From dfa8eaf24e5fd2de6673807a8b6959f256270aa1 Mon Sep 17 00:00:00 2001
From: Eremeev Danil <hole666@mail.ru>
Date: Tue, 5 May 2015 12:00:46 +0500
Subject: [PATCH] Added changeset, updated documentation and tests, changed
 test condition

---
 docs/changelog.rst                | 1 +
 docs/guide/querying.rst           | 9 ++++++++-
 mongoengine/queryset/transform.py | 3 ++-
 tests/queryset/queryset.py        | 4 +++-
 4 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/docs/changelog.rst b/docs/changelog.rst
index a27db5a4..53676562 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -16,6 +16,7 @@ Changes in 0.9.X - DEV
 - Django support was removed and will be available as a separate extension. #958
 - Don't send a "cls" option to ensureIndex (related to https://jira.mongodb.org/browse/SERVER-769)
 - Fix for updating sorting in SortedListField. #978
+- Added __ support to escape field name in fields lookup keywords that match operators names #949
 
 Changes in 0.9.0
 ================
diff --git a/docs/guide/querying.rst b/docs/guide/querying.rst
index 9d1dfd76..0a035469 100644
--- a/docs/guide/querying.rst
+++ b/docs/guide/querying.rst
@@ -39,6 +39,14 @@ syntax::
     # been written by a user whose 'country' field is set to 'uk'
     uk_pages = Page.objects(author__country='uk')
 
+.. note::
+
+   (version **0.9.0+**) if your field name is like mongodb operator name (for example
+   type, lte, lt...) and you want to place it at the end of lookup keyword
+   mongoengine automatically  prepend $ to it. To avoid this use  __ at the end of
+   your lookup keyword. For example if you field name is ``type`` and you want to
+   query by this field you must use ``.objects(user__type__="admin")`` instead of
+   ``.objects(user__type="admin")``
 
 Query operators
 ===============
@@ -663,4 +671,3 @@ following example shows how the substitutions are made::
         return comments;
     }
     """)
-
diff --git a/mongoengine/queryset/transform.py b/mongoengine/queryset/transform.py
index b08d450a..8ca3203c 100644
--- a/mongoengine/queryset/transform.py
+++ b/mongoengine/queryset/transform.py
@@ -44,7 +44,8 @@ def query(_doc_cls=None, _field_operation=False, **query):
         if len(parts) > 1 and parts[-1] in MATCH_OPERATORS:
             op = parts.pop()
 
-        if len(parts) > 1 and not parts[-1]:
+        #if user escape field name by __
+        if len(parts) > 1 and parts[-1]=="":
             parts.pop()
 
         negate = False
diff --git a/tests/queryset/queryset.py b/tests/queryset/queryset.py
index 5d21cb0c..30c59bfa 100644
--- a/tests/queryset/queryset.py
+++ b/tests/queryset/queryset.py
@@ -4595,16 +4595,18 @@ class QuerySetTest(unittest.TestCase):
     def test_last_field_name_like_operator(self):
         class EmbeddedItem(EmbeddedDocument):
             type = StringField()
+            name = StringField()
 
         class Doc(Document):
             item = EmbeddedDocumentField(EmbeddedItem)
 
         Doc.drop_collection()
 
-        doc = Doc(item=EmbeddedItem(type="axe"))
+        doc = Doc(item=EmbeddedItem(type="axe", name="Heroic axe"))
         doc.save()
 
         self.assertEqual(1, Doc.objects(item__type__="axe").count())
+        self.assertEqual(1, Doc.objects(item__name__="Heroic axe").count())
 
 if __name__ == '__main__':
     unittest.main()