1641866 - XUL prototype cache preference ( `nglayout.debug.disable_xul_cache`) is not updated correctly if deleted at runtime

Status: RESOLVED FIXED

(Core :: XUL, defect)

Description

[:Gijs (he/him)]

https://searchfox.org/mozilla-central/source/toolkit/content/tests/chrome/RegisterUnregisterChrome.js calls clearUserPref, which doesn't work because we reuse the previous value as the default/fallback argument to GetBoolPref - so if the pref is set to true and then removed, we will keep the value as true forever.

This is unlikely to ever happen to users, but it caused a number of test issues in that directory, and is trivial to fix.

Comment 1

[:Gijs (he/him)]

Attachment: Bug 1641866 - fix XUL cache disabling code to actually revert it, r?Mossop

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d537537515d6
fix XUL cache disabling code to actually revert it, r=mossop

Comment 3

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/d537537515d6

Comment 4

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

The patch landed in nightly and beta is affected.
:Gijs, is this bug important enough to require an uplift?
If not please set status_beta to wontfix.

For more information, please visit auto_nag documentation.

Comment 5

[:Gijs (he/him)]

Comment on attachment 9152768 [details]
Bug 1641866 - fix XUL cache disabling code to actually revert it, r?Mossop

Beta/Release Uplift Approval Request

• User impact if declined: n/a; testing impact would mean there'd be "surprising" test failures in some edgecases
• 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: n/a
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Very small change that affects a pref that doesn't appear in about:config and that users shouldn't have cause to set - and makes setting that pref more likely to have the correct effect
• String changes made/needed: None

Comment 6

[Julien Cristau [:jcristau]]

Comment on attachment 9152768 [details]
Bug 1641866 - fix XUL cache disabling code to actually revert it, r?Mossop

approved for 78.0b5

Comment 7

[Julien Cristau [:jcristau]]

https://hg.mozilla.org/releases/mozilla-beta/rev/c58d1f013eb6