do not sent htlcs after you've sent a close_clearing message

eclair-demo/src/main/scala/fr/acinq/eclair/channel/Channel.scala

@@ -284,6 +284,10 @@ class Channel(val them: ActorRef, val blockchain: ActorRef, val params: OurChann
    */
 
   when(NORMAL) {
+    case Event(c:CMD_ADD_HTLC, d: DATA_NORMAL) if d.ourClearing.isDefined =>
+      handleCommandError(sender, new RuntimeException("Cannot sent an update_add_htlc after a close_clearing message"))
+      stay
+
     case Event(c@CMD_ADD_HTLC(amount, rHash, expiry, nodeIds, origin, id_opt), d@DATA_NORMAL(commitments, _)) =>
       Try(Commitments.sendAdd(commitments, c)) match {
         case Success((commitments1, add)) => handleCommandSuccess(sender, add, d.copy(commitments = commitments1))

eclair-demo/src/main/scala/fr/acinq/eclair/channel/Commitments.scala

@@ -41,7 +41,7 @@ case class TheirCommit(index: Long, spec: CommitmentSpec, txid: BinaryData, thei
 /**
   * about theirNextCommitInfo:
   * we either:
-  * - have built and sign their next commit tx with their next revocation hash which can now be discarded
+  * - have built and signed their next commit tx with their next revocation hash which can now be discarded
   * - have their next revocation hash
   * So, when we've signed and sent a commit message and are waiting for their revocation message,
   * theirNextCommitInfo is their next commit tx. The rest of the time, it is their next revocation hash

eclair-demo/src/test/scala/fr/acinq/eclair/channel/simulator/states/e/NormalStateSpec.scala

@@ -521,6 +521,20 @@ class NormalStateSpec extends TestKit(ActorSystem("test")) with fixture.FunSuite
     }
   }
 
+  test("do not send htlcs after you've sent a close_clearing message") { case (alice, _, alice2bob, _, alice2blockchain, _) =>
+    within(30 seconds) {
+      val sender = TestProbe()
+      sender.send(alice, CMD_CLOSE(None))
+      alice2bob.expectMsgType[close_clearing]
+      val rand = new Random()
+      val R = rval(rand.nextInt(), rand.nextInt(), rand.nextInt(), rand.nextInt())
+      val H: sha256_hash = Crypto.sha256(R)
+      sender.send(alice, CMD_ADD_HTLC(1000000, H, locktime(Blocks(3))))
+      alice2bob.expectNoMsg(500 milliseconds)
+      awaitCond(alice.stateName == NORMAL)
+    }
+  }
+
   ignore("recv close_clearing (with unacked received htlcs)") { case (alice, bob, alice2bob, bob2alice, alice2blockchain, _) =>
     within(30 seconds) {
       val sender = TestProbe()