Forwarding an HTML message as plain text causes the message to get cut off

Hello,

I've noticed a bug and I think I've finally narrowed it down to the point where I can make a coherent report about it.

The symptoms are that when I forward a message, often the forwarded message is cut off.

For example, this message body from a message I forwarded this morning:

FYI. [Removed some text about how to follow up about this message.]

Thanks,
[My Name]

Forwarded message:

> From: [Sender Name & Email]
> To: [My Name & Email]
> Subject: Re: [Subject removed]
> Date: Sun, 4 Jul 2021 11:24:41 +0000
> 
> �

Note the weird special character at the end of the message (hope it comes through in this report) and the lack of any of the text from the forwarded message. (This is the whole message as it was received and as it appears in my Sent folder.)

This has been happening off and on for quite some time, but today I tried forwarding it again, thinking I'd just delete the first part.

At that point, I noticed that when I go to forward this message, the lines shown above are blue, but the rest of the message body is regular text color.

I tried to delete the area around where the character shows up, and it came up with the "Do you want to discard embedded HTML?" dialog. I clicked "Discard HTML." The whole quoted text of the forwarded message then turned blue. At that point, I forwarded the message without actually deleting anything, and it went through fine.

For purposes of reproducing this, it's probably worth mentioning here that I'm pretty sure I have every conceivable "compose messages in plain text" option selected because HTML emails are an Abomination Unto Nuggan.

Hope this helps! I'm on MailMate 1.13.2 (5673).