From 4a3ea263ef964a7fb7840544870834889f56f7e4 Mon Sep 17 00:00:00 2001
From: Russell Keith-Magee <russell@keith-magee.com>
Date: Thu, 27 Jan 2011 02:29:17 +0000
Subject: [PATCH] Fixed #14823 -- Corrected bootstrapping problems with
 register_serializers. Thanks to miker985@uw.edu for the report and draft
 patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15336 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/core/serializers/__init__.py   |  4 ++
 tests/modeltests/serializers/tests.py | 53 ++++++++++++++++++++++++++-
 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/django/core/serializers/__init__.py b/django/core/serializers/__init__.py
index bed1fa20dc..7afc94c1d0 100644
--- a/django/core/serializers/__init__.py
+++ b/django/core/serializers/__init__.py
@@ -48,6 +48,8 @@ def register_serializer(format, serializer_module, serializers=None):
     directly into the global register of serializers. Adding serializers
     directly is not a thread-safe operation.
     """
+    if serializers is None and not _serializers:
+        _load_serializers()
     module = importlib.import_module(serializer_module)
     if serializers is None:
         _serializers[format] = module
@@ -56,6 +58,8 @@ def register_serializer(format, serializer_module, serializers=None):
 
 def unregister_serializer(format):
     "Unregister a given serializer. This is not a thread-safe operation."
+    if not _serializers:
+        _load_serializers()
     del _serializers[format]
 
 def get_serializer(format):
diff --git a/tests/modeltests/serializers/tests.py b/tests/modeltests/serializers/tests.py
index 9b648a8d4e..01b4b68ac2 100644
--- a/tests/modeltests/serializers/tests.py
+++ b/tests/modeltests/serializers/tests.py
@@ -3,14 +3,65 @@ from datetime import datetime
 from StringIO import StringIO
 from xml.dom import minidom
 
+from django.conf import settings
 from django.core import serializers
 from django.db import transaction
 from django.test import TestCase, TransactionTestCase, Approximate
-from django.utils import simplejson
+from django.utils import simplejson, unittest
 
 from models import Category, Author, Article, AuthorProfile, Actor, \
                                     Movie, Score, Player, Team
 
+class SerializerRegistrationTests(unittest.TestCase):
+    def setUp(self):
+        self.old_SERIALIZATION_MODULES = getattr(settings, 'SERIALIZATION_MODULES', None)
+        self.old_serializers = serializers._serializers
+
+        serializers._serializers = {}
+        settings.SERIALIZATION_MODULES = {
+            "json2" : "django.core.serializers.json",
+        }
+
+    def tearDown(self):
+        serializers._serializers = self.old_serializers
+        if self.old_SERIALIZATION_MODULES:
+            settings.SERIALIZATION_MODULES = self.old_SERIALIZATION_MODULES
+        else:
+            delattr(settings, 'SERIALIZATION_MODULES')
+
+    def test_register(self):
+        "Registering a new serializer populates the full registry. Refs #14823"
+        serializers.register_serializer('json3', 'django.core.serializers.json')
+
+        public_formats = serializers.get_public_serializer_formats()
+        self.assertIn('json3', public_formats)
+        self.assertIn('json2', public_formats)
+        self.assertIn('xml', public_formats)
+
+    def test_unregister(self):
+        "Unregistering a serializer doesn't cause the registry to be repopulated. Refs #14823"
+        serializers.unregister_serializer('xml')
+        serializers.register_serializer('json3', 'django.core.serializers.json')
+
+        public_formats = serializers.get_public_serializer_formats()
+
+        self.assertNotIn('xml', public_formats)
+        self.assertIn('json3', public_formats)
+
+    def test_builtin_serializers(self):
+        "Requesting a list of serializer formats popuates the registry"
+        all_formats = set(serializers.get_serializer_formats())
+        public_formats = set(serializers.get_public_serializer_formats())
+
+        self.assertIn('xml', all_formats),
+        self.assertIn('xml', public_formats)
+
+        self.assertIn('json2', all_formats)
+        self.assertIn('json2', public_formats)
+
+        self.assertIn('python', all_formats)
+        self.assertNotIn('python', public_formats)
+
 class SerializersTestBase(object):
     @staticmethod
     def _comparison_value(value):