http://codereview.appspot.com/5649054/diff/1/lily/stencil-expression.cc File lily/stencil-expression.cc (right): http://codereview.appspot.com/5649054/diff/1/lily/stencil-expression.cc#newco... lily/stencil-expression.cc:31: nargs = scm_permanent_object (scm_cons (scm_cons (ly_symbol2scm ("dummy"), SCM_EOL), SCM_EOL)); dummy? The whole stuff is totally incomprehensible. It is not clear what is stored where and for what reason, and there is no documentation whatsoever. It was bad before, agreed, but it has become much worse.