eval.c:6724
static void
scope_dup(scope)
    struct SCOPE *scope;
{
    ID *tbl;
    VALUE *vars;

    scope->flags |= SCOPE_DONT_RECYCLE;
    if (scope->flags & SCOPE_MALLOC) return;

    if (scope->local_tbl) {
	tbl = scope->local_tbl;
	vars = ALLOC_N(VALUE, tbl[0]+1);
	*vars++ = scope->local_vars[-1];
	MEMCPY(vars, scope->local_vars, VALUE, tbl[0]);
	scope->local_vars = vars;
	scope->flags |= SCOPE_MALLOC;
    }
}
