[v3, v4] TeX parsing error \operatorname {\mathsf{f-tors}}A

[pkra]

The expression \operatorname {\mathsf{f-tors}}A gives me a parsing error.

In the browser (with a fairly recent v4 build), it's something like "e.string.substr(...).match(...) is null"

In node (on something close to v4-alpha):

mathjax-full/js/input/tex/ParseMethods.js:40
            c = parser.string.substr(parser.i - 1).match(env.multiLetterIdentifiers)[0];
                                                                                    ^

TypeError: Cannot read properties of null (reading '0')

It seems to come down to just the - inside the mathsf (or some other font variant), i.e., a more minimal example is \operatorname {\mathsf{-}}.

For completeness, this works fine in "real" LaTeX.

[dpvc]

I've made a PR to resolve the issue. It had to do with conflicting uses of a pattern for multi-character identifiers that is different for \operatorname and \mathsf. Thanks for the report.

[pkra]

Thanks so much!