[gnome-color-manager] Do not crash if gcm_libusb_pollfd_remove_all() is called without assigning a device

[Richard Hughes <rhughes src gnome org>]

commit 3385cd1c06bcf9d9dc40cd21737efa022d9c5106
Author: Richard Hughes <richard hughsie com>
Date:   Tue Jul 27 11:05:38 2010 +0100

    Do not crash if gcm_libusb_pollfd_remove_all() is called without assigning a device

 libcolor-glib/gcm-common.c |    2 +-
 libcolor-glib/gcm-usb.c    |    9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)
---
diff --git a/libcolor-glib/gcm-common.c b/libcolor-glib/gcm-common.c
index c90f15a..163521f 100644
--- a/libcolor-glib/gcm-common.c
+++ b/libcolor-glib/gcm-common.c
@@ -170,7 +170,7 @@ gcm_mat33_set_identity (GcmMat3x3 *src)
 void
 gcm_mat33_vector_multiply (const GcmMat3x3 *mat_src, const GcmVec3 *vec_src, GcmVec3 *vec_dest)
 {
-	g_return_if_fail (vec_src != vec_src);
+	g_return_if_fail (vec_src != vec_dest);
 	vec_dest->v0 = mat_src->m00 * vec_src->v0 +
 		       mat_src->m01 * vec_src->v1 +
 		       mat_src->m02 * vec_src->v2;
diff --git a/libcolor-glib/gcm-usb.c b/libcolor-glib/gcm-usb.c
index c536444..b5a628f 100644
--- a/libcolor-glib/gcm-usb.c
+++ b/libcolor-glib/gcm-usb.c
@@ -146,9 +146,16 @@ gcm_libusb_pollfd_remove_all (GcmUsb *usb)
 {
 	GcmUsbSource *source = usb->priv->source;
 	GPollFD *pollfd;
-	GSList *elem = source->pollfds;
+	GSList *elem;
+
+	/* never connected */
+	if (source == NULL) {
+		egg_debug ("never attached to a context");
+		return;
+	}
 
 	/* nothing to see here, move along */
+	elem = source->pollfds;
 	if (elem == NULL)
 		return;