[issue30245] possible overflow when organize struct.pack_into error message

[Serhiy Storchaka]

Changes by Serhiy Storchaka <storchaka+cpython at gmail.com>:


----------
components: +Extension Modules
stage: needs patch -> patch review

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue30245>
_______________________________________