1925334 - Disable experimental.json_parse_with_source by default in 132 beta and nightly

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P1)

Description

[Bryan Thrall [:bthrall]]

The JSON.parse with source feature is causing unacceptable slowdown, so it should be disabled by default in Nightly and the 132 Beta

Comment 1

[Bryan Thrall [:bthrall]]

Attachment: Bug 1925334 - Default to disabling JSON.parse with source r=dminor!

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d0f770cd79b2
Default to disabling JSON.parse with source r=dminor

Comment 3

[Sandor Molnar[:smolnar]]

Backed out for causing spider-monkey failures

Backout link: https://hg.mozilla.org/integration/autoland/rev/2f532998f27be91acaca62447975bf7b73c00c9f

Push with failures

Failure log ->

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7d7732fdbf27
Default to disabling JSON.parse with source r=dminor

Comment 5

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/7d7732fdbf27

Comment 6

[Ryan VanderMeulen [:RyanVM]]

Please nominate this for Beta approval.

Comment 7

[Bryan Thrall [:bthrall]]

Comment on attachment 9431642 [details]
Bug 1925334 - Default to disabling JSON.parse with source r=dminor!

Beta/Release Uplift Approval Request

• User impact if declined/Reason for urgency: Websites using JSON.parse with a reviver function could see significant performance regressions if the 'JSON.parse with source' feature is enabled by default.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Disabling the feature reverts to existing behavior
• String changes made/needed:
• Is Android affected?: Unknown

Comment 8

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9431642 [details]
Bug 1925334 - Default to disabling JSON.parse with source r=dminor!

Approved for 132.0rc1.

Comment 9

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-beta/rev/df1e9fe5def6

Comment 10

[Mathew Hodson]

This needs the release notes to be modified since this feature was scheduled for Firefox 132. It's already mentioned at https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/132#javascript and it could be moved to the experimental section there and mention that it is off by default.