onchaind: fix all_irrevocably_resolved test.

I was examining a test_onchain_timeout failure, and realized that we
were forgetting a peer even though we'd just spent the HTLC_TIMEOUT_TX!

This reveals that we weren't resolving an output when we stole the preimage
from it, like we should.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

onchaind/onchain.c

@@ -496,7 +496,7 @@ static bool all_irrevocably_resolved(struct tracked_output **outs)
 	size_t i;
 
 	for (i = 0; i < tal_count(outs); i++) {
-		if (outs[i]->resolved && outs[i]->resolved->depth < 100)
+		if (!outs[i]->resolved || outs[i]->resolved->depth < 100)
 			return false;
 	}
 	return true;
@@ -721,6 +721,17 @@ static void output_spent(struct tracked_output ***outs,
 			handle_htlc_onchain_fulfill(out, tx);
 			if (out->tx_type == THEIR_REVOKED_UNILATERAL)
 				steal_htlc_tx(out);
+			else {
+				/* BOLT #5:
+				 *
+				 * If the HTLC output is spent using the
+				 * payment preimage, the HTLC output is
+				 * considered *irrevocably resolved*, and the
+				 * node MUST extract the payment preimage from
+				 * the transaction input witness.
+				 */
+				ignore_output(out);
+			}
 			break;
 
 		case FUNDING_OUTPUT:

tests/test_lightningd.py

@@ -960,12 +960,19 @@ class LightningDTests(BaseLightningDTests):
 
         l1.daemon.wait_for_log('WIRE_PERMANENT_CHANNEL_FAILURE: timed out')
 
-        # 91 later, l2 is done.
-        bitcoind.generate_block(91)
+        # 2 later, l1 spends HTLC (5 blocks total).
+        bitcoind.generate_block(2)
+        l1.daemon.wait_for_log('Broadcasting OUR_DELAYED_RETURN_TO_WALLET .* to resolve OUR_HTLC_TIMEOUT_TX/DELAYED_OUTPUT_TO_US')
+        l1.daemon.wait_for_log('sendrawtx exit 0')
+
+        # 89 later, l2 is done.
+        bitcoind.generate_block(89)
         l2.daemon.wait_for_log('onchaind complete, forgetting peer')
 
         # Now, 100 blocks and l1 should be done.
-        bitcoind.generate_block(6)
+        bitcoind.generate_block(10)
+        assert not l1.daemon.is_in_log('onchaind complete, forgetting peer')
+        bitcoind.generate_block(1)
         l1.daemon.wait_for_log('onchaind complete, forgetting peer')
 
         # Payment failed, BTW