thread renames: skip the system comment IFF the renamer is the only commenter

[cellio]

meta:295463

Followup to #714: if the person renaming a comment thread is the only person who has commented so far, rename without adding the system comment. Such a change isn't putting words in anyone else's mouth or changing context out from other thread participants; it's as if the creator of the thread had used the new name from the start.

Let's include deleted comments in the check, because deleted comments can be undeleted. In the case where all activity is from one person, allow that person to silently rename. For anything else, keep the system comment (and people can flag if it's really just a typo fix).

[trichoplax]

In this case, do we still want a record of the change for auditing, but visible only to some (maybe only moderators)?

If a malicious user adds a new thread under someone's post with an offensive message in the title, and then edits the title before any moderators see it, presumably we still want moderators to see that this has happened in the event it was flagged?

[cellio]

That's a good point. Should we add the system comment as usual but delete it in this case? That way it's still there for mods (and I forget, curators?), but most people won't see it.

[trichoplax]

Should we add the system comment as usual but delete it in this case?

Interesting idea. That saves creating an extra type of comment visibility.

If curators can see deleted comments I guess it's just a question of whether this would be an irritation for curators if the majority of cases are innocuous. I would expect a curator who feels strongly about not wanting to see this to also not want to see most other deleted things though, so maybe just provide a user setting to switch off the Curate ability for users who don't want it, or who don't always want it. So for this issue, just deleting the system comment when the renamer is the only commenter sounds good to me.

[cellio]

I wouldn't even worry about special settings or modes. If we didn't have this and it was deleted by a mod in response to a flag, anybody who can see deleted comments would see it. You don't actually see deleted comments unless you ask for them (there's just a link saying "1 deleted; show anyway"), so it's not in people's faces. Simple is better.

Just tested because I couldn't remember: curators do not currently see deleted comments. So the number of affected people is pretty small.

[Oaphi]

Just keep in mind that the more we build around a feature that's supposed to be temporary, the harder it'll be to take it out in the future. Granted, there's not a lot of manpower to always go the "right way", but it still needs to be considered. If we outline architecture for proper thread history here (access control in particular), it should be more or less straightforward to implement.