From d7447437dd1d2bc722a2bc746d9af2fb8b9a1a28 Mon Sep 17 00:00:00 2001
From: Richard Hughes <richard@hughsie.com>
Date: Fri, 25 Jul 2008 17:17:22 +0100
Subject: [PATCH] only suppy an id for devices supplying the system

---
 src/devkit-power-source.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/devkit-power-source.c b/src/devkit-power-source.c
index c94e632..b205f52 100644
--- a/src/devkit-power-source.c
+++ b/src/devkit-power-source.c
@@ -548,6 +548,10 @@ devkit_power_source_get_id (DevkitPowerSource *source)
 	GString *string;
 	gchar *id = NULL;
 
+        /* only valid for devices supplying the system */
+        if (!source->priv->power_supply)
+                return id;
+
         /* only valid for batteries */
         if (source->priv->type != DEVKIT_POWER_TYPE_BATTERY)
                 return id;