core: use bus_unit_validate_load_state() for generating LoadError unit bus property

The load_error is only valid in some load_state cases, lets generate
prettier messages for other cases too, by reusing the
bus_unit_validate_load_state() call which does jus that.

Clients (such as systemctl) ignored LoadError unles LoadState was
"error" before. With this change they could even show LoadError in other
cases and it would show a useful name.

diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
index 84065ac..a728dbe 100644 (file)
--- a/src/core/dbus-unit.c
+++ b/src/core/dbus-unit.c
@@ -271,16 +271,18 @@ static int property_get_load_error(
                 sd_bus_error *error) {
 
         _cleanup_(sd_bus_error_free) sd_bus_error e = SD_BUS_ERROR_NULL;
-        int *n = userdata;
+        Unit *u = userdata;
+        int r;
 
         assert(bus);
         assert(reply);
-        assert(n);
+        assert(u);
 
-        if (*n != 0)
-                sd_bus_error_set_errno(&e, *n);
+        r = bus_unit_validate_load_state(u, &e);
+        if (r < 0)
+                return sd_bus_message_append(reply, "(ss)", e.name, e.message);
 
-        return sd_bus_message_append(reply, "(ss)", e.name, e.message);
+        return sd_bus_message_append(reply, "(ss)", NULL, NULL);
 }
 
 static int bus_verify_manage_units_async_full(
@@ -629,7 +631,7 @@ const sd_bus_vtable bus_unit_vtable[] = {
         BUS_PROPERTY_DUAL_TIMESTAMP("AssertTimestamp", offsetof(Unit, assert_timestamp), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
         SD_BUS_PROPERTY("Conditions", "a(sbbsi)", property_get_conditions, offsetof(Unit, conditions), 0),
         SD_BUS_PROPERTY("Asserts", "a(sbbsi)", property_get_conditions, offsetof(Unit, asserts), 0),
-        SD_BUS_PROPERTY("LoadError", "(ss)", property_get_load_error, offsetof(Unit, load_error), SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("LoadError", "(ss)", property_get_load_error, 0, SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Transient", "b", bus_property_get_bool, offsetof(Unit, transient), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Perpetual", "b", bus_property_get_bool, offsetof(Unit, perpetual), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("StartLimitIntervalUSec", "t", bus_property_get_usec, offsetof(Unit, start_limit.interval), SD_BUS_VTABLE_PROPERTY_CONST),