pixbuf-engine: Improve ThemePixbuf clean up functions

Make theme_pixbuf_destroy() NULL-safe like g_free(), and add a clear
function in the spirit of the g_clear_* family of functions.

https://bugzilla.gnome.org/show_bug.cgi?id=712536

2 files changed, 20 insertions, 2 deletions

diff --git a/modules/engines/pixbuf/pixbuf-render.c b/modules/engines/pixbuf/pixbuf-render.c
index 6fb93bc495..1b2fd991c8 100644
--- a/modules/engines/pixbuf/pixbuf-render.c
+++ b/modules/engines/pixbuf/pixbuf-render.c
@@ -492,8 +492,25 @@ theme_pixbuf_new (void)
 void
 theme_pixbuf_destroy (ThemePixbuf *theme_pb)
 {
-  theme_pixbuf_set_filename (theme_pb, NULL);
-  g_free (theme_pb);
+  if (G_LIKELY (theme_pb))
+    {
+      theme_pixbuf_set_filename (theme_pb, NULL);
+      g_free (theme_pb);
+    }
+}
+
+void
+theme_clear_pixbuf (ThemePixbuf **theme_pb)
+{
+#if GLIB_CHECK_VERSION (2, 34, 0)
+  g_clear_pointer (theme_pb, theme_pixbuf_destroy);
+#else
+  if (*theme_pb)
+    {
+      theme_pixbuf_destroy (*theme_pb);
+      *theme_pb = NULL;
+    }
+#endif
 }
 
 void         
diff --git a/modules/engines/pixbuf/pixbuf.h b/modules/engines/pixbuf/pixbuf.h
index c844421f38..03cbac9a57 100644
--- a/modules/engines/pixbuf/pixbuf.h
+++ b/modules/engines/pixbuf/pixbuf.h
@@ -188,6 +188,7 @@ struct _ThemeImage
 
 G_GNUC_INTERNAL ThemePixbuf *theme_pixbuf_new          (void);
 G_GNUC_INTERNAL void         theme_pixbuf_destroy      (ThemePixbuf  *theme_pb);
+G_GNUC_INTERNAL void         theme_clear_pixbuf        (ThemePixbuf **theme_pb);
 G_GNUC_INTERNAL void         theme_pixbuf_set_filename (ThemePixbuf  *theme_pb,
 					const char   *filename);
 G_GNUC_INTERNAL GdkPixbuf *  theme_pixbuf_get_pixbuf   (ThemePixbuf  *theme_pb);