From d76e4e71497b9b10ceed3de8979c77a07d283d57 Mon Sep 17 00:00:00 2001
From: 21M4TW <21m4tw@proton.me>
Date: Wed, 28 Jan 2026 15:23:11 +1030
Subject: [PATCH] lightningd: don't allow enableoffer on single-use offer.

Changelog-Fixed: enableoffer: Adding an error when trying to activate an used single use offer (don't crash!)
---
 common/jsonrpc_errors.h | 1 +
 lightningd/offer.c      | 4 ++++
 tests/test_pay.py       | 1 -
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/common/jsonrpc_errors.h b/common/jsonrpc_errors.h
index d3fe80d53..a2ea1bf1b 100644
--- a/common/jsonrpc_errors.h
+++ b/common/jsonrpc_errors.h
@@ -116,6 +116,7 @@ enum jsonrpc_errcode {
 	OFFER_BAD_INVREQ_REPLY = 1004,
 	OFFER_TIMEOUT = 1005,
 	OFFER_ALREADY_ENABLED = 1006,
+	OFFER_USED_SINGLE_USE = 1007,
 
 	/* Errors from datastore command */
 	DATASTORE_DEL_DOES_NOT_EXIST = 1200,
diff --git a/lightningd/offer.c b/lightningd/offer.c
index bd4357eb3..50edd4d4f 100644
--- a/lightningd/offer.c
+++ b/lightningd/offer.c
@@ -282,6 +282,10 @@ static struct command_result *json_enableoffer(struct command *cmd,
 		return command_fail(cmd, OFFER_ALREADY_ENABLED,
 				    "offer already active");
 
+	if (offer_status_single(status) && offer_status_used(status))
+		return command_fail(cmd, OFFER_USED_SINGLE_USE,
+				    "cannot activate an used single use offer");
+
 	if (command_check_only(cmd))
 		return command_check_done(cmd);
 
diff --git a/tests/test_pay.py b/tests/test_pay.py
index 980f39355..de53bb3c4 100644
--- a/tests/test_pay.py
+++ b/tests/test_pay.py
@@ -4509,7 +4509,6 @@ def test_fetchinvoice_3hop(node_factory, bitcoind):
     l1.rpc.call('fetchinvoice', {'offer': offer1['bolt12']})
 
 
-@pytest.mark.xfail(strict=True)
 def test_fetchinvoice(node_factory, bitcoind):
     # We remove the conversion plugin on l3, causing it to get upset.
     l1, l2, l3 = node_factory.line_graph(3, wait_for_announce=True,