swaybar: add NULL check when listing workspaces

[milkey-mouse]

For some reason my version of sway doesn't show workspace names:

$ swaymsg -t get_outputs
Output HDMI-A-1 '(null) (null) (null)' (inactive)
Output HDMI-A-2 '(null) (null) (null)' (inactive)

Which is weird, but it's no reason to crash swaybar. The field is
totally missing from the JSON, so it ends up doing strcmp(NULL, name)
which is undefined behavior.

[emersion]

I guess this can happen when all outputs are disabled.

Thanks!

[milkey-mouse]

That's the weird thing, none of my outputs are disabled. I'm writing this in a window on HDMI-A-1 right now. I think it's a graphics driver issue, but everything is working fine. I know get_outputs has worked correctly before so something else must have changed.

I do have workspaces turned off though (or at least, I only have one workspace enabled, and workspaces disabled on the swaybar config). Maybe that has something to do with it?

I didn't consider this worth opening an issue for because it seems harmless and I have no idea what the problem is (and it probably isn't sway's fault anyway).

[emersion]

Do you have debug logs?

Make sure to grab the latest wlroots commit, it contains some maybe-related fixes.

[milkey-mouse]

Here are my debug logs: https://gist.github.com/milkey-mouse/dac49c33fb66a55d558a3ef278a7c3f7

The problem shows up the same in sway/wlroots 1.4 and master, although master also takes ~10 seconds to exit (which sway 1.4 doesn't).

[Xyene]

This is caused by a bug upstream in json-c (json-c/json-c#599). #5349 and #5350 have more info; it's been fixed upstream but not yet repackaged everywhere.