cleanup: Use g_clear_signal_handler() where possible

This is inspired by 98892391d764d1cf where the usage of
`g_signal_handler_disconnect()` without resetting the corresponding
handler id later resulted in a bug. Using `g_clear_signal_handler()`
makes sure we avoid similar bugs and is almost always the better
alternative. We use it for new code, let's clean up the old code to
also use it.

A further benefit is that it can get called even if the passed id is
0, allowing us to remove a lot of now unnessecary checks, and the fact
that `g_clear_signal_handler()` checks for the right type size, forcing us
to clean up all places where we used `guint` instead of `gulong`.

No functional changes intended here and all changes should be trivial,
thus bundled in one big commit.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/940

1 files changed, 2 insertions, 2 deletions

diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index a64af1a46..b6368e83a 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -802,8 +802,8 @@ meta_monitor_manager_finalize (GObject *object)
 
   g_list_free_full (manager->logical_monitors, g_object_unref);
 
-  g_signal_handler_disconnect (manager->backend,
-                               manager->experimental_features_changed_handler_id);
+  g_clear_signal_handler (&manager->experimental_features_changed_handler_id,
+                          manager->backend);
 
   G_OBJECT_CLASS (meta_monitor_manager_parent_class)->finalize (object);
 }