tags aren't arranged alphabetically as the standard require

[riksoft]

Hi guys,
I've got this warning in Firefox:

downloadable font: Layout: tags aren't arranged alphabetically. (font-family: "websymbol" style:normal weight:normal stretch:normal src index:1) source:....

...where Websymbols is a webfont generated by Fontello.

Asking info about such unconprehensible message to Mozilla they told me that the OpenType specification requires several lists of tags (scripts, language systems, features) to be ordered alphabetically in the GSUB and GPOS tables and the Fontello tool doesn't.

In this page
https://www.microsoft.com/typography/otspec/chapter2.htm
searching the word "alphabetically" you can find the set of stuff that should be alphabetically ordered to be standard compliant.

[puzrin]

I never seen such warnign before.

1. Could you provide config.json from minimal sample (remove icons one-by-one until problem exists in demo page)?
2. What is you FF / OS version?

[riksoft]

You won't see such warning in the standard release of Firefox (v 53), but I'm on the Aurora channel of Firefox (Firefox Developer Edition 54.0a2 (2017-04-18) (64-bit)) and they have strengthen the validator. This will be soon on the standard version too.

OS: Linux Mint 18.1 Serena 64 bit,
DE: Mate

The warning is on a .woff that is only 7K containing 23 symbols all from fontawesome except 1 from fontelico:
"uid": "f0c301ac841dafc38d8eb1b933fc73e5",
"css": "spin",
"code": 59393,
"src": "fontelico"

If you think it's important I'll try to reduce such list.

[puzrin]

1. If possible - reduce it, yes. If not possible to reduce - attach config as is. Finally, i need config (or downloaded archive) to reproduce bug on my side.
2. Try to enable/disable hinting. Will it change something?

[riksoft]

I did some tests and I've reduced it to the bare minimum: I've chosen only the 1st symbol from fontawesome, downloaded the package and launched "demo.htm". Same thing choosing only the 1st symbol of fontelico. Both get warnings.

The 2 packages of test are together only 51 kB so I can attach them directly to this post.
fontello-3c78c192.zip
fontello-839d08eb.zip

To recap:

• open Firefox 54 (Developer Edition... ore wait some weeks for the standard version)
• CTRL + SHIFT + k to open the console
• Then open "demo.html" that is always present in the fontello zip package
  and you'll se the following warning:
  downloadable font: Layout: tags aren't arranged alphabetically. (font-family: "fontello" style:normal weight:normal stretch:normal src index:1) source: file:///home/.../fontello-3c78c192/font/fontello.woff?60804650

[puzrin]

1. I've reproduced this problem. It seems to happen only with enabled hinting. Can you confirm?
2. Fontello still use very old ttfautohint v1.1, but i'm not sure this issue was ever fixed.
3. This problem is not fatal, just warning, but everything still works.

@lemzwerg can you comment? How to reproduce:

• use FF 54 (aurora) from http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-mozilla-aurora/
• enable hinting in fontello and download any font (ttfa 1.1 will be used)
• open demo page and see warnig in console about bad tags order

[lemzwerg]

This problem is not related to ttfautohint. I've downloaded a font from fontello with and without hinting, and testing with ots-sanitize (from https://github.com/khaledhosny/ots) I get the layout warning for both fonts.

[puzrin]

@lemzwerg seems you are right. ots-sanitize from master report this warning for all cases. Thank you very much for the link!

@sabberworm could you take a look at https://github.com/fontello/svg2ttf/blob/master/lib/ttf/tables/gsub.js? Git history says, you are author of it :)

[puzrin]

Seems to be fixed in my simple checks. If any problem still exists - let be know.

@riksoft , @lemzwerg thanks again for your help!

[sabberworm]

@puzrin I’ve seen the warning before, it just didn’t occur to me that it was stemming from my code… Thanks for the fix.

[puzrin]

@sabberworm ots-sanitize is more informative. It said about problem with script tags order, and i just searched word "script" in sources :). Probably, this tool should be added to CI tests.

[riksoft]

Sorry for my huge delay of reply: I confirm now it's all OK! :)
Thanks Puzrin!
And by the way, thanks a lot for such a great website!