replace None per "" on all keys

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@17170 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/Inventory.py

@@ -116,11 +116,11 @@ class Inventory(Delivery):
     current_inventory_dict = {}
     current_inventory_key_id_list = ('resource_relative_url', 'variation_text')
     for line in current_inventory_list:
-      current_inventory_key = tuple(
-          [line[x] for x in current_inventory_key_id_list])
-      if current_inventory_key[1] is None:
-        # To be consistent
-        current_inventory_key = (current_inventory_key[0], "")
+      current_inventory_key = [line[x] for x in current_inventory_key_id_list]
+      for x in xrange(len(current_inventory_key)):
+        if current_inventory_key[x] is None:
+          current_inventory_key[x] = ""
+      current_inventory_key = tuple(current_inventory_key)
       try:
         current_inventory_by_sub_variation = \
             current_inventory_dict[current_inventory_key]