bug#29396: Comm bug verified

[Saint Michael]

Dear Maintainers
I guess the names are Richard M. Stallman and David MacKenzie.

I found a vierifiable bug in the utilitu comm. This is very important
because hundreds maybe thousands of application rely on this app to make
crucial decisions, in power plants, banks, etc. We nedd to trust it.

I have two files with phone numbers, one column, sorted (they pass the test
sort -c). One is large and the other one is small. The  comm -12
--check-order file1.csv file2.csv falis to find matches, but another
utility, join file1.csv file2.csv. does find a lot of matches.
The box is Centos 7 and


*comm --versioncomm (GNU coreutils) 8.22*

The only special think about my box is
export LC_ALL=C
please contact me to send you a zip file with the two files, or for
security, plain ascii files, or maybe you can login to our lab box and
execute the commands.