if no subblock, return nothing

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@37864 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/DiffUtils.py

@@ -104,6 +104,9 @@ class DiffFile:
     if self.binary:
       return '<b>Folder or binary file or just no changes!</b><br/><br/><br/>'
 
+    if not len(self.children):
+      return ''
+    
     html_list = []
     html_list.append('''
     <table style="text-align: left; width: 100%%; border: 0;" cellpadding="0" cellspacing="0">