[banshee] ServiceManager: check properly if a service is required (bgo#626659)

[Bertrand Lorentz <blorentz src gnome org>]

commit 77768e908843138977e7ae65a62cc873cf857448
Author: Andres G. Aragoneses <knocte gmail com>
Date:   Sun May 20 23:50:16 2012 +0100

    ServiceManager: check properly if a service is required (bgo#626659)
    
    There was infrastructure already in Banshee to determine if certain
    service initialized could be ignored or not: services which are
    fundamental to properly run Banshee where just marked with the
    interface IRequiredService. However the check for this was wrong,
    as it tried to check the type of the service instance, rather than
    the service type; then, the instance would be null if it couldn't
    be initialized, and a null value apparently cannot behave as we
    want when used with the 'is' operator.
    
    The check now is done against the type of the service that needs
    to be initialized, rather than the instance resultant of the
    initialization.
    
    This bug was causing fatal errors to be ignored and allowing the
    resuming of Banshee launch, which in the end caused other kind
    of exceptions unrelated to the root cause (i.e. NREs when the
    database file is locked or gets corrupted).
    
    Signed-off-by: Bertrand Lorentz <bertrand lorentz gmail com>

 .../Banshee.ServiceStack/ServiceManager.cs         |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/Core/Banshee.Services/Banshee.ServiceStack/ServiceManager.cs b/src/Core/Banshee.Services/Banshee.ServiceStack/ServiceManager.cs
index 374897c..5b54f69 100644
--- a/src/Core/Banshee.Services/Banshee.ServiceStack/ServiceManager.cs
+++ b/src/Core/Banshee.Services/Banshee.ServiceStack/ServiceManager.cs
@@ -181,7 +181,7 @@ namespace Banshee.ServiceStack
 
                 return service;
             } catch (Exception e) {
-                if (service is IRequiredService) {
+                if (typeof (IRequiredService).IsAssignableFrom (type)) {
                     Log.ErrorFormat ("Error initializing required service {0}",
                             service == null ? type.ToString () : service.ServiceName, false);
                     throw;