[Pkg-utopia-maintainers] Bug#1131877: NetworkManager configures dnsmasq to read all files in /etc/NetworkManager/dnsmasq.d/, including dpkg temporary files

[Jann Horn]

Package: network-manager
Version: 1.54.3

NetworkManager has this code in src/core/dns/nm-dns-dnsmasq.c:

```
argv[argv_idx++] = "--conf-dir=" CONFDIR;
```

This instructs NetworkManager to parse _all_ files in
/etc/NetworkManager/dnsmasq.d/ as config files, including temporary
files created by dpkg during package upgrades (*.dpkg-new, *.dpkg-tmp,
*.dpkg-old, *.dpkg-dist). If files in /etc/NetworkManager/dnsmasq.d/
are managed by a debian package, this can cause dnsmasq to fail to
start during package upgrades, because listing the same options in two
files can cause dnsmasq errors.

dnsmasq documents support for excluding files based on file extension,
maybe something like that would make sense?