Bug 180288 – Spacing around <mo> should only be added inside <mrow>

• Component: MathML
• Status: NEW

[Minsheng Liu]

Created attachment 328168 [details]
an example why space around <mo> can make horizontal stretch wrong

As said in RenderMathMLOperator.cpp:

> // FIXME: The spacing should only be added inside (perhaps inferred) mrow (http://www.w3.org/TR/MathML/chapter3.html#presm.opspacing).
>     preferredWidth = leadingSpace() + preferredWidth + trailingSpace();

For now the bug has little impact, but once 179682 (https://bugs.webkit.org/show_bug.cgi?id=179682) is resolved, it does affect the following case:

<math display="block">
  <mrow>
    <mover>
      <munder>
        <mtext>long text</mtext>
        <mo>&#x2192;</mo>
      </munder>
      <mo>⏞</mo>
    </mover>
  </mrow>
</math>

The outer brace will stretch to the arrow plus surrounding space.

[Frédéric Wang (:fredw)]

Right, spacing should actually be added to the whole embellished operator not the <mo> at its core see https://bugs.webkit.org/show_bug.cgi?id=124831#c1