Make load of local Document modules safer

Modules from local Document folders may override existing module.
If such local module can't be imported, the original module should be restored.
This is useful during upgrades.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@36101 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/Utils.py

@@ -920,15 +920,23 @@ def importLocalDocument(class_id, document_path = None):
     path = document_path
   path = os.path.join(path, "%s.py" % class_id)
 
+  module_path = 'Products.ERP5Type.Document.' + class_id
+  document_module = sys.modules.get(module_path)
   # Import Document Class and Initialize it
   f = open(path)
   try:
-    document_module = imp.load_source(
-          'Products.ERP5Type.Document.%s' % class_id, path, f)
+    document_module = imp.load_source(module_path, path, f)
     document_class = getattr(document_module, class_id)
     document_constructor = DocumentConstructor(document_class)
     document_constructor_name = "add%s" % class_id
     document_constructor.__name__ = document_constructor_name
+  except Exception:
+    f.close()
+    if document_module is not None:
+      sys.modules[module_path] = document_module
+    raise
+  else:
+    f.close()
     setattr(Products.ERP5Type.Document, class_id, document_module)
     setattr(Products.ERP5Type.Document, document_constructor_name,
                                       document_constructor)
@@ -936,8 +944,6 @@ def importLocalDocument(class_id, document_path = None):
     ModuleSecurityInfo('Products.ERP5Type.Document').declareProtected(
         Permissions.AddPortalContent, document_constructor_name,)
     InitializeClass(document_class)
-  finally:
-    f.close()
 
   # Temp documents are created as standard classes with a different constructor
   # which patches some methods are the instance level to prevent reindexing