1890976 - Disable legacy_mathvariant_attribute by default

Status: NEW

(Core :: MathML, task)

Description

[Frédéric Wang Nélar]

Disable support for the mathvariant attribute on MathML element (except mathvariant="normal"), see https://searchfox.org/firefox-main/rev/91e6069b9c1e7289d0c727b5110e144edc589204/modules/libpref/init/StaticPrefList.yaml#11142:

Stats of USE_COUNTER2_DEPRECATED_MathML_DeprecatedMathVariant_DOCUMENT over SCALARS_MATHML.DOC_COUNT:

beta	mathml	mathspace	
120	14750	912	6,18 %
119	13380	1570	11,73 %
118	10500	1810	17,24 %

Comment 1

[Frédéric Wang Nélar]

It seems this is still used by Wikipedia, for example I see at https://en.wikipedia.org/wiki/Fourier_transform#Definition:

<math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\widehat {f}}(\xi )=\int _{-\infty }^{\infty }f(x)\ e^{-i2\pi \xi x}\,dx,\quad \forall \xi \in \mathbb {R} .}">
  <semantics>
...
        <mrow class="MJX-TeXAtom-ORD">
          <mi mathvariant="double-struck">R</mi>
        </mrow>
...
    <annotation encoding="application/x-tex">{\displaystyle {\widehat {f}}(\xi )=\int _{-\infty }^{\infty }f(x)\ e^{-i2\pi \xi x}\,dx,\quad \forall \xi \in \mathbb {R} .}</annotation>
  </semantics>
</math>

I thought MediaWiki was working on a new mathml generator that fixes this issue, but I'm not sure it has been put in production yet.