Subject: grep -v always exiting with 1 for empty file

From: Andi Kleen <[email-masked]>
Date: Wed, 3 Jun 2020 20:26:41 -0700

% grep --version
grep (GNU grep) 3.4
...
% echo -n > foo
% grep -v foo foo ; echo $?
1

Would expect it to exit with zero in this case, since foo is not in the
file.

When the file is one byte it works as expected:

% echo > foo
% grep -v foo foo ; echo $?

0
%