[libsecret] Fix null-pointer dereference

[Stefan Walter <stefw src gnome org>]

commit 258ef1b8b812ac5a7c5f0468b1fe5ab6a8f700a2
Author: Stef Walter <stefw gnome org>
Date:   Wed Jun 27 16:38:35 2012 +0200

    Fix null-pointer dereference
    
     * In the corner case where we don't know about a collection/item
       but receive the CollectionChanged or ItemChanged signal,
       fix use of a null pointer

 library/secret-collection.c |    6 ++++--
 library/secret-service.c    |    6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)
---
diff --git a/library/secret-collection.c b/library/secret-collection.c
index d088d5b..da5cade 100644
--- a/library/secret-collection.c
+++ b/library/secret-collection.c
@@ -507,8 +507,10 @@ secret_collection_signal (GDBusProxy *proxy,
 
 		g_mutex_unlock (&self->pv->mutex);
 
-		secret_item_refresh (item);
-		g_object_unref (item);
+		if (item) {
+			secret_item_refresh (item);
+			g_object_unref (item);
+		}
 	}
 
 	g_variant_unref (paths);
diff --git a/library/secret-service.c b/library/secret-service.c
index 971c940..9b82f3b 100644
--- a/library/secret-service.c
+++ b/library/secret-service.c
@@ -403,8 +403,10 @@ secret_service_signal (GDBusProxy *proxy,
 
 		g_mutex_unlock (&self->pv->mutex);
 
-		secret_collection_refresh (collection);
-		g_object_unref (collection);
+		if (collection) {
+			secret_collection_refresh (collection);
+			g_object_unref (collection);
+		}
 	}
 
 	g_variant_unref (paths);