Highlights

• The Text Fragments creation UI was just activated in Firefox Nightly allowing you to share/reference a link anchor to any text snippet in a page
  • https://mastodon.social/@firefoxnightly/114805708639661562
  • This is held to Nightly for now while it is tested.
• Thanks to volunteer contributor Christina for introducing a new browserSettings.verticalTabs API which allows extensions to determine if vertical tabs are currently enabled (or to offer to enable it for the user) – Bug 1946600
• Henrik enabled async widget events for wheel scrolling by default in web-platform tests as part of Interop 2025, bringing Firefox to 100% pass rate on scrollend-related tests.
• We’ve updated our Opera migrator so that it works again after the Opera browser changed how it stores profile data. This fix was uplifted to Firefox 141 which should go out to release later this month.

Friends of the Firefox team

Resolved bugs (excluding employees)

Volunteers that fixed more than one bug

• Gregory Pappas [:gregp]

Project Updates

Add-ons / Web Extensions

Addon Manager & about:addons

• Fixed XPIProvider.processPendingFileChanges logic to not emit unnecessary warnings for locations with non-existing staging extensions subdirs while processing staged add-on installations – Bug 1974233
• Fixed downloaded XPI files not deleted when add-on install flow is cancelled – Bug 1639163
• Fixed Windows-specific crash on nsIFile::Contains called with a null path while writing the addon startup data to the extensions.json profile file –  Bug 1975674
• Removed old internal privileged helper nsIComponentManager.addBootstrappedManifestLocation – Bug 1953136

WebExtensions Framework

• Thanks to Nathan Teodosio for contributing end-to-end test coverage for the native messaging API exercised from a Firefox build running inside the snap package sandbox – Bug 1928096

DevTools

• Julian Descottes [:jdescottes] fixed an issue with StyleEditor pretty printing where we were adding blank lines when last declaration missed a semi colon (#1974450)
• Julian Descottes [:jdescottes] made User agent stylesheets read-only in the style editor (#1972844, #1974395, #1973508)
• Nicolas Chevobbe [:nchevobbe] added lock icon for rules in uneditable stylesheets in Rules view to be consistent and improve accessibility (we were only adding a subtle grey background, and UI state shouldn’t be conveyed with colors only (#1973935)
• Nicolas Chevobbe [:nchevobbe] improved Inspector markup search by highlighting results and scrolling to the first matching range (the match can be deep inside a text node) (#1259390, #1440229)
• Alexandre Poirot [:ochameau] made parent process modules visible when debugging Firefox for Android (#1973939)
• Julian Descottes [:jdescottes] fixed an issue in the Netmonitor Cache panel, who could be empty even when the response was cached (#1973036)
• Julian Descottes [:jdescottes] fixed displaying base 64 images in the Response panel and added a checkered background behind so they’re always visible (#1975429, #1975664)
• Julian Descottes [:jdescottes] added a mach devtools-node-test command to run devtools node tests (documentation: https://firefox-source-docs.mozilla.org/devtools/tests/node-tests.html)

WebDriver BiDi

• Sabina renamed Proxy capability class to ProxyConfiguration to avoid confusion with JavaScript Proxy class.
• Baku fixed a regression where adding a cookie through the WebDriver BiDi or Marionette APIs would fail with an error if the expiry value exceeded 400 days.
• Sasha updated the WebDriver BiDi cookie APIs to support “default” value in “sameSite” property to address recent changes in platform API which wouldn’t allow anymore to set “sameSite” equal ”none” and “secure” equals “false” on HTTPS pages.
• Bvandersloot added support in Marionette for interacting with CHIPS cookies (Cookies Having Independent Partitioned State).
• Bas fixed the mach command for firefox-ui-functional tests, which now works again when run without specifying a manifest or test path.
• Henrik removed the temporary remote.system-access-check.enabled preference in Firefox 141. This preference can no longer be used to disable system access checks when using WebDriver in Firefox’s chrome scope during testing.

Lint, Docs and Workflow

• Gijs landed a change to make the ESLint rule no-comparison-or-assignment-inside-ok work for Assert.ok() – previously it only worked for ok().

New Tab Page

• Special thanks to Jules who has been helping us get New Tab using design tokens / design system colours! New Tab is now at 84.22% propagation!
• Special thanks to rpl who has been plugging away at a fairly impressive stack of patches which will let us deploy trainhop updates for newtab via Nimbus / Experimenter!
• Nathan landed work related to a TrendingSearches widget which will run in an upcoming experiment
• Nathan also recently landed a fix that should help us avoid overlapping / overabundance of messages between New Tab and the rest of the browser.
• mconley posted a patch to add a moz-ohttp-image protocol handler to, in theory, request images privately over OHTTP, for use on newtab under certain circumstances.

Places

• Lazily loading `PlacesSemanticHistoryManager` (Standard8).
• Refactoring `PlacesQuery.sys.mjs` to split query and cache logic (James).
• Still trying to see if lowercasing tokens before SQL improves performance for `MatchAutoCompleteFunction` (James).
• Landed a simple patch that removed other Places expiration heuristics (James).
• Fixing unit tests for `History.fetch` returning referrer URI (James).
• Working on using `ConcurrentConnection` for favicon protocol handlers (Yazan).
• Looking into a memory leak in recent Favicons code (Marco).

Search and Navigation

• Unit Converter & Calculator
  • Landed a fix for incorrect unit conversions with long numbers (Yazan).
  • A fix is in review for negative calculator results displaying wrong in RTL builds (Yazan).
  • Landed a fix for negative converted results displaying wrong in RTL builds (Yazan).
• Unified Trust Panel
  • Reviews on initial implementation are done, about to land behind `browser.urlbar.trustPanel.featureGate` pref (Dale).
• Semantic History Search (Marco)
  • Sorted general results by frecency, including semantic.
  • Added telemetry for the database file size.
  • Added `available_semantic_sources` property to abandonment and engagement.
  • Added semantic history chunks calculation telemetry.
  • Working on distinguishing semantic and SERP history in telemetry events.
  • Next up: improving results quality (decreasing distance threshold, removing artificial 2-result limit, dynamic distance threshold).
  • Next: Following up with genAI about models being unusable in permanent Private Browsing mode.
• Multi-Context Address Bar (Dao)
  • Met up to discuss requirements for the search bar work.
  • Decided to put off Trending Search Suggestions and Utilities for new search bar implementation for now.
  • Nive is looking into bringing the unified search button to the search bar to ditch one-off buttons.
  • Breaking down initial work while waiting for the unified search button vs. one-off button decision.
• Custom Search Engines
  • A small patch is in review to let users add search engines from post forms with `role=search` (Moritz).
  • Favicons weren’t showing up right away after adding a search engine via the toolbar (Moritz).
  • If a search engine added by contextual search is removed, it can’t be re-added manually – a fix for this is in review (Moritz).

• General Search & Telemetry
  • Digging into our Bing stats to see if they match up with what Bing sees (Standard8).
  • Implemented SERP telemetry for the DuckDuckGo Shopping tab, just dealing with a test hiccup (Stephanie).
  • Started on Qwant’s shopping tab telemetry; it’s pretty similar to DDG, so hopefully a lot of the code can be reused (Stephanie).
  • Confirmed and closed a bug about Glean impression events for the Google shopping tab not reporting correctly (Stephanie).
  • Got a proof-of-concept patch for observing network requests for SERP telemetry (James).
  • Found out that ad clicks for Ecosia and Google ad services weren’t being reported right, and issued a fix (James).
  • Created a proof-of-concept patch to cache whether a user has used a search engine locally, instead of making new preferences for each one (James).

• General Address Bar
  • Fixed more TypeScript issues in the address bar code (Standard8).
  • Sometimes the search term sticks in the URL bar; investigated but couldn’t reproduce, so added a check and filed a follow-up for a refactor (James).
  • A bug fix for the URL bar falling back to the user-typed string instead of a suggestion when entering search mode landed (Yazan).
  • Getting ready to land a bug that removes the URL bar placeholder when `keyword.enabled` is false (Moritz).
  • Working on making sure the Unified Search Button UI makes sense when `keyword.enabled` is false (Dharma).
  • Ready to land a test for ctrl/accel/shift-clicking results in the URL bar (Dharma).
  • Still waiting for UX feedback on a bug to make command-clicking URL bar results open in a background tab on macOS (Dharma).