LGTM1; thanks for doing this so carefully. On Friday, September 26, 2025 at 12:05:02 PM UTC-7 Chromestatus wrote:
> *Contact emails* > [email protected] > > *Specification* > https://url.spec.whatwg.org/#idna > > *Summary* > IDNA is the mechanism for non-ASCII characters in domain names, encoding a > URL like http://네이버.한국/ as http://xn--950bt9s8xi.xn--3e0b707e/ (a > redirect to naver.com). The processing is defined by > https://www.unicode.org/reports/tr46/#Processing and is invoked by > https://url.spec.whatwg.org/#idna. The URL spec sets the CheckJoiners > flag, which enables the ContextJ rules in IDNA2008: > https://www.rfc-editor.org/rfc/rfc5892.html#appendix-A.1 > https://www.rfc-editor.org/rfc/rfc5892.html#appendix-A.2 This disallows > ZWNJ (U+200C ZERO WIDTH NON-JOINER) and ZWJ (U+200D ZERO WIDTH JOINER) in > most places in URLs. The implementation is to simply pass the > UIDNA_CHECK_CONTEXTJ option to ICU, where this rule is implemented: > https://source.chromium.org/chromium/chromium/src/+/main:third_party/icu/source/common/uts46.cpp;l=1137-1204;drc=8a1988938d4298fbe8fb499b1a59fe4b04a21b15 > > This would fix over 200 subtests in WPT relating to IDNA, which already > pass in Firefox and Safari: > https://chromium-review.googlesource.com/c/chromium/src/+/6990929 > https://wpt.fyi/results/url/IdnaTestV2.window.html All of the IdnaTestV2 > cases that would regress from shipping ICU 77 ( > https://chromestatus.com/feature/5143313833000960) would also be fixed > again by this change. > > *Blink component* > Blink>Network > <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3ENetwork%22> > > *Web Feature ID* > url <https://webstatus.dev/features/url> > > *Search tags* > idna <http:///features#tags:idna> > > *TAG review* > None > > *TAG review status* > Not applicable > > *Risks* > > > *Interoperability and Compatibility* > Interoperability is improved by bringing URL parsing closer to Firefox and > Safari. The web compat risk is most likely very low because the URLs that > will be rejected don't work at all in Firefox or Safari. On the other hand, > any breakage would be very severe for the same reason. To make this change > safely I would suggest a gradual Finch rollout. > > *Gecko*: Shipped/Shipping Shipped for a long time, exact version not found > > *WebKit*: Shipped/Shipping Shipped for a long time, exact version not > found > > *Web developers*: No signals > > *Other signals*: > > *WebView application risks* > > Does this intent deprecate or change behavior of existing APIs, such that > it has potentially high risk for Android WebView-based applications? > None > > > *Debuggability* > None > > *Will this feature be supported on all six Blink platforms (Windows, Mac, > Linux, ChromeOS, Android, and Android WebView)?* > Yes > > *Is this feature fully tested by web-platform-tests > <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?* > Yeshttps://wpt.fyi/results/url/IdnaTestV2.window.html > > *Flag name on about://flags* > None > > *Finch feature name* > UseIDNAContextJRules > > *Rollout plan* > (RARE) Experiment users ramp up over time > > *Requires code in //chrome?* > False > > *Tracking bug* > https://crbug.com/40765949 > > *Measurement* > Cannot be measured with use counters because the URL parser is used in > many places in Chrome, and not all of them have access to an > ExecutionContext or similar. UMA could be used and give a proportion of URL > parses affected metric, but given how many URLs are parsed and how rare > even valid IDNA URLs seem to be, the number is probably vanishingly small > and not informative of risk. > > *Estimated milestones* > Shipping on desktop 143 > Shipping on Android 143 > Shipping on WebView 143 > > *Anticipated spec changes* > > Open questions about a feature may be a source of future web compat or > interop issues. Please list open issues (e.g. links to known github issues > in the project for the feature specification) whose resolution may > introduce web compat/interop risk (e.g., changing to naming or structure of > the API in a non-backward-compatible way). > None > > *Link to entry on the Chrome Platform Status* > https://chromestatus.com/feature/6295810820145152?gate=5173132017139712 > > This intent message was generated by Chrome Platform Status > <https://chromestatus.com>. > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/040d089c-4b67-4284-ae7c-eff472db3984n%40chromium.org.
