830198 - Regression in font rendering in Firefox 18 on Linux amd64

Status: RESOLVED DUPLICATE of bug 828206

(Core :: Graphics: Text, defect)

Description

[Adam Harvey]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:18.0) Gecko/20100101 Firefox/18.0
Build ID: 20130104154748

Steps to reproduce:

Font rendering has regressed between Firefox 17.0.1 and Firefox 18 on my system, apparently due to subpixel rendering no longer working.

The installation on my system started with an official Mozilla x86_64 en_GB binary tarball, which was updated via the the Firefox automatic updater to Firefox 18. I'm running Debian Testing amd64, with Cinnamon as a desktop environment.


Actual results:

Font rendering regressed, particularly with coloured text on a white background (such as Twitter's Web interface).

Firefox 17.0.1 (correct): http://d.pr/i/aKdz
Firefox 18 (incorrect): http://d.pr/i/WTbH

Nothing else has changed on the system — I've tested this literally side by side.


Expected results:

Font rendering should have stayed with the Firefox 17.0.1 version.

Comment 1

[Kai Hendry]

I fail to notice a difference between http://d.pr/i/aKdz and http://d.pr/i/WTbH

Could you please put the PNG screenshot files some place sane?

Comment 2

[Adam Harvey]

Sorry, I should have specified that the most obvious problems is the colour fringing around the "TWEETS", "FOLLOWING" and "FOLLOWERS" labels. It's also probably going to be less obvious on some displays, of course, thanks to the wonders of subpixel rendering.

We'll try Imgur (and I'll also attach the PNGs to the bug report):

Firefox 17.0.1: http://i.imgur.com/yRHaC.png
Firefox 18: http://i.imgur.com/aKDkl.png

Comment 3

[Adam Harvey]

Attachment: Good font rendering in Firefox 17.0.1.

Comment 4

[Adam Harvey]

Attachment: Poor font rendering in Firefox 18.

Comment 5

[Kai Hendry]

Ok I see the difference now when I massively zoom the PNGs. I can't get FF17 & FF18 running on my same machine. However when I compare renderings between my X220 Archlinux running FF18 and FF17 running on Webconverger on a PC, tbh I can't see the difference. I'm using the twitter.com login form as a test point. Perhaps there is a better one?

Comment 6

[Adam Harvey]

Frustratingly, I can't reproduce it at the moment outside of a logged in Twitter session, and I haven't been able to write a page that reproduces it — replicating the color, font, background and text-shadow doesn't seem to trigger it in a standalone page. Weird.

Comment 7

[Matthias Versen [:Matti]]

Do you mean bug 828206 ?

Comment 8

[Adam Harvey]

This issue doesn't seem to require scrolling, but otherwise I'd say you're right, as a nightly does appear to fix it.

Sorry for the noise. I did search, but didn't apparently spot that bug.