bpo-30245: Fix possible overflow when organize struct.pack_into error message (#1682)

diff --git a/Misc/ACKS b/Misc/ACKS
index bee9eb0..6fe57d5 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -921,6 +921,7 @@
 Everett Lipman
 Mirko Liss
 Alexander Liu
+Yuan Liu
 Nick Lockwood
 Stephanie Lockwood
 Martin von Löwis
diff --git a/Misc/NEWS b/Misc/NEWS
index ada74a0..5066f57 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -345,6 +345,9 @@
 Library
 -------
 
+- bpo-30245: Fix possible overflow when organize struct.pack_into
+  error message.  Patch by Yuan Liu.
+  
 - bpo-30378: Fix the problem that logging.handlers.SysLogHandler cannot
   handle IPv6 addresses.