Found by Coverity.

(cherry picked from commit c8cee413dddd4a6bb45beb601b93c201ee1b5be1)

  git subtree pull --prefix shared/n-acd git@github.com:nettools/n-acd.git master --squash

Usually, we don't want to build with NDEBUG (because disabling regular
assertions is an untested configuration). Still, when we do, we get
compiler warnings.

Non-debug builds break with a compiler warning:

  $ ccache cc -Ishared/a4d2686@@n-acd@sta -Ishared -I../shared -I../shared/c-siphash/src -I../shared/c-list/src -I../shared/c-rbtree/src -fdiagnostics-color=always -DNDEBUG -pipe -D_FILE_OFFSET_BITS=64 -Werror -std=gnu11 -fdata-sections -ffunction-sections -O2 -g -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -fPIC -D_GNU_SOURCE -DSO_ATTACH_BPF=50 -std=c11 -Wno-pointer-arith -Wno-vla -MD -MQ 'shared/a4d2686@@n-acd@sta/n-acd_src_n-acd-probe.c.o' -MF 'shared/a4d2686@@n-acd@sta/n-acd_src_n-acd-probe.c.o.d' -o 'shared/a4d2686@@n-acd@sta/n-acd_src_n-acd-probe.c.o' -c ../shared/n-acd/src/n-acd-probe.c
  ../shared/n-acd/src/n-acd-probe.c: In function 'n_acd_probe_unlink':
  ../shared/n-acd/src/n-acd-probe.c:209:13: error: variable 'r' set but not used [-Werror=unused-but-set-variable]
           int r;
               ^

  $ cache cc -Ishared/a4d2686@@c-rbtree@sta -Ishared -I../shared -fdiagnostics-color=always -DNDEBUG -pipe -D_FILE_OFFSET_BITS=64 -Werror -std=gnu11 -fdata-sections -ffunction-sections -O2 -g -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -fPIC -std=c11 -MD -MQ 'shared/a4d2686@@c-rbtree@sta/c-rbtree_src_c-rbtree.c.o' -MF 'shared/a4d2686@@c-rbtree@sta/c-rbtree_src_c-rbtree.c.o.d' -o 'shared/a4d2686@@c-rbtree@sta/c-rbtree_src_c-rbtree.c.o' -c ../shared/c-rbtree/src/c-rbtree.c
  ../shared/c-rbtree/src/c-rbtree.c: In function 'c_rbtree_move':
  ../shared/c-rbtree/src/c-rbtree.c:456:18: error: variable 't' set but not used [-Werror=unused-but-set-variable]
           CRBTree *t;
                    ^

https://github.com/nettools/n-acd/pull/6
https://github.com/c-util/c-rbtree/pull/3

Partly revert the change from 35171b3c3f850a9136e48d12ead389ee80842268.
It's not our place to patch sources that we import via git-subtree.

Add missing trailing commas that avoids getting noise when another
file/parameter is added and eases reviewing changes[0].

[0] https://gitlab.gnome.org/GNOME/dconf/merge_requests/11#note_291585

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/merge_requests/21

[thaller@redhat.com: fix generated clients/common/settings-docs.h.in file
   and fix wrong change in src/systemd/src/libsystemd/sd-event/sd-event.c]

git subtree pull --prefix shared/n-acd git@github.com:nettools/n-acd.git master --squash

NM sometimes brings an interface temporarily down (for example to
change a VLAN MAC to align it to the parent interface's one). When
this happens, any recv() or send() in n-acd fails, the n-acd instance
is reset to the initial state and a DOWN event is reported to the
manager, which currently does not handle it. The result is an
inconsistent state.

There is no simple way of dealing with the DOWN event in the
manager. What we can do instead is to:

 - ignore errors during recv() because there is really nothing we can
   do, except for waiting timeouts to expire;

 - during probe, ignore errors during send() so that we don't exceed
   the probe timeout;

 - during announcement, retry after a send() error to ensure we send
   all 3 announcements.

https://bugzilla.redhat.com/show_bug.cgi?id=1578675

When doing announcements, use the the timeout specified by RFC
5227. Note that timeout_multiplier might be 0.

This aligns behavior to upstream version of n-acd.

...so that its prototype is compatible with GDestroyNotify:

src/devices/nm-acd-manager.c: In function ‘destroy_address_info’:
/usr/include/glib-2.0/glib/gmem.h:120:31: error: cast between incompatible function types from ‘NAcd * (*)(NAcd *)’ {aka ‘struct NAcd * (*)(struct NAcd *)’} to ‘void (*)(void *)’ [-Werror=cast-function-type]
     GDestroyNotify _destroy = (GDestroyNotify) (destroy);                      \
                               ^
src/devices/nm-acd-manager.c:430:2: note: in expansion of macro ‘g_clear_pointer’
  g_clear_pointer (&info->acd, n_acd_free);
  ^~~~~~~~~~~~~~~

The same change was done upstream, so the subsequent subtree pull of n-acd
won't mess this up.