[librsvg] Avoid crashing on an invalid atts field

[Christian Persch <chpe src gnome org>]

commit b54b065983e8fa7e2492fd0f741052c6f8441e4a
Author: Vincent Penquerc'h <vincent penquerch collabora co uk>
Date:   Thu Aug 18 12:59:23 2011 +0100

    Avoid crashing on an invalid atts field
    
    Initialize it to NULL at construction, and test for it being NULL
    before using it.

 rsvg-structure.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/rsvg-structure.c b/rsvg-structure.c
index 33889be..572036c 100644
--- a/rsvg-structure.c
+++ b/rsvg-structure.c
@@ -369,7 +369,7 @@ void
 _rsvg_node_svg_apply_atts (RsvgNodeSvg * self, RsvgHandle * ctx)
 {
     const char *id = NULL, *klazz = NULL, *value;
-    if (rsvg_property_bag_size (self->atts)) {
+    if (self->atts && rsvg_property_bag_size (self->atts)) {
         if ((value = rsvg_property_bag_lookup (self->atts, "class")))
             klazz = value;
         if ((value = rsvg_property_bag_lookup (self->atts, "id")))
@@ -406,6 +406,7 @@ rsvg_new_svg (void)
     svg->super.draw = rsvg_node_svg_draw;
     svg->super.free = _rsvg_svg_free;
     svg->super.set_atts = rsvg_node_svg_set_atts;
+    svg->atts = NULL;
     return &svg->super;
 }