Is it ok to be editing a post that might render someone's comment on that post as irrelevant?

Question

Let's say I have edited a post for (I believe) justified reasons (formatting, tagline etc)

Someone else left a comment relating to that content as well about the same time

After my edit, the comment looks detached and irrelevant

What is the nice way to let the author of the comment a chance to edit remove it?

1. leave a comment mentioning the original comenter explaining I rendered his comment obsolete?
2. do nothing, such is the way of life
3. not edit posts that will make someone's comments look, well, silly
4. mark it as a great comment to ease your conscience

Same goes with deleting your comment, making "reply" comments look out of context

What is the right thing to do?

Answer 1

Comments are the lowest thing in the pecking order. Improving questions or answers should not be avoided just to protect a comment.

You can always @notify the person who posted saying you fixed the problem (they'll probably delete) or flag the comment as "obsolete" if it's now such.

Don't upvote obsoleted comments and don't go out of your way to protect them. If content is important it should be an answer or an edit, not a comment. Most people will realise that comments are likely to suffer from this and won't judge the poster (for anything other than not deleting an obsoleted comment they're clearly aware of - if you know your comment is obsolete you should delete it).

Answer 2

Yes, it's fine - that's in part what comments are for. Simply flag the comment as obsolete afterwards so that it can be removed.

Answer 3

Is it ok to be editing a post that might render someone's comment on that post as irrelevant?

Yes, this is perfectly okay. Not only are comments largely irrelevant, but they're also ephemeral. One of their main purposes is to make a temporary suggestion to someone on how to revise or clarify a post. Once that's done, the comment serves no purpose and should be removed.

What is the nice way to let the author of the comment a chance to edit remove it?

1. leave a comment mentioning the original comenter explaining I rendered his comment obsolete?

I would definitely do this. Use the @reply system to send a courtesy ping to the user who left the original comment, informing them that you've made the suggested edit. This serves several purposes:

1. If they cared enough to leave a comment, they probably care about the topic under discussion. This gives them a chance to read your new thoughts, and if necessary, make further suggestions.
2. It gives them a chance to remove their now-obsolete comment.
3. If they downvoted, it gives them a chance to remove their now-invalid downvote.

If they never do come back, or never remove their comment, you can always flag the comment as "obsolete" to have a moderator remove it. Be sure to remove your response, also!

2. do nothing, such is the way of life

That might be the way of life, but I'm not sure it's particularly advantageous here.

3. not edit posts that will make someone's comments look, well, silly

No, this would definitely be the wrong thing to do.

4. mark it as a great comment to ease your conscience

I guess you could, but this does seem rather pointless.