bug#30525: Unexpected matches for input data from a patch file

[Paul Eggert]

SF Markus Elfring wrote:

> Which test result do you get for the command example
> “printf -- '\t\tif\n'|grep -E '^\s+[^i]'”?

I get a line like this:

                if

and this is the correct answer.

> * Does the tool “grep” output any extra colour information also for
>    matched tab characters?

Not with that test case, no. There is no color information at all. grep's 
--color option was not used.

> A similar clarification attempt resulted in a bit of better understanding
> for the software situation.
> https://github.com/beyondgrep/ack2/issues/661

That's a long page, which I don't have the patience to read to the end. As near 
as I can make out, the basic problem is that you didn't understand how grep is 
supposed to work, and reported its behavior as a bug. However, as far as I can 
see from the above example, grep is working as specified.