1378828 - Stale fontconfig status results in broken font rendering

Status: RESOLVED INVALID

(Core :: Graphics: Text, defect, P3)

Description

[:gerard-majax]

Attachment: Capture d'écran de 2017-07-06 17-34-48.png

STR:
 1. Load a Wikipedia page (e.g., https://fr.wikipedia.org/wiki/Haswell)

Expected:
 I can see main titles, like « Principales caractéristiques »

Actual:
 I don't.

Source code shows that the <h2><span> is there. Some other people don't have that problem. Very old builds (under mozregression) exhibits the same behavior).

Comment 1

[:gerard-majax]

Jonathan, it might be something similar to bug 1355770, I attached a view of the Font panel in the devtools inspector.

Comment 2

[:gerard-majax]

Changing the font-family from 'Linux Libertine' to something that does not include this name works around the issue.

Comment 3

[:gerard-majax]

Attachment: without linux libertine

Comment 4

[:gerard-majax]

The best mozregression could get me was: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=62d9b117c688&tochange=0f1d42a6745a

Getting further would not be possible, because of a lot of TaskCluster failured being reported.

Comment 5

[Jonathan Kew [:jfkthame]]

(In reply to Alexandre LISSY :gerard-majax from comment #4)
> The best mozregression could get me was:
> https://hg.mozilla.org/mozilla-central/
> pushloghtml?fromchange=62d9b117c688&tochange=0f1d42a6745a

This range includes bug 1056479, which seems like a very plausible culprit. I suspect there may be some kind of issue with @font-face loading in the gfxFcPlatformFontList backend.

Lee, this may not be exactly the part of the font code that you've worked on lately, but is there a chance you could try to reproduce this and debug what's going on?

Comment 6

[:gerard-majax]

For repro steps, it's 100% for me on ubuntu 17.04. It seems not to happen elsewhere. Not related to my profile as well.

Comment 7

[Lee Salzman [:lsalzman]]

(In reply to Alexandre LISSY :gerard-majax from comment #6)
> For repro steps, it's 100% for me on ubuntu 17.04. It seems not to happen
> elsewhere. Not related to my profile as well.

Alexandre, can you tar up your /etc/fonts directory (and please use the --dereference option so that symlinks are not included in the archive), and email it to me at [e-mail]? This will possibly enable me to reproduce the issue, which is necessary to investigate what's going on.

Comment 8

[Lee Salzman [:lsalzman]]

Also, does the problem still occur for you when using nightly? I am not able to reproduce here if I just install the Linux Libertine fonts package on Debian.

Comment 9

[:gerard-majax]

(In reply to Lee Salzman [:lsalzman] from comment #8)
> Also, does the problem still occur for you when using nightly? I am not able
> to reproduce here if I just install the Linux Libertine fonts package on
> Debian.

Yes, this is 100% repro with nightly. I don't reproduce either on my Debian desktop :)

Comment 10

[:gerard-majax]

Attachment: LOWriter: linux libertine VS liberation

FYI, the font seems to be rendering in LibreOffice though.

Comment 11

[:gerard-majax]

So, my bad. Lee asked me to perform some debug:
> $ fc-match "Linux Libertine"
> LinLibertine_RB.otf.dpkg-new: "Linux Libertine O" "Bold"

And adding -v would output:
> [...]
> 	file: "/usr/share/fonts/opentype/linux-libertine/LinLibertine_RB.otf.dpkg-new"(w)

The ".dpkg-new" part tricked me into thinking of something broken on my system. Indeed, after issuing:
> sudo apt reinstall fonts-linuxlibertine

Running again fc-match:
> $ fc-match "Linux Libertine"
> LinLibertine_R.otf: "Linux Libertine O" "Regular"

So my guess is that at some point, during an upgrade, something went bad, and this tricked some font cache. The fact that it worked in LibreOffice would suggest there is still a bug in our code, though, because of my reinstall, I cannot reproduce that issue anymore.

Hence closing as INVALID.

Comment 12

[:gerard-majax]

This Debian bug report might be related: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=835142