Categories: News

These Weeks in Firefox: Issue 81


  • Tab-to-search has been enabled in Nightly! When the URL bar autofills an origin having an installed search engine, users can press tab or down to pick a special shortcut result and enter Search Mode.
    • An animated GIF showing a user typing "duck" in their URL bar in Firefox, and then pressing Tab, putting the URL bar in a mode to send search queries to DuckDuckGo.

      If you like keyboard shortcuts to smooth your workflow, we hope this will make searching in Firefox faster and easier for you!

  • Emma Malysz added support for setting custom print margins from the new print preview UI (bug 1664570)
    • The new printing modal in Firefox Nightly showing the ability to set custom margins around the document.

      Set the margins as you see fit in our new and improved printing UI!

  • Windows users on the default Firefox theme can now enable a new Skeleton UI which will display immediately during Firefox startup (set the pref browser.startup.preXulSkeletonUI to true).
  • It’s now possible to delete the profiles you’ve uploaded. Go to and click on the delete button for the profiles you want to delete.
    • The page showing a user the list of profiles they've submitted. A popup is asking the user if they want to delete the uploaded profile that they've selected.

      Accidentally submitted a profile with information that you didn’t mean to share? This self-serve console lets you remedy that and control your data.

  • Device sharing state indicator icons have been added to the system tray on Windows
    • The system tray on Windows showing a new icon resembling a camera. A tooltip is telling the user that "You are sharing your camera. Click to control sharing."

      We want you to be aware that you’re sharing your devices over WebRTC, even when Firefox isn’t in the foreground.

  • Micah landed a new keyboard shortcut to show/hide the Bookmarks Toolbar (Ctrl+Shift+B on Windows/Linux, Cmd+Shift+B on macOS). The Library will now use Ctrl/Cmd+Shift+O

Friends of the Firefox team

Resolved bugs (excluding employees)

Fixed more than one bug

  • Itiel
  • Niklas Baumgardner

New contributors (🌟 = first patch)

Project Updates

Add-ons / Web Extensions

Addon Manager & about:addons

  • AddonManager.maybeInstalBuiltinAddon has been fixed to return a promise, as it was actually already documented in its jsdoc inline comment (Bug 1665150)

WebExtensions Framework

  • kmag landed some Fission-related changes to make some additional parts of the WebExtensions internals Fission-aware (in particular related to the “activeTab permission’s window matching” and “checking parent frames on content script injection”) – Bug 1646573

Developer Tools

  • DevTools Fission status page (wiki)
  • New add-on phab-test-policy by Nicolas Chevobbe
    • At the bottom of a Phabricator revision page, an add-on has automatically inserted an action to change the project tags. An autocomplete popup shows the various testing flags that can be set, per the new testing policy for mozilla-central.

      We believe this will help encourage more test writing, and make it clearer which patches are hard to test automatically (and which ones need closer scrutiny by our manual testers).

    • File bugs on github
  • New Add-on phab-conventional-comments by Nicolas Chevobbe


  • Nightly experiment to roll out hopefully by next week. 7 blocking bugs remain.


  • Gijs updated us to newer ESLint and eslint-plugin-no-unsanitized versions so we can now use `??=` and other logical assignment operators.


  • We wrote a script that, when building Fenix with a local android-components or GeckoView checkout, will tell you which commits to check out to ensure your Fenix + local ac/GV builds will build cleanly. Without this, frequently you’d check out master on both repositories and hope there were no breaking changes that would cause a build with no local changes to fail.Example run:
$ ./tools/ ../fenix
Building fenix with a local ac?

The last known ac nightly version that cleanly builds with your fenix checkout is...


To build with this version, checkout ac commit...


Password Manager

  • Bug 1134852 – Update password manager recipes from a server/kinto/Remote Settings. Thanks tgiles, this was a complex task spanning multiple products and components
  • Bug 1626764 – The “Sign in to Firefox” button should not have the label wrap to two lines. Thanks to contributor kenrick95
  • Bug 1647934 – Clean up a user’s login backup when it may no longer be useful
  • Bug 1660231 – Enable MASTER_PASSWORD_ENABLED telemetry probe on release

PDFs & Printing

  • Sam fixed a bug where printers reporting no available paper sizes would see errors bug 1663503
  • Mark has a patch to support submitting the print form immediately after opening with Enter bug 1666776
  • We’ve been ramping up our test coverage


  • Skeleton UI
    • Doug has patches up for review for animating it and is continuing to work on fixing bugs and oddities with it. Eg. ensuring it correctly handles maximized windows, which is hairier than expected.
    • Emma has been looking at getting the bounds of the urlbar rect for the early blank window paint
    • (Reminder: set the pref browser.startup.preXulSkeletonUI to dogfood this. Windows-only.)
  • As a team we’ve started discussing problems and paths forward for BHR (Background Hang Reporter).
  • Gijs has a patch for slow script telemetry from the parent process. This is to report on telemetry the cases where we would have previously shown a slow script dialog, which isn’t useful for the parent process.
  • Gijs landed more IO-off-the-main-thread work for downloads

Performance Tools

  • You can name the profiles by clicking on the top left profile title now.
    • An animated GIF showing a user clicking on the profile name in the profiler UI. A text field appears, and the user renames the profile to something easy to remember.

      This will make navigating through profiles much easier for our engineers.

  • Florian added a GetService marker that shows when an xpcom service gets first instantiated. The marker text only shows the cid; the contract id, or service name is shown in a label frame in the stack. Example profile:
  • Our contributors made some improvements on the track context menu:
    • Track context menu now shows only the right clicked process instead of showing everything. (Thanks adityachirania!)
    • Added a Hide “Track Name” to the track context menu. (Thanks CipherGirl!)
    • The context menu for a thread in the profiler UI. It shows toggles for showing and hiding threads only in the associated process.

      Improvements to our profiler means an easier time figuring out how we can make Firefox faster and more responsive.


Search and Navigation

  • The team is focusing on new opportunities related to vertical search, experiments will follow.
  • Consolidation of aliases and search keywords – Bug 1650874
    • UX working on better layout of search preferences
    • Development is temporarily on pause to concentrate on higher priorities
  • Urlbar Update 2
    • Polishing the feature to release in Firefox 83.
    • Clicking on the urlbar opens Top Sites also in Private Browsing windows, unless they have been disabled in urlbar preferences. Bug 1659752
    • Search Mode will always show search suggestions at the top. Bug 1664760


  • The global sharing indicator now only displays if the user is sharing their screen, and the microphone and camera mute toggles have been hidden by default.
    • You can turn these back on by going to about:preferences#experimental, and checking “WebRTC Global Mute Toggles”.
    • These are experimental because many sites don’t pay attention to the “muted” event, so they don’t update their UI when mute state is set.
  • The global sharing indicator is currently slated to ride out in Firefox 83.

One comment on “These Weeks in Firefox: Issue 81”

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  1. klop*cz wrote on

    Thank you for this Nightly News. It’s very appreciated.


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