def make_pass_decorator(object_type, ensure=False):
    """Given an object type this creates a decorator that will work
    similar to :func:`pass_obj` but instead of passing the object of the
    current context, it will find the innermost context of type
    :func:`object_type`.

    This generates a decorator that works roughly like this::

        from functools import update_wrapper

        def decorator(f):
            @pass_context
            def new_func(ctx, *args, **kwargs):
                obj = ctx.find_object(object_type)
                return ctx.invoke(f, obj, *args, **kwargs)
            return update_wrapper(new_func, f)
        return decorator

    :param object_type: the type of the object to pass.
    :param ensure: if set to `True`, a new object will be created and
                   remembered on the context if it's not there yet.
    """
    def decorator(f):
        def new_func(*args, **kwargs):
            ctx = get_current_context()
            if ensure:
                obj = ctx.ensure_object(object_type)
            else:
                obj = ctx.find_object(object_type)
            if obj is None:
                raise RuntimeError('Managed to invoke callback without a '
                                   'context object of type %r existing'
                                   % object_type.__name__)
            return ctx.invoke(f, obj, *args, **kwargs)
        return update_wrapper(new_func, f)
    return decorator