sd-bus: allow description to be set for system/user busses (#8594)

sd_bus_open/sd_bus_open_system/sd_bus_open_user are convenient, but
don't allow the description to be set. After they return, the bus is
is already started, and sd_bus_set_description() fails with -EBUSY.
It would be possible to allow sd_bus_set_description() to update the
description "live", but messages are already emitted from sd_bus_open
functions, so it's better to allow the description to be set in
sd_bus_open/sd_bus_open_system/sd_bus_open_user.

Fixes message like:
Bus n/a: changing state UNSET → OPENING

1 files changed, 3 insertions, 3 deletions

diff --git a/src/core/dbus.c b/src/core/dbus.c
index eb9ec44f5b..ace6ffa8cf 100644
--- a/src/core/dbus.c
+++ b/src/core/dbus.c
@@ -895,9 +895,9 @@ int bus_init_api(Manager *m) {
                 bus = sd_bus_ref(m->system_bus);
         else {
                 if (MANAGER_IS_SYSTEM(m))
-                        r = sd_bus_open_system(&bus);
+                        r = sd_bus_open_system_with_description(&bus, "bus-api-system");
                 else
-                        r = sd_bus_open_user(&bus);
+                        r = sd_bus_open_user_with_description(&bus, "bus-api-user");
                 if (r < 0)
                         return log_error_errno(r, "Failed to connect to API bus: %m");
 
@@ -959,7 +959,7 @@ int bus_init_system(Manager *m) {
         if (MANAGER_IS_SYSTEM(m) && m->api_bus)
                 bus = sd_bus_ref(m->api_bus);
         else {
-                r = sd_bus_open_system(&bus);
+                r = sd_bus_open_system_with_description(&bus, "bus-system");
                 if (r < 0)
                         return log_error_errno(r, "Failed to connect to system bus: %m");