Fixed #14567 -- Made ModelMultipleChoiceField return EmptyQuerySet as empty value

3 files changed, 30 insertions, 4 deletions

diff --git a/tests/modeltests/model_forms/tests.py b/tests/modeltests/model_forms/tests.py
index 038ce32287..947d0cf3c3 100644
--- a/tests/modeltests/model_forms/tests.py
+++ b/tests/modeltests/model_forms/tests.py
@@ -8,6 +8,7 @@ from django import forms
 from django.core.files.uploadedfile import SimpleUploadedFile
 from django.core.validators import ValidationError
 from django.db import connection
+from django.db.models.query import EmptyQuerySet
 from django.forms.models import model_to_dict
 from django.utils.unittest import skipUnless
 from django.test import TestCase
@@ -1035,8 +1036,8 @@ class OldFormForXTests(TestCase):
             f.clean([c6.id])
 
         f = forms.ModelMultipleChoiceField(Category.objects.all(), required=False)
-        self.assertEqual(f.clean([]), [])
-        self.assertEqual(f.clean(()), [])
+        self.assertIsInstance(f.clean([]), EmptyQuerySet)
+        self.assertIsInstance(f.clean(()), EmptyQuerySet)
         with self.assertRaises(ValidationError):
             f.clean(['10'])
         with self.assertRaises(ValidationError):
diff --git a/tests/regressiontests/forms/models.py b/tests/regressiontests/forms/models.py
index 2f3ee9fa31..6e9c269356 100644
--- a/tests/regressiontests/forms/models.py
+++ b/tests/regressiontests/forms/models.py
@@ -63,6 +63,12 @@ class ChoiceFieldModel(models.Model):
     multi_choice_int = models.ManyToManyField(ChoiceOptionModel, blank=False, related_name='multi_choice_int',
                                               default=lambda: [1])
 
+class OptionalMultiChoiceModel(models.Model):
+    multi_choice = models.ManyToManyField(ChoiceOptionModel, blank=False, related_name='not_relevant',
+                                          default=lambda: ChoiceOptionModel.objects.filter(name='default'))
+    multi_choice_optional = models.ManyToManyField(ChoiceOptionModel, blank=True, null=True,
+                                                   related_name='not_relevant2')
+
 
 class FileModel(models.Model):
     file = models.FileField(storage=temp_storage, upload_to='tests')
diff --git a/tests/regressiontests/forms/tests/models.py b/tests/regressiontests/forms/tests/models.py
index c351509cee..be75643b28 100644
--- a/tests/regressiontests/forms/tests/models.py
+++ b/tests/regressiontests/forms/tests/models.py
@@ -11,7 +11,7 @@ from django.test import TestCase
 from django.utils import six
 
 from ..models import (ChoiceOptionModel, ChoiceFieldModel, FileModel, Group,
-    BoundaryModel, Defaults)
+    BoundaryModel, Defaults, OptionalMultiChoiceModel)
 
 
 class ChoiceFieldForm(ModelForm):
@@ -19,6 +19,11 @@ class ChoiceFieldForm(ModelForm):
         model = ChoiceFieldModel
 
 
+class OptionalMultiChoiceModelForm(ModelForm):
+    class Meta:
+        model = OptionalMultiChoiceModel
+
+
 class FileForm(Form):
     file1 = FileField()
 
@@ -34,6 +39,21 @@ class TestTicket12510(TestCase):
             field = ModelChoiceField(Group.objects.order_by('-name'))
             self.assertEqual('a', field.clean(self.groups[0].pk).name)
 
+
+class TestTicket14567(TestCase):
+    """
+    Check that the return values of ModelMultipleChoiceFields are QuerySets
+    """
+    def test_empty_queryset_return(self):
+        "If a model's ManyToManyField has blank=True and is saved with no data, a queryset is returned."
+        form = OptionalMultiChoiceModelForm({'multi_choice_optional': '', 'multi_choice': ['1']})
+        self.assertTrue(form.is_valid())
+        # Check that the empty value is a QuerySet
+        self.assertTrue(isinstance(form.cleaned_data['multi_choice_optional'], models.query.QuerySet))
+        # While we're at it, test whether a QuerySet is returned if there *is* a value.
+        self.assertTrue(isinstance(form.cleaned_data['multi_choice'], models.query.QuerySet))
+
+
 class ModelFormCallableModelDefault(TestCase):
     def test_no_empty_option(self):
         "If a model's ForeignKey has blank=False and a default, no empty option is created (Refs #10792)."
@@ -103,7 +123,6 @@ class ModelFormCallableModelDefault(TestCase):
 <input type="hidden" name="initial-multi_choice_int" value="3" id="initial-id_multi_choice_int_1" /> <span class="helptext"> Hold down "Control", or "Command" on a Mac, to select more than one.</span></p>""")
 
 
-
 class FormsModelTestCase(TestCase):
     def test_unicode_filename(self):
         # FileModel with unicode filename and data #########################