background: Use g_clear_* helpers when possible

https://bugzilla.gnome.org/show_bug.cgi?id=707602

panels/background/bg-flickr-source.c

@@ -46,17 +46,8 @@ bg_flickr_source_dispose (GObject *object)
 {
   BgFlickrSourcePrivate *priv = BG_FLICKR_SOURCE (object)->priv;
 
-  if (priv->client)
+  g_clear_object (&priv->client);
-    {
+  g_clear_object (&priv->service);
-      g_object_unref (priv->client);
-      priv->client = NULL;
-    }
-
-  if (priv->service)
-    {
-      g_object_unref (priv->service);
-      priv->service = NULL;
-    }
 
   G_OBJECT_CLASS (bg_flickr_source_parent_class)->dispose (object);
 }

panels/background/bg-pictures-source.c

@@ -94,15 +94,10 @@ bg_pictures_source_dispose (GObject *object)
   if (priv->cancellable)
     {
       g_cancellable_cancel (priv->cancellable);
-      g_object_unref (priv->cancellable);
+      g_clear_object (&priv->cancellable);
-      priv->cancellable = NULL;
     }
 
-  if (priv->thumb_factory)
+  g_clear_object (&priv->thumb_factory);
-    {
-      g_object_unref (priv->thumb_factory);
-      priv->thumb_factory = NULL;
-    }
 
   G_OBJECT_CLASS (bg_pictures_source_parent_class)->dispose (object);
 }
@@ -112,17 +107,9 @@ bg_pictures_source_finalize (GObject *object)
 {
   BgPicturesSource *bg_source = BG_PICTURES_SOURCE (object);
 
-  if (bg_source->priv->thumb_factory)
+  g_clear_object (&bg_source->priv->thumb_factory);
-    {
-      g_object_unref (bg_source->priv->thumb_factory);
-      bg_source->priv->thumb_factory = NULL;
-    }
 
-  if (bg_source->priv->known_items)
+  g_clear_pointer (&bg_source->priv->known_items, g_hash_table_destroy);
-    {
-      g_hash_table_destroy (bg_source->priv->known_items);
-      bg_source->priv->known_items = NULL;
-    }
 
   g_clear_object (&bg_source->priv->picture_dir_monitor);
   g_clear_object (&bg_source->priv->cache_dir_monitor);

panels/background/bg-source.c

@@ -75,11 +75,7 @@ bg_source_dispose (GObject *object)
 {
   BgSourcePrivate *priv = BG_SOURCE (object)->priv;
 
-  if (priv->store)
+  g_clear_object (&priv->store);
-    {
-      g_object_unref (priv->store);
-      priv->store = NULL;
-    }
 
   G_OBJECT_CLASS (bg_source_parent_class)->dispose (object);
 }

panels/background/bg-wallpapers-source.c

@@ -72,16 +72,8 @@ bg_wallpapers_source_dispose (GObject *object)
 {
   BgWallpapersSourcePrivate *priv = BG_WALLPAPERS_SOURCE (object)->priv;
 
-  if (priv->thumb_factory)
+  g_clear_object (&priv->thumb_factory);
-    {
+  g_clear_object (&priv->xml);
-      g_object_unref (priv->thumb_factory);
-      priv->thumb_factory = NULL;
-    }
-  if (priv->xml)
-    {
-      g_object_unref (priv->xml);
-      priv->xml = NULL;
-    }
 
   G_OBJECT_CLASS (bg_wallpapers_source_parent_class)->dispose (object);
 }

panels/background/cc-background-item.c

@@ -140,8 +140,7 @@ cc_background_item_changes_with_time (CcBackgroundItem *item)
 static void
 update_size (CcBackgroundItem *item)
 {
-	g_free (item->priv->size);
+	g_clear_pointer (&item->priv->size, g_free);
-	item->priv->size = NULL;
 
 	if (item->priv->uri == NULL) {
 		item->priv->size = g_strdup ("");
@@ -272,8 +271,7 @@ update_info (CcBackgroundItem *item,
 		info = g_object_ref (_info);
 	}
 
-        g_free (item->priv->mime_type);
+	g_clear_pointer (&item->priv->mime_type, g_free);
-        item->priv->mime_type = NULL;
 
         if (info == NULL
             || g_file_info_get_content_type (info) == NULL) {

panels/background/cc-background-panel.c

@@ -101,8 +101,7 @@ cc_background_panel_dispose (GObject *object)
       /* cancel any copy operation */
       g_cancellable_cancel (priv->copy_cancellable);
 
-      g_object_unref (priv->copy_cancellable);
+      g_clear_object (&priv->copy_cancellable);
-      priv->copy_cancellable = NULL;
     }
 
   if (priv->capture_cancellable)
@@ -110,8 +109,7 @@ cc_background_panel_dispose (GObject *object)
       /* cancel screenshot operations */
       g_cancellable_cancel (priv->capture_cancellable);
 
-      g_object_unref (priv->capture_cancellable);
+      g_clear_object (&priv->capture_cancellable);
-      priv->capture_cancellable = NULL;
     }
 
   if (priv->chooser)
@@ -123,8 +121,7 @@ cc_background_panel_dispose (GObject *object)
   g_clear_object (&priv->thumb_factory);
   g_clear_object (&priv->display_screenshot);
 
-  g_free (priv->screenshot_path);
+  g_clear_pointer (&priv->screenshot_path, g_free);
-  priv->screenshot_path = NULL;
 
   g_clear_object (&priv->connection);
 
@@ -344,8 +341,7 @@ on_screenshot_finished (GObject *source,
 
   /* remove the temporary file created by the shell */
   g_unlink (panel->priv->screenshot_path);
-  g_free (priv->screenshot_path);
+  g_clear_pointer (&priv->screenshot_path, g_free);
-  priv->screenshot_path = NULL;
 
   cairo_destroy (cr);
   cairo_surface_destroy (surface);
@@ -478,8 +474,7 @@ reload_current_bg (CcBackgroundPanel *self,
   uri = g_settings_get_string (settings, WP_URI_KEY);
   if (uri && *uri == '\0')
     {
-      g_free (uri);
+      g_clear_pointer (&uri, g_free);
-      uri = NULL;
     }
   else
     {

panels/background/cc-background-xml.c

@@ -623,18 +623,12 @@ cc_background_xml_finalize (GObject *object)
 
         g_return_if_fail (xml->priv != NULL);
 
-	if (xml->priv->wp_hash) {
+	g_clear_pointer (&xml->priv->wp_hash, g_hash_table_destroy);
-		g_hash_table_destroy (xml->priv->wp_hash);
-		xml->priv->wp_hash = NULL;
-	}
 	if (xml->priv->item_added_id != 0) {
 		g_source_remove (xml->priv->item_added_id);
 		xml->priv->item_added_id = 0;
 	}
-	if (xml->priv->item_added_queue) {
+	g_clear_pointer (&xml->priv->item_added_queue, g_async_queue_unref);
-		g_async_queue_unref (xml->priv->item_added_queue);
-		xml->priv->item_added_queue = NULL;
-	}
 }
 
 static void