[gnome-color-manager] Handle a critical warning where there is no crtc for the output, although it's connected

[Richard Hughes <rhughes src gnome org>]

commit 833dd7b175e0fe8b32287de5adf5826f13391ad5
Author: Richard Hughes <richard hughsie com>
Date:   Thu Nov 5 12:01:55 2009 +0000

    Handle a critical warning where there is no crtc for the output, although it's connected

 src/gcm-utils.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/src/gcm-utils.c b/src/gcm-utils.c
index 4307da9..17b1df0 100644
--- a/src/gcm-utils.c
+++ b/src/gcm-utils.c
@@ -209,6 +209,12 @@ gcm_utils_set_gamma_for_device (GcmDevice *device, GError **error)
 
 	/* get crtc size */
 	crtc = gnome_rr_output_get_crtc (output);
+	if (crtc == NULL) {
+		if (error != NULL)
+			*error = g_error_new (1, 0, "failed to get crtc for device: %s", id);
+		goto out;
+	}
+
 	size = gcm_utils_get_gamma_size (crtc, error);
 	if (size == 0)
 		goto out;