I merged a question on programmers.stackexchange.com earlier today and 20 minutes or so later someone came along and answered it. Shouldn't that have been impossible?
Here's the original question. It was merged into this one.
Is it possible to merge the answer now or should the user repost manually?
No, that is eminently sometimes possible.
We don't block answers that are "in flight" at the time of close, the window for answering -- assuming you've started composing an answer before the question is closed -- is about 4 hours.
It does mean the user intentionally ignored the popup warnings that are queried from the server every 45 seconds as they composed the answer, however.
Ah, also, I just noticed that we disable the "post your answer" button in this case, so it also implies there was some problem with JavaScript on their end.
I need to look a little more, but I'm not sure locking is handled in the same way.
edit: indeed, for historical reasons (locking had nothing to do with blocking answers until ~6 months ago) the user would not be notified in this case and the javascript alert + disabling the submit would not fire. I'm adding that notification now.
That said -- it's still possible for answers to arrive after closing or locking, and the code does allow that in a 4 hour window, but it should be freakishly rare. Also, the post draft support should soften the blow of "losing" an answer since it'll be saved as a draft regardless.
I believe this can occur when the person writing the answer starts composing it before the merge, then submits it after taking a long time to write. The author may even be unaware that the question has been merged.
Of course, there's no way to know for sure if that happened in this case, at least without access to the "saved drafts" DB table.
