logind: fix getting property OnExternalPower via D-Bus

The BUS_DEFINE_PROPERTY_GET_GLOBAL macro requires a value as third
argument, so we need to call manager_is_on_external_power(). Otherwise
the function pointer is interpreted as a boolean and always returns
true:

```
$ busctl get-property org.freedesktop.login1 /org/freedesktop/login1 org.freedesktop.login1.Manager OnExternalPower
b true
$ /lib/systemd/systemd-ac-power  --verbose
no
```

Thanks: Helmut Grohne <helmut@subdivi.de>
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1021644

diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c
index 7fc96447d5c0cd324747faf8e994c3424539ac35..86a5decf3f3106ec7e5a3358d7b60e8bc8b25c72 100644 (file)
--- a/src/login/logind-dbus.c
+++ b/src/login/logind-dbus.c
@@ -372,7 +372,7 @@ static int property_get_scheduled_shutdown(
 static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_handle_action, handle_action, HandleAction);
 static BUS_DEFINE_PROPERTY_GET(property_get_docked, "b", Manager, manager_is_docked_or_external_displays);
 static BUS_DEFINE_PROPERTY_GET(property_get_lid_closed, "b", Manager, manager_is_lid_closed);
-static BUS_DEFINE_PROPERTY_GET_GLOBAL(property_get_on_external_power, "b", manager_is_on_external_power);
+static BUS_DEFINE_PROPERTY_GET_GLOBAL(property_get_on_external_power, "b", manager_is_on_external_power());
 static BUS_DEFINE_PROPERTY_GET_GLOBAL(property_get_compat_user_tasks_max, "t", CGROUP_LIMIT_MAX);
 static BUS_DEFINE_PROPERTY_GET_REF(property_get_hashmap_size, "t", Hashmap *, (uint64_t) hashmap_size);