bug#33552: Possible bug with handling -I option

[Jason Franklin]

Greetings,

I'm using grep version 3.1 on Ubuntu 18.04.

I noticed today that if you grep the attached file with:

grep -I \. cs.po | grep '^Binary'

... the message "Binary file ..." that should be suppressed still appears.  
That is, the -I option doesn't behave as expected here.

Is this intentional?

Thanks,
Jason

cs.po
Description: Text Data