Bug 169501 – u+0c9c, u+0cbc, u+0cbe combination has issue with core text engine

• Component: Text
• Status: RESOLVED FIXED

[P K]

Created attachment 304115 [details]
Attached screenshot, left Chrome, middle Firefox, Right Safari top, Right Bottom same word with another Open type font

Apple core text engine has trouble rendering above combination. 
Open the below weblinks in Safari in mac.
Same websites in google chrome (harfbuzz) in mac shows no issue rendering this text.

Search 'ಜ಼ಾಕಿರ್' in below website

Tunga webfont:
http://jathisamvada.prajavani.net/field-collection/field-responses/165

u+0c9c, u+0cbc, u+0cbe combination has issue with core text engine

[Alexey Proskuryakov]

Created attachment 304135 [details]
Sierra screenshot

This looks different for me in Safari 10.0.3 on macOS 10.12.3, but still not as expected. Adding screenshot.

[P K]

Created attachment 304159 [details]
Iphone screenshot

[P K]

Created attachment 304161 [details]
Diff between Tunga and KannadaMN font

I think something is different in your browser. It is not loading the webfont "Tunga" which is open type font, but instead loading one of the default system font in mac, "KannadaMN" which is an AAT font.

I don't know why Safari is not loading webfont from the website for you.

Its loading for me in Mac and also in iPhone. If it loading the webfont, then you will sees the issue. The problem is in the Apple CoreText engine working with gpos for open type font.

But I have Tunga font installed on both iPhone and mac. Maybe, thats why it is successfully loading the font.

Let me uninstall and try it.

[P K]

The website specifies Tunga (OTF) font but doesn't use webfont. So, if you don't have Tunga font installed on your machine, it will load system default font. In mac, it will load KannadaMN, in iPhone it will load KannadasangamMN.

Both KannadaMN (AAT) and KannadasangamMN (AAT) have long laundry list of issues. I will report them soon.

I have requested the website admin to either add Tunga (OTF) webfont or Google Noto Sans Kannada webfont (OTF), then you will witness same the issue.

[Alexey Proskuryakov]

The issue only reproducing with an additional font installed locally would explain the difference of course.

[P K]

Here is the webpage with different webfonts
http://kannadafont.blogspot.com/2017/03/case1-u0c9c-u0cbc-u0cbe-combination.html

For open type font: It is Tunga font issue which has issue but not Apple CoreText. Apple CoreText is rendering the open type text correctly.

For AAT: Both KannadaMN and KannadaSangamMN has issues in mac.

Google noto sans Kannada renders the text correctly.

[P K]

The error still persists even with nightly build. 

Please check.

Please fix this in Coretext also, so this issue is resolved system wide for mac OS and iOS.

[P K]

FYI. This issue is system mac OS and iOS.

[Myles C. Maxfield]

I can reproduce this with the Tunga font from http://kannada.oneindia.com/news/bangalore/e-kannada-exhibition-conversation-kannada-online-expo-ravindra-kalakshetra-114263.html

[Radar WebKit Bug Importer]

<rdar://problem/31542713>

[P K]

Resolved in high sierra n ios 11