[1.5.x] Fixed #20094 - Be more careful when checking for Iterator

Python 2.6 has some different behaviour when checking
isinstance(foo, collections.Iterator).
Backport of 829dc3c5 from master.

1 files changed, 2 insertions, 2 deletions

diff --git a/django/db/models/sql/where.py b/django/db/models/sql/where.py
index 47f4ffaba9..2841d130e1 100644
--- a/django/db/models/sql/where.py
+++ b/django/db/models/sql/where.py
@@ -4,7 +4,6 @@ Code to manage the creation and SQL rendering of 'where' constraints.
 
 from __future__ import absolute_import
 
-import collections
 import datetime
 from itertools import repeat
 
@@ -12,6 +11,7 @@ from django.utils import tree
 from django.db.models.fields import Field
 from django.db.models.sql.datastructures import EmptyResultSet
 from django.db.models.sql.aggregates import Aggregate
+from django.utils.itercompat import is_iterator
 from django.utils.six.moves import xrange
 
 # Connection types
@@ -51,7 +51,7 @@ class WhereNode(tree.Node):
             return
 
         obj, lookup_type, value = data
-        if isinstance(value, collections.Iterator):
+        if is_iterator(value):
             # Consume any generators immediately, so that we can determine
             # emptiness and transform any non-empty values correctly.
             value = list(value)