From e6317776c19fc93dcf43afe05db55b6fa78d7c30 Mon Sep 17 00:00:00 2001
From: Ross Lawley <ross.lawley@gmail.com>
Date: Tue, 19 Jun 2012 16:45:23 +0100
Subject: [PATCH] Fixes DBRef handling in _delta

refs: hmarr/mongoengine#518
---
 docs/changelog.rst      |  4 ++++
 mongoengine/base.py     |  9 +++++++--
 mongoengine/document.py |  3 ++-
 tests/test_document.py  | 42 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/docs/changelog.rst b/docs/changelog.rst
index de84e97d..7e38eae4 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -2,6 +2,10 @@
 Changelog
 =========
 
+Changes in 0.6.X
+================
+- Fixes error with _delta handling DBRefs
+
 Changes in 0.6.11
 ==================
 - Fixed inconsistency handling None values field attrs
diff --git a/mongoengine/base.py b/mongoengine/base.py
index 97ba76b9..a4c1599c 100644
--- a/mongoengine/base.py
+++ b/mongoengine/base.py
@@ -1043,11 +1043,16 @@ Invalid data to create a `%s` instance.\n%s""".strip() % (cls._class_name, error
             for path in set_fields:
                 parts = path.split('.')
                 d = doc
+                new_path = []
                 for p in parts:
-                    if p.isdigit():
+                    if isinstance(d, DBRef):
+                        break
+                    elif p.isdigit():
                         d = d[int(p)]
-                    else:
+                    elif hasattr(d, 'get'):
                         d = d.get(p)
+                    new_path.append(p)
+                path = '.'.join(new_path)
                 set_data[path] = d
         else:
             set_data = doc
diff --git a/mongoengine/document.py b/mongoengine/document.py
index a6bbb88c..ff9622aa 100644
--- a/mongoengine/document.py
+++ b/mongoengine/document.py
@@ -226,7 +226,7 @@ class Document(BaseDocument):
                 if cascade_kwargs:  # Allow granular control over cascades
                     kwargs.update(cascade_kwargs)
                 kwargs['_refs'] = _refs
-                self._changed_fields = []
+                #self._changed_fields = []
                 self.cascade_save(**kwargs)
 
         except pymongo.errors.OperationFailure, err:
@@ -246,6 +246,7 @@ class Document(BaseDocument):
         """Recursively saves any references / generic references on an object"""
         from fields import ReferenceField, GenericReferenceField
         _refs = kwargs.get('_refs', []) or []
+
         for name, cls in self._fields.items():
             if not isinstance(cls, (ReferenceField, GenericReferenceField)):
                 continue
diff --git a/tests/test_document.py b/tests/test_document.py
index 6f942f67..2b10c172 100644
--- a/tests/test_document.py
+++ b/tests/test_document.py
@@ -1667,6 +1667,48 @@ class DocumentTest(unittest.TestCase):
         self.assertEquals(p.owns[0], o)
         self.assertEquals(o.owner, p)
 
+    def test_circular_reference_deltas_2(self):
+
+        class Person( Document ):
+           name = StringField()
+           owns = ListField( ReferenceField( 'Organization' ) )
+           employer = ReferenceField( 'Organization' )
+
+        class Organization( Document ):
+           name = StringField()
+           owner = ReferenceField( 'Person' )
+           employees = ListField( ReferenceField( 'Person' ) )
+
+        Person.drop_collection()
+        Organization.drop_collection()
+
+        person = Person( name="owner" )
+        person.save()
+
+        employee = Person( name="employee" )
+        employee.save()
+
+        organization = Organization( name="company" )
+        organization.save()
+
+        person.owns.append( organization )
+        organization.owner = person
+
+        organization.employees.append( employee )
+        employee.employer = organization
+
+        person.save()
+        organization.save()
+        employee.save()
+
+        p = Person.objects.get(name="owner")
+        e = Person.objects.get(name="employee")
+        o = Organization.objects.first()
+
+        self.assertEquals(p.owns[0], o)
+        self.assertEquals(o.owner, p)
+        self.assertEquals(e.employer, o)
+
     def test_delta(self):
 
         class Doc(Document):