Fixing #10811 Prevet assigning of unsaved model to Foreign Key

[anubhav joshi]

I have tried fixiing #10811 https://code.djangoproject.com/ticket/10811

Earlier there were several errors popping up while running the test suite, but now I have fixed most of them.

Although there are 2 errors which  I am unable to fix some of them as I am unable to understand what the code is doing there.

Need help here..

https://github.com/django/django/pull/2162