Fixed #18432 -- Prevented the ForeignKey field from creating an invalid query when chained. Thanks, Jann Kleen.

tests/regressiontests/model_regress/tests.py

@@ -8,8 +8,7 @@ from django.test import TestCase, skipUnlessDBFeature
 from django.utils import tzinfo
 
 from .models import (Worker, Article, Party, Event, Department,
-    BrokenUnicodeMethod, NonAutoPK)
-
+    BrokenUnicodeMethod, NonAutoPK, Model1, Model2, Model3)
 
 
 class ModelTests(TestCase):
@@ -47,7 +46,7 @@ class ModelTests(TestCase):
         a = Article.objects.create(
             headline="Really, really big",
             pub_date=datetime.datetime.now(),
-            article_text = "ABCDE" * 1000
+            article_text="ABCDE" * 1000
         )
         a = Article.objects.get(pk=a.pk)
         self.assertEqual(len(a.article_text), 5000)
@@ -164,6 +163,19 @@ class ModelTests(TestCase):
             1
         )
 
+    def test_chained_fks(self):
+        """
+        Regression for #18432: Chained foreign keys with to_field produce incorrect query
+        """
+
+        m1 = Model1.objects.create(pkey=1000)
+        m2 = Model2.objects.create(model1=m1)
+        m3 = Model3.objects.create(model2=m2)
+
+        # this is the actual test for #18432
+        m3 = Model3.objects.get(model2=1000)
+        m3.model2
+
 
 class ModelValidationTest(TestCase):
     def test_pk_validation(self):