1994389 - First time in new profile about:telemetry page doesn't open and opens a raw data page

Status: VERIFIED FIXED

(Toolkit :: Telemetry, defect)

Description

[Adrian Florinescu [:aflorinescu]]

Attachment: raw_data.mp4

Found in

• 145.0b1

Affected versions

• 145.0b1
• 146.0a1

Tested platforms

• Affected platforms: Windows 11

Preconditions

• new profile, first open

Steps to reproduce

1. Open a new profile.
2. Access about:telemetry

Expected result
about:telemetry page is opened

Actual result
about:telemetry page is not opened in current tab, new tab is opened with data:application/json page

Regression Range:
Bug 1981496 - Remove redundant test extension and add locale extension to test_EnvironmentAddonBuilder_telemetry.js. r=willdurand
Differential Revision: https://phabricator.services.mozilla.com/D265966

Comment 1

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

:rpl, since you are the author of the regressor, bug 1981496, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 2

[Luca Greco [:rpl] [:luca] [:lgreco]]

I'm looking into this issue, I've been able to reproduce it locally and pinpoint it to the theme in the telemetry environment being set to null and because of that aboutTelemetry is hitting a TypeError (and open the telemetry data in JSON format in a new tab as a side effect of that).

The following is the stack trace of the error logged in the browser console (and aboutTelemetry.js:684 is the line that would be rendering active theme):

TypeError: can't convert null to object
    flattenObject chrome://global/content/aboutTelemetry.js:75
    explodeObject chrome://global/content/aboutTelemetry.js:96
    renderKeyValueObject chrome://global/content/aboutTelemetry.js:652
    createAddonSection chrome://global/content/aboutTelemetry.js:684
    render chrome://global/content/aboutTelemetry.js:629
    displayRichPingData chrome://global/content/aboutTelemetry.js:2417
    displayPingData chrome://global/content/aboutTelemetry.js:2398
    _doUpdateCurrentPingData chrome://global/content/aboutTelemetry.js:416
    _updateCurrentPingData chrome://global/content/aboutTelemetry.js:353
    aboutTelemetry.js:2402:13

The regression is very likely to have been introduced by this part of that stack of patches:

• https://hg-edge.mozilla.org/mozilla-central/rev/e0063671523e074c12e9febdc36c7dee20652a11#l2.37

The refactoring should have changed the timing of the EnvironmentAddonBuilder initialization, and so I'd expect the theme object to have been set to an empty object under the same corner case (brand new profile where the theme is not yet installed and activated).

As a side note, it looks like that none of the addon events that EnvironmentAddonBuilder is listening to are notifying the EnvironmentAddonBuilder when the default theme is getting installed and enabled, but given that updates to the environment
triggers the main ping and that changes in frequency of that ping may affect the certain metrics derived from it (DAU is one that
chutten mentioned me recently if I recall correctly) I'm hesitant to fix that pre-existing issue as part of this bugzilla issue tracking
specifically the more recent regression in behavior for about:telemetry, it may be worth filing it as a separate followup and looked
into separately from this regression.

Comment 3

[Luca Greco [:rpl] [:luca] [:lgreco]]

Attachment: Bug 1994389 - Fix about:telemetry tab fails to load correctly after first startup on a new profile. r?TravisLong!,willdurand!

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/39d07234cfea
https://hg.mozilla.org/integration/autoland/rev/99c1af5ed7f3
Fix about:telemetry tab fails to load correctly after first startup on a new profile. r=TravisLong,willdurand,toolkit-telemetry-reviewers

Comment 6

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/99c1af5ed7f3

Comment 7

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

The patch landed in nightly and beta is affected.
:rpl, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
  • See https://wiki.mozilla.org/Release_Management/Requesting_an_Uplift for documentation on how to request an uplift.
• If no, please set status-firefox145 to wontfix.

For more information, please visit BugBot documentation.

Comment 8

[Phabricator Automation]

firefox-beta Uplift Approval Request

• User impact if declined: None for users that do not open about:telemetry, but without the fix:
• loading an about:telemetry tab will open a second tab with the legacy telemetry payload (and would hit failures on a few QA automated tests).
• the ping including the environment.addons.theme set as null would be considered invalid when validated over the expected schema on the data pipeline side (see Bug 1994483)
• Code covered by automated testing: yes
• Fix verified in Nightly: no
• Needs manual QE test: yes
• Steps to reproduce for manual QE testing: Same STR as the one mentioned in comment 0.
• Risk associated with taking this patch: low
• Explanation of risk level: The changes included in the attached patch are limited to the 1-line small change to fix the regression (by making sure that the legacy telemetry environment.addons.theme property is set to an empty object instead of null when no active theme is available yet) and adds explicit test coverage for that expected behavior, without any other change on the implementation side.
• String changes made/needed: None
• Is Android affected?: no

Comment 9

[Luca Greco [:rpl] [:luca] [:lgreco]]

Attachment: Bug 1994389 - Fix about:telemetry tab fails to load correctly after first startup on a new profile. r?TravisLong!,willdurand!

Original Revision: https://phabricator.services.mozilla.com/D268749

Comment 10

[Pulsebot]

https://github.com/mozilla-firefox/firefox/commit/fce92f05f6a9
https://hg.mozilla.org/releases/mozilla-beta/rev/9c2377fd5c86

Comment 11

[Ciprian Georgiu, Desktop QA]

I've repro this issue on an affected Nightly build (2025-10-15) following the STR from comment 0 with Win 11.

The issue is verified as fixed on latest Nightly 146.0a1 with Win 11. I'll verify the fix on Beta 145 as well once the fix is available.

Comment 12

[Ciprian Georgiu, Desktop QA]

The bug is verified as fixed on Beta 145.0b4 (build downloaded from treeherder) under Win 11.