[andybak]

I think in that case - the new person should probably post a new question.

The point is that the original question - as framed - was better served by saying "if you go back a step and reexamine your assumptions, you'll find there is a better path to your intended goal".

The new person has a different goal or a different set of constraints.

[detaro]

Because asking new questions and getting them closed as duplicate because they sound vaguely similar to an existing question is sooo helpful an experience...

[andybak]

Yeah - but I'm just playing with hypothetical ideal cases here. "Annoying flawed habits of Stack Overflow moderators" isn't something that's on my list of things I'm thinking about. ;-)

EDIT - which got me thinking. Maybe the "correct" thing to do is answer the original question as asked but gently point out to the person asking it that there is probably a better solution for them if only they had asked a different question.

The original question still stands and has an answer useful for other people. The original questioner has the opportunity to learn and ask the question they should have asked in the first place.

It's going to be annoying for someone - so it should at least be the person that kicked things off in the first place.