/usr/lib/mysql-testsuite/std_data/bug35469.dat 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 | "1", "string1"
"2", "string2"
"3", "string3"
|