Re: Optional argument for `file-local-copy'

[Eli Zaretskii]

> From: Michael Albinus <address@hidden>
> Date: Sat, 29 Nov 2014 12:29:21 +0100
> 
> file-local-copy is a compiled Lisp function in `files.el'.
> 
> (file-local-copy FILE &optional REUSE-IF-ALREADY-EXISTS)
> 
> Copy the file FILE into a temporary file on this machine.
> Returns the name of the local copy, or nil, if FILE is directly
> accessible.
> 
> If REUSE-IF-ALREADY-EXISTS is non-nil, if there exists already a local
> copy of FILE, and if the file attributes of FILE have not been changed
> since the last copy operation, the name of the existing local copy of
> FILE will be returned.

"If" within another "if" is considered harmful.  Suggested rewording:

  REUSE-IF-ALREADY-EXISTS non-nil means return the name of an existing
  local copy of FILE, if FILE's file attributes didn't change since
  the last copy operation.

(I have no opinion on the rest of your proposal.)