liteAdaptor crashing on serialization

[pkra]

With v4.1.2 but using SRE 5.0.0-rc.2. (This didn't look like an SRE issue but perhaps it is.)

Doing something like this:

import { document } from "./lib/shared/document.js";

import { RegisterHTMLHandler } from '@mathjax/src/js/handlers/html.js';
import { HTMLDocument } from '@mathjax/src/js/handlers/html/HTMLDocument.js';
import { liteAdaptor } from '@mathjax/src/js/adaptors/liteAdaptor.js';

const adaptor = liteAdaptor();
RegisterHTMLHandler(adaptor);

const htmlLite = new HTMLDocument('', adaptor);
import { mathjax } from '@mathjax/src/js/mathjax.js';
import '@mathjax/src/mjs/util/asyncLoad/esm.js';

import { MathML } from '@mathjax/src/js/input/mathml.js';
import { SVG } from '@mathjax/src/js/output/svg.js';

const mml = new MathML();
const svg = new SVG();

const mj = mathjax.document('', { InputJax: mml, OutputJax: svg });
const mml2svg = (mathstring, options) => mathjax.handleRetriesFor(() => mj.convert(mathstring, options));

const input = '';

let mjxLite;
try {
    mjxLite = await mml2svg(input);
} catch (e) { console.log(e) };
document.body.innerHTML = adaptor.outerHTML(mjxLite);

with e.g. \ \widehat{\cdot }\ , SRE-enriched as

input

<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\ \widehat{\cdot }\ " data-semantic-type="punctuated" data-semantic-role="text" data-semantic-annotation="depth:1" data-semantic-id="7" data-semantic-children="0,3,4" data-semantic-attributes="latex:\ \widehat{\cdot }\ " data-semantic-collapsed="(7 (c 5 6) 0 3 4)" data-semantic-owns="0 3 4" data-semantic-structure="(7 0 (3 1 2) 4)" data-semantic-speech="ModifyingAbove dot With caret"><mtext data-latex="\ " data-semantic-type="text" data-semantic-role="space" data-semantic-annotation="clearspeak:unit;nemeth:number;depth:2" data-semantic-id="0" data-semantic-parent="7" data-semantic-attributes="latex:\ " data-semantic-speech=""> </mtext><mrow data-mjx-texclass="ORD" data-latex="\widehat{\cdot }"><mover data-semantic-type="overscore" data-semantic-role="multiplication" data-semantic-annotation="depth:2" data-semantic-embellished="operator" data-semantic-id="3" data-semantic-children="1,2" data-semantic-parent="7" data-semantic-attributes="latex:\widehat{\cdot };texclass:ORD" data-semantic-owns="1 2" data-semantic-speech="ModifyingAbove dot With caret"><mo data-mjx-texclass="BIN" data-latex="\cdot" data-semantic-type="operator" data-semantic-role="multiplication" data-semantic-annotation="nemeth:number;depth:3" data-semantic-id="1" data-semantic-parent="3" data-semantic-attributes="latex:\cdot;texclass:BIN" data-semantic-speech="dot" data-semantic-prefix="Base">⋅</mo><mo data-semantic-type="punctuation" data-semantic-role="overaccent" data-semantic-annotation="accent:overaccent;depth:3" data-semantic-id="2" data-semantic-parent="3" data-semantic-speech="caret" data-semantic-prefix="Overscript">^</mo></mover></mrow><mtext data-latex="\ " data-semantic-type="text" data-semantic-role="space" data-semantic-annotation="clearspeak:unit;nemeth:number;depth:2" data-semantic-id="4" data-semantic-parent="7" data-semantic-attributes="latex:\ " data-semantic-speech=""> </mtext></math>

gives me the following error

TypeError: Cannot read properties of undefined (reading 'attributes')
    at LiteAdaptor.hasAttribute (file://[snip]/node_modules/@mathjax/src/mjs/adaptors/liteAdaptor.js:341:35)
    at SvgMspace.handleAttributes (file://[snip]/node_modules/@mathjax/src/mjs/output/svg/Wrapper.js:267:30)
    at SvgMspace.standardSvgNodes (file://[snip]/node_modules/@mathjax/src/mjs/output/svg/Wrapper.js:56:14)
    at SvgMspace.toSVG (file://[snip]/node_modules/@mathjax/src/mjs/output/svg/Wrapper.js:13:31)
    at SvgInferredMrowNTD.addChildren (file://[snip]/node_modules/@mathjax/src/mjs/output/svg/Wrappers/mrow.js:71:27)
    at SvgInferredMrowNTD.toSVG (file://[snip]/node_modules/@mathjax/src/mjs/output/svg/Wrappers/mrow.js:19:22)
    at SvgTeXAtom.addChildren (file://[snip]/node_modules/@mathjax/src/mjs/output/svg/Wrapper.js:42:19)
    at SvgTeXAtom.toSVG (file://[snip]/node_modules/@mathjax/src/mjs/output/svg/Wrapper.js:13:14)
    at SvgTeXAtom.toSVG (file://[snip]/node_modules/@mathjax/src/mjs/output/svg/Wrappers/TeXAtom.js:10:23)
    at SvgTeXAtom.toEmbellishedSVG (file://[snip]/node_modules/@mathjax/src/mjs/output/svg/Wrapper.js:28:22)
file://[snip]/node_modules/@mathjax/src/mjs/adaptors/liteAdaptor.js:294
        return node.kind;
                    ^

TypeError: Cannot read properties of undefined (reading 'kind')
    at LiteAdaptor.kind (file://[snip]/node_modules/@mathjax/src/mjs/adaptors/liteAdaptor.js:294:21)
    at LiteParser.serialize (file://[snip]/node_modules/@mathjax/src/mjs/adaptors/lite/Parser.js:153:29)
    at LiteAdaptor.outerHTML (file://[snip]/node_modules/@mathjax/src/mjs/adaptors/liteAdaptor.js:317:28)
    at file://[snip]/lite.js:29:35

Node.js v25.2.1

The same happens with:

• \mathtt{v}:F_{\operatorname {nr}}^\times /n{\;\overset{\sim }{\longrightarrow }\;}\Gamma _{F_{\operatorname {nr}}}/n=\Gamma _F/n
• {\mathbb{T}}_L {\, \stackrel{\mathrm{def}}{=}\, }{\mathbb{R}}^n/L

[dpvc]

It turns out this is not related to the lite adaptor. It is actually an issue with the in-line line breaking code, and happens in the browser as well. A minimal example is

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mtext>&#xA0;</mtext>
  <mover>
    <mo>&#x22C5;</mo>
    <mo>^</mo>
  </mover>
</math>

The SRE attributes don't matter. I have a fix that I will put into a PR.

Your other two examples have a slightly different cause, though it is still due to in-line line breaking. I have a potential work-around, but I really want to find the root cause, which is higher up inequality the processing, and I haven't isolated it yet.

[dpvc]

It took some effort to track down the underlying issue, but it turns out that it is due to complex embellished operators (ones that have spaces as well as the operator itself) in in-line expressions that have line breaking. For example, with {\mathbb{T}}_L {\, \stackrel{\mathrm{def}}{=}\, }{\mathbb{R}}^n/L, the {\, \stackrel{\mathrm{def}}{=}\, } produces an mrow that is an embellished operator since the \stackrel is an embellished operator, and the spaces on either side makes the enclosing mrow be an embellished operator as well. So the potential line break for the equal sign has to be put outside that mrow.

Your original \ \widehat{\cdot}\ is also an embellished operator as a whole. The {\;\overset{\sim }{\longrightarrow }\;} also produces one of these complex embellished operators.

If course, {\;\overset{\sim }{\longrightarrow }\;} is better as \stackrel{\sim }{\longrightarrow }, while the spacing for {\, \stackrel{\mathrm{def}}{=}\, } would be better as just \stackrel{\mathrm{def}}{=}, or perhaps \!\stackrel{\mathrm{def}}{=} if you want to reduce the spacing after the subscript L. The \ \widehat{\cdot }\ should have the correct spacing as just \widehat{\cdot }, but MathJax seems to get that wrong. I will need to look into that (the TeX class is being set as ORD, but should be the same as the base). In the meantime, \mathrel{\widehat{\cdot }} should get the correct space.

I have made a PR to correct the crashes that you were seeing.

[pkra]

Thanks for looking into it so quickly!