Download as HTML and raw HTML doesn't display Math correctly anymore

[rmst]

The following document contains some math which is nicely displayed in the editor but when downloading as html the math becomes ugly and some things completely fail.

https://hackmd-ce.herokuapp.com/dRNM0WorQHuJCoFgm76iOQ

This is a regression that occurred both on hackmd.io and in codimd. Back in March when I wrote that document on hackmd.io the downloaded html displayed fine. Yet the exact same html that I downloaded in March doesn't render properly anymore now.

Edit: When I copy the head from the HTML of the online editor the math displays correctly again. So I guess it would be just a matter of updating the head used for the "Download HTML" function.

@jackycute You are working on hackmd.io, right? Maybe you could fix it there too? :P Btw, do you have a separate bug tracker for hackmd.io ?

Edit 2: #885 (inlining the resources) might have prevented the regression.

[davidmehren]

I would guess that the old html points to old versions of JS that were removed from the CDN. Which surprises me, because that would break all sites that use these old versions.

Could you post the head section of your old html file here?

@rmst We use this repo to tracking hackmd.io bugs

[rmst]

Here is the downloaded html file that doesn't render properly (obtained through clicking on the codimd link in my post above and then clicking on download HTML): spikes.html
I tried to copy the head here but for some reason the gihtub editor added weird symbols in, also the head is quite big.

@binotaliu thanks!