+
+ /*
+ * The trace's reference count is 0 if we're here. Increment
+ * it to avoid a double-destroy (possibly infinitely recursive).
+ * This could happen for example if a destruction listener did
+ * bt_object_get_ref() (or anything that causes
+ * bt_object_get_ref() to be called) on the trace (ref.
+ * count goes from 0 to 1), and then bt_object_put_ref(): the
+ * reference count would go from 1 to 0 again and this function
+ * would be called again.
+ */
+ trace->base.ref_count++;
+