lisp-mode-auto-fill

lisp-mode-auto-fill is an alias for `do-auto-fill' in `lisp-mode.el'.

(lisp-mode-auto-fill)

This function is obsolete since 23.1;
use `do-auto-fill' instead.

The default value for `normal-auto-fill-function'.
This is the default auto-fill function, some major modes use a different one.
Returns t if it really did any work.