Fixes this error:

  checking whether more special flags are required for pthreads... no
  checking for PTHREAD_PRIO_INHERIT... yes
  ./configure: line 30294: ,as_fn_error: command not found
  checking for a Python interpreter with version >= 3... python
  checking for python... /usr/bin/python

The $URL might already contain a ".git" suffix. Then $FULLNAME would
end up having two ".git" extensions. Fix that.

It doesn't work anymore:

  $ git clone git://github.com/thom311/libnl.git
  Cloning into 'libnl'...
  fatal: remote error:
    The unauthenticated git protocol on port 9418 is no longer supported.
  Please see https://github.blog/2021-09-01-improving-git-protocol-security-github/ for more information.

https://bugzilla.redhat.com/show_bug.cgi?id=2049421

!1189

The goal would be to ensure that a device cannot move to activated,
while a DNS update is still pending.

This does not really work for most cases. That is, because NMDevice does
not directly push DNS updates to NMDnsManager, instead, NMPolicy is
watching all device changes, and doing it. But when NMPolicy decides to
to that, may not be the right moment.

We really should let NMDevice (or better, NML3Cfg) directly talk to
NMDnsManager. Why not? They have all the information when new DNS
configuration is available. The only thing that NMPolicy does on top of
that, is determining which device has the best default route. NMPolicy
could continue to do that (or maybe NMDnsManager could), but the update
needs to be directly triggered by NMDevice/NML3Cfg.

While we have DNS updates pending, we cannot reach startup complete.

nm_dns_manager_get() is already a singleton. So users usually
can just get it whenever they need -- except during shutdown
after the singleton was destroyed. This is usually fine, because
users really should not try to get it late during shutdown.

However, if you subscribe a signal handler on the singleton, then you
will also eventually want to unsubscribe it. While the moment when you
subscribe it is clearly not during late-shutdown, it's not clear how
to ensure that the signal listener gets destroyed before the DNS manager
singleton.

So usually, whenever you are going to subscribe a signal, you need to
make sure that the target object stays alive long enough. Which may
mean to keep a reference to it.

Next, we will have NMDevice subscribe to the singleton. With above said,
that would mean that potentially every NMDevice needs to keep a
reference to the NMDnsManager. That is not best. Also, later NMManager
will face the same problem, because it will also subscribe to
NMDnsManager.

So, instead let NMManager own a reference to the NMDnsManager. This
ensures the lifetimes are properly guarded (NMDevice also references
NMManager already).

Also, access nm_dns_manager_get() lazy on first use, to only initialize
it when needed the first time (which might be quite late).

For example, if you have a dnsmasq service running and bound to port 53, then
NetworkManager's [main].dns=dnsmasq will fail to start. And we keep retrying
to start it. But then update pending would hang indefinitely, and devices could
not become active. That must not happen.

Give the DNS update only 5 seconds. If it's not done by then, assume we
have a problem and unblock.

We want to know when we are busy (have an update pending or on-going).
Implement that.

The "unbound" DNS plugin was very rudimentary and is deprecated since
commit 4a2fe098 ('man: mark [main].dns=unbound as deprecated') (Jun
2021).

It is part of dnssec-trigger tool, but the dnssec-trigger tool doesn't
actually use it. Instead it installs a dispatcher script
"/usr/lib/NetworkManager/dispatcher.d/01-dnssec-trigger".

Especially, since the plugin requires "/usr/libexec/dnssec-trigger-script",
which is provided by "dnssec-trigger" package on Fedora. At the same
time, the package provides the dispatcher script. So I don't this works
or anybody is using this.

https://mail.gnome.org/archives/networkmanager-list/2022-April/msg00002.html

This is used to signal that an update is pending or in progress.
For this to work, we also need to implement the stop() handle.
Otherwise, we couldn't abort pending requests, which is necessary
during shutdown (not today, but in the future).

CList is a great, simple data structure. Especially, if we can embed it
into the data we track.

Here we just create a (temporary) list of pointers. A GPtrArray is the
better data structure for that.

We copy the content of the hash table to an array, so that we can sort
the entries and they have a defined order.

We are not only interested in the keys, but the keys and the values.
Hence, use nm_utils_hash_to_array_with_buffer() which gives both at
the same time.

When we do something where the order makes a visible difference,
we should do it in a consistent way, that does not depend on arbitray
things. Sort the ifindexes from dirty_interfaces hash table.

Theoretically, this should be a GObject property, and not a signal.
But then I'd  also have to implement the get_property() function,
which is more hazzle than necessary. A signal will do nicely.

Currently NMDnsSystemdResolved does not implement "stop()". That is
about to change. Make sure to call stop before unreferencing the
instance.

NM_DNS_PLUGIN_GET_PRIVATE() macro was broken. Also NMDnsPluginPrivate
contained unused fields. Fix that.

The private data is unused at the moment, but will be used next.
Hence it is fixed and not removed.

We avoid printing raw pointer values. Also, in this case this is a
singleton, and we only create one instance of this type.

Note that we would still have printed the pointer instance while
constructing the instances, before setting it as singleton.

Just drop this.

nm_shutdown_wait_obj_register_object() today has no practical effect.
In the future it will block shutdown until the object gets destroyed.
We will want that NMDnsPlugin gets wrapped up during shut down, before
quitting.

We effectively already have this function, with the name
nm_utils_named_values_from_strdict(). Which is a decent name,
if you have a strdict. But it seems odd to use for other dictionaries.

Instead, add a variant with a different name. Naming is important,
and just to have the better name, the function is effectively duplicated.

NMUtilsNamedValue is a key-value tuple, usually the key is a string
(hence the name "Named").

But this struct is also useful for keys that are not strings.
Add another "name_ptr" union field to access the key that way.

The alternative would be to add another struct, which serves
a very similar purpose though.

https://bugzilla.redhat.com/show_bug.cgi?id=2073067

!1188

This code is now unused.

This is long replaced by nettools' n-dhcp4 client.
Drop it.

We still require NMDhcpSystemd for the DHCPv6 client.

Note that "[main].dhcp=systemd" now falls back to the internal client.
But this option was undocumented and internal anyway.

We write lease files for internal DHCP client ("systemd" and "nettools")
in a systemd-specific format. We want to drop systemd code, so we need
to have our own parsing code.

Granted, nettools only writes a single "ADDRESS=" line, so parsing that
would be easy. On the other hand, systemd's parser is not complicated
either (in particular, if we can steal their implementation). Also, it's
a commonly used format in systemd, so having the parser would allow us
to parse similar formats.

Also, we could opt to choose that format, where it makes sense.

On recent Fedora and RHEL we no longer have differing "rpm_version"
and "real_version". So usually "rpm_version" is just the same as
"real_version".

Update the template spec file to reflect that. For the "build_clean.sh"
script, we anyway always set them both to "__VERSION__".

  git subtree pull --prefix src/c-stdaux git@github.com:c-util/c-stdaux.git main --squash

f20e1cf2dfb1 build: verify cflags do not contain spaces
5333735eeb74 build: export cflags via declare_dependency()
d050374b1c1a build: export basic CFLAGS

git-subtree-dir: src/c-stdaux
git-subtree-split: f20e1cf2dfb177e77cc946331ed2d2a83169d8b9

  git subtree pull --prefix src/c-stdaux git@github.com:c-util/c-stdaux.git main --squash