decode issue on kmail for Japanese UTF-8 encoded e-mails

[Masaru Nomiya]

Hello,

As you probably know, for Japanese-language e-mails, there are
three types of character codes;

1. ISO-2022-JP
2. UTF-8
3. Shift_JIS

Here, kmail decodes ISO-2022-JP-encoded and Shift_JIS-encodede-mails
correctly, but cannot decode UTF-8-coded e-mails or Shift_JIS coded
-e-mails correctly, and the mail becomes garbled and cannot be read at
all.

However, with "kmail --msg e-mail", the source of the e-mails is
correctly displayed.

I have confirmed this with;

1. openSUSE Leap 15.1 -- kmail 18
2. openSUSE Leap 15.4 -- kmail 22
3. openSUE Tumbleweed -- kmail 22

There exits a bug in kmail, I think.

The cause of the garbled characters is that Japanese
UTF-8 encoded e-mails are decoded in ISO-8859-1 (or ISO-Latin-1).

FYI, the original e-mail;

 https://drive.google.com/file/d/1TOoiJwtD8_GNX-9Nkt93zHt23kJU_0eM/view?usp=share_link

the correct view with the e-mail client:

https://drive.google.com/file/d/1iYkdD6iLi20uswQpgzjZylk6XQXfKfWs/view?usp=share_link

and, kmail's view in my environment;

https://drive.google.com/file/d/1iYkdD6iLi20uswQpgzjZylk6XQXfKfWs/view?usp=share_link

Any idea?

Thanks, in advance.

---
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