[brasero/gnome-2-28] Avoid in rare cases (using valgrind mostly) to set error twice for GIO operations

[Philippe Rouquier <philippr src gnome org>]

commit 27fc2fc854521602eb8776d006b7d731ab50b62b
Author: Philippe Rouquier <bonfire-app wanadoo fr>
Date:   Sat Oct 17 15:54:29 2009 +0200

    Avoid in rare cases (using valgrind mostly) to set error twice for GIO operations

 libbrasero-media/brasero-gio-operation.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/libbrasero-media/brasero-gio-operation.c b/libbrasero-media/brasero-gio-operation.c
index 340cfd3..a5cf69e 100644
--- a/libbrasero-media/brasero-gio-operation.c
+++ b/libbrasero-media/brasero-gio-operation.c
@@ -148,13 +148,14 @@ brasero_gio_operation_wait_for_operation_end (BraseroGioOperation *operation,
 			g_error_free (operation->error);
 			operation->error = NULL;
 		}
-		else if (error)
+		else if (error && (*error) == NULL)
 			g_propagate_error (error, operation->error);
 		else
 			g_error_free (operation->error);
 
 		operation->error = NULL;
 	}
+
 	g_cancellable_reset (operation->cancel);
 	g_object_unref (operation->cancel);