Set the alternate device ID, not the object itself

If the daemon either de-duplicates or replaces the object passed emitted from
device-added then the object set as the alternate may not be the same instance
as the daemon version. This causes weird things to happen.

To make this less fragile, specify the *ID* of the object that should be the
alternate device, which allows the daemon to do clever things, and then assign
the object from the ID as the last step.

Although fixing no bug, this makes implementing future functionality easier.

plugins/dell/fu-plugin-dell.c

@@ -737,7 +737,7 @@ fu_plugin_dell_detect_tpm (FuPlugin *plugin, GError **error)
 		fu_device_add_flag (dev_alt, FWUPD_DEVICE_FLAG_REQUIRE_AC);
 		fu_device_add_flag (dev_alt, FWUPD_DEVICE_FLAG_LOCKED);
 		fu_device_add_icon (dev_alt, "computer");
-		fu_device_set_alternate (dev_alt, dev);
+		fu_device_set_alternate_id (dev_alt, fu_device_get_id (dev));
 		fu_device_add_parent_guid (dev_alt, tpm_guid);
 
 		/* If TPM is not owned and at least 1 flash left allow mode switching

plugins/dell/fu-self-test.c

@@ -42,6 +42,11 @@ static void
 _plugin_device_added_cb (FuPlugin *plugin, FuDevice *device, gpointer user_data)
 {
 	GPtrArray *devices = (GPtrArray *) user_data;
+	if (fu_device_get_alternate_id (device) != NULL) {
+		FuDevice *device_alt = _find_device_by_id (devices, fu_device_get_alternate_id (device));
+		if (device_alt != NULL)
+			fu_device_set_alternate (device, device_alt);
+	}
 	g_ptr_array_add (devices, g_object_ref (device));
 }
 

src/fu-device-private.h

@@ -18,6 +18,8 @@ gboolean	 fu_device_has_parent_guid		(FuDevice	*device,
 guint		 fu_device_get_order			(FuDevice	*device);
 void		 fu_device_set_order			(FuDevice	*device,
 							 guint		 order);
+void		 fu_device_set_alternate		(FuDevice	*device,
+							 FuDevice	*alternate);
 
 G_END_DECLS
 

src/fu-device.c

@@ -26,6 +26,7 @@
 static void fu_device_finalize			 (GObject *object);
 
 typedef struct {
+	gchar				*alternate_id;
 	gchar				*equivalent_id;
 	FuDevice			*alternate;
 	FuDevice			*parent;	/* noref */
@@ -152,6 +153,44 @@ fu_device_set_equivalent_id (FuDevice *device, const gchar *equivalent_id)
 	priv->equivalent_id = g_strdup (equivalent_id);
 }
 
+/**
+ * fu_device_get_alternate:
+ * @device: A #FuDevice
+ *
+ * Gets any alternate device ID. An alternate device may be linked to the primary
+ * device in some way.
+ *
+ * Returns: (transfer none): a #FuDevice or %NULL
+ *
+ * Since: 1.0.9
+ **/
+const gchar *
+fu_device_get_alternate_id (FuDevice *device)
+{
+	FuDevicePrivate *priv = GET_PRIVATE (device);
+	g_return_val_if_fail (FU_IS_DEVICE (device), NULL);
+	return priv->alternate_id;
+}
+
+/**
+ * fu_device_set_alternate:
+ * @device: A #FuDevice
+ * @alternate: Another #FuDevice
+ *
+ * Sets any alternate device ID. An alternate device may be linked to the primary
+ * device in some way.
+ *
+ * Since: 1.0.9
+ **/
+void
+fu_device_set_alternate_id (FuDevice *device, const gchar *alternate_id)
+{
+	FuDevicePrivate *priv = GET_PRIVATE (device);
+	g_return_if_fail (FU_IS_DEVICE (device));
+	g_free (priv->alternate_id);
+	priv->alternate_id = g_strdup (alternate_id);
+}
+
 /**
  * fu_device_get_alternate:
  * @device: A #FuDevice
@@ -159,6 +198,10 @@ fu_device_set_equivalent_id (FuDevice *device, const gchar *equivalent_id)
  * Gets any alternate device. An alternate device may be linked to the primary
  * device in some way.
  *
+ * The alternate object will be matched from the ID set in fu_device_set_alternate_id()
+ * and will be assigned by the daemon. This means if the ID is not found as an
+ * added device, then this function will return %NULL.
+ *
  * Returns: (transfer none): a #FuDevice or %NULL
  *
  * Since: 0.7.2
@@ -179,6 +222,8 @@ fu_device_get_alternate (FuDevice *device)
  * Sets any alternate device. An alternate device may be linked to the primary
  * device in some way.
  *
+ * This function is only usable by the daemon, not directly from plugins.
+ *
  * Since: 0.7.2
  **/
 void
@@ -893,6 +938,8 @@ fu_device_to_string (FuDevice *device)
 	tmp = fwupd_device_to_string (FWUPD_DEVICE (device));
 	if (tmp != NULL && tmp[0] != '\0')
 		g_string_append (str, tmp);
+	if (priv->alternate_id != NULL)
+		fwupd_pad_kv_str (str, "AlternateId", priv->alternate_id);
 	if (priv->equivalent_id != NULL)
 		fwupd_pad_kv_str (str, "EquivalentId", priv->equivalent_id);
 	keys = g_hash_table_get_keys (priv->metadata);
@@ -1158,6 +1205,7 @@ fu_device_finalize (GObject *object)
 	g_hash_table_unref (priv->metadata);
 	g_ptr_array_unref (priv->children);
 	g_ptr_array_unref (priv->parent_guids);
+	g_free (priv->alternate_id);
 	g_free (priv->equivalent_id);
 
 	G_OBJECT_CLASS (fu_device_parent_class)->finalize (object);

src/fu-device.h

@@ -98,6 +98,9 @@ FuDevice	*fu_device_new				(void);
 
 /* accessors */
 gchar		*fu_device_to_string			(FuDevice	*device);
+const gchar	*fu_device_get_alternate_id		(FuDevice	*device);
+void		 fu_device_set_alternate_id		(FuDevice	*device,
+							 const gchar	*alternate_id);
 const gchar	*fu_device_get_equivalent_id		(FuDevice	*device);
 void		 fu_device_set_equivalent_id		(FuDevice	*device,
 							 const gchar	*equivalent_id);
@@ -105,8 +108,6 @@ void		 fu_device_add_guid			(FuDevice	*device,
 							 const gchar	*guid);
 gchar		*fu_device_get_guids_as_str		(FuDevice	*device);
 FuDevice	*fu_device_get_alternate		(FuDevice	*device);
-void		 fu_device_set_alternate		(FuDevice	*device,
-							 FuDevice	*alternate);
 FuDevice	*fu_device_get_parent			(FuDevice	*device);
 GPtrArray	*fu_device_get_children			(FuDevice	*device);
 void		 fu_device_add_child			(FuDevice	*device,

src/fu-engine.c

@@ -2891,6 +2891,16 @@ fu_engine_add_device (FuEngine *self, FuDevice *device)
 	/* adopt any required children, which may or may not already exist */
 	fu_engine_adopt_children (self, device);
 
+	/* set any alternate objects on the device from the ID */
+	if (fu_device_get_alternate_id (device) != NULL) {
+		FuDevice *device_alt;
+		device_alt = fu_device_list_get_by_id (self->device_list,
+						       fu_device_get_alternate_id (device),
+						       NULL);
+		if (device_alt != NULL)
+			fu_device_set_alternate (device, device_alt);
+	}
+
 	/* notify all plugins about this new device */
 	if (!fu_device_has_flag (device, FWUPD_DEVICE_FLAG_REGISTERED))
 		fu_engine_plugin_device_register (self, device);