queryset-refactor: Infinite loop detection in model ordering was being a little

too aggressive. Fixed that.


git-svn-id: http://code.djangoproject.com/svn/django/branches/queryset-refactor@7224 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/sql/query.py

@@ -518,14 +518,14 @@ class Query(object):
 
         # If we get to this point and the field is a relation to another model,
         # append the default ordering for that model.
-        if len(joins) > 1 and opts.ordering:
+        if field.rel and len(joins) > 1 and opts.ordering:
             # Firstly, avoid infinite loops.
             if not already_seen:
-                already_seen = {}
+                already_seen = set()
             join_tuple = tuple([tuple(j) for j in joins])
             if join_tuple in already_seen:
                 raise FieldError('Infinite loop caused by ordering.')
-            already_seen[join_tuple] = True
+            already_seen.add(join_tuple)
 
             results = []
             for item in opts.ordering:

tests/regressiontests/queries/models.py

@@ -407,6 +407,11 @@ Traceback (most recent call last):
 ...
 FieldError: Infinite loop caused by ordering.
 
+# ... but you can still order in a non-recursive fashion amongst linked fields
+# (the previous test failed because the default ordering was recursive).
+>>> LoopX.objects.all().order_by('y__x__id')
+[]
+
 # If the remote model does not have a default ordering, we order by its 'id'
 # field.
 >>> Item.objects.order_by('creator', 'name')