Hidden groups shouldn't 404 if you do not have access

[r-a-y]

After looking at #7659, I decided to look into why we throw a 404 when we're on a hidden group instead of letting the user see a message of some kind.

Came across #3462 with the following explanation:

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For Hidden groups, I think we should change the behaviour so that if you don't have access, (all of) the link(s) 404. At the minute, you can see a "this is a hidden group and only invited members can join" message, but you can view the group title, description, and see the admin/moderator avatars.
This would be the same behaviour as if you try to access the group admin page URL without authorisation (it 404s), and I think it would be more consistent, as well as having the benefit of keeping the hidden group's title and description hidden.

The latter could be achieved by updating the templates but that means putting core logic into the default theme(!).

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The current behavior is poor UX in my opinion.

It seems the main points for throwing a 404 is to hide group data such as the title, description and avatars from being shown.

If that is the case, couldn't we just use wp_die() to output a message?

Attached patch does this and also displays a login form if the user isn't logged in.

Screenshot:

Patch is a working example, but we'd probably want to style the login form for a final iteration. wp_die() doesn't have a hook where we can inject CSS so we'd either have to override wp_die() via the 'wp_die_handler' filter or use inline CSS...

Let me know what you think.

[DJPaul]

For what it's worth, I still agree with the comments I made in the linked tickets from ~6 years ago.

[DJPaul]

Given no feedback from anyone else in the last 6 weeks, and that I feel very strongly about this, I don't think we should make this change. If a third party wants to contribute to the discussion, please re-open and comment.