Question

How to make Emacs to indent cases like this

switch ($foo) {
    case "foo":
        $foo .= " bar";
        break
    case "bar":
        $foo .= " baz";
        break
    default:
        $foo .= " undefined";
}

instead of

switch ($foo) {
case "foo":
    $foo .= " bar";
    break
case "bar":
    $foo .= " baz";
    break
default:
    $foo .= " undefined";
}

Answer 1

You need to add something like this to your .emacs (either as a general setting or for the specific programming modes you care about):

;; set this in all c-based programming modes
(add-hook 'c-mode-common-hook
          (lambda ()
             (c-set-offset 'case-label '+)))

to add this to another mode, use the same pattern above with the relevant mode name substituted in for the hook, e.g.: <mode-name>-hook.