_rpc::transfer_entry &entry, const crypto::hash &payment_id, const tools::wallet2::payment_details &pd);
+      void fill_transfer_entry(tools::wallet_rpc::transfer_entry &entry, const crypto::hash &payment_id, const tools::wallet2::pool_payment_details &pd);
       bool not_open(epee::json_rpc::error& er);
       uint64_t adjust_mixin(uint64_t mixin);
       void handle_rpc_exception(const std::exception_ptr& e, epee::json_rpc::error& er, int default_error_code);
diff --git a/src/wallet/wallet_rpc_server_commands_defs.h b/src/wallet/wallet_rpc_server_commands_defs.h
index ffc2e2d49..06f2456c3 100644
--- a/src/wallet/wallet_rpc_server_commands_defs.h
+++ b/src/wallet/wallet_rpc_server_commands_defs.h
@@ -794,6 +794,7 @@ namespace wallet_rpc
     std::string type;
     uint64_t unlock_time;
     cryptonote::subaddress_index subaddr_index;
+    bool double_spend_seen;
 
     BEGIN_KV_SERIALIZE_MAP()
       KV_SERIALIZE(txid);
@@ -807,6 +808,7 @@ namespace wallet_rpc
       KV_SERIALIZE(type);
       KV_SERIALIZE(unlock_time)
       KV_SERIALIZE(subaddr_index);
+      KV_SERIALIZE(double_spend_seen)
     END_KV_SERIALIZE_MAP()
   };