From 7343283f9fe90773c6659d0ec35ceecafa6c3b9d Mon Sep 17 00:00:00 2001
From: Bastien Teinturier <31281497+t-bast@users.noreply.github.com>
Date: Wed, 6 Jan 2021 18:37:29 +0100
Subject: [PATCH] Add test for duplicate temporary channel id (#1660)

This scenario was correctly handled, but we were missing test coverage.
---
 .../fr/acinq/eclair/channel/Channel.scala     |  2 --
 .../scala/fr/acinq/eclair/io/PeerSpec.scala   | 23 ++++++++++++++++++-
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/eclair-core/src/main/scala/fr/acinq/eclair/channel/Channel.scala b/eclair-core/src/main/scala/fr/acinq/eclair/channel/Channel.scala
index ed446d9fc..5952a355d 100644
--- a/eclair-core/src/main/scala/fr/acinq/eclair/channel/Channel.scala
+++ b/eclair-core/src/main/scala/fr/acinq/eclair/channel/Channel.scala
@@ -296,7 +296,6 @@ class Channel(val nodeParams: NodeParams, val wallet: EclairWallet, remoteNodeId
           context.system.eventStream.publish(ChannelCreated(self, peer, remoteNodeId, isFunder = false, open.temporaryChannelId, open.feeratePerKw, None))
           val fundingPubkey = keyManager.fundingPublicKey(localParams.fundingKeyPath).publicKey
           val channelKeyPath = keyManager.keyPath(localParams, channelVersion)
-          // TODO: maybe also check uniqueness of temporary channel id
           val minimumDepth = Helpers.minDepthForFunding(nodeParams, open.fundingSatoshis)
           val accept = AcceptChannel(temporaryChannelId = open.temporaryChannelId,
             dustLimitSatoshis = localParams.dustLimit,
@@ -346,7 +345,6 @@ class Channel(val nodeParams: NodeParams, val wallet: EclairWallet, remoteNodeId
       Helpers.validateParamsFunder(nodeParams, open, accept) match {
         case Left(t) => handleLocalError(t, d, Some(accept))
         case _ =>
-          // TODO: check equality of temporaryChannelId? or should be done upstream
           val remoteParams = RemoteParams(
             nodeId = remoteNodeId,
             dustLimit = accept.dustLimitSatoshis,
diff --git a/eclair-core/src/test/scala/fr/acinq/eclair/io/PeerSpec.scala b/eclair-core/src/test/scala/fr/acinq/eclair/io/PeerSpec.scala
index 7124dc860..00722920f 100644
--- a/eclair-core/src/test/scala/fr/acinq/eclair/io/PeerSpec.scala
+++ b/eclair-core/src/test/scala/fr/acinq/eclair/io/PeerSpec.scala
@@ -21,7 +21,7 @@ import akka.actor.Status.Failure
 import akka.testkit.{TestFSMRef, TestProbe}
 import com.google.common.net.HostAndPort
 import fr.acinq.bitcoin.Crypto.PublicKey
-import fr.acinq.bitcoin.{Btc, SatoshiLong, Script}
+import fr.acinq.bitcoin.{Block, Btc, SatoshiLong, Script}
 import fr.acinq.eclair.FeatureSupport.Optional
 import fr.acinq.eclair.Features.{StaticRemoteKey, Wumbo}
 import fr.acinq.eclair.TestConstants._
@@ -237,6 +237,27 @@ class PeerSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with StateTe
     monitor.expectMsg(FSM.Transition(reconnectionTask, ReconnectionTask.CONNECTING, ReconnectionTask.IDLE))
   }
 
+  test("don't spawn a channel with duplicate temporary channel id") { f =>
+    import f._
+
+    val probe = TestProbe()
+    system.eventStream.subscribe(probe.ref, classOf[ChannelCreated])
+    connect(remoteNodeId, peer, peerConnection)
+    assert(peer.stateData.channels.isEmpty)
+
+    val open = wire.OpenChannel(Block.RegtestGenesisBlock.hash, randomBytes32, 25000 sat, 0 msat, 483 sat, UInt64(100), 1000 sat, 1 msat, TestConstants.feeratePerKw, CltvExpiryDelta(144), 10, randomKey.publicKey, randomKey.publicKey, randomKey.publicKey, randomKey.publicKey, randomKey.publicKey, randomKey.publicKey, 0)
+    peerConnection.send(peer, open)
+    awaitCond(peer.stateData.channels.nonEmpty)
+    assert(probe.expectMsgType[ChannelCreated].temporaryChannelId === open.temporaryChannelId)
+    peerConnection.expectMsgType[AcceptChannel]
+
+    // open_channel messages with the same temporary channel id should simply be ignored
+    peerConnection.send(peer, open.copy(fundingSatoshis = 100000 sat, fundingPubkey = randomKey.publicKey))
+    probe.expectNoMsg(100 millis)
+    peerConnection.expectNoMsg(100 millis)
+    assert(peer.stateData.channels.size === 1)
+  }
+
   test("don't spawn a wumbo channel if wumbo feature isn't enabled") { f =>
     import f._