Optional arg FILE-NAME specifies the file to use.
If FILE-NAME is nil, use the value of `change-log-default-name'.
-If `change-log-default-name' is nil, behave as though it were 'ChangeLog'
+If `change-log-default-name' is nil, behave as though it were \"ChangeLog\"
\(or whatever we use on this operating system).
If `change-log-default-name' contains a leading directory component, then