Adding a completely new item via raw_id_fields overwrites contents of the many-to-many field
|Reported by:||Owned by:||nobody|
|Has patch:||no||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
Steps to reproduce:
Define a many-to-many field, use raw_id_fields for the admin. Populate the field in the admin with one or more IDs. In the admin, click its magnifying glass. Click Add on the index page, and add one. Click Save.
You're automatically returned to the admin page with ONLY the new ID showing up in the field. This behavior is great for most foreign keys, but for many-to-many fields, it risks losing previous entries.