/usr/lib/mysql-testsuite/include/have_gb2312.inc is in percona-server-test-5.6 5.6.22-rel71.0-0ubuntu4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | -- require r/have_gb2312.require
disable_query_log;
show collation like 'gb2312_chinese_ci';
enable_query_log;
|