[MERGE] Improve error handling in msgeditor._run_editor.

[Matthew D. Fuller]

On Thu, Dec 18, 2008 at 10:53:14AM +1100 I heard the voice of
Andrew Bennetts, and lo! it spake thus:
>
>      for varname in 'VISUAL', 'EDITOR':
>          if varname in os.environ:
> -            yield os.environ[varname]
> +            yield os.environ[varname], '$VISUAL'
                                          ^^^^^^^^^

That can't be right...

(well, OK, it can.  But it can also be wrong :)


-- 
Matthew Fuller     (MF4839)   |  fullermd at over-yonder.net
Systems/Network Administrator |  http://www.over-yonder.net/~fullermd/
           On the Internet, nobody can hear you scream.