Fix crash when using LocalizedUniqueSlugField in a bulk_create

tests/test_bulk.py

@@ -4,7 +4,7 @@ from django.db import models
 from django.conf import settings
 from django.test import TestCase
 
-from localized_fields.fields import LocalizedField
+from localized_fields.fields import LocalizedField, LocalizedUniqueSlugField
 
 from .data import get_init_values
 from .fake_model import get_fake_model
@@ -16,6 +16,9 @@ class LocalizedBulkTestCase(TestCase):
 
     @staticmethod
     def test_localized_bulk_insert():
+        """Tests that bulk inserts work properly when using
+        a :see:LocalizedField in the model."""
+
         model = get_fake_model(
             'BulkInsertModel',
             {
@@ -31,3 +34,25 @@ class LocalizedBulkTestCase(TestCase):
         ])
 
         assert model.objects.all().count() == 3
+
+    @staticmethod
+    def test_localized_slug_bulk_insert():
+        """Tests whether bulk inserts work properly when using
+        a :see:LocalizedUniqueSlugField in the model."""
+
+        model = get_fake_model(
+            'BulkSlugInsertModel',
+            {
+                'name': LocalizedField(),
+                'slug': LocalizedUniqueSlugField(populate_from='name', include_time=True),
+                'score': models.IntegerField()
+            }
+        )
+
+        objects = model.objects.bulk_create([
+            model(name={'en': 'english name 1', 'ro': 'romanian name 1'}, score=1),
+            model(name={'en': 'english name 2', 'ro': 'romanian name 2'}, score=2),
+            model(name={'en': 'english name 3', 'ro': 'romanian name 3'}, score=3)
+        ])
+
+        assert model.objects.all().count() == 3