Fixed #26230 -- Made default_related_name affect related_query_name.

docs/internals/deprecation.txt

@@ -138,6 +138,9 @@ details on these changes.
 * Support for the ``django.core.files.storage.Storage.accessed_time()``,
   ``created_time()``, and ``modified_time()`` methods will be removed.
 
+* Support for query lookups using the model name when
+  ``Meta.default_related_name`` is set will be removed.
+
 .. _deprecation-removed-in-1.10:
 
 1.10

docs/ref/models/fields.txt

@@ -1333,8 +1333,9 @@ The possible values for :attr:`~ForeignKey.on_delete` are found in
 
 .. attribute:: ForeignKey.related_query_name
 
-    The name to use for the reverse filter name from the target model.
-    Defaults to the value of :attr:`related_name` if it is set, otherwise it
+    The name to use for the reverse filter name from the target model. It
+    defaults to the value of :attr:`related_name` or
+    :attr:`~django.db.models.Options.default_related_name` if set, otherwise it
     defaults to the name of the model::
 
         # Declare the ForeignKey with related_query_name

docs/ref/models/options.txt

@@ -103,6 +103,8 @@ Django quotes column and table names behind the scenes.
     The name that will be used by default for the relation from a related object
     back to this one. The default is ``<model_name>_set``.
 
+    This option also sets :attr:`~ForeignKey.related_query_name`.
+
     As the reverse name for a field should be unique, be careful if you intend
     to subclass your model. To work around name collisions, part of the name
     should contain ``'%(app_label)s'`` and ``'%(model_name)s'``, which are
@@ -110,6 +112,30 @@ Django quotes column and table names behind the scenes.
     and the name of the model, both lowercased. See the paragraph on
     :ref:`related names for abstract models <abstract-related-name>`.
 
+    .. deprecated:: 1.10
+
+        This attribute now affects ``related_query_name``. The old query lookup
+        name is deprecated::
+
+            from django.db import models
+
+            class Foo(models.Model):
+                pass
+
+            class Bar(models.Model):
+                foo = models.ForeignKey(Foo)
+
+                class Meta:
+                    default_related_name = 'bars'
+
+        ::
+
+            >>> bar = Bar.objects.get(pk=1)
+            >>> # Using model name "bar" as lookup string is deprecated.
+            >>> Foo.object.get(bar=bar)
+            >>> # You should use default_related_name "bars".
+            >>> Foo.object.get(bars=bar)
+
 ``get_latest_by``
 -----------------
 

docs/releases/1.10.txt

@@ -704,6 +704,34 @@ longer than the 4000 byte limit of ``NVARCHAR2``, you should use ``TextField``
 field (e.g. annotating the model with an aggregation or using ``distinct()``)
 you'll need to change them (to defer the field).
 
+Using a model name as a query lookup when ``default_related_name`` is set
+-------------------------------------------------------------------------
+
+Assume the following models::
+
+    from django.db import models
+
+    class Foo(models.Model):
+        pass
+
+    class Bar(models.Model):
+        foo = models.ForeignKey(Foo)
+
+        class Meta:
+            default_related_name = 'bars'
+
+In older versions, :attr:`~django.db.models.Options.default_related_name`
+couldn't be used as a query lookup. This is fixed and support for the old
+lookup name is deprecated. For example, since ``default_related_name`` is set
+in model ``Bar``, instead of using the model name ``bar`` as the lookup::
+
+    >>> bar = Bar.objects.get(pk=1)
+    >>> Foo.object.get(bar=bar)
+
+use the default_related_name ``bars``::
+
+    >>> Foo.object.get(bars=bar)
+
 Miscellaneous
 -------------