Rename HTMLOrSVGElement mixin to HTMLOrSVGOrMathMLElement by lukewarlow · Pull Request #12416 · whatwg/html

lukewarlow · 2026-05-04T12:10:58Z

Rename HTMLOrSVGElement mixin to HTMLOrSVGOrMathMLElement

Also set default tabIndex value for MathML's a element to be 0.

Fixes #4702

SVG PR: w3c/svgwg#1103
MathML Core PR: w3c/mathml-core#324

At least two implementers are interested (and none opposed):
- N/A
Tests are written and can be reviewed and commented upon at:
- Untentative and rename HTMLOrSVGOrMathMLElement tests. web-platform-tests/wpt#59631
Implementation bugs are filed:
- Chromium: https://issues.chromium.org/u/1/issues/509407077
- Gecko: https://bugzilla.mozilla.org/show_bug.cgi?id=2036778
- WebKit: https://bugs.webkit.org/show_bug.cgi?id=313970
Corresponding HTML AAM & ARIA in HTML issues & PRs: N/A
MDN issue is filed: N/A
The top of this comment includes a clear commit message to use.

(See WHATWG Working Mode: Changes for more details.)

/dom.html ( diff )
/infrastructure.html ( diff )
/interaction.html ( diff )
/urls-and-fetching.html ( diff )

…der usage in MathML.

lukewarlow · 2026-05-04T12:27:52Z

Based on our last discussion in WhatNot I've gone with HTMLOrSVGOrMathMLElement rather than HTMLOrForeignElement. I've included MathML Core's newly added 'a' element to the tabIndex defaulting to 0 list, and various WPTs do check for that too.

lukewarlow · 2026-05-04T12:35:16Z

Mozilla implemented the original name of HTMLOrForeignElement and included it in MathMLElement

WebKit seems to have done the same, and I believe chromium were supportive before so I think we can consider this to have implementor interest.

If there's a lack of consensus or very clear spec on MathML <a> specifically I'm happy to drop that reference from this PR and wait till it's further specified and prototyped before including that change.

fred-wang · 2026-05-04T13:13:52Z

Mozilla implemented the original name of HTMLOrForeignElement and included it in MathMLElement

WebKit seems to have done the same, and I believe chromium were supportive before so I think we can consider this to have implementor interest.

FWIW Chromium has this too:
https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/html/html_or_foreign_element.idl;l=8;drc=047c7dc4ee1ce908d7fea38ca063fa2f80f92c77
https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/mathml/mathml_element.idl

In any case, I believe this name is not exposed to Web developers.

If there's a lack of consensus on MathML specifically I'm happy to drop that reference from this PR and wait till it's further specified and prototyped before including that change.

Just some more context on this.

Historically in MathML3 the href attribute was supported on all elements but there were safety concerns about it. At the end, the consensus seems to be that we want to introduce an <a> as a single linkable tag, similar to SVG/HTML, which would have similar layout as <mrow>.

MathML Core says any unknown MathML element should be laid out as as <mrow>. Chromium's MathML Core implementation has always had this behavior, and it was implemented some months ago in Firefox and WebKit. This means <a> is already laid out that way in any case.

Additionally, Firefox and WebKit's implementation of the href attribute is still working for <a> and also being deprecated on other elements, see https://bugzilla.mozilla.org/show_bug.cgi?id=2026848 and WebKit/WebKit#61628

Chromium's initial implementation of MathML Core does not support links, essentially because we couldn't find a consensus on the issue I mentioned above. But now that we agreed on having a single linkable element I personally think it makes sense to implement it. I don't think there is an official position from the Chromium project on that though.

annevk · 2026-05-04T13:31:23Z

I don't think we need implementer interest. That's been established by everyone doing this before it got standardized. Are any implementers failing any of the tentative tests? If so we should have implementation bugs.

lukewarlow · 2026-05-04T13:43:00Z

I've added bugs for each browser to at least rename the mixin, each of them appears to have at least one failure so I've linked to the relevant test to ensure its kept track of too. I suspect Eri or Fred will manage to fix them soon.

lukewarlow · 2026-05-04T14:32:42Z

Let me know if there's anythin else that's needed from me to get this merged. Thanks for the quick reiview!

See whatwg/html#12416 Bug: 509407077 Change-Id: Icdc9f615d9fedc3d716ed560f2457c33d455b78e Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7810461 Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org> Reviewed-by: Fredrik Söderquist <fs@opera.com> Commit-Queue: Frédéric Wang Nélar <fwang@igalia.com> Cr-Commit-Position: refs/heads/main@{#1624827}

https://bugs.webkit.org/show_bug.cgi?id=313970 Reviewed by Anne van Kesteren. See whatwg/html#12416 * Source/WebCore/CMakeLists.txt: * Source/WebCore/DerivedSources-input.xcfilelist: * Source/WebCore/DerivedSources-output.xcfilelist: * Source/WebCore/DerivedSources.make: * Source/WebCore/Sources.txt: * Source/WebCore/WebCore.xcodeproj/project.pbxproj: * Source/WebCore/html/HTMLElement.idl: * Source/WebCore/html/HTMLOrSVGOrMathMLElement.idl: Renamed from Source/WebCore/html/HTMLOrForeignElement.idl. * Source/WebCore/mathml/MathMLElement.idl: * Source/WebCore/svg/SVGElement.idl: Canonical link: https://commits.webkit.org/312609@main

…. r=emilio,webidl See whatwg/html#12416 Differential Revision: https://phabricator.services.mozilla.com/D298271

See whatwg/html#12416 Differential Revision: https://phabricator.services.mozilla.com/D298477

https://bugs.webkit.org/show_bug.cgi?id=311644 Reviewed by Anne van Kesteren. See whatwg/html#12416 * LayoutTests/imported/w3c/web-platform-tests/mathml/relations/html5-tree/tabindex-001.tentative-expected.txt: Update expectation now that the tests pass. * Source/WebCore/mathml/MathMLElement.cpp: (WebCore::MathMLElement::defaultTabIndex const): Make defaultTabIndex default to 0 for a elements and -1 otherwise. * Source/WebCore/mathml/MathMLElement.h: Override defaultTabIndex. Canonical link: https://commits.webkit.org/312681@main

…. r=emilio,webidl See whatwg/html#12416 Differential Revision: https://phabricator.services.mozilla.com/D298271 UltraBlame original commit: 719fef3ab93b726fd7f64a4d2054fd533205ef17

See whatwg/html#12416 Differential Revision: https://phabricator.services.mozilla.com/D298477 UltraBlame original commit: 129e7e3bcdf836fb42ffd5620ad930d4dcf013f5

…. r=emilio,webidl See whatwg/html#12416 Differential Revision: https://phabricator.services.mozilla.com/D298271 UltraBlame original commit: 719fef3ab93b726fd7f64a4d2054fd533205ef17

See whatwg/html#12416 Differential Revision: https://phabricator.services.mozilla.com/D298477 UltraBlame original commit: 129e7e3bcdf836fb42ffd5620ad930d4dcf013f5

…. r=emilio,webidl See whatwg/html#12416 Differential Revision: https://phabricator.services.mozilla.com/D298271 UltraBlame original commit: 719fef3ab93b726fd7f64a4d2054fd533205ef17

See whatwg/html#12416 Differential Revision: https://phabricator.services.mozilla.com/D298477 UltraBlame original commit: 129e7e3bcdf836fb42ffd5620ad930d4dcf013f5

See whatwg/html#12416 and https://html.spec.whatwg.org/multipage/urls-and-fetching.html#nonce-attributes Bug: 469878491 Change-Id: Ic9e3b77791eba23708bcbf1fafc57036eb45c96b Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7827786 Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org> Commit-Queue: Frédéric Wang Nélar <fwang@igalia.com> Cr-Commit-Position: refs/heads/main@{#1629086}

https://bugs.webkit.org/show_bug.cgi?id=314614 Reviewed by Anne van Kesteren. whatwg/html#12416 https://html.spec.whatwg.org/multipage/urls-and-fetching.html#nonce-attributes web-platform-tests/wpt#59809 * Source/WebCore/dom/Element.cpp: (WebCore::Element::attributeChanged): Also handle nonce setter for MathML. * Source/WebCore/mathml/MathMLElement.cpp: (WebCore::MathMLElement::insertionSteps): Hide nonce for MathML. * Source/WebCore/mathml/MathMLElement.h: Declare overridden method. Canonical link: https://commits.webkit.org/313075@main

whatwg/html#12416 https://html.spec.whatwg.org/multipage/interaction.html#the-autofocus-attribute https://w3c.github.io/mathml-core/#dfn-autofocus

…L r=webidl,smaug See whatwg/html#12416 and https://html.spec.whatwg.org/multipage/urls-and-fetching.html#nonce-attributes Differential Revision: https://phabricator.services.mozilla.com/D299705

whatwg/html#12416

…L r=webidl,smaug See whatwg/html#12416 and https://html.spec.whatwg.org/multipage/urls-and-fetching.html#nonce-attributes Differential Revision: https://phabricator.services.mozilla.com/D299705 UltraBlame original commit: dd195115475c7bed27347856a38d236013589459

…ibute on MathML elements., a=testonly Automatic update from web-platform-tests Add tests for autofocus content/IDL attribute on MathML elements. whatwg/html#12416 https://html.spec.whatwg.org/multipage/interaction.html#the-autofocus-attribute https://w3c.github.io/mathml-core/#dfn-autofocus -- wpt-commits: 4cc9a18629dffa80639bb996b56211ac13d5b29d wpt-pr: 59816

…lements., a=testonly Automatic update from web-platform-tests Add tests for focus()/blur() on MathML elements. whatwg/html#12416 -- wpt-commits: 5bdd10dd60f5b33793d99fd34b4551946fcf3751 wpt-pr: 59817

…ibute on MathML elements., a=testonly Automatic update from web-platform-tests Add tests for autofocus content/IDL attribute on MathML elements. whatwg/html#12416 https://html.spec.whatwg.org/multipage/interaction.html#the-autofocus-attribute https://w3c.github.io/mathml-core/#dfn-autofocus -- wpt-commits: 4cc9a18629dffa80639bb996b56211ac13d5b29d wpt-pr: 59816 UltraBlame original commit: c2998c5bd44ed0843fb6ad599c6c679032221ceb

…lements., a=testonly Automatic update from web-platform-tests Add tests for focus()/blur() on MathML elements. whatwg/html#12416 -- wpt-commits: 5bdd10dd60f5b33793d99fd34b4551946fcf3751 wpt-pr: 59817 UltraBlame original commit: 971ce4b08494ec650690c0d72bff18344a31b266

…ibute on MathML elements., a=testonly Automatic update from web-platform-tests Add tests for autofocus content/IDL attribute on MathML elements. whatwg/html#12416 https://html.spec.whatwg.org/multipage/interaction.html#the-autofocus-attribute https://w3c.github.io/mathml-core/#dfn-autofocus -- wpt-commits: 4cc9a18629dffa80639bb996b56211ac13d5b29d wpt-pr: 59816 UltraBlame original commit: c2998c5bd44ed0843fb6ad599c6c679032221ceb

…lements., a=testonly Automatic update from web-platform-tests Add tests for focus()/blur() on MathML elements. whatwg/html#12416 -- wpt-commits: 5bdd10dd60f5b33793d99fd34b4551946fcf3751 wpt-pr: 59817 UltraBlame original commit: 971ce4b08494ec650690c0d72bff18344a31b266

…ibute on MathML elements., a=testonly Automatic update from web-platform-tests Add tests for autofocus content/IDL attribute on MathML elements. whatwg/html#12416 https://html.spec.whatwg.org/multipage/interaction.html#the-autofocus-attribute https://w3c.github.io/mathml-core/#dfn-autofocus -- wpt-commits: 4cc9a18629dffa80639bb996b56211ac13d5b29d wpt-pr: 59816 UltraBlame original commit: c2998c5bd44ed0843fb6ad599c6c679032221ceb

…lements., a=testonly Automatic update from web-platform-tests Add tests for focus()/blur() on MathML elements. whatwg/html#12416 -- wpt-commits: 5bdd10dd60f5b33793d99fd34b4551946fcf3751 wpt-pr: 59817 UltraBlame original commit: 971ce4b08494ec650690c0d72bff18344a31b266

lukewarlow added 2 commits May 4, 2026 12:55

Rename HTMLOrSVGElement to HTMLOrSVGOrMathMLElement to reflect its wi…

4adb1a5

…der usage in MathML.

Define MathML's a element to have a default tabindex of 0.

bd774cc

lukewarlow mentioned this pull request May 4, 2026

Refer to new HTMLOrSVGOrMathMLElement mixin w3c/svgwg#1103

Merged

Add old id to dfn to maintain links

3ac4761

lukewarlow mentioned this pull request May 4, 2026

Rename HTMLOrForeignElement to HTMLOrSVGOrMathMLElement w3c/mathml-core#324

Merged

annevk approved these changes May 4, 2026

View reviewed changes

fred-wang mentioned this pull request May 4, 2026

Rename HTMLOrForeignElement to HTMLOrSVGOrMathMLElement WebKit/WebKit#64170

Merged

annevk merged commit 0965f59 into whatwg:main May 4, 2026
2 checks passed

fred-wang mentioned this pull request May 5, 2026

Bug 311644 tabIndex values are not set correctly for MathML elements WebKit/WebKit#64245

Merged

lando-worker Bot pushed a commit to mozilla-firefox/firefox that referenced this pull request May 5, 2026

Bug 2036778 - Set default tabIndex on MathML's a to 0. r=emilio

86fdf70

See whatwg/html#12416 Differential Revision: https://phabricator.services.mozilla.com/D298477

fred-wang mentioned this pull request May 12, 2026

Implement nonce-hiding for MathML elements WebKit/WebKit#64735

Merged

fred-wang added a commit to web-platform-tests/wpt that referenced this pull request May 13, 2026

Add tests for focus()/blur() on MathML elements.

5bdd10d

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Rename HTMLOrSVGElement mixin to HTMLOrSVGOrMathMLElement#12416

Rename HTMLOrSVGElement mixin to HTMLOrSVGOrMathMLElement#12416
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