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/shared/install.c b/src/shared/install.c
index 2c119e2dca..16504eef0f 100644
--- a/src/shared/install.c
+++ b/src/shared/install.c
@@ -1562,6 +1562,7 @@ int unit_file_set_default(
                 UnitFileScope scope,
                 const char *root_dir,
                 const char *file,
+                bool force,
                 UnitFileChange **changes,
                 unsigned *n_changes) {
 
@@ -1599,7 +1600,7 @@ int unit_file_set_default(
 
         path = strappenda(config_path, "/" SPECIAL_DEFAULT_TARGET);
 
-        r = create_symlink(i->path, path, true, changes, n_changes);
+        r = create_symlink(i->path, path, force, changes, n_changes);
         if (r < 0)
                 return r;