bug#23590: 25.0.94; Errors in default lgrep command

[Eli Zaretskii]

> Date: Sat, 23 Jul 2016 21:00:37 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: john.b.mastro@gmail.com, 23590@debbugs.gnu.org
> 
> > Grep exited abnormally with code 2 at ...
> 
> Because of this:
> 
> > grep: ..?*: No such file or directory

Actually, I see that "Is a directory" also caused exit code of 2.  So
I guess patches are welcome to add --directory=skip to the Grep
command when a preliminary test reveals that Grep supports it.