[MathML] none and mprescripts should be laid out as mrow elements

Ahmad-S792 · Ahmad Saleem · commit 74250f489695 · 2026-02-23T10:07:28.000-08:00
https://bugs.webkit.org/show_bug.cgi?id=308442 rdar://170940035 Reviewed by Frédéric Wang. This patch aligns WeKit with Gecko / Firefox and Blink / Chromium. Change none and mprescripts from MathMLPresentationElement to MathMLRowElement in mathtags.in so they get RenderMathMLRow. The spec [1] states: "The <mprescripts> element is laid out as an mrow element." [1] https://w3c.github.io/mathml-core/#prescripts-and-tensor-indices-mmultiscripts This consequently fixes stretchy operators inside these elements, as RenderMathMLRow calls stretchVerticalOperatorsAndLayoutChildren(). This is safe because all code handling these elements in RenderMathMLScripts.cpp uses tag name checks, not C++ type checks. * LayoutTests/TestExpectations: Progressions * LayoutTests/imported/w3c/web-platform-tests/mathml/presentation-markup/mrow/inferred-mrow-stretchy-expected.txt: Ditto * Source/WebCore/mathml/mathtags.in: > Rebaselines: * LayoutTests/platform/glib/accessibility/math-multiscript-attributes-expected.txt: * LayoutTests/platform/mac/accessibility/math-multiscript-attributes-expected.txt: * LayoutTests/accessibility/mac/mathml-multiscript-expected.txt: Canonical link: https://commits.webkit.org/308050@main
diff --git a/LayoutTests/TestExpectations b/LayoutTests/TestExpectations
@@ -2052,8 +2052,6 @@ imported/w3c/web-platform-tests/mathml/presentation-markup/operators/mo-movablel
 imported/w3c/web-platform-tests/mathml/presentation-markup/operators/op-dict-8.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/mathml/presentation-markup/operators/op-dict-9.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/mathml/presentation-markup/operators/painting-stretchy-operator-001.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/mathml/presentation-markup/scripts/mprescripts-001.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/mathml/presentation-markup/scripts/none-001.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/mathml/presentation-markup/scripts/underover-stretchy-002.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/mathml/relations/css-styling/display-with-overflow.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/mathml/relations/css-styling/floats/floating-inside-mathml-with-block-display.html [ ImageOnlyFailure ]
diff --git a/LayoutTests/accessibility/mac/mathml-multiscript-expected.txt b/LayoutTests/accessibility/mac/mathml-multiscript-expected.txt
@@ -93,11 +93,13 @@ Prescripts:
 
 Check multiscript with 'none' tags.
 Postscripts:
+	0. AXMathSuperscript = AXEmptyGroup
 	0. AXMathSubscript = AXMathNumber
 	1. AXMathSubscript = AXMathNumber
 
 Prescripts:
 	0. AXMathSuperscript = AXMathIdentifier
+	0. AXMathSubscript = AXEmptyGroup
 	1. AXMathSubscript = AXMathNumber
 
 PASS successfullyParsed is true
diff --git a/LayoutTests/imported/w3c/web-platform-tests/mathml/presentation-markup/mrow/inferred-mrow-stretchy-expected.txt b/LayoutTests/imported/w3c/web-platform-tests/mathml/presentation-markup/mrow/inferred-mrow-stretchy-expected.txt
@@ -9,8 +9,8 @@ PASS operator stretching inside Menclose
 PASS operator stretching inside Mpadded
 PASS operator stretching inside Unknown
 FAIL operator stretching inside Mtd assert_greater_than_equal: expected a number greater than or equal to 100 but got 10
-FAIL operator stretching inside None assert_greater_than_equal: expected a number greater than or equal to 100 but got 10
-FAIL operator stretching inside Mprescripts assert_greater_than_equal: expected a number greater than or equal to 100 but got 10
+PASS operator stretching inside None
+PASS operator stretching inside Mprescripts
 PASS operator stretching inside Mfenced
 PASS operator stretching inside A
 ↨
diff --git a/LayoutTests/platform/glib/accessibility/math-multiscript-attributes-expected.txt b/LayoutTests/platform/glib/accessibility/math-multiscript-attributes-expected.txt
@@ -65,6 +65,24 @@ AXRequired: 0
 AXChecked: 0
 AXPlatformAttributes: multiscript-type:post, tag:mi
 ------------
+AXRole: AXGroup
+AXParent: AXSection
+AXChildren: 0
+AXPosition:  { 8.00000, -33.0000 }
+AXSize: { 32.0000, 10.0000 }
+AXTitle:
+AXDescription:
+AXFocusable: 0
+AXFocused: 0
+AXSelectable: 0
+AXSelected: 0
+AXMultiSelectable: 0
+AXEnabled: 1
+AXExpanded: 0
+AXRequired: 0
+AXChecked: 0
+AXPlatformAttributes: tag:mprescripts
+------------
 AXRole: AXSubscript
 AXParent: AXSection
 AXChildren: 0
diff --git a/LayoutTests/platform/mac/accessibility/math-multiscript-attributes-expected.txt b/LayoutTests/platform/mac/accessibility/math-multiscript-attributes-expected.txt
@@ -100,6 +100,37 @@ AXEditableAncestor: (null)
 AXHighestEditableAncestor: (null)
 AXElementBusy: 0
 
+------------
+AXRole: AXGroup
+AXSubrole: AXEmptyGroup
+AXRoleDescription: group
+AXChildren:
+AXChildrenInNavigationOrder:
+AXHelp:
+AXParent:
+AXSize: NSSize: {27, 10}
+AXTitle:
+AXDescription:
+AXValue:
+AXFocused: 0
+AXEnabled: 1
+AXWindow:
+AXSelectedTextMarkerRange: (null)
+AXStartTextMarker:
+AXEndTextMarker:
+AXVisited: 0
+AXLinkedUIElements:
+AXSelected: 0
+AXBlockQuoteLevel: 0
+AXTopLevelUIElement:
+AXLanguage:
+AXDOMIdentifier:
+AXDOMClassList:
+AXFocusableAncestor:
+AXEditableAncestor: (null)
+AXHighestEditableAncestor: (null)
+AXElementBusy: 0
+
 ------------
 AXRole: AXGroup
 AXSubrole: AXMathIdentifier
diff --git a/Source/WebCore/mathml/mathtags.in b/Source/WebCore/mathml/mathtags.in
@@ -33,9 +33,9 @@ mtable interfaceName=MathMLPresentationElement, JSInterfaceName=MathMLElement
 mtr interfaceName=MathMLPresentationElement, JSInterfaceName=MathMLElement
 mtd interfaceName=MathMLPresentationElement, JSInterfaceName=MathMLElement
 mmultiscripts interfaceName=MathMLScriptsElement, JSInterfaceName=MathMLElement
-mprescripts interfaceName=MathMLPresentationElement, JSInterfaceName=MathMLElement
+mprescripts interfaceName=MathMLRowElement, JSInterfaceName=MathMLElement
 menclose interfaceName=MathMLMencloseElement, JSInterfaceName=MathMLElement
-none interfaceName=MathMLPresentationElement, JSInterfaceName=MathMLElement
+none interfaceName=MathMLRowElement, JSInterfaceName=MathMLElement
 semantics interfaceName=MathMLSelectElement, JSInterfaceName=MathMLElement
 
 maligngroup interfaceName=MathMLPresentationElement, JSInterfaceName=MathMLElement
