libnm-glib: NULL out priv fields on dispose()

In some situations, objects might get used after being disposed, so
clear out their various priv fields so we don't try to access unreffed
objects, freed strings, etc.

https://bugzilla.gnome.org/show_bug.cgi?id=674473

20 files changed, 98 insertions, 186 deletions

diff --git a/include/nm-glib-compat.h b/include/nm-glib-compat.h
index 30b83e0d5..e953f6ebc 100644
--- a/include/nm-glib-compat.h
+++ b/include/nm-glib-compat.h
@@ -42,6 +42,16 @@
 		g_simple_async_result_set_from_error (result, __error); \
 		g_error_free (__error); \
 	} G_STMT_END
+
+#define g_clear_object(object_ptr) \
+	G_STMT_START { \
+		GObject **__obj_p = object_ptr; \
+		if (*__obj_p) { \
+			g_object_unref (*__obj_p); \
+			*__obj_p = NULL; \
+		} \
+	} G_STMT_END
+
 #endif
 
 #endif  /* NM_GLIB_COMPAT_H */
diff --git a/libnm-glib/nm-access-point.c b/libnm-glib/nm-access-point.c
index a6218ed94..9c11c04d9 100644
--- a/libnm-glib/nm-access-point.c
+++ b/libnm-glib/nm-access-point.c
@@ -41,7 +41,6 @@ G_DEFINE_TYPE (NMAccessPoint, nm_access_point, NM_TYPE_OBJECT)
 #define NM_ACCESS_POINT_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_ACCESS_POINT, NMAccessPointPrivate))
 
 typedef struct {
-	gboolean disposed;
 	DBusGProxy *proxy;
 
 	NM80211ApFlags flags;
@@ -431,14 +430,7 @@ dispose (GObject *object)
 {
 	NMAccessPointPrivate *priv = NM_ACCESS_POINT_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_access_point_parent_class)->dispose (object);
-		return;
-	}
-
-	priv->disposed = TRUE;
-
-	g_object_unref (priv->proxy);
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_access_point_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-active-connection.c b/libnm-glib/nm-active-connection.c
index 81b1f0116..f170121b5 100644
--- a/libnm-glib/nm-active-connection.c
+++ b/libnm-glib/nm-active-connection.c
@@ -49,7 +49,6 @@ G_DEFINE_TYPE_WITH_CODE (NMActiveConnection, nm_active_connection, NM_TYPE_OBJEC
 #define NM_ACTIVE_CONNECTION_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_ACTIVE_CONNECTION, NMActiveConnectionPrivate))
 
 typedef struct {
-	gboolean disposed;
 	DBusGProxy *proxy;
 
 	char *connection;
@@ -357,18 +356,13 @@ dispose (GObject *object)
 {
 	NMActiveConnectionPrivate *priv = NM_ACTIVE_CONNECTION_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_active_connection_parent_class)->dispose (object);
-		return;
-	}
-
-	priv->disposed = TRUE;
-
 	if (priv->devices) {
 		g_ptr_array_foreach (priv->devices, (GFunc) g_object_unref, NULL);
 		g_ptr_array_free (priv->devices, TRUE);
+		priv->devices = NULL;
 	}
-	g_object_unref (priv->proxy);
+
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_active_connection_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-client.c b/libnm-glib/nm-client.c
index 781ce4c46..4a908e0f0 100644
--- a/libnm-glib/nm-client.c
+++ b/libnm-glib/nm-client.c
@@ -53,8 +53,6 @@ G_DEFINE_TYPE_WITH_CODE (NMClient, nm_client, NM_TYPE_OBJECT,
 #define NM_CLIENT_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_CLIENT, NMClientPrivate))
 
 typedef struct {
-	gboolean disposed;
-
 	DBusGProxy *client_proxy;
 	DBusGProxy *bus_proxy;
 	gboolean manager_running;
@@ -1517,24 +1515,23 @@ dispose (GObject *object)
 {
 	NMClientPrivate *priv = NM_CLIENT_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_client_parent_class)->dispose (object);
-		return;
-	}
-
-	if (priv->perm_call)
+	if (priv->perm_call) {
 		dbus_g_proxy_cancel_call (priv->client_proxy, priv->perm_call);
+		priv->perm_call = NULL;
+	}
 
-	g_object_unref (priv->client_proxy);
-	g_object_unref (priv->bus_proxy);
+	g_clear_object (&priv->client_proxy);
+	g_clear_object (&priv->bus_proxy);
 
 	free_object_array (&priv->devices);
 	dispose_and_free_object_array (&priv->active_connections);
 
 	g_slist_foreach (priv->pending_activations, (GFunc) activate_info_free, NULL);
 	g_slist_free (priv->pending_activations);
+	priv->pending_activations = NULL;
 
 	g_hash_table_destroy (priv->permissions);
+	priv->permissions = NULL;
 
 	G_OBJECT_CLASS (nm_client_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-device-bond.c b/libnm-glib/nm-device-bond.c
index 7d8bf578f..07ec4e8ec 100644
--- a/libnm-glib/nm-device-bond.c
+++ b/libnm-glib/nm-device-bond.c
@@ -215,10 +215,7 @@ dispose (GObject *object)
 {
 	NMDeviceBondPrivate *priv = NM_DEVICE_BOND_GET_PRIVATE (object);
 
-	if (priv->proxy) {
-		g_object_unref (priv->proxy);
-		priv->proxy = NULL;
-	}
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_device_bond_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-device-bt.c b/libnm-glib/nm-device-bt.c
index bd8ccd285..b175f37d4 100644
--- a/libnm-glib/nm-device-bt.c
+++ b/libnm-glib/nm-device-bt.c
@@ -42,8 +42,6 @@ typedef struct {
 	char *hw_address;
 	char *name;
 	guint32 bt_capabilities;
-
-	gboolean disposed;
 } NMDeviceBtPrivate;
 
 enum {
@@ -273,13 +271,7 @@ dispose (GObject *object)
 {
 	NMDeviceBtPrivate *priv = NM_DEVICE_BT_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_device_bt_parent_class)->dispose (object);
-		return;
-	}
-	priv->disposed = TRUE;
-
-	g_object_unref (priv->proxy);
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_device_bt_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-device-ethernet.c b/libnm-glib/nm-device-ethernet.c
index 2c35a977b..bc61b1fed 100644
--- a/libnm-glib/nm-device-ethernet.c
+++ b/libnm-glib/nm-device-ethernet.c
@@ -44,8 +44,6 @@ typedef struct {
 	char *perm_hw_address;
 	guint32 speed;
 	gboolean carrier;
-
-	gboolean disposed;
 } NMDeviceEthernetPrivate;
 
 enum {
@@ -280,14 +278,7 @@ dispose (GObject *object)
 {
 	NMDeviceEthernetPrivate *priv = NM_DEVICE_ETHERNET_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_device_ethernet_parent_class)->dispose (object);
-		return;
-	}
-
-	priv->disposed = TRUE;
-
-	g_object_unref (priv->proxy);
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_device_ethernet_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-device-infiniband.c b/libnm-glib/nm-device-infiniband.c
index 4f2882367..4dee29daf 100644
--- a/libnm-glib/nm-device-infiniband.c
+++ b/libnm-glib/nm-device-infiniband.c
@@ -224,10 +224,7 @@ dispose (GObject *object)
 {
 	NMDeviceInfinibandPrivate *priv = NM_DEVICE_INFINIBAND_GET_PRIVATE (object);
 
-	if (priv->proxy) {
-		g_object_unref (priv->proxy);
-		priv->proxy = NULL;
-	}
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_device_infiniband_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-device-modem.c b/libnm-glib/nm-device-modem.c
index 09b6df10b..40597bf3c 100644
--- a/libnm-glib/nm-device-modem.c
+++ b/libnm-glib/nm-device-modem.c
@@ -44,8 +44,6 @@ typedef struct {
 
 	NMDeviceModemCapabilities caps;
 	NMDeviceModemCapabilities current_caps;
-
-	gboolean disposed;
 } NMDeviceModemPrivate;
 
 enum {
@@ -225,14 +223,7 @@ dispose (GObject *object)
 {
 	NMDeviceModemPrivate *priv = NM_DEVICE_MODEM_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_device_modem_parent_class)->dispose (object);
-		return;
-	}
-
-	priv->disposed = TRUE;
-
-	g_object_unref (priv->proxy);
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_device_modem_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-device-olpc-mesh.c b/libnm-glib/nm-device-olpc-mesh.c
index 96e1c3619..9d14aa0b6 100644
--- a/libnm-glib/nm-device-olpc-mesh.c
+++ b/libnm-glib/nm-device-olpc-mesh.c
@@ -227,14 +227,8 @@ dispose (GObject *object)
 {
 	NMDeviceOlpcMeshPrivate *priv = NM_DEVICE_OLPC_MESH_GET_PRIVATE (object);
 
-	if (priv->companion) {
-		g_object_unref (priv->companion);
-		priv->companion = NULL;
-	}
-	if (priv->proxy) {
-		g_object_unref (priv->proxy);
-		priv->proxy = NULL;
-	}
+	g_clear_object (&priv->companion);
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_device_olpc_mesh_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-device-vlan.c b/libnm-glib/nm-device-vlan.c
index 7ebc8dd5c..6ff729276 100644
--- a/libnm-glib/nm-device-vlan.c
+++ b/libnm-glib/nm-device-vlan.c
@@ -238,10 +238,7 @@ dispose (GObject *object)
 {
 	NMDeviceVlanPrivate *priv = NM_DEVICE_VLAN_GET_PRIVATE (object);
 
-	if (priv->proxy) {
-		g_object_unref (priv->proxy);
-		priv->proxy = NULL;
-	}
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_device_vlan_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-device-wifi.c b/libnm-glib/nm-device-wifi.c
index aba43f99f..01f0468c3 100644
--- a/libnm-glib/nm-device-wifi.c
+++ b/libnm-glib/nm-device-wifi.c
@@ -43,7 +43,6 @@ G_DEFINE_TYPE (NMDeviceWifi, nm_device_wifi, NM_TYPE_DEVICE)
 void _nm_device_wifi_set_wireless_enabled (NMDeviceWifi *device, gboolean enabled);
 
 typedef struct {
-	gboolean disposed;
 	DBusGProxy *proxy;
 
 	char *hw_address;
@@ -608,15 +607,8 @@ dispose (GObject *object)
 {
 	NMDeviceWifiPrivate *priv = NM_DEVICE_WIFI_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_device_wifi_parent_class)->dispose (object);
-		return;
-	}
-
-	priv->disposed = TRUE;
-
 	clean_up_aps (NM_DEVICE_WIFI (object), FALSE);
-	g_object_unref (priv->proxy);
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_device_wifi_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-device-wimax.c b/libnm-glib/nm-device-wimax.c
index e49b4f31a..de99b7c16 100644
--- a/libnm-glib/nm-device-wimax.c
+++ b/libnm-glib/nm-device-wimax.c
@@ -42,7 +42,6 @@ G_DEFINE_TYPE (NMDeviceWimax, nm_device_wimax, NM_TYPE_DEVICE)
 void _nm_device_wimax_set_wireless_enabled (NMDeviceWimax *wimax, gboolean enabled);
 
 typedef struct {
-	gboolean disposed;
 	DBusGProxy *proxy;
 
 	char *hw_address;
@@ -593,18 +592,18 @@ dispose (GObject *object)
 {
 	NMDeviceWimaxPrivate *priv = NM_DEVICE_WIMAX_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_device_wimax_parent_class)->dispose (object);
-		return;
+	if (priv->hw_address) {
+		g_free (priv->hw_address);
+		priv->hw_address = NULL;
 	}
 
-	priv->disposed = TRUE;
-
-	g_free (priv->hw_address);
-	g_free (priv->bsid);
+	if (priv->bsid) {
+		g_free (priv->bsid);
+		priv->bsid = NULL;
+	}
 
 	clean_up_nsps (NM_DEVICE_WIMAX (object), FALSE);
-	g_object_unref (priv->proxy);
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_device_wimax_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-device.c b/libnm-glib/nm-device.c
index a8a63382d..5346b9d84 100644
--- a/libnm-glib/nm-device.c
+++ b/libnm-glib/nm-device.c
@@ -60,7 +60,6 @@ G_DEFINE_TYPE_WITH_CODE (NMDevice, nm_device, NM_TYPE_OBJECT,
 #define NM_DEVICE_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_DEVICE, NMDevicePrivate))
 
 typedef struct {
-	gboolean disposed;
 	DBusGProxy *proxy;
 
 	char *iface;
@@ -265,26 +264,13 @@ dispose (GObject *object)
 {
 	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_device_parent_class)->dispose (object);
-		return;
-	}
-
-	priv->disposed = TRUE;
-
-	g_object_unref (priv->proxy);
-	if (priv->ip4_config)
-		g_object_unref (priv->ip4_config);
-	if (priv->dhcp4_config)
-		g_object_unref (priv->dhcp4_config);
-	if (priv->ip6_config)
-		g_object_unref (priv->ip6_config);
-	if (priv->dhcp6_config)
-		g_object_unref (priv->dhcp6_config);
-	if (priv->client)
-		g_object_unref (priv->client);
-	if (priv->active_connection)
-		g_object_unref (priv->active_connection);
+	g_clear_object (&priv->proxy);
+	g_clear_object (&priv->ip4_config);
+	g_clear_object (&priv->dhcp4_config);
+	g_clear_object (&priv->ip6_config);
+	g_clear_object (&priv->dhcp6_config);
+	g_clear_object (&priv->client);
+	g_clear_object (&priv->active_connection);
 
 	G_OBJECT_CLASS (nm_device_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-object.c b/libnm-glib/nm-object.c
index 43f5dec71..e333f9f41 100644
--- a/libnm-glib/nm-object.c
+++ b/libnm-glib/nm-object.c
@@ -78,7 +78,7 @@ typedef struct {
 
 	GSList *notify_props;
 	guint32 notify_id;
-	gboolean inited, disposed;
+	gboolean inited;
 
 	GSList *reload_results;
 	guint reload_remaining;
@@ -194,13 +194,6 @@ dispose (GObject *object)
 {
 	NMObjectPrivate *priv = NM_OBJECT_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_object_parent_class)->dispose (object);
-		return;
-	}
-
-	priv->disposed = TRUE;
-
 	if (priv->notify_id) {
 		g_source_remove (priv->notify_id);
 		priv->notify_id = 0;
@@ -208,12 +201,18 @@ dispose (GObject *object)
 
 	g_slist_foreach (priv->notify_props, (GFunc) g_free, NULL);
 	g_slist_free (priv->notify_props);
+	priv->notify_props = NULL;
 
 	g_slist_foreach (priv->property_interfaces, (GFunc) g_free, NULL);
 	g_slist_free (priv->property_interfaces);
+	priv->property_interfaces = NULL;
+
+	g_clear_object (&priv->properties_proxy);
 
-	g_object_unref (priv->properties_proxy);
-	dbus_g_connection_unref (priv->connection);
+	if (priv->connection) {
+		dbus_g_connection_unref (priv->connection);
+		priv->connection = NULL;
+	}
 
 	G_OBJECT_CLASS (nm_object_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-remote-connection.c b/libnm-glib/nm-remote-connection.c
index c5e386439..e8b99dff9 100644
--- a/libnm-glib/nm-remote-connection.c
+++ b/libnm-glib/nm-remote-connection.c
@@ -72,7 +72,6 @@ typedef struct {
 	GSList *calls;
 
 	gboolean visible;
-	gboolean disposed;
 } NMRemoteConnectionPrivate;
 
 #define NM_REMOTE_CONNECTION_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_REMOTE_CONNECTION, NMRemoteConnectionPrivate))
@@ -477,14 +476,14 @@ dispose (GObject *object)
 	NMRemoteConnection *self = NM_REMOTE_CONNECTION (object);
 	NMRemoteConnectionPrivate *priv = NM_REMOTE_CONNECTION_GET_PRIVATE (object);
 
-	if (!priv->disposed) {
-		priv->disposed = TRUE;
+	while (g_slist_length (priv->calls))
+		remote_call_complete (self, priv->calls->data);
 
-		while (g_slist_length (priv->calls))
-			remote_call_complete (self, priv->calls->data);
+	g_clear_object (&priv->proxy);
 
-		g_object_unref (priv->proxy);
+	if (priv->bus) {
 		dbus_g_connection_unref (priv->bus);
+		priv->bus = NULL;
 	}
 
 	G_OBJECT_CLASS (nm_remote_connection_parent_class)->dispose (object);
diff --git a/libnm-glib/nm-remote-settings.c b/libnm-glib/nm-remote-settings.c
index 040d9126a..19d865c06 100644
--- a/libnm-glib/nm-remote-settings.c
+++ b/libnm-glib/nm-remote-settings.c
@@ -61,8 +61,6 @@ typedef struct {
 	DBusGProxy *dbus_proxy;
 
 	guint fetch_id;
-
-	gboolean disposed;
 } NMRemoteSettingsPrivate;
 
 enum {
@@ -1043,29 +1041,35 @@ dispose (GObject *object)
 	NMRemoteSettings *self = NM_REMOTE_SETTINGS (object);
 	NMRemoteSettingsPrivate *priv = NM_REMOTE_SETTINGS_GET_PRIVATE (self);
 
-	if (priv->disposed)
-		return;
-
-	priv->disposed = TRUE;
-
-	if (priv->fetch_id)
+	if (priv->fetch_id) {
 		g_source_remove (priv->fetch_id);
+		priv->fetch_id = 0;
+	}
 
 	while (g_slist_length (priv->add_list))
 		add_connection_info_dispose (self, (AddConnectionInfo *) priv->add_list->data);
 
-	if (priv->connections)
+	if (priv->connections) {
 		g_hash_table_destroy (priv->connections);
+		priv->connections = NULL;
+	}
 
-	if (priv->pending)
+	if (priv->pending) {
 		g_hash_table_destroy (priv->pending);
+		priv->pending = NULL;
+	}
 
 	g_free (priv->hostname);
+	priv->hostname = NULL;
 
-	g_object_unref (priv->dbus_proxy);
-	g_object_unref (priv->proxy);
-	g_object_unref (priv->props_proxy);
-	dbus_g_connection_unref (priv->bus);
+	g_clear_object (&priv->dbus_proxy);
+	g_clear_object (&priv->proxy);
+	g_clear_object (&priv->props_proxy);
+
+	if (priv->bus) {
+		dbus_g_connection_unref (priv->bus);
+		priv->bus = NULL;
+	}
 
 	G_OBJECT_CLASS (nm_remote_settings_parent_class)->dispose (object);
 }
diff --git a/libnm-glib/nm-secret-agent.c b/libnm-glib/nm-secret-agent.c
index 19f55c0e2..02f7419b9 100644
--- a/libnm-glib/nm-secret-agent.c
+++ b/libnm-glib/nm-secret-agent.c
@@ -79,8 +79,6 @@ typedef struct {
 	gboolean auto_register;
 	gboolean suppress_auto;
 	gboolean auto_register_id;
-
-	gboolean disposed;
 } NMSecretAgentPrivate;
 
 enum {
@@ -878,29 +876,28 @@ dispose (GObject *object)
 	NMSecretAgent *self = NM_SECRET_AGENT (object);
 	NMSecretAgentPrivate *priv = NM_SECRET_AGENT_GET_PRIVATE (self);
 
-	if (!priv->disposed) {
-		priv->disposed = TRUE;
-
-		if (priv->registered)
-			nm_secret_agent_unregister (self);
-
-		if (priv->auto_register_id)
-			g_source_remove (priv->auto_register_id);
+	if (priv->registered)
+		nm_secret_agent_unregister (self);
 
-		g_free (priv->identifier);
-		g_free (priv->nm_owner);
+	if (priv->auto_register_id) {
+		g_source_remove (priv->auto_register_id);
+		priv->auto_register_id = 0;
+	}
 
-		while (priv->pending_gets)
-			get_secrets_info_finalize (self, priv->pending_gets->data);
+	g_free (priv->identifier);
+	priv->identifier = NULL;
+	g_free (priv->nm_owner);
+	priv->nm_owner = NULL;
 
-		if (priv->dbus_proxy)
-			g_object_unref (priv->dbus_proxy);
+	while (priv->pending_gets)
+		get_secrets_info_finalize (self, priv->pending_gets->data);
 
-		if (priv->manager_proxy)
-			g_object_unref (priv->manager_proxy);
+	g_clear_object (&priv->dbus_proxy);
+	g_clear_object (&priv->manager_proxy);
 
-		if (priv->bus)
-			dbus_g_connection_unref (priv->bus);
+	if (priv->bus) {
+		dbus_g_connection_unref (priv->bus);
+		priv->bus = NULL;
 	}
 
 	G_OBJECT_CLASS (nm_secret_agent_parent_class)->dispose (object);
diff --git a/libnm-glib/nm-vpn-plugin.c b/libnm-glib/nm-vpn-plugin.c
index 23685384a..2de3e9fea 100644
--- a/libnm-glib/nm-vpn-plugin.c
+++ b/libnm-glib/nm-vpn-plugin.c
@@ -63,9 +63,6 @@ typedef struct {
 	DBusGConnection *connection;
 	char *dbus_service_name;
 
-	/* GObject-y stuff */
-	gboolean disposed;
-
 	/* Temporary stuff */
 	guint connect_timer;
 	guint quit_timer;
@@ -590,15 +587,10 @@ dispose (GObject *object)
 	NMVPNServiceState state;
 	GError *err = NULL;
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_vpn_plugin_parent_class)->dispose (object);
-		return;
-	}
-
-	priv->disposed = TRUE;
-
-	if (priv->fail_stop_id)
+	if (priv->fail_stop_id) {
 		g_source_remove (priv->fail_stop_id);
+		priv->fail_stop_id = 0;
+	}
 
 	state = nm_vpn_plugin_get_state (plugin);
 
diff --git a/libnm-glib/nm-wimax-nsp.c b/libnm-glib/nm-wimax-nsp.c
index 39553ced1..980f7ced5 100644
--- a/libnm-glib/nm-wimax-nsp.c
+++ b/libnm-glib/nm-wimax-nsp.c
@@ -37,7 +37,6 @@ G_DEFINE_TYPE (NMWimaxNsp, nm_wimax_nsp, NM_TYPE_OBJECT)
 #define NM_WIMAX_NSP_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_WIMAX_NSP, NMWimaxNspPrivate))
 
 typedef struct {
-	gboolean disposed;
 	DBusGProxy *proxy;
 
 	char *name;
@@ -217,14 +216,7 @@ dispose (GObject *object)
 {
 	NMWimaxNspPrivate *priv = NM_WIMAX_NSP_GET_PRIVATE (object);
 
-	if (priv->disposed) {
-		G_OBJECT_CLASS (nm_wimax_nsp_parent_class)->dispose (object);
-		return;
-	}
-
-	priv->disposed = TRUE;
-
-	g_object_unref (priv->proxy);
+	g_clear_object (&priv->proxy);
 
 	G_OBJECT_CLASS (nm_wimax_nsp_parent_class)->dispose (object);
 }