Bug fix: don't pointlessly download a transaction we already have because we're broadcasting it.

This is a regression caused by the TxConfidenceTable rewrite: previously it pinned entire transactions and that was used to notice that a broadcast was happening. Now it only pins confidence objects. So instead we use the confidence.source property: if it's SELF then we assume we have it somewhere in the address space and don't bother downloading it when a peer announces it. If it's UNKNOWN then PeerGroup.broadcastTransaction will set it to SELF.

core/src/main/java/org/bitcoinj/core/Peer.java

@@ -1073,6 +1073,9 @@ public class Peer extends PeerSocketHandler {
             if (conf.numBroadcastPeers() > 1) {
                 // Some other peer already announced this so don't download.
                 it.remove();
+            } else if (conf.getSource().equals(TransactionConfidence.Source.SELF)) {
+                // We created this transaction ourselves, so don't download.
+                it.remove();
             } else {
                 log.debug("{}: getdata on tx {}", getAddress(), item.hash);
                 getdata.addItem(item);

core/src/main/java/org/bitcoinj/core/PeerGroup.java

@@ -1795,7 +1795,11 @@ public class PeerGroup implements TransactionBroadcaster {
      * which is calculated by watching the transaction propagate across the network and be announced by peers.</p>
      */
     public TransactionBroadcast broadcastTransaction(final Transaction tx, final int minConnections) {
-        // TODO: Context being owned by BlockChain isn't right w.r.t future intentions so it shouldn't really be optional here.
+        // If we don't have a record of where this tx came from already, set it to be ourselves so Peer doesn't end up
+        // redownloading it from the network redundantly.
+        if (tx.getConfidence().getSource().equals(TransactionConfidence.Source.UNKNOWN)) {
+            tx.getConfidence().setSource(TransactionConfidence.Source.SELF);
+        }
         final TransactionBroadcast broadcast = new TransactionBroadcast(this, tx);
         broadcast.setMinConnections(minConnections);
         // Send the TX to the wallet once we have a successful broadcast.

core/src/test/java/org/bitcoinj/core/TransactionBroadcastTest.java

@@ -64,6 +64,7 @@ public class TransactionBroadcastTest extends TestWithPeerGroup {
     public void fourPeers() throws Exception {
         InboundMessageQueuer[] channels = { connectPeer(1), connectPeer(2), connectPeer(3), connectPeer(4) };
         Transaction tx = new Transaction(params);
+        tx.getConfidence().setSource(TransactionConfidence.Source.SELF);
         TransactionBroadcast broadcast = new TransactionBroadcast(peerGroup, tx);
         final AtomicDouble lastProgress = new AtomicDouble();
         broadcast.setProgressCallback(new TransactionBroadcast.ProgressCallback() {
@@ -92,10 +93,11 @@ public class TransactionBroadcastTest extends TestWithPeerGroup {
         assertFalse(future.isDone());
         assertEquals(0.0, lastProgress.get(), 0.0);
         inbound(channels[1], InventoryMessage.with(tx));
-        pingAndWait(channels[1]);
         future.get();
         Threading.waitForUserCode();
         assertEquals(1.0, lastProgress.get(), 0.0);
+        // There is no response from the Peer as it has nothing to do.
+        assertNull(outbound(channels[1]));
     }
 
     @Test