CP-17631: Don't use a default QEMU keymap

[simonjbeaumont]

Until now we have been defaulting the keymap to en-us but this
prevents VNC clients from using the QEMU ExtendedKeyEvent extension for
passing raw scan codes.

If a keymap is not passed to QEMU, it will default to using en-us
anyway but will enable the ExtendedKeyEvent extension.

This does not change the behaviour for when a keymap has actually been
specified. In this case, it is still honoured and passed to QEMU with
the -k option.

Signed-off-by: Si Beaumont simon.beaumont@citrix.com

[simonjbeaumont]

Depends on xapi-project/xen-api#2676

[euanh]

Please define a type synonym for bytes list to make this signature read a bit more easily. For example:

type params = bytes list
let cmdline_of_disp info =
   let combine_opts : params option list -> params = fun opts ->
   ...

[simonjbeaumont]

This is moot if I do what you asked in #272 (diff)

[euanh]

You can get the same effect without needing the combine_opts function:

let vnc_opts_of ip_addr_opt auto port keymap =
    let ip_addr = Opt.default "127.0.0.1" ip_addr_opt in
    let port = if auto then "1" else string_of_int port in
    let unused_opt = if auto then ["-vncunused"] else [] in
    let vnc_opt = ["-vnc"; ip_addr ^ ":" ^ port] in
    let keymap_opt = ["-k"; keymap] in
    List.flatten [unused_opt; vnc_opt; keymap_opt]

You should be able to make similar changes in other functions which are using combine_opts.

[simonjbeaumont]

Good point. I'll do this, and for the vga opts too.

[simonjbeaumont]

@euanh I think I've resolved all the style problems. Removing the "needs updating" and "reviewed" labels. Can you confirm you're happy (or otherwise)?

[euanh]