parse_isolinux: Support grub menuentry shortcuts for UEFI boot menus.

Closes: #798908
Backport from unstable.

debian/changelog

@@ -12,6 +12,8 @@ debian-cd (3.1.17-jessie) UNRELEASED; urgency=medium
     + tools/boot/jessie/boot-arm: Add kernels and other bits to
       armel/armhf images
     + Check for file size on update CD/DVD generation
+    + parse_isolinux: Support grub menuentry shortcuts for UEFI boot menus.
+      Closes: #798908
 
  -- Steve McIntyre <93sam@debian.org>  Mon, 20 Apr 2015 12:36:57 +0100
 

tools/boot/jessie/parse_isolinux

@@ -69,13 +69,17 @@ sub print_kernel {
     my $t = shift;
     my %k = %{$t};
     my $initrd;
+    my $hotkey = "";
 
+    if ($k{"label"} =~ m,\^(\S),) {
+	$hotkey = lc "--hotkey=$1 ";
 	$k{"label"} =~ s/\^//;
+    }
     if ($k{"append"} =~ s? (initrd=\S+)??) {
 	$initrd = $1;
 	$initrd =~ s?^.*initrd=??;
     }
-    print_indent "menuentry '$pre" . $k{"label"} . "' {\n";
+    print_indent "menuentry $hotkey'$pre" . $k{"label"} . "' {\n";
     print_indent "    set background_color=black\n";
     print_indent "    linux    " . $k{"kernel"} . " " . $k{"append"} . "\n";
     print_indent "    initrd   $initrd\n";