[grilo] core: Fix double-free protection assert when unloading a plugin twice

[Juan A. Suarez Romero <jasuarez src gnome org>]

commit 1c2a33adb18d25b9214c3a9859e72bf3bc01af0d
Author: Mike Ruprecht <mike ruprecht collabora co uk>
Date:   Thu Feb 21 15:39:28 2013 -0600

    core: Fix double-free protection assert when unloading a plugin twice
    
    When calling g_module_close() twice on the same module, it throws a
    g_return_if_fail() assertion stating ref_count > 0 fails. It's
    effectively like g_object_unref().
    
    This patch prevents g_module_close() being called twice on the same
    module by unsetting it from the plugin instance when closing it
    in grl_registry_unload_plugin().
    
    https://bugzilla.gnome.org/show_bug.cgi?id=694390

 src/grl-registry.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/grl-registry.c b/src/grl-registry.c
index e9d7e04..bab4d70 100644
--- a/src/grl-registry.c
+++ b/src/grl-registry.c
@@ -1227,6 +1227,7 @@ grl_registry_unload_plugin (GrlRegistry *registry,
 
   if (grl_plugin_get_module (plugin)) {
       g_module_close (grl_plugin_get_module (plugin));
+      grl_plugin_set_module (plugin, NULL);
   }
 
   return TRUE;