Sort the list of document's cabinets.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

HISTORY.rst

@@ -9,7 +9,7 @@
   to Jesaja Everling (@jeverling) for the report.
 - Sort the list of root cabinets. Thanks to Thomas Plotkowiak
   for the request.
-
+- Sort the list of a document's cabinets.
 
 2.7.1 (2017-09-03)
 ==================

mayan/apps/cabinets/apps.py

@@ -48,9 +48,11 @@ class CabinetsApp(MayanAppConfig):
 
         APIEndPoint(app=self, version_string='1')
 
+        # Add explicit order_by as DocumentCabinet ordering Meta option has no
+        # effect.
         Document.add_to_class(
             'document_cabinets',
-            lambda document: DocumentCabinet.objects.filter(documents=document)
+            lambda document: DocumentCabinet.objects.filter(documents=document).order_by('parent__label', 'label')
         )
 
         ModelPermission.register(