Fixed #16317 -- Fixed dumpdata for self-referencing models and natural keys

Thanks aldaran for the patch.

django/core/management/commands/dumpdata.py

@@ -150,11 +150,11 @@ def sort_dependencies(app_list):
             for field in model._meta.fields:
                 if hasattr(field.rel, 'to'):
                     rel_model = field.rel.to
-                    if hasattr(rel_model, 'natural_key'):
+                    if hasattr(rel_model, 'natural_key') and rel_model != model:
                         deps.append(rel_model)
             for field in model._meta.many_to_many:
                 rel_model = field.rel.to
-                if hasattr(rel_model, 'natural_key'):
+                if hasattr(rel_model, 'natural_key') and rel_model != model:
                     deps.append(rel_model)
             model_dependencies.append((model, deps))
 

tests/regressiontests/fixtures_regress/fixtures/forward_ref_lookup.json

@@ -10,6 +10,7 @@
         "pk": "2",
         "model": "fixtures_regress.store",
         "fields": {
+            "main": null,
             "name": "Amazon"
         }
     },
@@ -17,6 +18,7 @@
         "pk": "3",
         "model": "fixtures_regress.store",
         "fields": {
+            "main": null,
             "name": "Borders"
         }
     },
@@ -29,4 +31,4 @@
             "stores": [["Amazon"], ["Borders"]]
         }
     }
-]
\ No newline at end of file
+]

tests/regressiontests/fixtures_regress/models.py

@@ -91,6 +91,7 @@ class TestManager(models.Manager):
 class Store(models.Model):
     objects = TestManager()
     name = models.CharField(max_length=255)
+    main = models.ForeignKey('self', null=True)
 
     class Meta:
         ordering = ('name',)

tests/regressiontests/fixtures_regress/tests.py

@@ -478,7 +478,7 @@ class NaturalKeyFixtureTests(TestCase):
         )
         self.assertEqual(
             stdout.getvalue(),
-            """[{"pk": 2, "model": "fixtures_regress.store", "fields": {"name": "Amazon"}}, {"pk": 3, "model": "fixtures_regress.store", "fields": {"name": "Borders"}}, {"pk": 4, "model": "fixtures_regress.person", "fields": {"name": "Neal Stephenson"}}, {"pk": 1, "model": "fixtures_regress.book", "fields": {"stores": [["Amazon"], ["Borders"]], "name": "Cryptonomicon", "author": ["Neal Stephenson"]}}]"""
+            """[{"pk": 2, "model": "fixtures_regress.store", "fields": {"main": null, "name": "Amazon"}}, {"pk": 3, "model": "fixtures_regress.store", "fields": {"main": null, "name": "Borders"}}, {"pk": 4, "model": "fixtures_regress.person", "fields": {"name": "Neal Stephenson"}}, {"pk": 1, "model": "fixtures_regress.book", "fields": {"stores": [["Amazon"], ["Borders"]], "name": "Cryptonomicon", "author": ["Neal Stephenson"]}}]"""
         )
 
     def test_dependency_sorting(self):