Ticket #16311: patch_list_filter_limit_to_related.diff

django/db/models/fields/__init__.py

@@ -356 +356 @@
     def get_validator_unique_lookup_type(self):
         return '%s__exact' % self.name
 
-    def get_choices(self, include_blank=True, blank_choice=BLANK_CHOICE_DASH):
+    def get_choices(self, include_blank=True, blank_choice=BLANK_CHOICE_DASH, limit_choices_to={}):
         """Returns choices with a default blank choices included, for use
         as SelectField choices for this field."""
         first_choice = include_blank and blank_choice or []
         if self.choices:
             return first_choice + list(self.choices)
         rel_model = self.rel.to
+        if not limit_choices_to:
+            limit_choices_to = self.rel.limit_choices_to
         if hasattr(self.rel, 'get_related_field'):
-            lst = [(getattr(x, self.rel.get_related_field().attname), smart_unicode(x)) for x in rel_model._default_manager.complex_filter(self.rel.limit_choices_to)]
+            lst = [(getattr(x, self.rel.get_related_field().attname), smart_unicode(x)) for x in rel_model._default_manager.complex_filter(limit_choices_to)]
         else:
-            lst = [(x._get_pk_val(), smart_unicode(x)) for x in rel_model._default_manager.complex_filter(self.rel.limit_choices_to)]
+            lst = [(x._get_pk_val(), smart_unicode(x)) for x in rel_model._default_manager.complex_filter(limit_choices_to)]
         return first_choice + lst
 
     def get_choices_default(self):

django/contrib/admin/filterspecs.py

@@ -80 +80 @@
         self.lookup_val = request.GET.get(self.lookup_kwarg, None)
         self.lookup_val_isnull = request.GET.get(
                                       self.lookup_kwarg_isnull, None)
-        self.lookup_choices = f.get_choices(include_blank=False)
+        limit_choices_to = {}
+        if getattr(model_admin, '%s_filter_related_only' % f.name, False):
+            limit_choices_to['pk__in'] = set(model_admin.queryset(request).values_list(f.name, flat=True))
+        self.lookup_choices = f.get_choices(include_blank=False, limit_choices_to=limit_choices_to)
 
     def has_output(self):
         if isinstance(self.field, models.related.RelatedObject) \