Bug 234817 – [JSC] Fix Intl.PluralRules.selectRange input validation

• Status: RESOLVED
• Resolution: FIXED
• Component: New Bugs

[Yusuke Suzuki]

[JSC] Fix Intl.PluralRules.selectRange input validation

[Yusuke Suzuki]

Created attachment 448230 [details]
Patch

[Alexey Shvayka]

Comment on attachment 448230 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=448230&action=review

> Source/JavaScriptCore/ChangeLog:8
> +        Add specified argument validation to Intl.PluralRules.selectRange.

Should we include a spec link (https://tc39.es/proposal-intl-numberformat-v3/out/pluralrules/proposed.html#sec-intl.pluralrules.prototype.selectrange)? It's a bit non-trivial to find.

> Source/JavaScriptCore/runtime/IntlPluralRules.cpp:288
> +    if (isNegativeZero(end) && start >= 0)

Hmm, this is interesting: spec's numeric operators (< / <= / > / >=) for Number should "refer to the relevant operations within IEEE 754-2019" (paragraph 3 of https://tc39.es/ecma262/multipage/notational-conventions.html#sec-mathematical-operations).
Does the IEEE 754 differentiate between -0 and 0 in comparison operators? Comparing `-0.0 < 0.0` C++ doubles yields `false`.

[Yusuke Suzuki]

Comment on attachment 448230 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=448230&action=review

>> Source/JavaScriptCore/ChangeLog:8
>> +        Add specified argument validation to Intl.PluralRules.selectRange.
> 
> Should we include a spec link (https://tc39.es/proposal-intl-numberformat-v3/out/pluralrules/proposed.html#sec-intl.pluralrules.prototype.selectrange)? It's a bit non-trivial to find.

Nice, added.

>> Source/JavaScriptCore/runtime/IntlPluralRules.cpp:288
>> +    if (isNegativeZero(end) && start >= 0)
> 
> Hmm, this is interesting: spec's numeric operators (< / <= / > / >=) for Number should "refer to the relevant operations within IEEE 754-2019" (paragraph 3 of https://tc39.es/ecma262/multipage/notational-conventions.html#sec-mathematical-operations).
> Does the IEEE 754 differentiate between -0 and 0 in comparison operators? Comparing `-0.0 < 0.0` C++ doubles yields `false`.

This is aligned to Intl.NumberFormat.formatRange implementation, and IIRC, there is a test for this in test262.
And ICU can distinguish -0 and +0, so I think we should check that here for the sane semantics.

[Yusuke Suzuki]

Created attachment 448247 [details]
Patch

[EWS]

Committed r287546 (245681@main): <https://commits.webkit.org/245681@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 448247 [details].

[Radar WebKit Bug Importer]

<rdar://problem/87068803>