systemctl: make sure we terminate the bus connection first, and then close the pager...

If "systemctl -H" is used, let's make sure we first terminate the bus
connection, and only then close the pager. If done in this order ssh will get
an EOF on stdin (as we speak D-Bus through ssh's stdin/stdout), and then
terminate. This makes sure the standard error we were invoked on is released by
ssh, and only that makes sure we don't deadlock on the pager which waits for
all clients closing its input pipe.

(Similar fixes for the various other xyzctl tools that support both pagers and
-H)

Fixes: #3543

diff --git a/src/login/loginctl.c b/src/login/loginctl.c
index abc3cf38c91a731034b3296be752bfd468ce785b..fd1e9b9c2898341ab78eda2865da51c3b8ff92c8 100644 (file)
--- a/src/login/loginctl.c
+++ b/src/login/loginctl.c
@@ -2037,7 +2037,7 @@ static int loginctl_main(int argc, char *argv[], sd_bus *bus) {
 }
 
 int main(int argc, char *argv[]) {
-        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        sd_bus *bus = NULL;
         int r;
 
         setlocale(LC_ALL, "");
@@ -2059,6 +2059,8 @@ int main(int argc, char *argv[]) {
         r = loginctl_main(argc, argv, bus);
 
 finish:
+        sd_bus_flush_close_unref(bus);
+
         pager_close();
         polkit_agent_close();