1763113 - Users set preferences are converted to default preferences if the user is enrolled in a rollout that sets the same value

Status: NEW

(Firefox :: Normandy Client, defect)

Description

[Maria Heres, inactive, contact Ecosystem QA]

Attachment: Screencast 2022-04-05 18 23 52.mp4

[Note]:

• This interferes with user choice in the case of a rollback. The user set value which was converted to default value is reset to the build default in a rollback.

[Affected Versions]:

• Firefox Release 99.0 (Build ID: 20220330194208)

[Affected Platforms]:

• Windows 10
• macOS 12.3
• Linux Mint 20.2

[Prerequisites]:

• Have Firefox open.
• Have a Stage Rollout set (this rollout modifies “javascript.options.wasm_caching” to “false”).
• Have a user.js file saved on your computer to enroll in the rollout.

[Steps to reproduce]:

1. Go to “about:config” and modify “javascript.options.wasm_caching” to “false”.
2. Restart the browser.
3. Copy the user.js file to the profile folder and restart the browser.
4. Restart the browser.
5. Go to “about:config” and observe the “javascript.options.wasm_caching” preference.

[Expected result]:

• The preference remains as a user set value even after enrollment in the rollout (i.e. is represented with a bold font).

[Actual result]:

• The user set preference is converted to a default preference after enrollment in a rollout which sets the preference to the same value (i.e. is represented with an unbolded font).

[Additional Notes]:

• Attached is a recording of the issue.