#28822 ensure we don't try and sort by pivot_column fields by accident

pivot_column fields aren't sortable so in the case where we're sorting by an arbitrary field, ensure it's not a pivot_column. Iterate though the field list until we reach one that works.

Author: KP

tests/test_api_long.py

@@ -28,8 +28,15 @@ def test_automated_find(self):
                 continue
 
             # trying to use some different code paths to the other find test
+            # pivot_column fields aren't valid for sorting so ensure we're 
+            # not using one.
+            order_field = None
+            for field_name, field in fields.iteritems():
+                if field['data_type']["value"] != 'pivot_column':
+                    order_field = field_name
+                    break       
             # TODO for our test project, we haven't populated these entities....
-            order = [{'field_name': fields.keys()[0], 'direction': direction}]
+            order = [{'field_name': order_field, 'direction': direction}]
             if "project" in fields:
                 filters = [['project', 'is', self.project]]
             else: