Ticket #16759: query_carefull_clone.patch

django/db/models/sql/where.py

@@ -3 +3 @@
 """
 import datetime
 from itertools import repeat
+from copy import copy
 
 from django.utils import tree
 from django.db.models.fields import Field
@@ -286 +287 @@
     def __init__(self, alias, col, field):
         self.alias, self.col, self.field = alias, col, field
 
+    def __deepcopy__(self, memodict):
+        return copy(self)
+
     def __getstate__(self):
         """Save the state of the Constraint for pickling.
 

django/db/models/sql/expressions.py

@@ -1 +1 @@
 from django.core.exceptions import FieldError
 from django.db.models.fields import FieldDoesNotExist
 from django.db.models.sql.constants import LOOKUP_SEP
+from copy import deepcopy
 
 class SQLEvaluator(object):
     def __init__(self, expression, query, allow_joins=True):
@@ -11 +12 @@
         self.contains_aggregate = False
         self.expression.prepare(self, query, allow_joins)
 
+    def __deepcopy__(self, memodict):
+        memodict[id(self.opts)] = self.opts
+
+        obj = self.__class__.__new__(self.__class__)
+        obj.__dict__ = deepcopy(self.__dict__, memodict)
+        return obj
+
     def prepare(self):
         return self