728557 - Rendering issue with Kannada on Mac

Status: NEW

(Core :: Layout: Text and Fonts, defect)

Description

[Sunil]

Attachment: Snapshots-Comparing-Firefox-Chrome-Safari.zip

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_2) AppleWebKit/534.52.7 (KHTML, like Gecko) Version/5.1.2 Safari/534.52.7

Steps to reproduce:

This was tried on Mac OS X Lion(10.7.2). The issue could be present in Snow Leopard as well.

1. Launch Firefox.
2. Type "ಕೋ" (You could copy paste from this).
3. Notice the difference in rendering.



Actual results:

The character "ಕೋ" gets split. This behavior is seen for all consonants.(Vyanjanas). This split behavior is seen for these combinations. ಕೀ ಕೇ ಕೈ ಕೋ.

All articles would invariably have various combinations of these consonants. But they are unreadable through Firefox on Mac. This issue blocks me from using firefox on Mac. All of my friends aren't using Firefox on Mac to read kannada because of this issue.


Expected results:

Correct rendering should be preserved. This issue is not present in windows/Linux.

More Info
1. Issue-With-Rendering-Kannada-On-Firefox-For-Mac.png - I have attached the correct rendering in Safari/Chrome on Mac OSX.
2. Difference-In-Title-And-Document - The upper portion is correct rendering.
3. Correct-Rendering-In-Chrome
4. Correct-Rendering-On-Safari.

Comment 2

[Jonathan Kew [:jfkthame]]

The problem is occurring with the Kannada vowel signs that should be rendered in two parts, one on each side of the preceding consonant; apparently this behavior is not being supported correctly.

I expect a similar issue could occur with U+0D4A..0D4C in Malayalam and maybe U+0C48 in Telugu, U+17C4..17C5 in Khmer, and probably a few other examples that I'm forgetting offhand. However, OS X 10.6 doesn't include fonts supporting any of these scripts, so I'm not able to test them at this moment (I'm not at my 10.7 system just now).

Comment 3

[Chris Lawson (gone)]

Jonathan: did you mean to confirm this bug, then?

Comment 4

[philippe (part-time)]

Attachment: minimal testcase

Comment 5

[philippe (part-time)]

confirming on 10.7.3 based on the attached test case.

Comment 6

[Jonathan Kew [:jfkthame]]

Yes, I see the problem when using the Kannada Sangam MN font on 10.7.

Interestingly, I *don't* see similar issues with Malayalam (which I expected, as noted in comment 2); the "split vowel" letters appear to render correctly there.

Comment 7

[Sunil]

Is there any update on this ? This is a major issue which is preventing most of us from using firefox on Mac.

I confirmed the issue to be present in Firefox 29 and Mac 10.9.2.

Comment 8

[Hemantha Holla]

I using Gubbi and Lohit Kannada fonts to work around this. In other applications (like Safari and Chrome), these two show similar problems (but not same - split consonant clusters instead of split vowels), but render perfectly in Firefox. Install via Fontbook and set as default for Kannada in Firefox preferences.

https://fedorahosted.org/lohit/
https://github.com/aravindavk/Gubbi

Comment 9

[nayajhen]

Confirming that the issue persists in Yosemite 10.10.1 & Firefox 34.0. If anyone has any pointers on where and how I might look into fixing this, that'd be much appreciated. Perhaps I can give it a shot?

Comment 10

[Jonathan Kew [:jfkthame]]

This is essentially the same as the Bengali problem described in bug 686225. I think I've just figured out what is causing it, and will post a patch there.

Comment 12

[Graham Perrin]

(In reply to Sunil from comment #0)

> …
> 2. Type "ಕೋ" (You could copy paste from this).
> 3. Notice the difference in rendering.

As far as I can tell, that is not reproducible in Firefox ESR 52.6.0, Waterfox 56.0.4.1 or Firefox Quantum on Mac OS X 10.9.5.