From 89785da1c5f0f3166fc6cf5cf03dcc6e4136bf6d Mon Sep 17 00:00:00 2001
From: Stefan Wojcik <wojcikstefan@gmail.com>
Date: Mon, 16 Sep 2013 23:50:13 -0700
Subject: [PATCH] fix validation for a nested DictField

---
 mongoengine/fields.py  | 19 +++++++++++++++++--
 tests/fields/fields.py |  6 ++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/mongoengine/fields.py b/mongoengine/fields.py
index 419f2ef7..2635b817 100644
--- a/mongoengine/fields.py
+++ b/mongoengine/fields.py
@@ -735,6 +735,21 @@ class SortedListField(ListField):
                           reverse=self._order_reverse)
         return sorted(value, reverse=self._order_reverse)
 
+def key_not_string(d):
+    """ Helper function to recursively determine if any key in a dictionary is
+    not a string.
+    """
+    for k, v in d.items():
+        if not isinstance(k, basestring) or (isinstance(v, dict) and key_not_string(v)):
+            return True
+
+def key_has_dot_or_dollar(d):
+    """ Helper function to recursively determine if any key in a dictionary
+    contains a dot or a dollar sign.
+    """
+    for k, v in d.items():
+        if ('.' in k or '$' in k) or (isinstance(v, dict) and key_has_dot_or_dollar(v)):
+            return True
 
 class DictField(ComplexBaseField):
     """A dictionary field that wraps a standard Python dictionary. This is
@@ -761,11 +776,11 @@ class DictField(ComplexBaseField):
         if not isinstance(value, dict):
             self.error('Only dictionaries may be used in a DictField')
 
-        if any(k for k in value.keys() if not isinstance(k, basestring)):
+        if key_not_string(value):
             msg = ("Invalid dictionary key - documents must "
                    "have only string keys")
             self.error(msg)
-        if any(('.' in k or '$' in k) for k in value.keys()):
+        if key_has_dot_or_dollar(value):
             self.error('Invalid dictionary key name - keys may not contain "."'
                        ' or "$" characters')
         super(DictField, self).validate(value)
diff --git a/tests/fields/fields.py b/tests/fields/fields.py
index 8791781c..a9db8619 100644
--- a/tests/fields/fields.py
+++ b/tests/fields/fields.py
@@ -1109,9 +1109,15 @@ class FieldTest(unittest.TestCase):
         post.info = {'$title': 'test'}
         self.assertRaises(ValidationError, post.validate)
 
+        post.info = {'nested': {'$title': 'test'}}
+        self.assertRaises(ValidationError, post.validate)
+
         post.info = {'the.title': 'test'}
         self.assertRaises(ValidationError, post.validate)
 
+        post.info = {'nested': {'the.title': 'test'}}
+        self.assertRaises(ValidationError, post.validate)
+
         post.info = {1: 'test'}
         self.assertRaises(ValidationError, post.validate)