Add g_settings_sync() and use it

docs/reference/gio/gio-sections.txt

@@ -2135,6 +2135,7 @@ g_settings_new_with_path
 g_settings_new_with_context
 g_settings_new_with_context_and_path
 g_settings_supports_context
+g_settings_sync
 g_settings_get_value
 g_settings_set_value
 g_settings_is_writable

gio/gio.symbols

@@ -1467,6 +1467,7 @@ g_settings_get_double
 g_settings_set_double
 g_settings_get_boolean
 g_settings_set_boolean
+g_settings_sync
 #endif
 #endif
 

gio/gsettings-tool.c

@@ -213,26 +213,9 @@ handle_set (gint   *argc,
       goto out;
     }
 
+  g_settings_sync (NULL);
   ret = 0;
 
-  /* XXX: workaround for now
-   *
-   * if we exit() so quickly, GDBus may not have had a chance to
-   * actually send the message (since we're using it async).
-   *
-   * GDBusConnection has no API to sync or wait for messages to be sent,
-   * so we send a meaningless message and wait for the reply to ensure
-   * that all messages that came before must have been sent.
-   */
-  {
-    GDBusConnection *session;
-
-    session = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, NULL);
-    g_dbus_connection_call_sync (session, "org.gtk.DoesNotExist", "/",
-                                 "org.gtk.DoesNotExist", "Workaround",
-                                 g_variant_new ("()"), NULL, 0, -1, NULL, NULL);
-  }
-
  out:
   g_option_context_free (context);
 

gio/gsettings.c

@@ -1860,5 +1860,33 @@ g_settings_set_strv (GSettings           *settings,
   return g_settings_set_value (settings, key, array);
 }
 
+/**
+ * g_settings_sync:
+ * @context: the context to sync, or %NULL
+ *
+ * Ensures that all pending operations for the given context are
+ * complete.
+ *
+ * Writes made to a #GSettings are handled asynchronously.  For this
+ * reason, it is very unlikely that the changes have it to disk by the
+ * time g_settings_set() returns.
+ *
+ * This call will block until all of the writes have made it to the
+ * backend.  Since the mainloop is not running, no change notifications
+ * will be dispatched during this call (but some may be queued by the
+ * time the call is done).
+ **/
+void
+g_settings_sync (const gchar *context)
+{
+  GSettingsBackend *backend;
+
+  if (context == NULL)
+    context = "";
+
+  backend = g_settings_backend_get_with_context (context);
+  g_settings_backend_sync (backend);
+}
+
 #define __G_SETTINGS_C__
 #include "gioaliasdef.c"

gio/gsettings.h

@@ -132,6 +132,7 @@ void                    g_settings_delay                                (GSettin
 void                    g_settings_apply                                (GSettings          *settings);
 void                    g_settings_revert                               (GSettings          *settings);
 gboolean                g_settings_get_has_unapplied                    (GSettings          *settings);
+void                    g_settings_sync                                 (const gchar        *context);
 
 /**
  * GSettingsBindSetMapping:

gio/gsettingsbackend.c

@@ -1219,5 +1219,20 @@ g_settings_backend_setup (const gchar      *context,
                        g_object_ref (backend));
 }
 
+/*< private >
+ * g_settings_backend_sync:
+ * @backend: a #GSettingsBackend
+ *
+ * Syncs the backend.
+ */
+void
+g_settings_backend_sync (GSettingsBackend *backend)
+{
+  GSettingsBackendClass *class = G_SETTINGS_BACKEND_GET_CLASS (backend);
+
+  if (class->sync)
+    class->sync (backend);
+}
+
 #define __G_SETTINGS_BACKEND_C__
 #include "gioaliasdef.c"

gio/gsettingsbackendinternal.h

@@ -103,5 +103,7 @@ GPermission *                   g_settings_backend_get_permission       (GSettin
                                                                          const gchar                          *path);
 G_GNUC_INTERNAL
 GMainContext *                  g_settings_backend_get_active_context   (void);
+G_GNUC_INTERNAL
+void                            g_settings_backend_sync                 (GSettingsBackend                     *backend);
 
 #endif  /* __G_SETTINGS_BACKEND_INTERNAL_H__ */