Some message dates rewritten to "now" on restore.

[Leftium]

Full steps to reproduce the issue:

1. Backup emails with GYB.
2. Restore emails with GYB (to a different email address).

Expected outcome:
Dates are preserved.

Actual outcome:
Some dates are changed to "now" date.

Notes:

• ~42% of "in:sent" message dates were rewritten to "now." (3,809/9,038)
• ~10% of all message dates were rewritten to "now." (18,551/195,729)
• "--clean" was not used.
• The source Gmail account was already a collection of various email accounts (other email accounts were forwarding emails to this account, and other email accounts had already been imported via IMAP/Outlook)
• Presumably there is a bug in the way GYB is calling the Google API, or a bug in the API itself.
• It seems the Gmail API rewrites the "Date" header to now if it rewrites another header (like removing quotes from the "From" header). Or if just adding a time zone offset to the Date itself? Is there some way to ensure the Gmail API doesn't do this?
• Sometimes messages with rewritten dates are restored multiple times (searching for the rfc822msgid returns multiple messages, all with different dates less than a minute apart)

Sample message where "Date" header was rewritten:

Original

From: "J*** M*****" <m*****[email protected]>
To: <w*******@carleton.edu>
Subject: hey Hans
Date: Wed, 23 Aug 2000 05:01:16
Message-ID: <15eb01c82368$46efc9f0$d4cf5dd0$@edu>
MIME-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7bit
X-Mailer: Microsoft Outlook Express 5.50.4133.2400
Thread-Index: AcZRahYIdq3e/QfWTG+/6JQFXkJtWg==
X-OlkEid: 1A647033011E848FB761854FBE6605E33324AA1F
x-mimeole: Produced By Microsoft MimeOLE V6.00.2800.1106

Restored

X-Google-Smtp-Source: AGHT+IFH0BpcjkbadkVS/jlRYj3nSwZko6UUJyNCypxV8dK/g7BKxj20TwgRZwbgzYUuEWPqRK9fAehnOKUHmtnlbQ==
X-Received: by 2002:a0c:fe91:0:b0:63f:8839:658 with SMTP id d17-20020a0cfe91000000b0063f88390658mr2749634qvs.1.1692122605179;
        Tue, 15 Aug 2023 11:03:25 -0700 (PDT)
Received: from 879096941799 named unknown by gmailapi.google.com with HTTPREST; Tue, 15 Aug 2023 13:03:25 -0500
From: J*** M***** <m*****[email protected]>
To: <w*******@carleton.edu>
Subject: hey Hans
Date: Tue, 15 Aug 2023 13:03:25 -0500
Message-ID: <15eb01c82368$46efc9f0$d4cf5dd0$@edu>
MIME-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7bit
X-Mailer: Microsoft Outlook Express 5.50.4133.2400
Thread-Index: AcZRahYIdq3e/QfWTG+/6JQFXkJtWg==
X-OlkEid: 1A647033011E848FB761854FBE6605E33324AA1F
x-mimeole: Produced By Microsoft MimeOLE V6.00.2800.1106

Sample message where "Date" header was preserved:

Original

From: J*** M***** <l******@gmail.com>
Mime-Version: 1.0 (1.0)
Date: Tue, 23 Sep 2014 22:53:38 -0500
Delivered-To: l******@gmail.com
Message-ID: <-2717672033979977412@unknownmsgid>
Subject: Marla's Caribbean Cuisine
To: N**** C**** <c********[email protected]>
Content-Type: text/plain; charset=UTF-8

Restored

X-Google-Smtp-Source: AGHT+IE+cKdd/uBOSDm75XjH7FDQB769oqlfyYnd9Im9o1SajB5r9BzpeZ3NyODaxaUxdYC06XShb5a0WxdFyJeHGg==
X-Received: by 2002:a0c:e3c3:0:b0:63c:ec39:13d0 with SMTP id e3-20020a0ce3c3000000b0063cec3913d0mr9116257qvl.64.1692092336136;
        Tue, 15 Aug 2023 02:38:56 -0700 (PDT)
Received: from 879096941799 named unknown by gmailapi.google.com with HTTPREST; Tue, 15 Aug 2023 05:38:56 -0400
From: J*** M***** <l******@gmail.com>
Mime-Version: 1.0 (1.0)
Date: Tue, 23 Sep 2014 22:53:38 -0500
Delivered-To: l******@gmail.com
Message-ID: <-2717672033979977412@unknownmsgid>
Subject: Marla's Caribbean Cuisine
To: N**** C**** <c********[email protected]>
Content-Type: text/plain; charset=UTF-8