Fixed #11150 -- Removed dependency on cStringIO in ImageField validation....

            # Since we're about to use the file again we have to reset the

            # file object if possible.

            if hasattr(file, 'reset'):

                file.reset()

            if hasattr(file, 'seek') and callable(file.seek):

                file.seek(0)

            # verify() is the only method that can spot a corrupt PNG,

            #  but it must be called immediately after the constructor

        self.assertEqual(instance.image.name, 'foo/test4.png')

        instance.delete()

        # Test image field when cStringIO is not available

        from django.forms import fields

        from StringIO import StringIO

        old_StringIO = fields.StringIO

        fields.StringIO = StringIO

        try:

            f = ImageFileForm(

                data={'description': u'An image'},

                files={'image': SimpleUploadedFile('test.png', image_data)})

            self.assertEqual(f.is_valid(), True)

        finally:

            fields.StringIO = old_StringIO

    def test_media_on_modelform(self):

        # Similar to a regular Form class you can define custom media to be used on

        # the ModelForm.