Re: [PATCH] send-email: lazily assign editor variable

Junio C Hamano wrote:

We would want to describe what kind of problems they are better than "may
lead to problems", though.  Something like this?

    b4479f0 (add -i, send-email, svn, p4, etc: use "git var GIT_EDITOR",
    2009-10-30) introduced the use of "git var GIT_EDITOR" to obtain the
    preferred editor program, instead of reading environment variables
    themselves.

    However, "git var GIT_EDITOR" run without a tty (think "cron job") would
    give a fatal error "Terminal is dumb, but EDITOR unset".  This is not a
    problem for add-i, svn, p4 and callers of git_editor() defined in
    git-sh-setup, as all of these call it just before launching the editor.
    At that point, we know the caller wants to edit, and they cannot without a
    tty.

    But send-email ran this near the beginning of the program, even if it is
    not going to use any editor (e.g. run without --compose).  Fix this by
    calling the command only when we edit a file.

Yes, please.  It would be more precise to

  s/without a tty/with TERM=dumb/

in the second paragraph but regardless this is a good description of the
problem.