unknown file I/O primitive: file-acl

[Harry Putnam]

M-x version
GNU Emacs 24.4.50.1 (i686-pc-linux-gnu, GTK+ Version 3.10.7)
of 2014-04-13 on reader

I get this problem when using a user emacs to open files as root.

That is, logged in as user but opening files as root thru tramp.

C-x c-f /address@hidden:/etc/exim4/exim4.conf.template

(PS -  seems to default to su - to get root)

Ok, make my edit and attempt to save with C-x C-s, but get this
warning /error or whatever it is:

tramp-file-name-for-operation: \
       unknown file I/O primitive: file-acl

And am unable to save the file.

Has this already been fixed? ... I haven't `pulled' for a couple of
weeks.

I got reams of bunkem googling on this, but not an easy job to tell
what has happened, if anything on this problem.

-------       -------       ---=---       -------       -------

Backtrace:
Debugger entered--Lisp error: (error "unknown file I/O primitive: file-acl")
  signal(error ("unknown file I/O primitive: file-acl"))
  error("unknown file I/O primitive: %s" file-acl)
  tramp-file-name-for-operation(file-acl 
"/su:address@hidden:/etc/exim4/exim4.conf.template")
  apply(tramp-file-name-for-operation file-acl 
"/su:address@hidden:/etc/exim4/exim4.conf.template")
  tramp-file-name-handler(file-acl 
"/su:address@hidden:/etc/exim4/exim4.conf.template")
  file-acl("/su:address@hidden:/etc/exim4/exim4.conf.template")
  file-extended-attributes("/su:address@hidden:/etc/exim4/exim4.conf.template")

[...] snipped byte code

  backup-buffer()
  basic-save-buffer-2()
  basic-save-buffer-1()
  basic-save-buffer()
  save-buffer(1)
  call-interactively(save-buffer nil nil)
  command-execute(save-buffer)