Categories: Uncategorized

These Weeks in Firefox: Issue 94


  • On macOS, scrollbars now squish during rubber-banding.
  • We’re working on supporting native fullscreen on macOS. Turn it on by enabling the pref full-screen-api.macos-native-full-screen. This will (among other things) create new fullscreen Spaces for videos. You could, for example, put a fullscreen YouTube video in native Split Screen next to another application.
  • We’re also working on enhanced dark mode support for macOS (Bug 1623686). Enable this by turning on the pref widget.macos.respect-system-appearance. Recent fixes include a dark library window (Bug 1698763), dark page info dialog (Bug 1698754), and a dark “Clear Recent History” window (Bug 1710269).
  • We’ve announced the deprecation of the canvas drawWindow WebExtension method, due to incompatibility with the Fission architecture:
  • about:welcome got major updates for Firefox 89. This includes new animations, icons, and accessibility improvements.

Friends of the Firefox team

For contributions from May 4 to May 18 2021, inclusive.

Resolved bugs (excluding employees)

New contributors (🌟 = first patch)

Project Updates

Add-ons / Web Extensions

Addon Manager & about:addons
  • Landed some more styling tweaks for making sure about:addons does better match the new Proton UI conventions: Bug 1709464 and Bug 1709655
WebExtensions Framework
  • More Fission-related changes landed in Firefox 90: Bug 1708238
  • Work related to the “manifest_version 3”: Support for new web_accessible_resources manifest property formats – Bug 1696580, Bug 1697334
WebExtension APIs
  • Starting from Firefox 90, Extensions will be allowed to use the Cache web API from extension pages to cache HTTP resources (caching an HTTP URL using the Cache web API will be still enforcing the extensions host permissions, as it would if the extension would be fetching from the same URLs using fetch or XHR) – Bug 1575625 and Bug 1710138
    • Thanks to André Natal for contributing this change as part of his work on the Project Bergamot extension


Lint and Docs

macOS Spotlight

  • Native context menus landed in Firefox 89! This closes the 21-year-old bug 34572.
    • We also fixed a number of follow-up issues, like supporting dark mode context menus on macOS 10.14+.

Messaging System

New Tab Page

  • Accessibility bug fixes for the “personalize” drawer allowing it to operate better with screen readers (Bug 1707022) Thanks to :eeejay for the patches! Also a fix for high contrast mode (Bug 1708248) thanks to :morgan and :thecount
  • Snippets has been disabled in Firefox 89 (Bug 1709984)


  • dthayer has a patch up for review to reduce the UI freezes caused by sending SessionStore data to the SessionFile worker.
  • mconley would like to experiment with the about:home startup cache using Nimbus, and is considering having the startup cache enabled in MR1.1.
  • mconley fixed Bug 1703494 – Remove sync layout flush for hamburger menu opening with proton
  • emalysz landed a patch to provide async support for promise workers, and removed OS.File from PageThumbs.jsm. Only 3 callers of OS.File left during startup!
  • Several BHR improvements:
    • Improved dashboard:
      • It’s possible to navigate to the data of previous days, and to link to a specific day.
      • For hangs with an associated bug, the whiteboard annotation is shown in the top right
      • when using the filter box, the filtered word is highlighted in the stack on the right side.
    • Better data:
      • (chrome) JS function names are now included in BHR stacks.
      • these label frames are now visible: “ChromeUtils::Import”, “mozJSSubScriptLoader::DoLoadSubScriptWithOptions”, “nsThreadManager::SpinEventLoop”, “Category observer notification”, “Services_Resolve”, “Task”
    • Doug is working on showing annotations (eg. “UserInteracting”, “browser.tabs.opening”) in the dashboard

Performance Tools

Proton / MR1

Search and Navigation

  • Daisuke fixed a bug on Linux where opening new tabs by middle clicking the tabs bar could paste clipboard contents into the urlbar. Bug 1710289
  • Daisuke also fixed a bug where pasting a string ending with a combination of CR, LF may drop the search terms. Bug 1709971
  • Marco landed a patch improving the tooltips and accessible text when adding new OpenSearch engines – Bug 1706334
  • Mark fixed a bug in the separate search bar, where certain characters could be shown encoded in the results panel – Bug 1529220


  • Screenshots now factors in Firefox zoom values
  • We’ve accepted an Outreachy intern who will start next week!

No comments yet

Post a comment

Leave a Reply

Your email address will not be published. Required fields are marked *