Subject: 28.0.90; segfault in lock_file

From: Po Lu <[email-masked]>
Date: Sun, 09 Jan 2022 14:04:23 +0800

This write in `lock_file':

      memcpy (dot, replacement, replacementlen);

Ends up writing one byte outside dot.

I could not find the problem, but someone else may want to take a look.
Thanks.