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

> 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.