1897590 - Fingerprinting protection with +AllTargets does not trigger the RoundedWindowSize behavior

Status: VERIFIED FIXED

(Core :: Privacy: Anti-Tracking, defect, P3)

Description

[Chas Belov]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:126.0) Gecko/20100101 Firefox/126.0

Steps to reproduce:

1. On Firefox, Settings, General, Startup, checked Open previous windows and tabs
2. Opened multiple windows of various widths.
3. In about:config, set:

privacy.resistFingerprinting = false
privacy.fingerprintingProtection = true
privacy.fingerprintingProtection.overrides = +AllTargets,-FrameRate

3. Quit Firefox
4. Launch Firefox

Actual results:

Windows reopen at the size they were when I closed Firefox.

Expected results:

Windows reopen at the default size.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Privacy: Anti-Tracking' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Fatih Kilic [:fkilic]]

I can reproduce it. The window appears at rounded size for a moment before resizing to its old size, though I couldn't find the resize mechanism. It doesn't happen with "Open previous windows and tabs" unchecked (specifically happens only when browser.startup.page = 3 = resume previous browser session). So I assume it has to do with loading of old window sizes.

Comment 3

[Fatih Kilic [:fkilic]]

Attachment: Bug 1897590: Check RoundWindowSize RFPTarget before restoring tab sizes. r?tjr

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/17849362bda7
Check RoundWindowSize RFPTarget before restoring tab sizes. r=tjr,sessionstore-reviewers,dao

Comment 5

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/17849362bda7

Comment 6

[Bianca Hidecuti, Desktop Test Engineering [:bhidecuti]]

I was able to reproduce the issue on Firefox 126.0, using macOS 14.4, while following the steps mentioned in Comment 0.
Verified as fixed on Firefox 128.0-build2 RC, using macOS 14.4, Ubuntu 22.04 and Windows 11. All previously opened windows reopen at the default size.