Re: M-x grep: broken buffer with pipes

[Sam Steingold]

Juri Linkov wrote:
> > M-x grep RET 'defvar.*buffer' *.el | grep -v '"' RET
> > (the shell command is "grep -nH -e 'defvar.*buffer' *.el | grep -v '"'")
> > The *grep* buffer now contains (correctly) about 10% fewer matches, and
> > <file> and <line> are still good, but the <defvar foo-buffer> part is no
> > longer yellow.
>
> You can customize `grep-highlight-matches' to the value `always'
> if you are content with the problems it might cause like
> http://thread.gmane.org/gmane.emacs.devel/83316

this happens with "emacs -q".
i.e., the default value of this variable is incorrect.

indeed, when I customize this variable to nil, the problem goes away.

> > That lack of match highlighting is not a big deal, however, there is
> > a hugely more horrible problem: one cannot click on the file name to visit
> > the file.
> > When you click on the file name, the file selection menu appears, with the
> > default being ^[[K<file> where "^[" stands for the escape character (ESC
> > (27, #o33, #x1b)) and <file> is the file name you clicked on.
> > So, where do these 3 spurious characters (ESC [ K) come from?
>
> I guess these escape sequences come from the grep switch --color that
> outputs them around the matched strings.  However, I can't reproduce your
> problem.  When I click on the file name that lacks of match highlighting,
> it still visits the source file.  What grep version do you have?

grep (GNU grep) 2.5.1