[folks] Always throw an error in async functions, to avoid breaking (C) API later.

[Travis Reitter <treitter src gnome org>]

commit 1a905f6b5a02c7dc4ec01cc51012a4722ba592bc
Author: Travis Reitter <travis reitter collabora co uk>
Date:   Mon Jul 26 17:58:36 2010 +0200

    Always throw an error in async functions, to avoid breaking (C) API later.

 folks/backend-store.vala         |    2 +-
 folks/individual-aggregator.vala |    6 +++---
 folks/persona-store.vala         |    2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/folks/backend-store.vala b/folks/backend-store.vala
index ad66a3a..f253dfa 100644
--- a/folks/backend-store.vala
+++ b/folks/backend-store.vala
@@ -72,7 +72,7 @@ public class Folks.BackendStore : Object {
    * environment variable, if it's set. If it's not set, backends will be
    * searched for in a path set at compilation time.
    */
-  public async void load_backends () {
+  public async void load_backends () throws GLib.Error {
       assert (Module.supported());
 
       var path = Environment.get_variable ("FOLKS_BACKEND_DIR");
diff --git a/folks/individual-aggregator.vala b/folks/individual-aggregator.vala
index fead467..1e9ab6e 100644
--- a/folks/individual-aggregator.vala
+++ b/folks/individual-aggregator.vala
@@ -117,7 +117,7 @@ public class Folks.IndividualAggregator : Object
    * condition could occur, with the signal being emitted before your code has
    * connected to them, and { link Individual}s getting "lost" as a result.
    */
-  public async void prepare ()
+  public async void prepare () throws GLib.Error
     {
       this.backend_store.load_backends ();
     }
@@ -315,7 +315,7 @@ public class Folks.IndividualAggregator : Object
    *
    * @param individual the { link Individual} to remove
    */
-  public async void remove_individual (Individual individual)
+  public async void remove_individual (Individual individual) throws GLib.Error
     {
       foreach (unowned Persona persona in individual.personas)
         yield persona.store.remove_persona (persona);
@@ -328,7 +328,7 @@ public class Folks.IndividualAggregator : Object
    *
    * @param persona the { link Persona} to remove
    */
-  public async void remove_persona (Persona persona)
+  public async void remove_persona (Persona persona) throws GLib.Error
     {
       yield persona.store.remove_persona (persona);
     }
diff --git a/folks/persona-store.vala b/folks/persona-store.vala
index 814b7b1..42df206 100644
--- a/folks/persona-store.vala
+++ b/folks/persona-store.vala
@@ -143,5 +143,5 @@ public abstract class Folks.PersonaStore : Object
    *
    * @param persona the { link Persona} to remove
    */
-  public abstract async void remove_persona (Persona persona);
+  public abstract async void remove_persona (Persona persona) throws GLib.Error;
 }