Hi everyone, Here is my status report for February 2025.

At the beginning of the month, I worked on releasing 14.0.5 and 13.5.12. I prepared them, and after we built them, I also signed them. I also took some time to repurpose an old computer for this task to run it in an environment completely isolated from my usual developer machine.

However, Tor Browser 14.0.5 had a problem [tor-browser#43468] and crashed on older macOS versions because of an upstream WebRTC update. For some reason, Firefox and Mullvad Browser were not affected. So, I investigated to find the cause of the problem and created a patch, both for us and for Firefox [Bug 1946501].

After that, I went back to work on uplifts. The first was Bug 1923260 [Bug 1923260], a patch initially sent to us by a contributor. Upstream asked for some changes, but I had to verify them, and it has been a while since I made some C++ changes to Firefox specific to Android that needed to be debugged first.

While waiting for the letterboxing improvements to land, I started checking a problem with the initial size of Firefox windows when system scaling is enabled [tor-browser#43205]. Eventually, it was a platform-specific problem 😭. On Windows, some intermediate rounding (spread across several functions) leads to a wrong final window size being passed to the OS API [Bug 1947439]. On Linux, some window sizes are never applied, even when set with external tools such as xdotool. I think the problem is somewhere in the X.org server rather than being a response from Firefox. So, I decided to write a workaround at a higher level since fixing the actual causes would have been much longer and complicated.

Also about screen size, I started a patch [tor-browser!1388] to change how we spoof the sizes of the outer window and of the screen. Currently, we lie about them being the same as the inner window. However, this stands out compared to usual values and sometimes leads to the misdetection of our users as bots. My current patch still needs some changes, so it hasn't been merged, yet.

After that, I resumed integration of the Lox crates on Tor Browser. Our initial approach was to use a WASM blob, but we decided to integrate the actual crates for several reasons [tor-browser#43096].

Finally, I resumed the RR rebase effort [tor-browser#43512]: I rebased from Firefox 130 to 131 and from 131 to 132, and I also reviewed Bea's rebase from 129 to 130.

Best, Pier

[Bug 1923260] https://bugzilla.mozilla.org/show_bug.cgi?id=1923260 [tor-browser#43468] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/43468 [Bug 1946501] https://bugzilla.mozilla.org/show_bug.cgi?id=1946501 [tor-browser#43205] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/43205 [Bug 1947439] https://bugzilla.mozilla.org/show_bug.cgi?id=1947439 [tor-browser#43096] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/43096 [tor-browser!1388] https://gitlab.torproject.org/tpo/applications/tor-browser/-/merge_requests/... [tor-browser#43512] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/43512