Hi everyone! Here is my status report for January 2025.

At the beginning of this month, I continued fixing the letterboxing tests needed for the uplift process. There were several platform-specific failures, so I had to set up a Windows build and test environment for Firefox. It was the first time (we usually cross-compile Tor Browser), and it took me some time. Eventually, I got the Bug [0] to add some letterboxing exemptions landed. Then, I opened a stack of patches (authored by ma1) on Phabricator for the next Bug [1]. They have not been merged, yet, because some parts still need the desktop theme reviewers' approval.

I also continued to help formalize the RR rebase process, and we merged the first version [2]. After that, I created the first MR to start this process, with the rebase of our patches onto Firefox 129 [3]. I checked the Firefox release calendar [4], and I suggested we keep a pace of one RR rebase every week. If we manage to, we will reach upstream by the end of March, with the rebase onto Firefox 138, and we will have some time in case we have problems with some versions since our objective is to be in sync with Firefox 129b1, which is scheduled for around the end of April.

This month, I also tried to continue the fingerprinting fight effort, which involved some investigations that eventually resulted in small tasks. I started with v-sync on Wayland after we got an issue about possible refresh rate leaks [5]. Another task was controlling our macOS font allow list [6]. I had to verify some details in various macOS versions, and eventually, I will have to ask about Japanese fonts to Mozilla experts. Then, I started investigating why new windows are rounded incorrectly [7] and I briefly checked the overlay scrollbars [8].

Apart from this, I also helped with the regular releases. I rebased alpha onto 128.6.0esr at the beginning of the month, and I prepared the 14.5a2 release. Then, at the end of the month, I rebased stable and alpha onto 128.7.0esr and legacy onto 115.20.0esr.

Finally, I started writing an uplift wish list for ESR 140 [9].

Best, Pier

[0] https://bugzilla.mozilla.org/show_bug.cgi?id=1555815 [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1556016 [2] https://gitlab.torproject.org/tpo/applications/tor-browser/-/merge_requests/... [3] https://gitlab.torproject.org/tpo/applications/tor-browser/-/merge_requests/... [4] https://whattrainisitnow.com/ [5] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/43236 [6] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/43378 [7] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/43205 [8] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/22137 [9] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/40789#no...