Avoided unnecessary recreation of RelatedObjects

Refs #19399. Thanks to Track alias KJ for the patch.

django/core/management/validation.py

@@ -27,7 +27,6 @@ def get_validation_errors(outfile, app=None):
     """
     from django.db import models, connection
     from django.db.models.loading import get_app_errors
-    from django.db.models.fields.related import RelatedObject
     from django.db.models.deletion import SET_NULL, SET_DEFAULT
 
     e = ModelErrorCollection(outfile)
@@ -154,7 +153,7 @@ def get_validation_errors(outfile, app=None):
                     e.add(opts, "Field '%s' under model '%s' must have a unique=True constraint." % (f.rel.field_name, f.rel.to.__name__))
 
                 rel_opts = f.rel.to._meta
-                rel_name = RelatedObject(f.rel.to, cls, f).get_accessor_name()
+                rel_name = f.related.get_accessor_name()
                 rel_query_name = f.related_query_name()
                 if not f.rel.is_hidden():
                     for r in rel_opts.fields:
@@ -278,7 +277,7 @@ def get_validation_errors(outfile, app=None):
                 )
 
             rel_opts = f.rel.to._meta
-            rel_name = RelatedObject(f.rel.to, cls, f).get_accessor_name()
+            rel_name = f.related.get_accessor_name()
             rel_query_name = f.related_query_name()
             # If rel_name is none, there is no reverse accessor (this only
             # occurs for symmetrical m2m relations to self). If this is the

django/db/models/options.py

@@ -4,7 +4,6 @@ import re
 from bisect import bisect
 
 from django.conf import settings
-from django.db.models.related import RelatedObject
 from django.db.models.fields.related import ManyToManyRel
 from django.db.models.fields import AutoField, FieldDoesNotExist
 from django.db.models.fields.proxy import OrderWrt
@@ -424,10 +423,10 @@ class Options(object):
                 for f in klass._meta.local_fields:
                     if f.rel and not isinstance(f.rel.to, six.string_types):
                         if self == f.rel.to._meta:
-                            cache[RelatedObject(f.rel.to, klass, f)] = None
-                            proxy_cache[RelatedObject(f.rel.to, klass, f)] = None
+                            cache[f.related] = None
+                            proxy_cache[f.related] = None
                         elif self.concrete_model == f.rel.to._meta.concrete_model:
-                            proxy_cache[RelatedObject(f.rel.to, klass, f)] = None
+                            proxy_cache[f.related] = None
         self._related_objects_cache = cache
         self._related_objects_proxy_cache = proxy_cache
 
@@ -468,7 +467,7 @@ class Options(object):
                     if (f.rel
                             and not isinstance(f.rel.to, six.string_types)
                             and self == f.rel.to._meta):
-                        cache[RelatedObject(f.rel.to, klass, f)] = None
+                        cache[f.related] = None
         if app_cache_ready():
             self._related_many_to_many_cache = cache
         return cache

django/forms/models.py

@@ -702,14 +702,11 @@ class BaseInlineFormSet(BaseModelFormSet):
     """A formset for child objects related to a parent."""
     def __init__(self, data=None, files=None, instance=None,
                  save_as_new=False, prefix=None, queryset=None, **kwargs):
-        from django.db.models.fields.related import RelatedObject
         if instance is None:
             self.instance = self.fk.rel.to()
         else:
             self.instance = instance
         self.save_as_new = save_as_new
-        # is there a better way to get the object descriptor?
-        self.rel_name = RelatedObject(self.fk.rel.to, self.model, self.fk).get_accessor_name()
         if queryset is None:
             queryset = self.model._default_manager
         if self.instance.pk: