Fixed #26230 -- Made default_related_name affect related_query_name.

django/db/models/fields/related.py

@@ -290,8 +290,13 @@ class RelatedField(Field):
 
         if not cls._meta.abstract:
             if self.remote_field.related_name:
-                related_name = force_text(self.remote_field.related_name) % {
+                related_name = self.remote_field.related_name
+            else:
+                related_name = self.opts.default_related_name
+            if related_name:
+                related_name = force_text(related_name) % {
                     'class': cls.__name__.lower(),
+                    'model_name': cls._meta.model_name.lower(),
                     'app_label': cls._meta.app_label.lower()
                 }
                 self.remote_field.related_name = related_name

django/db/models/fields/reverse_related.py

@@ -187,11 +187,6 @@ class ForeignObjectRel(object):
                 return None
         if self.related_name:
             return self.related_name
-        if opts.default_related_name:
-            return opts.default_related_name % {
-                'model_name': opts.model_name.lower(),
-                'app_label': opts.app_label.lower(),
-            }
         return opts.model_name + ('_set' if self.multiple else '')
 
     def get_cache_name(self):

django/db/models/sql/query.py

@@ -7,6 +7,7 @@ databases). The abstraction barrier only works one way: this module has to know
 all about the internals of models in order to get the information it needs.
 """
 import copy
+import warnings
 from collections import Counter, Iterator, Mapping, OrderedDict
 from itertools import chain, count, product
 from string import ascii_uppercase
@@ -30,6 +31,7 @@ from django.db.models.sql.where import (
     AND, OR, ExtraWhere, NothingNode, WhereNode,
 )
 from django.utils import six
+from django.utils.deprecation import RemovedInDjango20Warning
 from django.utils.encoding import force_text
 from django.utils.tree import Node
 
@@ -1288,6 +1290,19 @@ class Query(object):
             except FieldDoesNotExist:
                 if name in self.annotation_select:
                     field = self.annotation_select[name].output_field
+                elif pos == 0:
+                    for rel in opts.related_objects:
+                        if (name == rel.related_model._meta.model_name and
+                                rel.related_name == rel.related_model._meta.default_related_name):
+                            related_name = rel.related_name
+                            field = opts.get_field(related_name)
+                            warnings.warn(
+                                "Query lookup '%s' is deprecated in favor of "
+                                "Meta.default_related_name '%s'."
+                                % (name, related_name),
+                                RemovedInDjango20Warning, 2
+                            )
+                            break
 
             if field is not None:
                 # Fields that contain one-to-many relations with a generic