mh-write-file-functions

mh-write-file-functions is a Lisp macro in `mh-compat.el'.

(mh-write-file-functions)

Return `write-file-functions' if it exists.
Otherwise return `local-write-file-hooks'.
This macro exists purely for compatibility. The former symbol is used
in Emacs 22 onward while the latter is used in previous versions and
XEmacs.