From 680b512fc1509ca05cf56fada30f6b833735362a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gilberto=20Gon=C3=A7alves?= <lursty@gmail.com>
Date: Sat, 22 Jun 2013 14:05:12 +0100
Subject: [PATCH] Fixed #20587 -- Made convert_values handle None values

---
 django/db/backends/sqlite3/base.py |  3 +++
 tests/backends/tests.py            | 37 +++++++++++++++++++++++++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/django/db/backends/sqlite3/base.py b/django/db/backends/sqlite3/base.py
index a2d925ac3f8..18c4029649e 100644
--- a/django/db/backends/sqlite3/base.py
+++ b/django/db/backends/sqlite3/base.py
@@ -250,6 +250,9 @@ class DatabaseOperations(BaseDatabaseOperations):
         and gets dates and datetimes wrong.
         For consistency with other backends, coerce when required.
         """
+        if value is None:
+            return None
+
         internal_type = field.get_internal_type()
         if internal_type == 'DecimalField':
             return util.typecast_decimal(field.format_number(value))
diff --git a/tests/backends/tests.py b/tests/backends/tests.py
index b6e3e9e36f0..c6cad56ec1a 100644
--- a/tests/backends/tests.py
+++ b/tests/backends/tests.py
@@ -11,9 +11,12 @@ from django.core.management.color import no_style
 from django.db import (connection, connections, DEFAULT_DB_ALIAS,
     DatabaseError, IntegrityError, transaction)
 from django.db.backends.signals import connection_created
+from django.db.backends.sqlite3.base import DatabaseOperations
 from django.db.backends.postgresql_psycopg2 import version as pg_version
 from django.db.backends.util import format_number
 from django.db.models import Sum, Avg, Variance, StdDev
+from django.db.models.fields import (AutoField, DateField, DateTimeField,
+    DecimalField, IntegerField, TimeField)
 from django.db.utils import ConnectionHandler
 from django.test import (TestCase, skipUnlessDBFeature, skipIfDBFeature,
     TransactionTestCase)
@@ -402,7 +405,7 @@ class EscapingChecksDebug(EscapingChecks):
     pass
 
 
-class SqlliteAggregationTests(TestCase):
+class SqliteAggregationTests(TestCase):
     """
     #19360: Raise NotImplementedError when aggregating on date/time fields.
     """
@@ -418,6 +421,38 @@ class SqlliteAggregationTests(TestCase):
                 models.Item.objects.all().aggregate, aggregate('last_modified'))
 
 
+class SqliteChecks(TestCase):
+
+    @unittest.skipUnless(connection.vendor == 'sqlite',
+                         "No need to do SQLite checks")
+    def test_convert_values_to_handle_null_value(self):
+        database_operations = DatabaseOperations(connection)
+        self.assertEqual(
+            None,
+            database_operations.convert_values(None, AutoField(primary_key=True))
+        )
+        self.assertEqual(
+            None,
+            database_operations.convert_values(None, DateField())
+        )
+        self.assertEqual(
+            None,
+            database_operations.convert_values(None, DateTimeField())
+        )
+        self.assertEqual(
+            None,
+            database_operations.convert_values(None, DecimalField())
+        )
+        self.assertEqual(
+            None,
+            database_operations.convert_values(None, IntegerField())
+        )
+        self.assertEqual(
+            None,
+            database_operations.convert_values(None, TimeField())
+        )
+
+
 class BackendTestCase(TestCase):
 
     def create_squares_with_executemany(self, args):