I find it hard to believe that this hasn't been asked before, but I wasn't able to find a dupe.
I've seen several new users go through these steps:
- post a code sample, without any other info, that contains multiple bugs
- get a fix for one of the bugs
- recompile and get a different error
- post a new question with nearly the same code but a different error
Usually, I and/or someone else will gently poke those users to let them know that they can edit their earlier questions instead of making a new post.
A certain new user made three such posts yesterday (one, two — 10k only, three) and just posted again about the same issue. I was about to post another comment asking him to edit an earlier post, but I noticed that his code today was somewhat different than it was yesterday.
Based on that code change, is this a legit separate question, even though it deals with the same topic discussed yesterday? One of the earlier answers even mentions code 450 vs. code 530. And, more generally, when is it appropriate to post a new question about a topic you've recently asked SO/SF/SU about, instead of editing the earlier post?