Commit fd589719 authored by Anubhav Joshi's avatar Anubhav Joshi Committed by Tim Graham
Browse files

Fixed problem with refs #10811. 

When 'to_field' is specified with a FK, then we need to check the pk value
the object.
parent add78c58

django/db/models/fields/related.py

+3 −3
Original line number Diff line number Diff line
@@ -623,13 +623,13 @@ class ReverseSingleRelatedObjectDescriptor(object): 
        # Set the values of the related field.

        else:

            for lh_field, rh_field in self.field.related_fields:

                val = getattr(value, rh_field.attname)

                if val is None:

                pk = value._get_pk_val()

                if pk is None:

                    raise ValueError(

                        'Cannot assign "%r": "%s" instance isn\'t saved in the database.' %

                        (value, self.field.rel.to._meta.object_name)

                    )

                setattr(instance, lh_field.attname, val)

                setattr(instance, lh_field.attname, getattr(value, rh_field.attname))



        # Since we already know what the related object is, seed the related

        # object caches now, too. This avoids another db hit if you get the

tests/many_to_one_regress/models.py

+5 −1
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ class Third(models.Model): 




class Parent(models.Model):

    name = models.CharField(max_length=20)

    name = models.CharField(max_length=20, unique=True)

    bestchild = models.ForeignKey('Child', null=True, related_name='favored_by')
@@ -35,6 +35,10 @@ class Child(models.Model): 
    parent = models.ForeignKey(Parent)





class ToFieldChild(models.Model):

    parent = models.ForeignKey(Parent, to_field='name')





# Multiple paths to the same model (#7110, #7125)

@python_2_unicode_compatible

class Category(models.Model):

tests/many_to_one_regress/tests.py

+8 −3
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ from django.db import models 
from django.test import TestCase



from .models import (

    First, Third, Parent, Child, Category, Record, Relation, Car, Driver)

    First, Third, Parent, Child, ToFieldChild, Category, Record, Relation, Car, Driver)





class ManyToOneRegressionTests(TestCase):
@@ -71,6 +71,11 @@ class ManyToOneRegressionTests(TestCase): 
                % (p, Child.parent.field.rel.to._meta.object_name)):

            Child(parent=p)



        with self.assertRaisesMessage(ValueError,

                'Cannot assign "%r": "%s" instance isn\'t saved in the database.'

                % (p, Child.parent.field.rel.to._meta.object_name)):

            ToFieldChild(parent=p)



        # Creation using attname keyword argument and an id will cause the

        # related object to be fetched.

        p = Parent.objects.get(name="Parent")