Fixed a misleading error message given when disallowed character occurs in a draft filename.

 - Legacy-Id: 4946

Author: levkowetz

ietf/submit/parsers/plain_parser.py

@@ -55,7 +55,12 @@ def parse_filename(self):
             filename = re.sub('\.txt$', '', filename)
             extra_chars = re.sub('[0-9a-z\-]', '', filename)
             if extra_chars:
-                self.parsed_info.add_error(u'Filename contains non alpha-numeric character: %s' % (', '.join(set(extra_chars))).decode('ascii','replace'))
+                if len(extra_chars) == 1:
+                    self.parsed_info.add_error((u'The filename contains a disallowed character: %s ' % (', '.join(set(extra_chars))).decode('ascii','replace')) +
+                                                u'(see http://www.ietf.org/id-info/guidelines.html#naming for details).')
+                else:
+                    self.parsed_info.add_error((u'The filename contains disallowed characters: %s ' % (', '.join(set(extra_chars))).decode('ascii','replace')) +
+                                                u'(see http://www.ietf.org/id-info/guidelines.html#naming for details).')
             match_revision = revisionre.match(filename)
             if match_revision:
                 self.parsed_info.metadraft.revision = match_revision.group(1)