435545 - Arabic fonts appear disconnected on Facebook only

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[Maged]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008051206 Firefox/3.0
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008051206 Firefox/3.0

Arabic fonts appear disconnected on Facebook only but they look OK on all other sites that use Arabic which I have visited so far.

Reproducible: Always

Steps to Reproduce:
everytime u access any page on facebook that has some Arabic content

Comment 1

[Max Shawabkeh]

Confirming. The error is caused by the Lucida Grande font used on Facebook. Attaching test case.

Comment 2

[Max Shawabkeh]

Attachment: Lucida Grande Arabic Rendering Bug

Comment 3

[Simon Montagu :smontagu]

If this is a problem with the font, does it work correctly in other browsers?

Comment 4

[Max Shawabkeh]

Tested and works fine in Firefox 2.0.0.14 and IE7.

Comment 6

[Simon Montagu :smontagu]

I am still unable to reproduce this. Maybe it only occurs with a specific version of the Lucida Grande font for Windows? The Lucida Grande that I have, which ships with Safari, doesn't include any glyphs for Arabic, so facebook falls back to Tahoma which works fine.

Comment 7

[Max Shawabkeh]

I'm fairly sure I'm using the one that ships with Windows XP by default. Not sure if license and whatnot allows me to upload it for testing, but that exact version is available at http://www.osx-e.com/downloads/misc/macfonts.html.

I've also just tested on Linux (Kubuntu) and the bug is reproducible at least in Beta 5 and Final with that same font.

Comment 8

[Mohammad Alshalabi]

Simon, Lucida Grande works fine on FF2, IE and other browsers on windows.. only in FF3 it looks disconnected with arabic text.. 

Comment 9

[Simon Montagu :smontagu]

I strongly doubt that the font at http://www.osx-e.com/downloads/misc/macfonts.html ships with Windows XP by default. As the URL suggests, it's a Mac font, and so has a "mort" table but no GSUB table, which means that the Linux and Windows rendering engines can't find the contextual forms for Arabic characters (FF2 does its own Arabic shaping and doesn't use the data from the font). In other words, this is the converse of bug 361986, and I guess we could fix in a similar way.

Comment 10

[Benoit Jacob [:bjacob] (mostly away)]

No activity here in a long time, but comment 9 suggests there's something we could do. assigning to Simon.

Comment 11

[Simon Montagu :smontagu]

I'm not the right owner for this: I was aware of bug 361986 when I wrote comment 9, but I don't know where to begin writing a patch to do the opposite of it.

Comment 12

[Jonathan Kew [:jfkthame]]

So this is about users who shoot themselves in the foot by installing bootleg Mac fonts that don't work properly on their non-Mac system, and then complaining that the fonts don't work properly. We could detect and work around the issue, but it's a pretty low priority IMO.