Categories: Uncategorized

These Weeks in Firefox: Issue 89


Friends of the Firefox team

For contributions made from February 23, 2021 to March 9, 2021, inclusive.


Resolved bugs (excluding employees)

Fixed more than one bug

  • Itiel
  • Mattias de los Rios Rogers [:delosrogers]
  • Michelle Goossens
  • Oliver Pope
  • Patrick Storz
  • Andrei Petcu
  • RAHUL SAWRA[:rsawra]
  • Sebastian Zartner [:sebo]
  • Tim Nguyen :ntim
  • Tom Schuster [:evilpie]
  • Tom Tung [:tt, :ttung]

New contributors (🌟 = first patch)

Project Updates

Add-ons / Web Extensions
WebExtensions Framework
  • Fixed a bug in MatchGlob that was triggering a browser main process hang when an extension was passing to browser.tabs.query a URL with many redundant wildcards characters – Bug 1570868
  • Investigated and fixed a tabs API regression introduced in Firefox 86 – Bug 1694699 (the underlying issue was actually an old typo on the tabbrowser side, fixed in Bug 1498432)
WebExtension APIs
  • Added “url” support in the optional filtering option supported by the browser.tabs.onUpdated API event – Bug 1680279

Developer Tools

  • Browser toolbox now starts even if there are pending updates (bug, contributed by :nalexander)
  • Inactive CSS support improved – new warning displayed when grid-template* is used on non-grid containers (bug)
  • The team is focusing on fixing remaining Fission M7 blockers

Installer & Updater

  • 1120863 – nalexander fixed a longstanding issue with running the Browser Toolbox when an update is pending.
  • nalexander’s work on the background update task continues, landed 1695797 (only process updates if we’re the only instance running) and 1695754 (background task docs).
  • 1691486 – bytesized extended per-installation preferences beyond just
  • 1690064 – bytesized made uninstalling and reinstalling more consistently clear per-installation prefs and updates.
  • 1685213 – agashlin landed shortcut and taskbar pinning telemetry

Messaging System

Password Manager

PDFs & Printing

  • Tom Schuster – Bug 1694844 – Fixed a bug where the print dialog wouldn’t open on linux if CUPS wasn’t installed


Performance Tools

  • Added nested event loop markers. Example profile:
  • Fix for broken JIT stacks is underway and it’s very promising so far. Prototype working on Windows x64.
Side by side stack charts from the Firefox profiler. Previously there were some stacks that don’t belong here and that was making it hard to analyze. Now the text is shown completely and not constrained

Firefox Profiler has improved the appearance of the stack chart


  • Oliver [:popeoliv] finished moving PiP site overrides from the WebCompat addon into its own addon (bug 1690076)
    • Special thanks to Rob Wu, Dennis Schubert, and Thomas Wisniewski for helping us through this
  • Oliver [:popeoliv] fixed a JavaScript error where contentWindow isn’t available when calling requestIdleCallback (bug 1676569)
  • Hunter [:whjones526] started a prototype patch that allows users to move the PiP toggle button to either the right or left side (bug 1550453)

Search and Navigation


  • pbz and jib have patches up that will grant a ~50s grace period for a site to reacquire a device that they’d previously been given access to, without re-prompting.


One comment on “These Weeks in Firefox: Issue 89”

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  1. Steve Reed wrote on

    Love using Firefox Nightly! Although today the capture screenshot tool is nowhere to be found! Hope that is just a “today thing”! Thanks for letting us use the Nightly build! It is fun!


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