[FIX]report_sxw : fix strip_name function that cut a name to a given length in a report. It no longer crash when no name is given to the function.

bzr revid: csn@openerp.com-20130208135704-4jvc9odchlulefx6

openerp/report/report_sxw.py

@@ -189,6 +189,8 @@ class rml_parse(object):
         return newtag, attrs
 
     def _ellipsis(self, char, size=100, truncation_str='...'):
+        if not char:
+            return ''
         if len(char) <= size:
             return char
         return char[:size-len(truncation_str)] + truncation_str