1706809 - Forward/"edit as new" not working for format=flowed, DelSp, ISO-2022-JP and format=flowed, quoted-printable

Status: UNCONFIRMED

(MailNews Core :: MIME, defect)

Description

[José M. Muñoz]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.85 Safari/537.36

Steps to reproduce:

Forward/"edit as new" not working for format=flowed, DelSp, ISO-2022-JP and format=flowed, QP

This continues from bug 1702197 comment #37.

Forward/"edit as new" not working for format=flowed, DelSp, ISO-2022-JP was originally reported in bug 1230968.
Forward/"edit as new" not working for format=flowed, QP was originally reported in bug 1689804. That bug was backed out from TB 78 ESR and reverted in bug 1702197.

In TB 78 format=flowed, DelSp, ISO-2022-JP is broken since switching vom uconv to encoding_rs. encoding_rs inserts a replacement character <?> for an empty ASCII run, see bug 1508136 for details. This empty ASCII run consists of ESC ( B at the end of each line of the test message.

The breakage of format=flowed, QP was caused by 1230968. Removing
https://searchfox.org/comm-central/rev/30a3fdb9e1779af4c10d8e7b9f54e9feee9dde06/mailnews/mime/src/mimemsg.cpp#166-168
from https://hg.mozilla.org/comm-central/rev/99eb42a1fd3dba3a2cfaec4bb7a84bf36ebe3c1d#l1.31
and the then dead code
https://searchfox.org/comm-central/rev/30a3fdb9e1779af4c10d8e7b9f54e9feee9dde06/mailnews/mime/src/mimetpfl.cpp#323-327
from https://hg.mozilla.org/comm-central/rev/99eb42a1fd3dba3a2cfaec4bb7a84bf36ebe3c1d#l2.18
fixes the issue for QP but for the format=flowed, DelSp, ISO-2022-JP re-introduces the unwanted spaces which will show instead of the <?>.

Comment 1

[José M. Muñoz]

Attachment: longline-ja-JP.eml

From bug 1230968 attachment #8696494 [details].

Comment 2

[José M. Muñoz]

Attachment: test-spanish-text.eml

From bug 1702197 attachment 9217177 [details].