channeld: remove changes_pending flags.

These used to be necessary as we could have feerate changes which
we couldn't track: now we do, we don't need these flags.

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

channeld/channeld.c

@@ -2531,15 +2531,6 @@ static void peer_reconnect(struct peer *peer,
 			send_fail_or_fulfill(peer, htlc);
 	}
 
-	/* Corner case: we will get upset with them if they send
-	 * commitment_signed with no changes.  But it could be that we sent a
-	 * feechange, they acked, and now they want to commit it; we can't
-	 * even tell by seeing if fees are different (short of saving full fee
-	 * state in database) since it could be a tiny feechange, or two
-	 * feechanges which cancelled out. */
-	if (peer->channel->funder == LOCAL)
-		peer->channel->changes_pending[LOCAL] = true;
-
 	peer_billboard(true, "Reconnected, and reestablished.");
 
 	/* BOLT #2:

channeld/full_channel.c

@@ -624,13 +624,6 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	if (htlcp)
 		*htlcp = htlc;
 
-	/* This is simply setting changes_pending[receiver] unless it's
-	 * an exotic state (i.e. channel_force_htlcs) */
-	if (htlc_state_flags(htlc->state) & HTLC_LOCAL_F_PENDING)
-		channel->changes_pending[LOCAL] = true;
-	if (htlc_state_flags(htlc->state) & HTLC_REMOTE_F_PENDING)
-		channel->changes_pending[REMOTE] = true;
-
 	return CHANNEL_ERR_ADD_OK;
 }
 
@@ -720,8 +713,6 @@ enum channel_remove_err channel_fulfill_htlc(struct channel *channel,
 			     htlc->id, htlc_state_name(htlc->state));
 		return CHANNEL_ERR_HTLC_NOT_IRREVOCABLE;
 	}
-	/* The HTLC owner is the recipient of the fulfillment. */
-	channel->changes_pending[owner] = true;
 
 	dump_htlc(htlc, "FULFILL:");
 
@@ -765,8 +756,6 @@ enum channel_remove_err channel_fail_htlc(struct channel *channel,
 			     htlc->id, htlc_state_name(htlc->state));
 		return CHANNEL_ERR_HTLC_NOT_IRREVOCABLE;
 	}
-	/* The HTLC owner is the recipient of the failure. */
-	channel->changes_pending[owner] = true;
 
 	dump_htlc(htlc, "FAIL:");
 	if (htlcp)
@@ -1008,29 +997,23 @@ bool channel_update_feerate(struct channel *channel, u32 feerate_per_kw)
 		     side_to_str(!channel->funder), feerate_per_kw);
 
 	start_fee_update(channel->fee_states, channel->funder, feerate_per_kw);
-
-	channel->changes_pending[!channel->funder] = true;
 	return true;
 }
 
 bool channel_sending_commit(struct channel *channel,
 			    const struct htlc ***htlcs)
 {
+	int change;
 	const enum htlc_state states[] = { SENT_ADD_HTLC,
 					   SENT_REMOVE_REVOCATION,
 					   SENT_ADD_REVOCATION,
 					   SENT_REMOVE_HTLC };
 	status_debug("Trying commit");
 
-	if (!channel->changes_pending[REMOTE]) {
-		assert(change_htlcs(channel, REMOTE, states, ARRAY_SIZE(states),
-				    htlcs, "testing sending_commit") == 0);
-		return false;
-	}
-
-	change_htlcs(channel, REMOTE, states, ARRAY_SIZE(states),
+	change = change_htlcs(channel, REMOTE, states, ARRAY_SIZE(states),
 			      htlcs, "sending_commit");
-	channel->changes_pending[REMOTE] = false;
+	if (!change)
+		return false;
 
 	return true;
 }
@@ -1049,31 +1032,23 @@ bool channel_rcvd_revoke_and_ack(struct channel *channel,
 			      htlcs, "rcvd_revoke_and_ack");
 
 	/* Their ack can queue changes on our side. */
-	if (change & HTLC_LOCAL_F_PENDING)
-		channel->changes_pending[LOCAL] = true;
-
-	return channel->changes_pending[LOCAL];
+	return (change & HTLC_LOCAL_F_PENDING);
 }
 
 /* FIXME: We can actually merge these two... */
 bool channel_rcvd_commit(struct channel *channel, const struct htlc ***htlcs)
 {
+	int change;
 	const enum htlc_state states[] = { RCVD_ADD_REVOCATION,
 					   RCVD_REMOVE_HTLC,
 					   RCVD_ADD_HTLC,
 					   RCVD_REMOVE_REVOCATION };
 
 	status_debug("Received commit");
-	if (!channel->changes_pending[LOCAL]) {
-		assert(change_htlcs(channel, LOCAL, states, ARRAY_SIZE(states),
-				    htlcs, "testing rcvd_commit") == 0);
+	change = change_htlcs(channel, LOCAL, states, ARRAY_SIZE(states),
+			      htlcs, "rcvd_commit");
+	if (!change)
 		return false;
-	}
-
-	change_htlcs(channel, LOCAL, states, ARRAY_SIZE(states), htlcs,
-		     "rcvd_commit");
-
-	channel->changes_pending[LOCAL] = false;
 	return true;
 }
 
@@ -1089,10 +1064,7 @@ bool channel_sending_revoke_and_ack(struct channel *channel)
 			      "sending_revoke_and_ack");
 
 	/* Our ack can queue changes on their side. */
-	if (change & HTLC_REMOTE_F_PENDING)
-		channel->changes_pending[REMOTE] = true;
-
-	return channel->changes_pending[REMOTE];
+	return (change & HTLC_REMOTE_F_PENDING);
 }
 
 size_t num_channel_htlcs(const struct channel *channel)

common/initial_channel.c

@@ -43,8 +43,6 @@ struct channel *new_initial_channel(const tal_t *ctx,
 	channel->funding_pubkey[LOCAL] = *local_funding_pubkey;
 	channel->funding_pubkey[REMOTE] = *remote_funding_pubkey;
 	channel->htlcs = NULL;
-	channel->changes_pending[LOCAL] = channel->changes_pending[REMOTE]
-		= false;
 
 	/* takes() if necessary */
 	channel->fee_states = dup_fee_states(channel, fee_states);

common/initial_channel.h

@@ -53,9 +53,6 @@ struct channel {
 	/* All live HTLCs for this channel */
 	struct htlc_map *htlcs;
 
-	/* Do we have changes pending for ourselves/other? */
-	bool changes_pending[NUM_SIDES];
-
 	/* Fee changes, some which may be in transit */
 	struct fee_states *fee_states;