Fixed #26290 -- Warned that paginating an unordered QuerySet may result in inconsistent results. (c4980e28) · Commits · Dom Sekotill / django

django/core/paginator.py

+17 −0

Original line number	Diff line number	Diff line
		import collections
		import warnings
		from math import ceil

		from django.utils import six
		from django.utils.functional import cached_property


		class UnorderedObjectListWarning(RuntimeWarning):
		pass


		class InvalidPage(Exception):
		pass

		@@ -22,6 +27,7 @@ class Paginator(object):
		def __init__(self, object_list, per_page, orphans=0,
		allow_empty_first_page=True):
		self.object_list = object_list
		self._check_object_list_is_ordered()
		self.per_page = int(per_page)
		self.orphans = int(orphans)
		self.allow_empty_first_page = allow_empty_first_page
		@@ -94,6 +100,17 @@ class Paginator(object):
		"""
		return six.moves.range(1, self.num_pages + 1)

		def _check_object_list_is_ordered(self):
		"""
		Warn if self.object_list is unordered (typically a QuerySet).
		"""
		if hasattr(self.object_list, 'ordered') and not self.object_list.ordered:
		warnings.warn(
		'Pagination may yield inconsistent results with an unordered '
		'object_list: {!r}'.format(self.object_list),
		UnorderedObjectListWarning
		)


		QuerySetPaginator = Paginator # For backwards-compatibility.

tests/admin_views/admin.py

+1 −1

Original line number	Diff line number	Diff line
		@@ -481,7 +481,7 @@ class FieldOverridePostAdmin(PostAdmin):

		class CustomChangeList(ChangeList):
		def get_queryset(self, request):
		return self.root_queryset.filter(pk=9999) # Does not exist
		return self.root_queryset.order_by('pk').filter(pk=9999) # Doesn't exist


		class GadgetAdmin(admin.ModelAdmin):

tests/pagination/tests.py

+17 −9

Original line number	Diff line number	Diff line
		@@ -5,6 +5,7 @@ from datetime import datetime

		from django.core.paginator import (
		EmptyPage, InvalidPage, PageNotAnInteger, Paginator,
		UnorderedObjectListWarning,
		)
		from django.test import TestCase
		from django.utils import six
		@@ -256,7 +257,7 @@ class ModelPaginationTests(TestCase):
		a.save()

		def test_first_page(self):
		paginator = Paginator(Article.objects.all(), 5)
		paginator = Paginator(Article.objects.order_by('id'), 5)
		p = paginator.page(1)
		self.assertEqual("<Page 1 of 2>", six.text_type(p))
		self.assertQuerysetEqual(p.object_list, [
		@@ -265,9 +266,7 @@ class ModelPaginationTests(TestCase):
		"<Article: Article 3>",
		"<Article: Article 4>",
		"<Article: Article 5>"
		],
		ordered=False
		)
		])
		self.assertTrue(p.has_next())
		self.assertFalse(p.has_previous())
		self.assertTrue(p.has_other_pages())
		@@ -278,7 +277,7 @@ class ModelPaginationTests(TestCase):
		self.assertEqual(5, p.end_index())

		def test_last_page(self):
		paginator = Paginator(Article.objects.all(), 5)
		paginator = Paginator(Article.objects.order_by('id'), 5)
		p = paginator.page(2)
		self.assertEqual("<Page 2 of 2>", six.text_type(p))
		self.assertQuerysetEqual(p.object_list, [
		@@ -286,9 +285,7 @@ class ModelPaginationTests(TestCase):
		"<Article: Article 7>",
		"<Article: Article 8>",
		"<Article: Article 9>"
		],
		ordered=False
		)
		])
		self.assertFalse(p.has_next())
		self.assertTrue(p.has_previous())
		self.assertTrue(p.has_other_pages())
		@@ -303,7 +300,7 @@ class ModelPaginationTests(TestCase):
		Tests proper behavior of a paginator page __getitem__ (queryset
		evaluation, slicing, exception raised).
		"""
		paginator = Paginator(Article.objects.all(), 5)
		paginator = Paginator(Article.objects.order_by('id'), 5)
		p = paginator.page(1)

		# Make sure object_list queryset is not evaluated by an invalid __getitem__ call.
		@@ -323,3 +320,14 @@ class ModelPaginationTests(TestCase):
		)
		# After __getitem__ is called, object_list is a list
		self.assertIsInstance(p.object_list, list)

		def test_paginating_unordered_queryset_raises_warning(self):
		msg = (
		"Pagination may yield inconsistent results with an unordered "
		"object_list: <QuerySet [<Article: Article 1>, "
		"<Article: Article 2>, <Article: Article 3>, <Article: Article 4>, "
		"<Article: Article 5>, <Article: Article 6>, <Article: Article 7>, "
		"<Article: Article 8>, <Article: Article 9>]>"
		)
		with self.assertRaisesMessage(UnorderedObjectListWarning, msg):
		Paginator(Article.objects.all(), 5)

tests/sitemaps_tests/test_http.py

+1 −1

Original line number	Diff line number	Diff line
		@@ -194,7 +194,7 @@ class HTTPSitemapTests(SitemapTestsBase):
		Check to make sure that the raw item is included with each
		Sitemap.get_url() url result.
		"""
		test_sitemap = GenericSitemap({'queryset': TestModel.objects.all()})
		test_sitemap = GenericSitemap({'queryset': TestModel.objects.order_by('pk').all()})

		def is_testmodel(url):
		return isinstance(url['item'], TestModel)

tests/sitemaps_tests/urls/http.py

+2 −2

Original line number	Diff line number	Diff line
		@@ -27,7 +27,7 @@ class SimpleI18nSitemap(Sitemap):
		i18n = True

		def items(self):
		return I18nTestModel.objects.all()
		return I18nTestModel.objects.order_by('pk').all()


		class EmptySitemap(Sitemap):
		@@ -115,7 +115,7 @@ sitemaps_lastmod_descending = OrderedDict([
		])

		generic_sitemaps = {
		'generic': GenericSitemap({'queryset': TestModel.objects.all()}),
		'generic': GenericSitemap({'queryset': TestModel.objects.order_by('pk').all()}),
		}