merge with mainline

diff --cc util/grub-mkrescue.in
index cb20ec8d0ee9a148f3fec382915a3d8645477754,f8445a1e356322e27540155f4724a4efcf83687a..36cce31ecb3b57901ca491004aa2e748076cff0f
--- 1/util/grub-mkrescue.in
--- 2/util/grub-mkrescue.in
+++ b/util/grub-mkrescue.in
@@@ -51,14 -53,18 +53,18 @@@ Make GRUB rescue image
  
    -h, --help              print this message and exit
    -v, --version           print the version information and exit
 -  --output=FILE           save output in FILE [required]
 +  -o, --output=FILE       save output in FILE [required]
    --modules=MODULES       pre-load specified modules MODULES
    --rom-directory=DIR     save rom images in DIR [optional]
+   --xorriso=FILE          use FILE as xorriso [optional]
    --grub-mkimage=FILE     use FILE as grub-mkimage
  
- $self generates a bootable rescue image with specified source files or directories.
+ $self generates a bootable rescue image with specified source files, source
+ directories, or mkisofs options listed by: xorriso -as mkisofs -help
+ Option -- switches to native xorriso command mode. or directories.
  
  Report bugs to <bug-grub@gnu.org>.
+ Mail xorriso support requests to <bug-xorriso@gnu.org>.
  EOF
  }
  
@@@ -114,18 -89,12 +120,19 @@@ d
        PATH=${override_dir}:$PATH
        export PATH
        ;;
 +
 +    --grub-mkimage)
 +      grub_mkimage=`argument $option "$@"`; shift ;;
      --grub-mkimage=*)
        grub_mkimage=`echo "$option" | sed 's/--grub-mkimage=//'` ;;
-     -*)
-       echo "Unrecognized option \`$option'" 1>&2
-       usage
-       exit 1
-       ;;
++
++    --xorriso)
++      xorriso=`argument $option "$@"`; shift ;;
+     --xorriso=*)
+         xorriso=`echo "${option}/" | sed 's/--xorriso=//'` ;;
++
      *)
 -      source="${source} ${option}" ;;
 +      source="${source} ${option} $@"; break ;;
      esac
  done