SVG output + explorer = math processing errors

[pkra]

I see this failure at http://codepen.io/pkra/pen/yOWrWQ (with the dist built from current master).

Also, only one expression (the first display-style expression) has the usual Math processing error in the DOM.

lastError gives

MathJax.Hub.lastError
TypeError: Cannot read property 'root' of null
    at Object.AddSpeech (https://beta.mathjax.org/mathjax/contrib/a11y/Assistive-Explore.js?rev=2.6.1:1:5904)
    at Object.AddEvent (https://beta.mathjax.org/mathjax/contrib/a11y/Assistive-Explore.js?rev=2.6.1:1:5825)
    at Object.Register (https://beta.mathjax.org/mathjax/contrib/a11y/Assistive-Explore.js?rev=2.6.1:1:4595)
    at Function.execute (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:3084)
    at cb (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:2661)
    at Execute (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:7293)
    at ExecuteHooks (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:10599)
    at Function.execute (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:3084)
    at cb (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:2661)
    at Execute (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:7293)
    at Post (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:9345)
    at Object.processOutput (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:40062)
    at Function.execute (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:3084)
    at Function.WAITEXECUTE (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:5827)
    at cb (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:2661)
    at Function.WAITEXECUTE (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:6016)
    at cb (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:2661)
    at Execute (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:7293)
    at Object.loadComplete (https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML-full:19:15890)
    at https://cdn.mathjax.org/mathjax/2.6-latest/jax/output/SVG/fonts/TeX/Main/Regular/BasicLatin.js?rev=2.6.1:19:19138

Switching to a different renderer + refreshing the page resets ok.

[dpvc]

It turns out that this is due to a bug in the getJaxForMath() method of the SVG renderer. It has to check if an element has class name MathJax_SVG_Display, but while the math is being processed (part of the equation chunking), the class name is MathJax_SVG_Display MathJax_Processing. The MathJax_Processing is removed when the chunk is displayed, so most of the time when getJaxFromMath() is used, this works. But because the explorer responds to New Math signals immediately, and this occurs while the math is still not displayed, when the explorer tries to look up the jax for the math, the test fails.

I will fix it, but it isn an upstream bug, not a RespEq one.

[dpvc]

This is resolved in the respeq119 branch of my fork of MathJax.

[pkra]

Fixed.

[pkra]

I'm still seeing this problem (using the copy on the beta CDN)

[zorkow]

I think it is a timing issue. The patch in explorer.js never gets called.

[pkra]

Yes. Maybe it needs to go into the menu to load right away?

[dpvc]

@zorkow, make sure you have the SVG renderer selected. It does get triggered for me. I have been out this morning, but will take a loot at it.

[dpvc]

Maybe it needs to go into the menu to load right away?

No, it needs to be part of explorer, since that can be loaded separately.