From 6efd6faa3f5a467012fa4ee128889104ca0ba6f7 Mon Sep 17 00:00:00 2001
From: Ross Lawley <ross.lawley@gmail.com>
Date: Tue, 30 Jul 2013 10:30:16 +0000
Subject: [PATCH] Fixed QuerySetNoCache.count() caching (#410)

---
 docs/changelog.rst               |  1 +
 mongoengine/queryset/base.py     | 10 ++--------
 mongoengine/queryset/queryset.py | 15 +++++++++++++++
 tests/queryset/queryset.py       | 21 +++++++++++++++++++++
 4 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/docs/changelog.rst b/docs/changelog.rst
index 9112b2b8..e2f07bc0 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -4,6 +4,7 @@ Changelog
 
 Changes in 0.8.4
 ================
+- Fixed QuerySetNoCache.count() caching (#410)
 - Don't follow references in _get_changed_fields (#422, #417)
 - Allow args and kwargs to be passed through to_json (#420)
 
diff --git a/mongoengine/queryset/base.py b/mongoengine/queryset/base.py
index e88feb30..a6ba49b2 100644
--- a/mongoengine/queryset/base.py
+++ b/mongoengine/queryset/base.py
@@ -60,7 +60,6 @@ class BaseQuerySet(object):
         self._none = False
         self._as_pymongo = False
         self._as_pymongo_coerce = False
-        self._len = None
 
         # If inheritance is allowed, only return instances and instances of
         # subclasses of the class being used
@@ -331,14 +330,9 @@ class BaseQuerySet(object):
             :meth:`skip` that has been applied to this cursor into account when
             getting the count
         """
-        if self._limit == 0:
+        if self._limit == 0 and with_limit_and_skip:
             return 0
-        if with_limit_and_skip and self._len is not None:
-            return self._len
-        count = self._cursor.count(with_limit_and_skip=with_limit_and_skip)
-        if with_limit_and_skip:
-            self._len = count
-        return count
+        return self._cursor.count(with_limit_and_skip=with_limit_and_skip)
 
     def delete(self, write_concern=None, _from_doc_delete=False):
         """Delete the documents matched by the query.
diff --git a/mongoengine/queryset/queryset.py b/mongoengine/queryset/queryset.py
index 9cfb1b6f..1437e76b 100644
--- a/mongoengine/queryset/queryset.py
+++ b/mongoengine/queryset/queryset.py
@@ -94,6 +94,21 @@ class QuerySet(BaseQuerySet):
             except StopIteration:
                 self._has_more = False
 
+    def count(self, with_limit_and_skip=True):
+        """Count the selected elements in the query.
+
+        :param with_limit_and_skip (optional): take any :meth:`limit` or
+            :meth:`skip` that has been applied to this cursor into account when
+            getting the count
+        """
+        if with_limit_and_skip is False:
+            return super(QuerySet, self).count(with_limit_and_skip)
+
+        if self._len is None:
+            self._len = super(QuerySet, self).count(with_limit_and_skip)
+
+        return self._len
+
     def no_cache(self):
         """Convert to a non_caching queryset
 
diff --git a/tests/queryset/queryset.py b/tests/queryset/queryset.py
index 0ec41fac..9c04c0be 100644
--- a/tests/queryset/queryset.py
+++ b/tests/queryset/queryset.py
@@ -3483,6 +3483,27 @@ class QuerySetTest(unittest.TestCase):
             people.count()  # count is cached
             self.assertEqual(q, 1)
 
+    def test_no_cached_queryset(self):
+        class Person(Document):
+            name = StringField()
+
+        Person.drop_collection()
+        for i in xrange(100):
+            Person(name="No: %s" % i).save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+            people = Person.objects.no_cache()
+
+            [x for x in people]
+            self.assertEqual(q, 1)
+
+            list(people)
+            self.assertEqual(q, 2)
+
+            people.count()
+            self.assertEqual(q, 3)
+
     def test_cache_not_cloned(self):
 
         class User(Document):