[glide] API guards for GlideImage

[Robert Carr <racarr src gnome org>]

commit 7f16da60343c33eba3de1a4da441f0820851b948
Author: Robert Carr <racarr Valentine localdomain>
Date:   Fri May 7 13:33:44 2010 -0400

    API guards for GlideImage

 libglide/glide-image.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/libglide/glide-image.c b/libglide/glide-image.c
index 75b5ff8..2378167 100644
--- a/libglide/glide-image.c
+++ b/libglide/glide-image.c
@@ -398,6 +398,8 @@ glide_image_set_from_file (GlideImage *image,
   CoglTextureFlags flags = COGL_TEXTURE_NONE;
   gchar *resource, *resource_file;
   
+  g_return_val_if_fail (GLIDE_IS_IMAGE (image), FALSE);
+  
   priv = image->priv;
   resource = glide_actor_add_resource (GLIDE_ACTOR (image), filename);
 
@@ -477,5 +479,6 @@ glide_image_new_from_file (const gchar *filename,
 const gchar *
 glide_image_get_filename (GlideImage *image)
 {
+  g_return_val_if_fail (GLIDE_IS_IMAGE (image), NULL);
   return image->priv->filename;
 }