bug#2397: 23.0.90; grep no longer highlights the match

[Juri Linkov <juri@jurta.org>]

>> Also please eval `M-x grep RET set RET'
>
> Sorry, I don't understand. That does nothing; it just exits with no matches
> found - there are no file arguments specified. And in which directory? With
> which `grep' switches? I don't follow.
>
>> and show the value of the environment variable `TERM'.

`M-x grep RET set RET' should print a list of grep environment variables
in a Unix-like shell instead of running a grep command.  But it seems
your shell where grep runs is not bash.  Perhaps this is the cause of
your problems.

> M-: (getenv "TERM) gives "dumb", both in emacs -Q and in my own environment
> (i.e., after loading the cywin libraries I mentioned).

It is normal that (getenv "TERM") gives "dumb".  More important is to see
the value of "TERM" in the grep environment.  Could you try some other
command instead of "grep" to see the value of "TERM" after running the
`grep' command?  For example, `M-x grep RET echo $TERM RET'.

-- 
Juri Linkov
http://www.jurta.org/emacs/