The -moz-font-feature-settings contextual swash (cswh) is on by default




7 years ago
7 years ago


(Reporter: braddunzer, Assigned: jfkthame)


Firefox Tracking Flags

(Not tracked)



(1 attachment)



7 years ago
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.186 Safari/535.1

Steps to reproduce:

Used Adobe Calson Pro as a @font-face web font on a web page

Actual results:

The alternative capital swash is shown by default on the italic version of the font. However, by using the -moz-font-feature-settings: "cswh=0" the swash can be removed.

Expected results:

This should not be on by default. 
You can see a working example of this at

Comment 1

7 years ago
Update:: sorry that is contextual swash not capital swash
I can see that with Firefox 6 and older release builds (Fx 4+). Gecko 1.9.2 (Camino 2.1b2) doesn't show the issue.

The font fails to load on the most recent Aurora nightly build, though. The Error console logs an cryptic error message:
Error: downloadable font: download failed (font-family: "ACaslonPro_Italic" style:normal weight:normal stretch:normal src index:0): status=2147746065
Source Code:
@font-face {   font-family: "ACaslonPro_Italic";   font-style: normal;   font-weight: normal;   src: url(""); }
Component: General → Layout: Text
Ever confirmed: true
Product: Firefox → Core
QA Contact: general → layout.fonts-and-text

Comment 3

7 years ago
Correct the font is served from our WebINK servers and uses user-agent sniffing to hand down the correct font and Nightly builds will not work with our service.

Do I need to provide another sample page
Yes, I pointed this out to Behdad and it's already fixed upstream:

Jonathan, would it make sense to consider updating harfbuzz code after the sync tomorrow?
Summary: The -moz-font-feature-settings capital swash or cswh is on by default → The -moz-font-feature-settings contextual swash (cswh) is on by default

Comment 5

7 years ago
Created attachment 562683 [details] [diff] [review]
patch, remove cswh from default features

This just removes 'cswh' from the default features.

Yes, we'll want to take a full HB update sometime soon, but that will involve a bunch of work (there are significant API changes), so let's do this as an interim fix for the specific issue here.
Assignee: nobody → jfkthame
Attachment #562683 - Flags: review?(jdaggett)


7 years ago
Attachment #562683 - Flags: review?(jdaggett) → review+

Comment 6

7 years ago
Last Resolved: 7 years ago
Resolution: --- → FIXED

Comment 7

7 years ago
Thanks for the quick work everyone. I look forward to seeing this show up in a build soon


Comment 8

7 years ago
Jonathan, you should have added cswh to Arabic when removing from generic shaper.  Not a huge deal if you're going to rebase soon anyway.

Comment 9

7 years ago
You're right - but let's see if we can get bug 695857 landed this month, which will supersede all this.
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