Function payment_result_infer

plugins/libplugin-pay.c:1188–1218

Try to infer the erring_node, erring_channel and erring_direction from what * we know, but don't override the values that are returned by `waitsendpay`. */

/* Try to infer the erring_node, erring_channel and erring_direction from what
 * we know, but don't override the values that are returned by `waitsendpay`.  */
static void payment_result_infer(struct route_hop *route,
				 struct payment_result *r)
{
	int i, len;
	assert(r != NULL);

	if (r->code == 0 || r->erring_index == NULL || route == NULL)
		return;

	len = tal_count(route);
	i = *r->erring_index;
	/* This can actually be greater than the route length?  Perhaps
	 * multi-hop routehints?  Ignore. */
	if (i > len)
		return;

	if (r->erring_node == NULL)
		r->erring_node = &route[i-1].node_id;

	/* The above check was enough for the erring_node, but might be off
	 * by one on channel and direction, in case the destination failed on
	 * us. */
	if (i == len)
		return;

	if (r->erring_channel == NULL)
		r->erring_channel = &route[i].scid;

	if (r->erring_direction == NULL)
		r->erring_direction = &route[i].direction;
}

/* If a node takes too much fee or cltv, the next one reports it.  We don't
 * know who to believe, but log it */