请教大神，将链表数据按照从小到大的顺序重新排列哪里错了啊

bool range(list*&L) //使链表数据由小到大排列
{
    if (L->next==NULL||L->next->next==NULL)//只有一个元素或者是空表
    {
        return false;
    }
    list *p=L->next,*q=p,*pre=L;
    while (p->next!=NULL)
    {
        q=p->next;
        while (pre!=p)
        {
            if ( q->date< pre->next->date )
            {
                p->next=q->next;
                q->next=pre->next;
                pre->next=q;
                break;
            }
            else
            pre=pre->next;
        }
        p=p->next;
        pre=L;
    }
    return true;
}