Upgrade to Thunderbird 78 ESR
Originally created by @intrigeri on #17148 (Redmine)
Thunderbird 78 was released mid-July 2020; it's been uploaded to Debian experimental already.
Thunderbird 68 should become EOL on 2020-09-22, which in theory will be our deadline for upgrading to v78, and thus to get the built-in OpenPGP support enabled by default in Thunderbird 78.2 (#17147 (closed)). However, there's a good chance that the Thunderbird 78 package won't be ready for Buster in time for Tails 4.11 yet, so:
- Either we can build custom a Buster backport earlier, and ship it in Tails 4.11.
- Or this all will really get first shipped in Tails 4.12.
The two Thunderbird patches we created to replace TorBirdy were upstreamed (#17283 (closed)) and should be part of Thunderbird 78, so they can be dropped from the patches we apply on top. Those are:
config/chroot_local-includes/usr/share/tails/build/thunderbird-patches/Avoid-local-timestamp-disclosure-in-Date-header.patchconfig/chroot_local-includes/usr/share/tails/build/thunderbird-patches/Avoid-spellchecking-language-disclosure-in-Content-Language-header.patch
In the upstream patches, the pref mail.mime.avoid_fingerprinting was
split into two new prefs, which have to be enabled instead:
mail.suppress_content_languagemail.sanitize_date_header