[gitg] Added robohash fallback for avatar cache

[Jesse van den Kieboom <jessevdk src gnome org>]

commit c5fe703e8192bd64a1c5842e547da16fb49e6b01
Author: Jesse van den Kieboom <jessevdk gmail com>
Date:   Sat Jul 6 16:02:56 2013 +0200

    Added robohash fallback for avatar cache

 libgitg/gitg-avatar-cache.vala |   28 +++++++++++++++++++++-------
 1 files changed, 21 insertions(+), 7 deletions(-)
---
diff --git a/libgitg/gitg-avatar-cache.vala b/libgitg/gitg-avatar-cache.vala
index 1a59f92..c6fb791 100644
--- a/libgitg/gitg-avatar-cache.vala
+++ b/libgitg/gitg-avatar-cache.vala
@@ -54,15 +54,32 @@ public class Gitg.AvatarCache : Object
                var gravatar = @"http://www.gravatar.com/avatar/$(id)?d=404&s=50";
                var gfile = File.new_for_uri(gravatar);
 
+               var pixbuf = yield read_avatar_from_file(id, gfile, cancellable);
+
+               if (pixbuf == null)
+               {
+                       gravatar = @"http://robohash.org/$(id).png?size=50x50";
+                       gfile = File.new_for_uri(gravatar);
+
+                       pixbuf = yield read_avatar_from_file(id, gfile, cancellable);
+               }
+
+               d_cache[id] = pixbuf;
+               return pixbuf;
+       }
+
+       private async Gdk.Pixbuf? read_avatar_from_file(string       id,
+                                                       File         file,
+                                                       Cancellable? cancellable)
+       {
                InputStream stream;
 
                try
                {
-                       stream = yield gfile.read_async(Priority.LOW, cancellable);
+                       stream = yield file.read_async(Priority.LOW, cancellable);
                }
                catch
                {
-                       d_cache[id] = null;
                        return null;
                }
 
@@ -71,17 +88,14 @@ public class Gitg.AvatarCache : Object
 
                loader.set_size(50, 50);
 
-               var pixbuf = yield read_avatar(id, stream, buffer, loader, cancellable);
-               d_cache[id] = pixbuf;
-
-               return pixbuf;
+               return yield read_avatar(id, stream, buffer, loader, cancellable);
        }
 
        private async Gdk.Pixbuf? read_avatar(string           id,
                                              InputStream      stream,
                                              uint8[]          buffer,
                                              Gdk.PixbufLoader loader,
-                                             Cancellable?     cancellable = null)
+                                             Cancellable?     cancellable)
        {
                ssize_t n;