refresh_from_db() does not create "soft links" on model_instances that are pointed to by another model's OneToOneField

[Keith Hostetler]

Sorry for the poor summary, it is difficult to explain in words. I have a project to demo this bug attached to this ticket, but I will try to explain the bug anyway in steps and the setup.

Setup:

• 2 models (A and B)
• B has a OneToOne to A
• Both A and B have a field (ie TextField)
• Setup either a signal or override save() for A to update B's TextField to equal that of A's on save() or post_save for signals

Steps:

• Create instance of A
• Get another copy of the instance of A via A.objects.get()
• Create instance of B using the copy of the instance of A
• Do refresh_from_db() on original instance of A
• Try to access B from A

The project I have provided is a slim version of this problem that demonstrates it with signals, overriden save(), and basic set and save inside the test. The basic set and save works, but the other two fail when using the above steps. Run the test suite to see.