core: convert PID 1 to libsystemd-bus

This patch converts PID 1 to libsystemd-bus and thus drops the
dependency on libdbus. The only remaining code using libdbus is a test
case that validates our bus marshalling against libdbus' marshalling,
and this dependency can be turned off.

This patch also adds a couple of things to libsystem-bus, that are
necessary to make the port work:

- Synthesizing of "Disconnected" messages when bus connections are
  severed.

- Support for attaching multiple vtables for the same interface on the
  same path.

This patch also fixes the SetDefaultTarget() and GetDefaultTarget() bus
calls which used an inappropriate signature.

As a side effect we will now generate PropertiesChanged messages which
carry property contents, rather than just invalidation information.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/core/target.c b/src/core/target.c
index 3fffa0d2f5..68be22b38d 100644
--- a/src/core/target.c
+++ b/src/core/target.c
@@ -205,6 +205,7 @@ DEFINE_STRING_TABLE_LOOKUP(target_state, TargetState);
 
 const UnitVTable target_vtable = {
         .object_size = sizeof(Target),
+
         .sections =
                 "Unit\0"
                 "Target\0"
@@ -225,7 +226,7 @@ const UnitVTable target_vtable = {
         .sub_state_to_string = target_sub_state_to_string,
 
         .bus_interface = "org.freedesktop.systemd1.Target",
-        .bus_message_handler = bus_target_message_handler,
+        .bus_vtable = bus_target_vtable,
 
         .status_message_formats = {
                 .finished_start_job = {