[gnome-color-manager] Don't crash when we click on a PPD virtual profile

[Richard Hughes <rhughes src gnome org>]

commit 01fb1f3e325b7bf04dc10ff14fff48ccc060d68a
Author: Richard Hughes <richard hughsie com>
Date:   Tue May 10 02:44:41 2011 +0100

    Don't crash when we click on a PPD virtual profile

 src/gcm-profile.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/src/gcm-profile.c b/src/gcm-profile.c
index 2459451..c4e40ca 100644
--- a/src/gcm-profile.c
+++ b/src/gcm-profile.c
@@ -1303,6 +1303,10 @@ gcm_profile_generate_vcgt (GcmProfile *profile, guint size)
 	cmsFloat32Number in;
 	guint i;
 
+	/* not an actual profile */
+	if (priv->lcms_profile == NULL)
+		goto out;
+
 	/* get tone curves from profile */
 	vcgt = cmsReadTag (priv->lcms_profile, cmsSigVcgtType);
 	if (vcgt == NULL || vcgt[0] == NULL) {