track double spending in the txpool

Transactions in the txpool are marked when another transaction
is seen double spending one or more of its inputs.
This is then exposed wherever appropriate.

Note that being marked with this "double spend seen" flag does
NOT mean this transaction IS a double spend and will never be
mined: it just means that the network has seen at least another
transaction spending at least one of the same inputs, so care
should be taken to wait for a few confirmations before acting
upon that transaction (ie, mostly of use for merchants wanting
to accept unconfirmed transactions).

1 files changed, 6 insertions, 6 deletions

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);
         }
       }
     }