From a7b5ad8b19a08d7d57302ece74f6e26d2887fd9f Mon Sep 17 00:00:00 2001
From: Paulo <commonzenpython@gmail.com>
Date: Tue, 19 Sep 2017 12:51:19 -0500
Subject: [PATCH] Fixed #27846 -- Made Model.refresh_from_db() clear cached
 relations.

---
 django/db/models/base.py |  6 ++++++
 tests/basic/models.py    |  4 ++++
 tests/basic/tests.py     | 13 ++++++++++++-
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/django/db/models/base.py b/django/db/models/base.py
index dc59143eb57..87bd8c09bf5 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -627,6 +627,12 @@ class Model(metaclass=ModelBase):
                 related_val = None if rel_instance is None else getattr(rel_instance, field.target_field.attname)
                 if local_val != related_val or (local_val is None and related_val is None):
                     field.delete_cached_value(self)
+
+        # Clear cached relations.
+        for field in self._meta.related_objects:
+            if field.is_cached(self):
+                field.delete_cached_value(self)
+
         self._state.db = db_instance._state.db
 
     def serializable_value(self, field_name):
diff --git a/tests/basic/models.py b/tests/basic/models.py
index c08b147ac47..40de6ae7de5 100644
--- a/tests/basic/models.py
+++ b/tests/basic/models.py
@@ -17,6 +17,10 @@ class Article(models.Model):
         return self.headline
 
 
+class FeaturedArticle(models.Model):
+    article = models.OneToOneField(Article, models.CASCADE, related_name='featured')
+
+
 class ArticleSelectOnSave(Article):
     class Meta:
         proxy = True
diff --git a/tests/basic/tests.py b/tests/basic/tests.py
index d8775621163..7a99ab0cf02 100644
--- a/tests/basic/tests.py
+++ b/tests/basic/tests.py
@@ -10,7 +10,7 @@ from django.test import (
 )
 from django.utils.translation import gettext_lazy
 
-from .models import Article, ArticleSelectOnSave, SelfRef
+from .models import Article, ArticleSelectOnSave, FeaturedArticle, SelfRef
 
 
 class ModelInstanceCreationTests(TestCase):
@@ -711,3 +711,14 @@ class ModelRefreshTests(TestCase):
         a = Article.objects.create(pub_date=datetime.now())
         with self.assertNumQueries(0):
             a.refresh_from_db(fields=[])
+
+    def test_refresh_clears_reverse_related(self):
+        """refresh_from_db() clear cached reverse relations."""
+        article = Article.objects.create(
+            headline='Parrot programs in Python',
+            pub_date=datetime(2005, 7, 28),
+        )
+        self.assertFalse(hasattr(article, 'featured'))
+        FeaturedArticle.objects.create(article_id=article.pk)
+        article.refresh_from_db()
+        self.assertTrue(hasattr(article, 'featured'))