[1.0.X] Fixed #9985 -- qs.values_list(...).values(...) was constructing incorrect SQL.

Backport of r9717 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@9718 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 9 insertions, 0 deletions

diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index bc32ead930..1d4001bab0 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -1535,6 +1535,15 @@ class BaseQuery(object):
         """
         return not (self.low_mark or self.high_mark)
 
+    def clear_select_fields(self):
+        """
+        Clears the list of fields to select (but not extra_select columns).
+        Some queryset types completely replace any existing list of select
+        columns.
+        """
+        self.select = []
+        self.select_fields = []
+
     def add_fields(self, field_names, allow_m2m=True):
         """
         Adds the given (model) fields to the select set. The field names are