$ find * -type f |xargs perl contrib/scripts/spdx.pl
  $ git rm contrib/scripts/spdx.pl

We no longer add these. If you use Emacs, configure it yourself.

Also, due to our "smart-tab" usage the editor anyway does a subpar
job handling our tabs. However, on the upside every user can choose
whatever tab-width he/she prefers. If "smart-tabs" are used properly
(like we do), every tab-width will work.

No manual changes, just ran commands:

    F=($(git grep -l -e '-\*-'))
    sed '1 { /\/\* *-\*-  *[mM]ode.*\*\/$/d }'     -i "${F[@]}"
    sed '1,4 { /^\(#\|--\|dnl\) *-\*- [mM]ode/d }' -i "${F[@]}"

Check remaining lines with:

    git grep -e '-\*-'

The ultimate purpose of this is to cleanup our files and eventually use
SPDX license identifiers. For that, first get rid of the boilerplate lines.

I also like this because it's non-obvious that subscription IDs from
GDBusConnection are "guint" (contrary to signal handler IDs which are
"gulong"). So, by using this API you get a compiler error when using the
wrong type.
In the past, when switching to nm_clear_g_signal_handler() this uncovered
multiple bugs where the wrong type was used to hold the ID.

... and nm_dbus_connection_call_get_name_owner().

We will use the D-Bus connection of our NMDBusManager singleton more.
Use a macro.

- it's shorter to type and it's one distinct word.

- the name indicates what this is: the main D-Bus connection singleton.
  By searching for this name we can find all users that care about using
  this singleton.

(cherry picked from commit 81833358786b0fdd0668ef92b0bdc1361fa980b3)

From the files under "shared/nm-utils" we build an internal library
that provides glib-based helper utilities.

Move the files of that basic library to a new subdirectory
"shared/nm-glib-aux" and rename the helper library "libnm-core-base.la"
to "libnm-glib-aux.la".

Reasons:

 - the name "utils" is overused in our code-base. Everything's an
   "utils". Give this thing a more distinct name.

 - there were additional files under "shared/nm-utils", which are not
   part of this internal library "libnm-utils-base.la". All the files
   that are part of this library should be together in the same
   directory, but files that are not, should not be there.

 - the new name should better convey what this library is and what is isn't:
   it's a set of utilities and helper functions that extend glib with
   funcitonality that we commonly need.

There are still some files left under "shared/nm-utils". They have less
a unifying propose to be in their own directory, so I leave them there
for now. But at least they are separate from "shared/nm-glib-aux",
which has a very clear purpose.

(cherry picked from commit 80db06f768e47541eae7d66ef48fbe47bf1a69ce)

The proxy does nothing for us, except overhead.

We can directly subscribe to "NameOwnerChanged" signals on the
GDBusConnection. Also, instead of asynchronously creating the
GDBusProxy, asynchronously call "GetNameOwner". That's what the
proxy does anyway.

GDBusConnection is actually a decent API. We don't need another layer on
top of that, for functionality that we don't use.

Also, don't use G_BUS_TYPE_SYSTEM, but use the GDBusConnection that
also the bus-manager uses. For all practical purposes, that is the
connection was want to use also in NMDnsSystemdResolved.

Every (failed) attempt to D-Bus activate a service results in log-messages
from dbus-daemon. It must be avoided to spam the logs that way.

Let connectivity check not only ask whether systemd-resolved is enabled
(and NetworkManager would like to push information there), but also
whether it looks like the service is actually available. That is,
either it has a name-owner or it's not blocked from starting.

The previous workaround was to configure main.systemd-resolved=no
in NetworkManager.conf. But that requires explict configuration.