// try to merge back to an existing request
iter = m_delayed_requests.lower_bound(object_off);
- if (iter == m_delayed_requests.end() || iter->first > object_off) {
+ if (iter != m_delayed_requests.begin() &&
+ (iter == m_delayed_requests.end() || iter->first > object_off)) {
iter--;
}
if (iter != m_delayed_requests.end() &&