[pinpoint] cairo: Add a warning when not able to generate a video thumbnail

[Damien Lespiau <dlespiau src gnome org>]

commit 8c4702f967943ce14b2cf55f9f20f973c2c23140
Author: Damien Lespiau <damien lespiau intel com>
Date:   Wed Aug 17 14:14:43 2011 +0100

    cairo: Add a warning when not able to generate a video thumbnail
    
    So we know it has failed instead of doing it silently.

 pp-cairo.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/pp-cairo.c b/pp-cairo.c
index a97aa41..79ece8c 100644
--- a/pp-cairo.c
+++ b/pp-cairo.c
@@ -371,7 +371,10 @@ _cairo_render_background (CairoRenderer *renderer,
 
         pixbuf = gst_video_thumbnailer_get_shot (file, cancellable);
         if (pixbuf == NULL)
-          break;
+          {
+            g_warning ("Could not create video thumbmail for %s", file);
+            break;
+          }
 
         surface = _cairo_new_surface_from_pixbuf (pixbuf);
         g_hash_table_insert (renderer->surfaces, g_strdup (file), surface);