Wait for new participant admission before the poll fixture opens its group session

tests/test_chat_poll_network.c

@@ -228,6 +228,10 @@ int main(void) {
     seed_members(x, ed, owner_private, 4);
     struct NODE_CONN_DIRECT* bd = connect_node(1, 3, ports[3]);
     assert(wait_new_transport(1, 3, bd));
+    uint64_t admission_deadline = get_time_tb() + 150000;
+    while (!topo_node_sqlite_member_allowed(nodes[1]->topo_sqlite_db, channel, nodes[3]->node_id) &&
+        get_time_tb() < admission_deadline) uasync_poll(ua, 5);
+    assert(topo_node_sqlite_member_allowed(nodes[1]->topo_sqlite_db, channel, nodes[3]->node_id));
     assert(topo_group_peer_open(topo_groups_find(nodes[1]->topo_groups, gid), nodes[3]->node_id, &groups[3]) == 0);
     assert(topo_group_peer_open(topo_groups_find(nodes[3]->topo_groups, gid), nodes[1]->node_id, &groups[4]) == 0);
     assert(wait_ready(groups[3]) && wait_ready(groups[4])); subscribe(1, 3);