404426 - Poor rendering of Hebrew text in Firefox 3.0b1 as well as 2.0.0.9 on Mac OS X 10.5.1

Status: RESOLVED INCOMPLETE

(Core :: Graphics, defect)

Description

[Christopher V. Kimball]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.9) Gecko/20071025 Firefox/2.0.0.9
Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.9) Gecko/20071025 Firefox/2.0.0.9

I provide the Hebrew bible in Hebrew at a free, non-denominational site http://www.tanach.us/Tanach.xml.  The text contains accents not used in modern Israeli Hebrew, but are part of the Unicode 4.1 standard.  

Firefox renders the text acceptably on all recent Windows systems and on Linux systems with Pango enabled (export MOZ_ENABLE_PANGO=1).  

Rendering on Mac OS X systems has been either non-existent or poor.  These results are for Mac OS X 10.5.1 and this bug is directed only at Mac OS X systems.

Firefox 3.0 offered the hope that the rendering problems on the Mac would be repaired.  This note demonstrates rendering on Firefox 3.0b1 is still a problem.

The test page is at http://www.tanach.us/Fonts/FontTest.html .

Screen shots are available at http://www.cvkimball.com/Pieces/  .  Three files are provided: 
.
1. FF2009.tiff shows the test page on Firefox 2.0.0.9 .

2. FF30b1.tiff shows the test page on Firefox 3.0b1.

3. Safari304.tiff shows the test page on the Safari 3.0.4 browser.  Safari doesn't perform Javascript-directed XSL transformations and can't display the site.

Reproducible: Always

Steps to Reproduce:
1. Download the SBL Hebrew font at http://www.tanach.us/Fonts/SBL_Hbrw.ttf .  Only this Unicode 4.1 font has a complete Unicode 4.1 character table for this example.

2. Install the SBL Hebrew font.

3. View http://www.tanach.us/Fonts/FontTest.html with either Firefox 2.0.0.9 or Firefox 3.0b1.

4. Examine the text comparisons. 

   a. Upper row shows the system font and the SBL Hebrew font for the same word.

   b. The lower row compares rendering on the browser in the left column with the excellent rendering obtainable on all recent Windows systems.

Actual Results:  
1. Firefox 2.0.0.9 fails to recognize the existence of the font as both columns in the first row are the same.  (File FF2009.tiff)

2. Firefox 3.0b1 recognizes the SBL Hebrew font as the texts on the left and right sides of the firs column are different.  (File FF30b1.tiff)

3. In Firefox 3.0b1 the accents and vowels are shifted about 1/2 a character width to the left. The character ']' rotated 90 degrees counter-clockwise appears.

Expected Results:  
1. In the first row of the FontTest.html page the text in the left and right columns should differ.

2. In the second row of FontTest.html, the text in the left columns should look like the text in the right columns.

The SBL Hebrew 1.5 font (6/5/2007) passes the Mac OS X FontBook validation.

The poor rendering in Firefox 3.0b1 matches that of the Safari browser. (File Safari304.tiff)  Firefox on Linux systems yield similar rendering without Pango.  If Pango is enabled on Linux systems, the rendering is better than on either Firefox 3.0b1 or Safari.

Comment 1

[John Daggett (:jtd)]

Attachment: testcase screenshot in FF 2.0.0.9 (converted from tiff)

Comment 2

[John Daggett (:jtd)]

Attachment: testcase screenshot in FF 3b1 (converted from tiff)

Comment 3

[John Daggett (:jtd)]

Attachment: another testcase

Includes other fonts that ship with Mac OS X (using additional install)

Comment 4

[John Daggett (:jtd)]

Attachment: screenshot of another testcase

Comment 5

[John Daggett (:jtd)]

Looks like the root of this problem is that diacritics are not positioned correctly.  Guessing this is caused by ATSUI not supporting OpenType layout tables (CoreText on 10.5 does from what I've heard).

Comment 6

[John Daggett (:jtd)]

Attachment: correct screenshot of another testcase in FF3

Comment 7

[Marcia Knous [:marcia]]

I know you filed this bug for 10.5.1, but does this happen on 10.4 as well? If it only a 10.5 bug I usually add [10.5] in the summary for tracking purposes.

Comment 8

[Christopher V. Kimball]

The bug also occurs on Mac OS X 10.4.9.  I don't know about earlier versions.

Comment 9

[Simon Montagu :smontagu]

In a trunk build with --enable-coretext on 10.5.8, the rendering with the SBL Hebrew font is just the same as without CoreText. With Ezra SIL, on the other hand, the diacritic positioning is much improved. I would say that it was perfect whenever there is only one diacritic per base consonant, but a little off when there are more than one.

Comment 10

[Simon Montagu :smontagu]

Attachment: SBL Hebrew and Ezra SIL fonts compared

Comment 11

[Joe Drew (not getting mail)]

Simon, those renderings are all identical, I think?

Comment 12

[Joe Drew (not getting mail)]

Never mind! I only have one Hebrew font on my machine. I thought I was looking at an image.

Comment 13

[Alin Ilea, Desktop Test Engineering]

Marking this as Resolved > Incomplete since the last real activity on this issue was 11 years ago and it might not be relevant anymore.
Feel free to re-open if the issue is still reproducible on your end in the latest FF versions.