Deleting a user which has an unreviewed first kb article revision will delete the entire kb article even if the follow up revisions were reviewed

[emilghittasv]

Preconditions
Sign in to SUMO

Steps to reproduce
Steps to reproduce the behavior:

1. Go to https://support.allizom.org/en-US/kb/new.
2. Proceed with creating a new kb article and do not approve the first revision.
3. Create a new revision (with the same user or with a different one).
4. Approve the revision from step 3.
5. Delete the user from the preconditions.

Expected behavior
The first revision is dropped (since it was unreviewed) but the reviewed ones are kept.

Actual behavior
The entire kb article is deleted.

Desktop:

• OS: Windows 11
• Browser: Firefox

Additional context
This issue is reproducible in stage.

[akatsoulas]

@escattone by the time I realized that you have taken this issue, I had opened the PR. My apologies. Feel free to review or discard
mozilla/kitsune#6574

[escattone]

Here's what is happening:

• User1 first creates an un-approved revision for a fresh document. It's essential that this un-approved revision is created first, because it becomes the based_on for the next step.
• User2 creates an approved revision. This revision's based_on gets assigned to the un-approved revision of the first step above.
• User1 is deleted.
• This line is fine. It's this line that triggers the cascade of deletes that eventually deletes the document itself:
  • The unapproved revision is deleted.
  • Because the based_on of the approved revision is set to the unapproved revision, and because the on_delete is set to cascade, the approved revision is also deleted.
  • Because the current_revision of the document is set to the approved revision, and because the on_delete is set to cascade, the document is deleted.

[emilghittasv]

I can confirm that this issue is verified fixed in stage.

I'm moving this ticket inside the release column.