* grub-core/normal/main.c (read_config_file): Provide config_file and

config_directory.
	* util/grub.d/41_custom.in: Use config_directoy when available.

util/grub.d/41_custom.in

@@ -1,6 +1,8 @@
 #!/bin/sh
 cat <<EOF
-if [ -f  \$prefix/custom.cfg ]; then
+if [ -f  \${config_directory}/custom.cfg ]; then
+  source \${config_directory}/custom.cfg
+elif [ -z "\${config_directory}" -a -f  \$prefix/custom.cfg ]; then
   source \$prefix/custom.cfg;
 fi
 EOF