Ticket #12876: bug12876.patch

django/db/models/sql/query.py

@@ -148 +148 @@
         return sql % params
 
     def __deepcopy__(self, memo):
-        result= self.clone()
+        result = self.clone(memo=memo)
         memo[id(self)] = result
         return result
 
@@ -199 +199 @@
         """
         return self.model._meta
 
-    def clone(self, klass=None, **kwargs):
+    def clone(self, klass=None, memo=None, **kwargs):
         """
         Creates a copy of the current instance. The 'kwargs' parameter can be
         used by clients to update attributes after copying has taken place.
@@ -223 +223 @@
         obj.dupe_avoidance = self.dupe_avoidance.copy()
         obj.select = self.select[:]
         obj.tables = self.tables[:]
-        obj.where = deepcopy(self.where)
+        obj.where = deepcopy(self.where, memo=memo)
         obj.where_class = self.where_class
         if self.group_by is None:
             obj.group_by = None
         else:
             obj.group_by = self.group_by[:]
-        obj.having = deepcopy(self.having)
+        obj.having = deepcopy(self.having, memo=memo)
         obj.order_by = self.order_by[:]
         obj.low_mark, obj.high_mark = self.low_mark, self.high_mark
         obj.distinct = self.distinct
         obj.select_related = self.select_related
         obj.related_select_cols = []
-        obj.aggregates = deepcopy(self.aggregates)
+        obj.aggregates = deepcopy(self.aggregates, memo=memo)
         if self.aggregate_select_mask is None:
             obj.aggregate_select_mask = None
         else:
@@ -256 +256 @@
             obj._extra_select_cache = self._extra_select_cache.copy()
         obj.extra_tables = self.extra_tables
         obj.extra_order_by = self.extra_order_by
-        obj.deferred_loading = deepcopy(self.deferred_loading)
+        obj.deferred_loading = deepcopy(self.deferred_loading, memo=memo)
         if self.filter_is_sticky and self.used_aliases:
             obj.used_aliases = self.used_aliases.copy()
         else:

tests/modeltests/many_to_one/models.py

@@ -263 +263 @@
 >>> Reporter.objects.filter(article__reporter__exact=r).distinct()
 [<Reporter: John Smith>]
 
+# You can stick a query that references a model in the model itself and then
+# deepcopy that without having maximum recursion depth exceeded problems.
+>>> r.cached_query = Article.objects.filter(reporter=r)
+>>> from copy import deepcopy
+>>> deepcopy(r)
+<Reporter: John Smith>
+
 # Check that implied __exact also works.
 >>> Reporter.objects.filter(article__reporter=r).distinct()
 [<Reporter: John Smith>]