After running "dm-tool lock" on a Sway session (Wayland) all xwayland applications use a different font

[Alex Dowson]

Hi, experiencing a minor issue with lightdm and Sway. Not too sure whether this should be an issue for the Sway developers or lightdm but I thought I'd try here first. It's not a big issue but I thought it would be best to report it. I also have some log files if it's of any use (though they don't seem to have any useful information for this issue).

Operating System: Parabola GNU/Linux-libre (based on Arch Linux, see: https://wiki.parabola.nu/Main_Page )
Greeter = lightdm-gtk-greeter
Window Manager = Sway (i3wm for Wayland and some additions).

Steps to reproduce:

1. Start lightdm with the GTK greeter
2. Login to a Sway session
3. Install and run "lxappearance" to set a font for your xwayland GTK applications. I used "Cantarell". You can also test QT applications, I used QuiteRSS since it lets you set the font.
4. Run any xwayland application (I used Thunar, though any will work) and confirm that the font is the one you chose in step three. When I tested it, Thunar did use Cantarell, see: https://i.imgur.com/ZEXrNsD.png
6. Run "dm-tool lock" from a terminal window to lock your screen.
7. Unlock your screen
8. Restart the xwayland application and it should change font. When I tested it, Thunar started using a completely different font which seems familiar but I can't identify it, see: https://i.imgur.com/rIRdNp9.png

If you try the same with a native application (almost all Gnome applications are native to Wayland, e.g. gnome-system-monitor) you'll notice that the font remains the same. Only xwayland applications seem to be affected. Tested QuiteRSS (written in QT5) and it also changes font, even though when you look at the font settings remain untouched.

I don't have any other DE's or WM's that run in Wayland installed on my machine so I'll have to assume that this is only a problem with Sway for now.

Expected Functionality:

lightdm should not change the fonts of all xwayland application after locking the screen.

[Robert Ancell (robert-ancell)]

Re-assigning to the greeter. LightDM doesn't interact with fonts in any way, so it's more likely something related to the greeter doing this.