add unified-invoices config option and warnings

contrib/startup_regtest.sh

@@ -108,6 +108,7 @@ start_nodes() {
 			funder-fuzz-percent=0
 			lease-fee-base-sat=2sat
 			lease-fee-basis=50
+			unified-invoices
 			EOF
 		fi
 

lightningd/invoice.c

@@ -699,7 +699,8 @@ add_routehints(struct invoice_info *info,
 	       bool *warning_capacity,
 	       bool *warning_deadends,
 	       bool *warning_offline,
-	       bool *warning_private_unused)
+	       bool *warning_private_unused,
+		   bool *warning_fallbacks)
 {
 	const struct chanhints *chanhints = info->chanhints;
 	bool node_unpublished;
@@ -797,6 +798,7 @@ add_routehints(struct invoice_info *info,
 	*warning_offline = false;
 	*warning_deadends = false;
 	*warning_private_unused = false;
+	*warning_fallbacks = info->cmd->ld->unified_invoices && info->b11->fallbacks;
 	if (amount_msat_greater(needed, avail_capacity)) {
 		struct amount_msat tot;
 
@@ -836,7 +838,8 @@ invoice_complete(struct invoice_info *info,
 		 bool warning_capacity,
 		 bool warning_deadends,
 		 bool warning_offline,
-		 bool warning_private_unused)
+		 bool warning_private_unused,
+		 bool warning_fallbacks)
 {
 	struct json_stream *response;
 	u64 inv_dbid;
@@ -907,6 +910,10 @@ invoice_complete(struct invoice_info *info,
 		json_add_string(response, "warning_private_unused",
 				"Insufficient incoming capacity, once private channels were excluded (try exposeprivatechannels=true?)");
 
+	if (warning_fallbacks)
+		json_add_string(response, "warning_fallbacks",
+				"Not tracking on-chain payments for custom fallback addresses");
+
 	return command_success(info->cmd, response);
 }
 
@@ -918,14 +925,15 @@ static void listincoming_done(const char *buffer,
 {
 	struct lightningd *ld = info->cmd->ld;
 	struct command_result *ret;
-	bool warning_mpp, warning_capacity, warning_deadends, warning_offline, warning_private_unused;
+	bool warning_mpp, warning_capacity, warning_deadends, warning_offline, warning_private_unused, warning_fallbacks;
 
 	ret = add_routehints(info, buffer, toks,
 			     &warning_mpp,
 			     &warning_capacity,
 			     &warning_deadends,
 			     &warning_offline,
-			     &warning_private_unused);
+			     &warning_private_unused,
+				 &warning_fallbacks);
 	if (ret)
 		return;
 
@@ -937,7 +945,8 @@ static void listincoming_done(const char *buffer,
 			 warning_capacity,
 			 warning_deadends,
 			 warning_offline,
-			 warning_private_unused);
+			 warning_private_unused,
+			 warning_fallbacks);
 	db_commit_transaction(ld->wallet->db);
 }
 
@@ -1110,6 +1119,7 @@ static struct command_result *json_invoice(struct command *cmd,
 		   p_opt_def("cltv", param_number, &cltv,
 			     cmd->ld->config.cltv_final),
 		   p_opt_def("deschashonly", param_bool, &hashonly, false),
+		//    p_opt_def("unified_invoices", param_bool, &hashonly, cmd->ld->unified_invoices),
 #if DEVELOPER
 		   p_opt("dev-routes", param_array, &routes),
 #endif
@@ -1131,6 +1141,12 @@ static struct command_result *json_invoice(struct command *cmd,
 	}
 
 	if (fallbacks) {
+		if (cmd->ld->unified_invoices) {
+			log_info(cmd->ld->log,
+					"WARNING: Not tracking on-chain payments "
+				    "for custom fallback addresses"
+					);
+		}
 		size_t i;
 		const jsmntok_t *t;
 
@@ -1193,7 +1209,7 @@ static struct command_result *json_invoice(struct command *cmd,
 	plugin = find_plugin_for_command(cmd->ld, "listincoming");
 	if (!plugin) {
 		return invoice_complete(info, true,
-					false, false, false, false, false);
+					false, false, false, false, false, false);
 	}
 
 	req = jsonrpc_request_start(info, "listincoming",

lightningd/lightningd.h

@@ -369,6 +369,9 @@ struct lightningd {
 	/* --experimental-upgrade-protocol */
 	bool experimental_upgrade_protocol;
 
+	/* --unified-invoices */
+	bool unified_invoices;
+
 	/* For anchors: how much do we keep for spending close txs? */
 	struct amount_sat emergency_sat;
 };

lightningd/options.c

@@ -1483,6 +1483,9 @@ static void register_opts(struct lightningd *ld)
 	opt_register_noarg("--experimental-upgrade-protocol",
 			   opt_set_bool, &ld->experimental_upgrade_protocol,
 			   "experimental: allow channel types to be upgraded on reconnect");
+	opt_register_noarg("--unified-invoices",
+			   opt_set_bool, &ld->unified_invoices,
+			   "emit unified invoices and mark them as paid if payment is received on-chain");
 	clnopt_witharg("--database-upgrade", OPT_SHOWBOOL,
 		       opt_set_db_upgrade, NULL,
 		       ld,