Zammad: Deletion of notes impossible if internal and communication = true

Infos:

• Used Zammad version: 3.2
• Installation method (source, package, ..): any
• Operating system: any
• Database + version: any
• Elasticsearch version: any
• Browser + version: any (tested and verified on Chrome)
• Ticket-ID (original issue): #1060109
• Ticket-ID (regression affected users): #1080817

Expected behavior:

When changing notes to communication: true, you still can delete your own created internal notes (within the 10 minutes).

Actual behavior:

When changing notes to communication: true, you won't be able to delete your own internal notes within 10 minutes any longer. This requies you to have agent rights only (so nothing administrative).

Sidenote:

SLAs ignore internal notes (if the communication attribute is set to true) which is why it still should be possible to delete them and (if not, admins shouldn't be allowed as well).

I think it's the following line striking here:
https://github.com/zammad/zammad/blob/f35cd7fbe9d94b8353147c420853b369e82d46ee/app/controllers/ticket_articles_controller.rb#L151

Steps to reproduce the behavior:

• change the ticket article type 'note' from communication: false to communication: true
• login as agent
• open any ticket (or create a new one)
• post an internal note to the ticket
• (deletion button is presented) try to delete the note
  
  
  
  • error message not authorized (admin permission required)! or not authorized is returned via UI
  
  

Yes I'm sure this is a bug and no feature request or a general question.