listpays: change type answer is bolt11 is null

plugins/pay.c

@@ -1702,7 +1702,11 @@ static void add_new_entry(struct json_stream *ret,
 			  const struct pay_mpp *pm)
 {
 	json_object_start(ret, NULL);
-	json_add_string(ret, "bolt11", pm->b11);
+    if(pm->b11){
+	    json_add_string(ret, "bolt11", pm->b11);
+    }else{
+        json_add_sha256(ret, "payment_hash", pm->payment_hash);
+    }
 	json_add_string(ret, "status", pm->status);
 	if (pm->label)
 		json_add_tok(ret, "label", pm->label, buf);

tests/test_pay.py

@@ -3216,3 +3216,27 @@ def test_bolt11_null_after_pay(node_factory, bitcoind):
 
     pays = l2.rpc.listpays()["pays"]
     assert pays[0]["bolt11"] == invl1
+
+
+def test_listpay_resutl_with_paymod(node_factory, bitcoind):
+    """
+    The object of this test is to verify the correct behavior
+    of the RPC command listpay e with two different type of
+    payment, such as: keysend (without invoice) and pay (with invoice).
+    l1 -> keysend -> l2
+    l2 -> pay invoice -> l3
+    """
+
+    amount_sat = 10 ** 6
+
+    l1, l2, l3 = node_factory.line_graph(3)
+
+    invl2 = l2.rpc.invoice(amount_sat * 2, "inv_l2", "inv_l2")
+    l1.rpc.pay(invl2['bolt11'])
+
+    l2.rpc.keysend(l3.info['id'], amount_sat * 2, "keysend_l3")
+
+    assert 'bolt11' in l1.rpc.listpays()['pays'][0]
+    assert 'payment_hash' in l2.rpc.listpays()['pays'][0]
+    assert 'payment_hash' not in l1.rpc.listpays()['pays'][0]
+    assert 'bolt11' not in l2.rpc.listpays()['pays'][0]