offers: don't add blinded path from a disconnected peer.

Really, any peer without a live channel is a bad prospect.

This requires us to wire the "enabled" flag through listincoming:
fortunately that's an internal, undocumented interface, so we don't
have a schema change.

Changelog-Fixed: Offline peers no longer selected for blinded paths..

Signed-off-by: Rusty Russell <[email protected]>
Fixes: #8127

Author: rustyrussell

plugins/offers.c

@@ -339,6 +339,7 @@ static struct command_result *listincoming_done(struct command *cmd,
 		u8 *features;
 		const char *err;
 		struct amount_msat feebase;
+		bool enabled;
 
 		err = json_scan(tmpctx, buf, t,
 				"{id:%,"
@@ -347,14 +348,16 @@ static struct command_result *listincoming_done(struct command *cmd,
 				"htlc_max_msat:%,"
 				"fee_base_msat:%,"
 				"fee_proportional_millionths:%,"
-				"cltv_expiry_delta:%}",
+				"cltv_expiry_delta:%,"
+				"enabled:%}",
 				JSON_SCAN(json_to_pubkey, &ci.id),
 				JSON_SCAN(json_to_msat, &ci.capacity),
 				JSON_SCAN(json_to_msat, &ci.htlc_min),
 				JSON_SCAN(json_to_msat, &ci.htlc_max),
 				JSON_SCAN(json_to_msat, &feebase),
 				JSON_SCAN(json_to_u32, &ci.feeppm),
-				JSON_SCAN(json_to_u32, &ci.cltv));
+				JSON_SCAN(json_to_u32, &ci.cltv),
+				JSON_SCAN(json_to_bool, &enabled));
 		if (err) {
 			plugin_log(cmd->plugin, LOG_BROKEN,
 				   "Could not parse listincoming: %s",
@@ -363,6 +366,10 @@ static struct command_result *listincoming_done(struct command *cmd,
 		}
 		ci.feebase = feebase.millisatoshis; /* Raw: feebase */
 
+		/* Don't pick a peer which is disconnected */
+		if (!enabled)
+			continue;
+
 		/* Not presented if there's no channel_announcement for peer:
 		 * we could use listpeers, but if it's private we probably
 		 * don't want to blinded route through it! */

plugins/topology.c

@@ -670,6 +670,7 @@ listpeerchannels_listincoming_done(struct command *cmd,
 		peer_features = gossmap_node_get_features(tmpctx, gossmap, peer);
 		if (peer_features)
 			json_add_hex_talarr(js, "peer_features", peer_features);
+		json_add_bool(js, "enabled", ourchan->half[!dir].enabled);
 		json_object_end(js);
 	}
 done:

tests/test_pay.py

@@ -5679,7 +5679,6 @@ def test_blindedpath_privchan(node_factory, bitcoind):
     l1.rpc.pay(inv['invoice'])
 
 
-@pytest.mark.xfail(strict=True)
 def test_blindedpath_noaddr(node_factory, bitcoind):
     l1, l2 = node_factory.line_graph(2, wait_for_announce=True,
                                      opts={'dev-allow-localhost': None})