Minor tweaks

rest_framework/serializers.py

@@ -393,6 +393,9 @@ class ListSerializer(BaseSerializer):
         return ReturnList(serializer=self)
 
     def get_value(self, dictionary):
+        """
+        Given the input dictionary, return the field value.
+        """
         # We override the default field access in order to support
         # lists in HTML forms.
         if html.is_html_input(dictionary):
@@ -442,6 +445,9 @@ class ListSerializer(BaseSerializer):
         )
 
     def save(self, **kwargs):
+        """
+        Save and return a list of object instances.
+        """
         assert self.instance is None, (
             "Serializers do not support multiple update by default, only "
             "multiple create. For updates it is unclear how to deal with "

rest_framework/utils/field_mapping.py

@@ -219,9 +219,11 @@ def get_relation_kwargs(field_name, relation_info):
             kwargs['required'] = False
         if model_field.null:
             kwargs['allow_null'] = True
+        if model_field.validators:
+            kwargs['validators'] = model_field.validators
         if getattr(model_field, 'unique', False):
             validator = UniqueValidator(queryset=model_field.model._default_manager)
-            kwargs['validators'] = [validator]
+            kwargs['validators'] = kwargs.get('validators', []) + [validator]
 
     return kwargs