--- quake1-data-2.40.ebuild-orig	2006-06-21 17:38:08.000000000 +0100
+++ quake1-data-2.40.ebuild	2006-06-21 17:47:39.000000000 +0100
@@ -20,6 +20,12 @@
 
 pkg_setup() {
 	games_pkg_setup
+
+	if built_with_use "games-fps/quake1-demodata" symlink ; then
+		eerror "The symlink for the demo data conflicts with the cdinstall data"
+		die "Unmerge games-fps/quake1-demodata to remove the conflict"
+	fi
+
 	export CDROM_SET_NAMES=("Existing Install" "Quake CD" "Ultimate Quake Collection")
 	cdrom_get_cds id1:q101_int.1:Setup/ID1
 }