Fix duplicate validation errors for GenericIPAddressField with protocol

rest_framework/utils/field_mapping.py

@@ -208,7 +208,11 @@ def get_field_kwargs(field_name, model_field):
         if isinstance(model_field, models.GenericIPAddressField):
             validator_kwarg = [
                 validator for validator in validator_kwarg
-                if validator is not validators.validate_ipv46_address
+                if validator not in (
+                    validators.validate_ipv46_address,
+                    validators.validate_ipv4_address,
+                    validators.validate_ipv6_address,
+                )
             ]
         # Our decimal validation is handled in the field code, not validator code.
         if isinstance(model_field, models.DecimalField):

tests/test_model_serializer.py

@@ -439,6 +439,42 @@ class Meta:
                          'Unexpected number of validation errors: '
                          '{}'.format(s.errors))
 
+    def test_ip_address_validation_with_protocol_ipv4(self):
+        class IPAddressFieldModel(models.Model):
+            address = models.GenericIPAddressField(protocol='IPv4')
+
+            class Meta:
+                app_label = 'test_model_serializer'
+
+        class TestSerializer(serializers.ModelSerializer):
+            class Meta:
+                model = IPAddressFieldModel
+                fields = '__all__'
+
+        s = TestSerializer(data={'address': 'not an ip address'})
+        self.assertFalse(s.is_valid())
+        self.assertEqual(1, len(s.errors['address']),
+                         'Unexpected number of validation errors: '
+                         '{}'.format(s.errors))
+
+    def test_ip_address_validation_with_protocol_ipv6(self):
+        class IPAddressFieldModel(models.Model):
+            address = models.GenericIPAddressField(protocol='IPv6')
+
+            class Meta:
+                app_label = 'test_model_serializer'
+
+        class TestSerializer(serializers.ModelSerializer):
+            class Meta:
+                model = IPAddressFieldModel
+                fields = '__all__'
+
+        s = TestSerializer(data={'address': 'not an ip address'})
+        self.assertFalse(s.is_valid())
+        self.assertEqual(1, len(s.errors['address']),
+                         'Unexpected number of validation errors: '
+                         '{}'.format(s.errors))
+
 
 @pytest.mark.skipif('not postgres_fields')
 class TestPosgresFieldsMapping(TestCase):