Closing curlies are pulled up into comments

[cfuehrmann]

Consider the following kdl snippet:

xkb {
    // You can set rules, model, layout, variant and options.
    // For more information, see xkeyboard-config(7).

    // For example:
    // layout "us,ru"
    layout "de"
    variant "nodeadkeys"
    // options "grp:win_space_toggle,compose:ralt,ctrl:nocaps"
}

Applying parse followed by fmt followed by to_string yields this broken snippet:

xkb {
    // You can set rules, model, layout, variant and options.
    // For more information, see xkeyboard-config(7).
    // For example:
    // layout "us,ru"
    layout "de"
    variant "nodeadkeys"
// options "grp:win_space_toggle,compose:ralt,ctrl:nocaps"}

Note how the bracket got pulled into the comment line. (Also, a horizontal line got deleted and an indentation is wrong.)