681950 - firefox split farsi words for embed fonts since version 6 (B-Ferdosi font is buggy)

Status: RESOLVED INVALID

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

Description

[Vahid Reza Y]

Attachment: a sample that will show what is wrong !

User Agent: Mozilla/5.0 (Windows NT 5.1; rv:6.0) Gecko/20100101 Firefox/6.0
Build ID: 20110811165603

Steps to reproduce:

i did nothing everything was fine before version 6 update


Actual results:

after version 6 update, my websites that use embed fonts via css like this :

@font-face {
    font-family: "bferdosi";
    src: local("bferdosi"), url("fonts/bferdosi.ttf") format("opentype");
}

all words split into not joined characters !


Expected results:

the browser should show the characters joined !

Comment 1

[Alice0775 White]

Regression window
Works:
http://hg.mozilla.org/mozilla-central/rev/d761dc1a15f5
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0a1) Gecko/20110501 Firefox/6.0a1 ID:20110502015456
Fails:
http://hg.mozilla.org/mozilla-central/rev/9b312736f4ca
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0a1) Gecko/20110501 Firefox/6.0a1 ID:20110502020655
Pushlog:
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=d761dc1a15f5&tochange=9b312736f4ca

Comment 2

[Jonathan Kew [:jfkthame]]

I downloaded the font http://www.lservices.ir/fonts/fa.ttf that is linked from the URL given, and checked it with Microsoft's Font Validator tool.[1] This reported several errors in the font's GSUB table (which is required for proper Arabic shaping).

Firefox has become stricter about validating downloaded fonts before they're used, and will strip OpenType layout tables (GSUB/GPOS/GDEF) if problems are found in them. This means that some poorly-engineered fonts that may have worked in earlier versions will no longer work as expected.

The solution is for font developers and web authors to validate their fonts and correct any errors that are reported; this will usually resolve problems like this.

[1] See http://www.microsoft.com/typography/FontValidator.mspx

Comment 3

[j.j.]

It's caused by a faulty font and I assume we won't add different treatment to fix this special font.
-> INVALID

Comment 4

[Vahid Reza Y]

[for knowledge : this font is a persian/farsi font , it is not arabic, arabic is a division of farsi alphabet and it has not 4 characters of it !]

here we have two understanding :

1.firefox is more strict and conditional on embed fonts since version 6, B Ferdousi is only a font from a popular 17 persian fonts [B Esfahan, B Nazanin, B Yaghut And so on ..] , please understand that the victim here is persian language that the characters are joined, all latin based characters,Japanese and ... are safe cause they are not joined !

2.the font is not validated and faulty then firefox shouldn't care about it ! and if you have this understanding i should ask why firefox developers have gained such understanding in version 6 after 8,9 years while open type fotns are much older ! 

anyway if it is not a bug, it is still a very bad experience in firefox 6 for persian developers!

Comment 5

[Alice0775 White]

The site fixed the problematic font.
I cannot reproduce any more.

http://hg.mozilla.org/mozilla-central/rev/e58e98a89827
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:9.0a1) Gecko/20110825 Firefox/9.0a1 ID:20110825030823

Comment 6

[j.j.]

Reporter, you should try to contact the font developers and report the issue to them. And probably link them to this Mozilla bug. Thanks!