format = format[:2]
return format
+
+def validate_changes_format(format, field):
+ """
+ Validate a tuple-representation of a .changes Format: field. Raises
+ UnknownFormatError if the field is invalid, otherwise return type is
+ undefined.
+ """
+
+ if (format < (1, 5) or format > (1, 8)):
+ raise UnknownFormatError, repr(format)
+
+ if field != 'files' and format < (1, 8):
+ raise UnknownFormatError, repr(format)