Katex: \not (and \neq) broken in ~~Chrome 72~~ Safari

[joergklein]

$\neq$ or $\not =$ doesn't work correctly. Please take a look into the documentation too.

[edemaine]

@joergklein What environment are you using KaTeX in? The $` ... `$ notation looks like Gitlab. Perhaps you should be asking your question in a Gitlab forum.

Does any math expression work for you? I'm guessing not, and that it's something about your configuration.

\neq and \not= are definitely supported by KaTeX; see the demo page. They are also documented in the list of supported features.

[joergklein]

Yes it is Gitlab. When I type on the demo page neq then I see / =.
When I type not= then I see also / =.
You wrote neq not= . Please take a look at the screen shot

[edemaine]

@joelburget What web browser are you using? Safari perhaps?

Here's what I see on Chrome on Windows:

[joergklein]

The OS is CentOS 7. The browser Chrome displays the wrong charakter. Firefox displays the correct character.
Google Chrome | 72.0.3626.81 (Official Build) (64-bit)
Revision | ac8b982e05014492d1bd7d317628a4f22a97ffa0-refs/branch-heads/3626@{#796}
OS | Linux

[edemaine]

What version of Chrome? I'm using 71.0.3578.98.

[q234rty]

Having the same issue with Chrome 72.0.3626.96 on Windows.

[edemaine]

OK, I updated to Chrome 72, and that seems to be the issue. I can now reproduce the problem. Chrome must have changed how it works with accents. ☹️

[edemaine]

I believe there's a problem with the \not character in the font that we need to fix. I find this view (from opentype.js.org) confusing, but in particular the advanceWidth of 1289 seems way too big: (sorry, this was the wrong glyph)

@kevinbarabash Do you remember any outstanding issues here, e.g., plans to regularize this character? I think we already switched away from combining characters (https://github.com/KaTeX/katex-fonts/issues/3 lists some other accents where this still needs to happen).

[matteo-ronchetti]

Got the same problem in Chrome 72, as a workaround I replaced "not =" with "=not\," and it shows the symbol correctly (see demo).

[edemaine]

Actually, I think the glyph is fine -- it has no negative leading space. My current theory is that, because we use U+0338 for the glyph, which is a combining character (which we did because there is no non-combining LONG SOLIDUS Unicode slot), Chrome forces it to the left. Why Chrome 72 changed this, I'm not sure (nor have I found documentation). I'll have to try mapping it to a different slot, and see if that fixes the problem...

[edemaine]

https://github.com/KaTeX/katex-fonts/pull/58 is (most of) a fix to this bug.

[kevinbarabash]

This is ridiculous. First Safari can't handle negative advance so we get rid of it and then Chrome decides to add negative advance to combining characters that don't have it. 😞

@edemaine thanks for coming up with a fix for this. 🙂

[infusion]

Can confirm this problem with \neq on OSX and newest Chrome 72.0.3626.109

[robbienohra]

I'm having the same issue with Chrome 72.0.3626.109 on my Mac and also Chrome 72.0.3626.105 on Android.
Freakin' hell.

[edemaine]

@kevinbarabash Could you review the fix in https://github.com/KaTeX/katex-fonts/pull/58?

[eneso]

Same issue with Chrome 72

[edemaine]

@eneso On which platform? Chrome 71 worked fine for me on Windows.

[eneso]

Actually, it is appearing correctly on my laptop which is using Chrome 71. Yesterday I was having this issue on my desktop which is using Chrome 72.

[robbienohra]

Anything I can do to help speed up the fix? @edemaine do you need us to test your fix? I'm currently on GatsbyJS using the css dependency require(katex/dist/katex.min.css)

[edemaine]

For those in a rush to deploy this fix (as I was) and using KaTeX via npm, you can use

npm install https://github.com/edemaine/KaTeX/tarball/fixnot-dist

to get a release with this bug fixed -- but also with potentially dangerous unprotected \includegraphics support, so beware!

[robbienohra]

Thanks, dude!

[ylemkimon]

v0.10.1 is released, which includes a hotfix to this bug!

[d00mw01f]

After v0.10.1 release neq broken in Safari:

[edemaine]

That's unfortunate... I unfortunately do not have easy access to Safari, so it would be nice to get confirmation, and some analysis as to what's going on. How does the \not accent differ from other accent characters?

[d00mw01f]

Reproduced both on real mac in Safari and in browserstack.
Also reproduced on iPhone in Safari, Chrome and Firefox (do they have same engine?)
I tried to investigate the problem and managed to find that Safari doesn't render @not symbol (\ue020). But it will render symbol if it has border. Hope this will help.

[ylemkimon]

[D]o they have same engine?

Non-Safari browsers use the same engine, WebKit.

[congxinUSC]

Am I the only one seeing a not filled square after the update on Chrome 72 & Safari?

[jhugon61]

FWIW, a colleague suggested a workaround which appears to work on Safari with 0.10.1: use cancel= instead of neq. Granted the display is different for these two commands, but maybe others will find this is a useful workaround until the issue is fixed.

[nrailgun]

same issue on firefox 66.

[kevinbarabash]

I've published 0.10.2 with a fix for this on Safari.

[jhugon61]

Thank you very much, Kevin.
~~~~~
Jacques Hugon
jacques.[email protected]
~~~~~

On May 13, 2019, at 5:09 AM, Kevin Barabash [e-mail] wrote:

I've published 0.10.2 with a fix for this on Safari.
https://user-images.githubusercontent.com/1044413/57593755-e1cde280-750a-11e9-9b4a-7eedb27116bc.png
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[kevinbarabash]

@jhugon61 it was @ylemkimon who actually fixed the issue. I just did the publish.