More strict check for IBusPanelService.

chrome/browser/chromeos/input_method/ibus_controller_impl.cc

Index: chrome/browser/chromeos/input_method/ibus_controller_impl.cc
diff --git a/chrome/browser/chromeos/input_method/ibus_controller_impl.cc b/chrome/browser/chromeos/input_method/ibus_controller_impl.cc
index 266ab4c43089e4e3b1d608812f270bb67c44f218..d0c5092df69165ec7e5fbb0f1989f6482dc2a5c6 100644
--- a/chrome/browser/chromeos/input_method/ibus_controller_impl.cc
+++ b/chrome/browser/chromeos/input_method/ibus_controller_impl.cc
@@ -485,8 +485,12 @@ IBusControllerImpl::~IBusControllerImpl() {
         this);
 
     // Disconnect signals for the panel service as well.
-    IBusPanelService* ibus_panel_service = IBUS_PANEL_SERVICE(
-        g_object_get_data(G_OBJECT(ibus_), kPanelObjectKey));
+    void* attached_data = g_object_get_data(G_OBJECT(ibus_), kPanelObjectKey);

[Yusuke Sato, 2012/05/23 00:43:08]

please add a comment which explains when/why g_object_get_data returns null or
an invalid object.

[Seigo Nonaka, 2012/05/23 00:56:59]

I don't know why g_object_get_data fails. (I doubt "g_object_unref" but not not
sure.) I continue to investigate this issue. This fix is just temporally.
On 2012/05/23 00:43:08, Yusuke Sato wrote:

+    if (!attached_data)
+      return;
+    if (!G_TYPE_CHECK_INSTANCE_TYPE(attached_data, IBUS_TYPE_PANEL_SERVICE))
+      return;
+    IBusPanelService* ibus_panel_service = IBUS_PANEL_SERVICE(attached_data);
     if (ibus_panel_service) {
       g_signal_handlers_disconnect_by_func(
           ibus_panel_service,