Fix ModelSerializer custom named fields with source on model

rest_framework/serializers.py

@@ -1010,7 +1010,9 @@ def get_fields(self):
                 continue
 
             extra_field_kwargs = extra_kwargs.get(field_name, {})
-            source = extra_field_kwargs.get('source', '*') != '*' or field_name
+            source = extra_field_kwargs.get('source', '*')
+            if source == '*':
+                source = field_name
 
             # Determine the serializer field class and keyword arguments.
             field_class, field_kwargs = self.build_field(

tests/test_model_serializer.py

@@ -1135,3 +1135,24 @@ class Meta:
         serializer = TestUniqueChoiceSerializer(data={'name': 'choice1'})
         assert not serializer.is_valid()
         assert serializer.errors == {'name': ['unique choice model with this name already exists.']}
+
+
+class TestFieldSource(TestCase):
+    def test_named_field_source(self):
+        class TestSerializer(serializers.ModelSerializer):
+
+            class Meta:
+                model = RegularFieldsModel
+                fields = ('number_field',)
+                extra_kwargs = {
+                    'number_field': {
+                        'source': 'integer_field'
+                    }
+                }
+
+        expected = dedent("""
+            TestSerializer():
+                number_field = IntegerField(source='integer_field')
+        """)
+        self.maxDiff = None
+        self.assertEqual(unicode_repr(TestSerializer()), expected)