Fix: Flie.objects.only("id") query when deleting a user.

[wiltso]

Description

When deleting a User object, Django's django.db.models.deletion.Collector will make a query like this: File.objects.filter(owner=user).only("id"). This then leads to a recursion error due to that the filler.models.File object requires that the following fields are present:

• _file_size
• sha1
• is_public

Related resources

• https://github.com/django-cms/django-filer/issues/1290

Checklist

• [x] I have opened this pull request against master
• [x] I have added or modified the tests when changing logic
• [x] I have followed the conventional commits guidelines to add meaningful information into the changelog
• [x] I have read the contribution guidelines and I have joined #workgroup-pr-review on Slack to find a “pr review buddy” who is going to review my pull request.

[codecov[bot]]

Codecov Report

Merging #1308 (320c7ff) into master (34803bc) will increase coverage by 0.05%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1308      +/-   ##
==========================================
+ Coverage   72.39%   72.45%   +0.05%     
==========================================
  Files          72       72              
  Lines        3268     3275       +7     
  Branches      532      532              
==========================================
+ Hits         2366     2373       +7     
  Misses        735      735              
  Partials      167      167              

Impacted Files	Coverage Δ
filer/models/filemodels.py	86.95% <100.00%> (+0.40%)	:arrow_up:

[vinitkumar]

@wiltso Do you remember if the error you got is almost like this?

IntegrityError at /admin/customroles/siteuser/
update or delete on table "auth_user" violates foreign key constraint "filer_file_owner_id_b9e32671_fk_auth_user_id" on table "filer_file"
DETAIL: Key (id)=(89) is still referenced from table "filer_file".

[wiltso]

I was actually getting an recursion error. You can replicate it by doing File.objects.filter(owner=u).only("id").

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale[bot]]

This will now be closed due to inactivity, but feel free to reopen it.

[fsbraun]

@wiltso Sorry, that this got "lost". I would like to take it up. I'd really appreciate, if we could add a test for it:

• Create user
• Create filer object
• Delete user

Do you think you could add such an test?

[fsbraun]

@wiltso I've created a follow-up PR (#1357) that includes the cherry-pick of this PR and a simple test. I really would like to get this fix merged now.

[fsbraun]

Implemented in #1357