1787117 - Unicode rendering issue since Firefox 104.0 update

Status: RESOLVED INVALID

(Core :: Graphics: Text, defect)

Description

[Kamal]

Attachment: firefox-104.0-sinhala-language-rendering-issue.png

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:104.0) Gecko/20100101 Firefox/104.0

Steps to reproduce:

Access a web page which uses Sinhala unicode using Firefox 104.0.

An example page: https://mahanayaka.trekmentor.com/mahanayakavada

I am on Ubuntu 20.04. The problem does not occur if downgraded to Firefox 103.0.

Actual results:

Parts of Sinhala characters overlap with other characters.

Expected results:

No overlapping should happen.

Comment 1

[Alice0775 White]

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=d4598339bb9b1daef007c19e3899dd4768d1c330&tochange=900a74d4a5cea7a63bb247ff473394fb81de3f06

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

:RyanVM, since you are the author of the regressor, bug 1776802, could you take a look?
For more information, please visit auto_nag documentation.

Comment 3

[Ryan VanderMeulen [:RyanVM]]

This looks like upstream issue https://github.com/harfbuzz/harfbuzz/issues/3725. Reporter, can you please see if the solutions shown in that bug work for you?

Comment 4

[Ryan VanderMeulen [:RyanVM]]

As far as I can tell, Chrome 105 will also ship with the HarfBuzz 4.4.1 release (104 is current stable).

Comment 5

[Kamal]

It worked. Noto font on github has been fixed. However, I ended up using LKLUG_T font to get the familiar appearance.

Steps I followed on Ubuntu 20.04:

1. Download lklugt.ttf from https://wrdingham.co.uk/fonts/lklugt.html and save as /usr/share/fonts/truetype/sinhala/lklugt.ttf
2. Edit /etc/fonts/conf.avail/65-nonlatin.conf and change occurrences of LKLUG to LKLUG_T
3. Run this command: fc-cache -fv
4. Restart Firefox and visit the Sinhala site

Thank you for the help provided!

Kamal

Comment 6

[Ryan VanderMeulen [:RyanVM]]

Thanks for the confirmation! I'm going to close this as Invalid for now as my understanding is that Google doesn't intend to address this on the HarfBuzz side of things, but we'll keep an eye out for any changes upstream in case they change their mind after Chrome 105 ships the change soon.