The bot occasionally posts the same comments twice on Github

[Guoxiong Li]

Hi all,

When we send an email to reply to a RFR email, the bot will post a comment
on Github for us.
But sometimes the bot may post the same comments twice.
Please see this email[1]. We expect that the bot will post one comment to
the corresponding PR[2].
But actually, the bot posted two same comments[3][4].

It is an intermittent issue. Sometimes, the bot behaves correctly.
Even today, the bot can operate normally at one PR[5] but fails at another
PR[6][7].

Is it a known issue?
Anyway, it is good to fix it so that the redundant information won't be
generated.

[1]
https://mail.openjdk.java.net/pipermail/compiler-dev/2021-May/016981.html
[2] https://github.com/openjdk/jdk/pull/4157
[3] https://github.com/openjdk/jdk/pull/4157#issuecomment-846605316
[4] https://github.com/openjdk/jdk/pull/4157#issuecomment-846605322
[5] https://github.com/openjdk/jdk/pull/3976#issuecomment-847663710
[6] https://github.com/openjdk/jdk/pull/4167#issuecomment-847595516
[7] https://github.com/openjdk/jdk/pull/4167#issuecomment-847595538

Best Regards,
-- Guoxiong