NULL pointers passed to *printf

[Strahinja]

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Issue description

Under OpenBSD, a bunch of lines like

  8 Mar  4 15:45:23 host dunst: vfprintf %s NULL in "[%16s:%04d] summary %s"
  7 Mar  4 15:45:23 host dunst: vfprintf %s NULL in "[%16s:%04d] appname %s"
  6 Mar  4 15:45:23 host dunst: vfprintf %s NULL in "[%16s:%04d] script %s"
  5 Mar  4 15:45:23 host dunst: vfprintf %s NULL in "[%16s:%04d] frame %s"

are added to /var/log/messages. These appear whenever some program passes NULL to the *printf family of functions in OpenBSD. It seems that those come from settings.c, where the struct members are passed to LOG_D without checking if they are NULL.

Installation info

• Version: Dunst - A customizable and lightweight notification-daemon 1.9.2 (2023-04-20)
• Install type: package
• Window manager / Desktop environment: dwm
• Distro: OpenBSD-release 7.4

Minimal dunstrc

# Dunstrc here

[bynect]

We rely heavily on printing null strings with the assumption that they will be printed as "(null)". Is there no way to turn off those logs?

[Strahinja]

The messages are written by syslogd(8), which can only filter them according to log facility and level. Still, I find it shocking that passing NULLs seems to be a practice rather than an oversight.

[bynect]

It is more of an historical artifact. Anyway I checked and it seems ub, so we may want to change that in the near future

[bynect]

@Strahinja if you find that there are some other nulls I forgot to handle feel free to reopen this 👍🏻