If commenting is closed for a content type, then hide all comment-related settings

[alanmels]

Description of the bug

As title suggests, if commenting is closed for a content type, then all comment-related settings should not be available.

Steps To Reproduce

To reproduce the behavior:

1. Go to 'admin/structure/types/manage/any_content_type'
2. Click on 'Comment settings' option on the vertical menu and check the "Closed comments" option.

3. All other comment-related settings on the same page should be hidden immediately, but they are still there.

4. After saving this page, the Comment fields and Comment display tabs should disappear, but they are still there.

[laryn]

In general I like the premise of this issue, but... is it possible that comments have been open and are then closed, but the existing comments should still be visible? (e.g. there's even a core feature to "automatically close comments on old content" -- is it acceptable to hide all comment-related controls for that situation?)

[alanmels]

@laryn, all the respective options and tabs are supposed to be just hidden (or prevented access to), so whenever a user needs to re-visit them s/he would just go to the Comment settings, check on the Open comments option and all hidden options on the same page would become available right away, and the two tabs - after the form is saved.

[avpaderno]

Hiding all the settings form fields basing on the value of a single setting seems a bad UX design, to me. Hiding a single form field is more acceptable (although I take a better UX would make some form fields disabled). Hiding a tab basing on a setting value seems bad design too; users should change the value for Default comment setting for new content to see those tabs and change back the value of Default comment setting for new content.

[ghost]

Not sure if this is a duplicate of, or just similar to, this other issue: https://github.com/backdrop/backdrop-issues/issues/3016

But worth mentioning in any case.