clutter: Safely transform paths to strings and vice versa

GValues containing objects and strings can be set to NULL, which means
the transformation functions from ClutterPath to string and vice versa
must be NULL-safe.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2625
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2929>

1 files changed, 12 insertions, 5 deletions

diff --git a/clutter/clutter/clutter-path.c b/clutter/clutter/clutter-path.c
index 9c0155de8..6d0fc0110 100644
--- a/clutter/clutter/clutter-path.c
+++ b/clutter/clutter/clutter-path.c
@@ -211,19 +211,26 @@ static void
 clutter_value_transform_path_string (const GValue *src,
                                      GValue       *dest)
 {
-  gchar *string = clutter_path_get_description (src->data[0].v_pointer);
+  if (src->data[0].v_pointer != NULL)
+    {
+      gchar *string = clutter_path_get_description (src->data[0].v_pointer);
 
-  g_value_take_string (dest, string);
+      g_value_take_string (dest, string);
+    }
 }
 
 static void
 clutter_value_transform_string_path (const GValue *src,
                                      GValue       *dest)
 {
-  ClutterPath *new_path;
+  const char *str;
 
-  new_path = clutter_path_new_with_description (g_value_get_string (src));
-  g_value_take_object (dest, new_path);
+  str = g_value_get_string (src);
+  if (str != NULL)
+    {
+      ClutterPath *new_path = clutter_path_new_with_description (str);
+      g_value_take_object (dest, new_path);
+    }
 }
 
 static void