1 files changed, 46 insertions, 1 deletions
diff --git a/tests/schema/tests.py b/tests/schema/tests.py
index a765528d50..7276912c71 100644
--- a/tests/schema/tests.py
+++ b/tests/schema/tests.py
@@ -14,7 +14,8 @@ from django.db.models.deletion import CASCADE, PROTECT
 from django.db.models.fields import (
     AutoField, BigAutoField, BigIntegerField, BinaryField, BooleanField,
     CharField, DateField, DateTimeField, IntegerField, PositiveIntegerField,
-    SlugField, TextField, TimeField, UUIDField,
+    SlugField, SmallAutoField, SmallIntegerField, TextField, TimeField,
+    UUIDField,
 )
 from django.db.models.fields.related import (
     ForeignKey, ForeignObject, ManyToManyField, OneToOneField,
@@ -1179,6 +1180,28 @@ class SchemaTests(TransactionTestCase):
         # Fail on PostgreSQL if sequence is missing an owner.
         self.assertIsNotNone(Author.objects.create(name='Bar'))
 
+    def test_alter_autofield_pk_to_smallautofield_pk_sequence_owner(self):
+        """
+        Converting an implicit PK to SmallAutoField(primary_key=True) should
+        keep a sequence owner on PostgreSQL.
+        """
+        with connection.schema_editor() as editor:
+            editor.create_model(Author)
+        old_field = Author._meta.get_field('id')
+        new_field = SmallAutoField(primary_key=True)
+        new_field.set_attributes_from_name('id')
+        new_field.model = Author
+        with connection.schema_editor() as editor:
+            editor.alter_field(Author, old_field, new_field, strict=True)
+
+        Author.objects.create(name='Foo', pk=1)
+        with connection.cursor() as cursor:
+            sequence_reset_sqls = connection.ops.sequence_reset_sql(no_style(), [Author])
+            if sequence_reset_sqls:
+                cursor.execute(sequence_reset_sqls[0])
+        # Fail on PostgreSQL if sequence is missing an owner.
+        self.assertIsNotNone(Author.objects.create(name='Bar'))
+
     def test_alter_int_pk_to_autofield_pk(self):
         """
         Should be able to rename an IntegerField(primary_key=True) to
@@ -1211,6 +1234,28 @@ class SchemaTests(TransactionTestCase):
         with connection.schema_editor() as editor:
             editor.alter_field(IntegerPK, old_field, new_field, strict=True)
 
+    @isolate_apps('schema')
+    def test_alter_smallint_pk_to_smallautofield_pk(self):
+        """
+        Should be able to rename an SmallIntegerField(primary_key=True) to
+        SmallAutoField(primary_key=True).
+        """
+        class SmallIntegerPK(Model):
+            i = SmallIntegerField(primary_key=True)
+
+            class Meta:
+                app_label = 'schema'
+
+        with connection.schema_editor() as editor:
+            editor.create_model(SmallIntegerPK)
+        self.isolated_local_models = [SmallIntegerPK]
+        old_field = SmallIntegerPK._meta.get_field('i')
+        new_field = SmallAutoField(primary_key=True)
+        new_field.model = SmallIntegerPK
+        new_field.set_attributes_from_name('i')
+        with connection.schema_editor() as editor:
+            editor.alter_field(SmallIntegerPK, old_field, new_field, strict=True)
+
     def test_alter_int_pk_to_int_unique(self):
         """
         Should be able to rename an IntegerField(primary_key=True) to