391924 - arabic rendering: applying font to a part of a word, applies it to whole word

Status: RESOLVED DUPLICATE of bug 236135

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

Description

[Atif.hussain]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6

I want to be able to render font properties, like color/bold/size to a part of a n Arabic word. 

In Arabic, script is in a running writing. Character glyphs are mostly joined. 
But, when i try to apply font to a section of the word, it gets applied to the whole word.
Eg: قيل when i try to give a red color to middle character, it becomes ق ي ل

Whereas in IE, I am able to selectively apply color to a consonant+vowel pair. 
It would be a lot better, if it can be separately colored.

Reproducible: Always

Steps to Reproduce:
1. View html content ق<b>ي</b>ل in Firefox(here, IE renders partly correctly)
2.
3.
Actual Results:  
rendered as:
 ق ي ل 
with colored ي 

Expected Results:  
should have been:
  قيل 
with colored ي 

universal problem in text rendering engine. Can be repeated any no. of times.