1906116 - Firefox picks up broken ligatures from somewhere on fresh postmarketOS (Linux) installs even though all other apps are fine

Status: UNCONFIRMED

(Core :: Layout: Text and Fonts, defect, P3)

Description

[Ellie]

Attachment: Screenshot_20240703_160010.png

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:127.0) Gecko/20100101 Firefox/127.0

Steps to reproduce:

1. Install postmarketOS https://postmarketos.org/ (e.g. get the generic x64 version in qemu)
2. Install KDE Plasma or GNOME or Phosh as a desktop environment
3. DON'T install anything else other than firefox. Most notably, don't install anything that might pull in more fonts (like the wine compatibility layer, any document readers, any latex or general text layouting software, ...)
4. Launch firefox. You can either use the built-in firefox-esr by postmarketOS, or the official build, I've seen this issue by both.
5. Type all sorts of letter combinations into the firefox address bar to find the broken ligatures. They seem to slightly vary between installs.

Actual results:

Random broken ligatures affecting seemingly random letter combinations. Last time I saw this on another postmarketOS install, it affected different letters than this time.

Expected results:

Fonts are fine, since they are in anything else. Even if the desired font Firefox would ideally use isn't available (which is probably the case, since installing random additional system fonts will at some point usually fix this) then Firefox should probably do a better job at picking a font that works.

Sorry if this is actually a postmarketOS bug, but I assumed since everything else is fine it seems to be some Firefox quirk.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::Layout: Text and Fonts' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

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

The severity field is not set for this bug.
:emilio, could you have a look please?

For more information, please visit BugBot documentation.

Comment 3

[Emilio Cobos Álvarez [:emilio]]

I can't repro this using the following:

pmbootstrap init; pmbootstrap install

Choosing gnome as the UI, then running:

pmbootstrap qemu --image-size=4G

I'll try with plasma but could you provide more concrete STR? Alternatively, could you inspect the broken ligature and see which font is used in the devtools font panel? Thanks.

Comment 4

[Emilio Cobos Álvarez [:emilio]]

Can't repro in plasma either, so for now going with S3 for now :)

Comment 5

[Ellie]

I have sadly since installed more fonts to fix this so there's no easy way for me to get back into this state, but I can confirm this also happens on OpenSUSE, and I would assume on many distros. However, you'll need to start with a minimal base system. To do that, DON'T use the desktop image of openSUSE Tumbleweed but rather the minimal server image, same for postmarketOS, and then try to install as little as possible to just get a GNOME or KDE session running. Then fetch the Mozilla build of firefox. You should then be very likely to see this problem, since the "full" desktop installs seem to install a wider variety of fonts out of the box which seems to work around this problem.

I get that without all important base fonts, Firefox can't render everything fully as intended. However, if all other GTK+ and Qt applications manage to display basic sans serif fonts correctly without strange broken ligatures, it just seems a little like a self-inflicted unnecessary breakage for Firefox to seemingly go out of it's way to use broken ligatures. I hope that view of it makes sense, and I'm not just mixing up something here as a user.

Comment 6

[Jonathan Kew [:jfkthame]]

I don't think Firefox is doing anything specific to cause this; rather, it looks like there's a font present that (probably) has incorrect OpenType tables, and that happens to be the font that Firefox is getting by default in that particular environment. It's possible that other applications are getting a different default font, or that they disable various OpenType features in their UI rendering, so that the problem doesn't show up there, but to confirm exactly what's happening (and how we can perhaps avoid/work around it) we really need to determine what font is involved.

Comment 7

[Jonathan Kew [:jfkthame]]

I was going to try and install a minimal OpenSUSE VM, but the opensuse.org site currently appears to be down.... :(