Handle non-exist encoding

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@22433 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/EmailDocument.py

@@ -281,7 +281,7 @@ class EmailDocument(File, TextDocument):
         if part_encoding not in (None, 'utf-8',):
           try:
             text_result = part.get_payload(decode=1).decode(part_encoding).encode('utf-8')
-          except UnicodeDecodeError:
+          except (UnicodeDecodeError, LookupError):
             text_result = part.get_payload(decode=1)
         else:
           text_result = part.get_payload(decode=1)
@@ -290,7 +290,7 @@ class EmailDocument(File, TextDocument):
         if part_encoding not in (None, 'utf-8',):
           try:
             return part.get_payload(decode=1).decode(part_encoding).encode('utf-8')
-          except UnicodeDecodeError:
+          except (UnicodeDecodeError, LookupError):
             return part.get_payload(decode=1)
         return part.get_payload(decode=1)
     return text_result