From 6694d7c5aeeab45980765909f45e51672eef0386 Mon Sep 17 00:00:00 2001
From: Jonathan Kim <jkimbo@gmail.com>
Date: Mon, 1 Jul 2019 17:36:16 +0100
Subject: [PATCH 1/2] Fix default manager check

---
 graphene_django/fields.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/graphene_django/fields.py b/graphene_django/fields.py
index 8c8fa2bd7..eb1215ead 100644
--- a/graphene_django/fields.py
+++ b/graphene_django/fields.py
@@ -101,7 +101,7 @@ def resolve_connection(cls, connection, default_manager, args, iterable):
             iterable = default_manager
         iterable = maybe_queryset(iterable)
         if isinstance(iterable, QuerySet):
-            if iterable is not default_manager:
+            if iterable.model.objects is not default_manager:
                 default_queryset = maybe_queryset(default_manager)
                 iterable = cls.merge_querysets(default_queryset, iterable)
             _len = iterable.count()

From daee6e53514f0061629862c60f39e40f58393145 Mon Sep 17 00:00:00 2001
From: Jonathan Kim <jkimbo@gmail.com>
Date: Mon, 1 Jul 2019 18:27:35 +0100
Subject: [PATCH 2/2] Add test

---
 graphene_django/tests/test_query.py | 51 +++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/graphene_django/tests/test_query.py b/graphene_django/tests/test_query.py
index 484a225aa..f4661221c 100644
--- a/graphene_django/tests/test_query.py
+++ b/graphene_django/tests/test_query.py
@@ -1065,3 +1065,54 @@ class Query(graphene.ObjectType):
     result = schema.execute(query)
     assert not result.errors
     assert result.data == expected
+
+
+def test_should_preserve_prefetch_related(django_assert_num_queries):
+    class ReporterType(DjangoObjectType):
+        class Meta:
+            model = Reporter
+            interfaces = (graphene.relay.Node,)
+
+    class FilmType(DjangoObjectType):
+        reporters = DjangoConnectionField(ReporterType)
+
+        class Meta:
+            model = Film
+            interfaces = (graphene.relay.Node,)
+
+    class Query(graphene.ObjectType):
+        films = DjangoConnectionField(FilmType)
+
+        def resolve_films(root, info):
+            qs = Film.objects.prefetch_related("reporters")
+            return qs
+
+    r1 = Reporter.objects.create(first_name="Dave", last_name="Smith")
+    r2 = Reporter.objects.create(first_name="Jane", last_name="Doe")
+
+    f1 = Film.objects.create()
+    f1.reporters.set([r1, r2])
+    f2 = Film.objects.create()
+    f2.reporters.set([r2])
+
+    query = """
+        query {
+            films {
+                edges {
+                    node {
+                        reporters {
+                            edges {
+                                node {
+                                    firstName
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    """
+    schema = graphene.Schema(query=Query)
+    with django_assert_num_queries(3) as captured:
+        result = schema.execute(query)
+    assert not result.errors