Add theme_mod to disable Header Text as default

[grapplerulrich]

There is no way to disable the header text as default.

A trick would be to do something like this but then there is no default color.

function custom_header_setup() {
        add_theme_support( 'custom-header', array(
                'default-text-color' => 'blank',
        ) );
        set_theme_mod( $name, $value );
}
add_action( 'after_setup_theme', 'custom_header_setup' );`

I think this would follow up from https://core.trac.wordpress.org/ticket/18887

My idea would be

function display_header_text() {
        if ( ! current_theme_supports( 'custom-header', 'header-text' ) )
                return false;

        $header_text = get_theme_mod( 'header_text', get_theme_support( 'custom-header', 'display-header-text' ) );
        return $header_text;
}

Files that would need to be updated.
​https://github.com/WordPress/WordPress/blob/master/wp-admin/custom-header.php#L609
​https://github.com/WordPress/WordPress/blob/master/wp-includes/theme.php#L991
​https://github.com/WordPress/WordPress/blob/master/wp-includes/theme.php#L1407

[celloexpressions]

Let's see what a patch looks like here, keeping the Customizer in mind.

[melchoyce]

Closing per above convo in Slack