Follow-up from "Remove border radius for diff comments"
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The following discussion from !208361 should be addressed:
From @clavimoniere's [suggestion](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/208361#note_2813655702):
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Looks like this is the case.
Here's a code comment thread in an archived project's MR:
| Your changes | Prod |
|--------------|------|
|  |  |
The same applies when the discussion is locked and you are not allowed to comment:
| Your changes | Prod |
|--------------|------|
|  |  |
It's not visible because there is no background/border, but your changes _do_ fix the styles of this element when the user is signed out:
| Your changes | Prod |
|--------------|------|
|  |  |
So I think instead of removing this, some other conditional application is necessary, because sometimes this does need to be rounded (seems like only when the project is archived or discussion is locked and the current user can't comment?)
>>>
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