[librsvg] rsvg-gobject.c: Tighten an assertion

[Federico Mena Quintero <federico src gnome org>]

commit 712ec1f7a261287d15491de401188a9c60924cca
Author: Federico Mena Quintero <federico gnome org>
Date:   Tue Aug 8 09:49:06 2017 -0500

    rsvg-gobject.c: Tighten an assertion

 rsvg-gobject.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/rsvg-gobject.c b/rsvg-gobject.c
index d8c6d63..cfb09c8 100644
--- a/rsvg-gobject.c
+++ b/rsvg-gobject.c
@@ -104,6 +104,8 @@ free_nodes (RsvgHandle *self)
 {
     int i;
 
+    g_assert (self->priv->all_nodes != NULL);
+
     for (i = 0; i < self->priv->all_nodes->len; i++) {
         RsvgNode *node;