A small demo of DRF issue 3219 that might cause dataloss in a multipart PATCH request when a nested serializer is present.

Issue link

The Demo has a "Startup" class because that was the one present in my larger project where I discovered this issue.

The issue itself is described at the link above, and on the code level see: https://github.com/elnygren/drf-issue-3219/blob/master/DRFerror/views.py#L33

Short description of the problem:

• see the views.py above first
• validated_data is populated with an empty OrderedDict() object for admin
• serializer.save() is usually implemented in a way that could then null this relationship to admin as an OrderedDict is not a admin object, but an empty object.
• like described at the link, this issue could be present in other DRF Fields.

Dependencies

• Python 3.4.3
• requirements.txt:
  • Django 1.7.4
  • Django Rest Framework 3.1.3
  • Pillow (for file uploads)

Database state:

• create a root user and another user
• see dumpdata for Startup

PATCH request: