[tor-project] PieroV's Monthly Status Report, February 2024

[Pier Angelo Vendrame]

Hi everyone!
Here is my status report for February 2024.

As anticipated in my previous report, I have been working on 
implementing the possibility of setting Mullvad Browser as the default 
browser on Windows for most of this month.
It involved several steps.
The first one was to start customizing MOZ_APP_DISPLAYNAME in our 
browsers to allow installing one build from each channel (stable, alpha, 
nightly) without conflicts [0].
As a wanted side effect, alpha and nightly app bundles for macOS now 
contain the channel in their name. The original issue about this [1] was 
opened in 2018 😄️.
The second step was to adapt Firefox's default browser agent. It's a 
companion exe that helps in various tasks. We disabled it because it 
isn't compatible with MinGW. Luckily, the compatibility problems affect 
only some features we are not interested in, so we could disable them 
and create a reduced agent that is enough for our needs.
The final step was to extend the installer to register all the various 
file associations. I hoped to deal with this step later because it was 
very involved (lots of Windows registry), but it turned out to be necessary.
We're implementing these changes in Mullvad Browser. Only the macOS 
changes apply also to Tor Browser.

This month, I also took some time to start a different approach to the 
big rebases we do for our browsers.
Traditionally, we stay on Mozilla ESR's channel, and once per year, we 
skip all the Firefox versions between the two ESRs.
I wondered if we could instead spread this work during the year and make 
more rebases that are smaller and, therefore, potentially easier to review.
I've started from Firefox 115 and arrived at Firefox 120. So far, it 
seems to me that the differences are indeed easier to recognize and explain.

Other tasks I did include the usual monthly rebase and fixing more 
fingerprinting issues. I also turned off the OS spoofing in HTTP 
User-Agent in Mullvad Browser [2] and helped a volunteer who's trying to 
reproduce our builds in F-Droid [3].
Finally, I opened an issue about what we'll need from Arti for Tor 
Browser [4].

Best,
Pier

[0] 
https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/42398
[1] 
https://gitlab.torproject.org/tpo/applications/tor-browser-build/-/issues/40569
[2] 
https://gitlab.torproject.org/tpo/applications/mullvad-browser/-/issues/234
[3] 
https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/27539
[4] https://gitlab.torproject.org/tpo/core/arti/-/issues/1303