[rygel] media-export: Disable plugin if error while init

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit de58de51650832802b7c344ca692e7b163898534
Author: Jens Georg <mail jensge org>
Date:   Sun Oct 24 00:48:33 2010 +0200

    media-export: Disable plugin if error while init
    
    If there's a problem reading the database e.g. disable plugin right
    away

 .../rygel-media-export-object-factory.vala         |    7 ++++++-
 .../media-export/rygel-media-export-plugin.vala    |   11 ++++++++++-
 .../rygel-media-export-root-container.vala         |   10 ++++++++--
 3 files changed, 24 insertions(+), 4 deletions(-)
---
diff --git a/src/plugins/media-export/rygel-media-export-object-factory.vala b/src/plugins/media-export/rygel-media-export-object-factory.vala
index a1a62dc..ce34bd4 100644
--- a/src/plugins/media-export/rygel-media-export-object-factory.vala
+++ b/src/plugins/media-export/rygel-media-export-object-factory.vala
@@ -33,7 +33,12 @@ internal class Rygel.MediaExport.ObjectFactory : Object {
                                               string     title,
                                               uint       child_count) {
         if (id == "0") {
-            return RootContainer.get_instance () as DBContainer;
+            try {
+                return RootContainer.get_instance () as DBContainer;
+            } catch (Error error) {
+                // Must not fail - plugin is disabled if this fails
+                assert_not_reached ();
+            }
         } else if (id.has_prefix (QueryContainer.PREFIX)) {
             return new QueryContainer (media_db, id, title);
         } else {
diff --git a/src/plugins/media-export/rygel-media-export-plugin.vala b/src/plugins/media-export/rygel-media-export-plugin.vala
index 37ef684..de3087a 100644
--- a/src/plugins/media-export/rygel-media-export-plugin.vala
+++ b/src/plugins/media-export/rygel-media-export-plugin.vala
@@ -79,6 +79,15 @@ public class Rygel.MediaExport.Plugin : Rygel.MediaServerPlugin {
     }
 
     public override MediaContainer? get_root_container (GUPnP.Context context) {
-        return RootContainer.get_instance ();
+        try {
+            return RootContainer.get_instance ();
+        } catch (Error error) {
+            warning ("Could not create root container: %s. " +
+                     "Disabling plugin",
+                     error.message);
+            this.available = false;
+        }
+
+        return new NullContainer ();
     }
 }
diff --git a/src/plugins/media-export/rygel-media-export-root-container.vala b/src/plugins/media-export/rygel-media-export-root-container.vala
index ffea4cd..deb15d2 100644
--- a/src/plugins/media-export/rygel-media-export-root-container.vala
+++ b/src/plugins/media-export/rygel-media-export-root-container.vala
@@ -47,17 +47,23 @@ public class Rygel.MediaExport.RootContainer : Rygel.MediaExport.DBContainer {
     private MediaContainer filesystem_container;
 
     private static MediaContainer instance = null;
+    private static Error          creation_error = null;
 
     internal const string FILESYSTEM_FOLDER_NAME = "Files & Folders";
     internal const string FILESYSTEM_FOLDER_ID   = "Filesystem";
 
-    public static MediaContainer get_instance () {
+    public static MediaContainer get_instance () throws Error {
         if (RootContainer.instance == null) {
             try {
                 RootContainer.instance = new RootContainer ();
             } catch (Error error) {
-                warning (_("Failed to create instance of database"));
+                // cache error for further calls and create Null container
                 RootContainer.instance = new NullContainer ();
+                RootContainer.creation_error = error;
+            }
+        } else {
+            if (creation_error != null) {
+                throw creation_error;
             }
         }