Do not export or import non-existing properties of BT objects.

Example of bad behavior:
 - "short_title" property is not used / has no associated field
 - in export code getProperty('short_title') returns None
 - and a bt/short_title file is created, containing str(None)
 - when reimporting this BT, bt/short_title is read, and obj.short_title is set
    to 'None' string
 - as a result, bt.getShortTitle() wrongly returns "None" _string_



git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@32926 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/BusinessTemplate.py

@@ -5553,6 +5553,8 @@ Business Template is a set of definitions, such as skins, portal types and categ
                   'install_object_list_list', 'id_generator', 'bt_for_diff'):
           continue
         value = self.getProperty(id)
+        if value is None:
+          continue
         if prop_type in ('text', 'string', 'int', 'boolean'):
           bta.addObject(obj=value, name=id, path=path+os.sep+'bt', ext='')
         elif prop_type in ('lines', 'tokens'):

product/ERP5/Tool/TemplateTool.py

@@ -256,6 +256,11 @@ class TemplateTool (BaseTool):
             except KeyError:
               continue
             value = tar.extractfile(info).read()
+            if value is 'None':
+              # At export time, we used to export non-existent properties:
+              #   str(obj.getProperty('non-existing')) == 'None'
+              # Discard them
+              continue
             if prop_type == 'text' or prop_type == 'string' \
                                    or prop_type == 'int':
               prop_dict[pid] = value
@@ -320,6 +325,11 @@ class TemplateTool (BaseTool):
           if not os.path.exists(prop_path):
             continue          
           value = open(prop_path, 'rb').read()
+          if value is 'None':
+            # At export time, we used to export non-existent properties:
+            #   str(obj.getProperty('non-existing')) == 'None'
+            # Discard them
+            continue
           if prop_type in ('text', 'string', 'int', 'boolean'):
             prop_dict[pid] = value
           elif prop_type in ('lines', 'tokens'):