if (thread == top && (thread = thread->child) == NULL) {
/* return value depends on action requested */
if (flag & (M_THREAD_COLLAPSE | M_THREAD_UNCOLLAPSE))
if (thread == top && (thread = thread->child) == NULL) {
/* return value depends on action requested */
if (flag & (M_THREAD_COLLAPSE | M_THREAD_UNCOLLAPSE))