Displays form token for unfiltered comments.

Will only display nonce token if the current user has permissions for
unfiltered html. Won’t display the token for other users.

The function was backported to 2.0.10 and was added to versions 2.1.3 and
above. Does not exist in versions prior to 2.0.10 in the 2.0 branch and in
the 2.1 branch, prior to 2.1.3. Technically added in 2.2.0.

Backported to 2.0.10.

function wp_comment_form_unfiltered_html_nonce() {
	$post    = get_post();
	$post_id = $post ? $post->ID : 0;

	if ( current_user_can( 'unfiltered_html' ) ) {
		wp_nonce_field( 'unfiltered-html-comment_' . $post_id, '_wp_unfiltered_html_comment_disabled', false );
		echo "n";
	}
}