[upstream] Thunderbird filters doesn't handle base64 encoded message

[Bartłomiej Żogała]

User is able to define e-mail filters in Thunderbird. This can cover multiple fields like From:, To:, Subject: and Content . Using Content option allows a way to provide string which will be matched against e-mail content. Although this doesn't work when message is base64 encoded - this format is properly displayed by Thunderbird but it seems filters came to early and match user provided clear text against encoded text in e-mail.

I confirmed this by defining filter with base64 fragment as desired string but this is not an option for more dynamic messages - adding one space before clear text string will change entrie string due to how base64 encode work so it needs to fully decode e-mail and then apply filters

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: thunderbird 1:68.10.0+build1-0ubuntu0.18.04.1
Uname: Linux 5.10.0-051000rc6-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.20
Architecture: amd64
BuildID: 20200629235513
CurrentDesktop: ubuntu:GNOME
Date: Mon Dec 14 02:19:49 2020
DefaultProfileExtensions: extensions.sqlite corrupt or missing
DefaultProfileIncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
DefaultProfileLocales: extensions.sqlite corrupt or missing
DefaultProfilePrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/thunderbird/omni.ja:greprefs.js:1141
DefaultProfileThemes: extensions.sqlite corrupt or missing
InstallationDate: Installed on 2015-05-08 (2046 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=pl_PL.UTF-8
 SHELL=/bin/bash
Profiles:
 Profile1 (Default) - LastVersion=None/None (Out of date)
 Profile0 - LastVersion=68.10.0/20200629235513 (In use)
SourcePackage: thunderbird
UpgradeStatus: Upgraded to bionic on 2018-08-26 (840 days ago)

[Olivier Tilloy (osomon)]

Thank you for the bug report. This sounds like an upstream problem, would you mind reporting it at https://bugzilla.mozilla.org/enter_bug.cgi#h=dupes%7CThunderbird and sharing the link to it here once done? Thanks in advance!