CS Mapping rule bug: User matcher does not work correctly for usernames with dot

Given the following scenario, the placement engine does not work as expected.
A user with a '.' (dot) inside his/her username submits a job.
Let the username be "test.user"

There are 2 mapping rules:
1. The matcher matches the user with name "test.user" and has an associated mapping rule action that sets the default queue to "root.user".
2. The second mapping rule matches the same user ("test.user") and places the application to the default queue.

Expactation:
When the user with username "root.user" submits a job, the application will be placed to queue "root.user".

Observed behaviour:
The application is placed to test_dot_user.

This means that the dot is replaced to "dot" too early so that the default queue is set incorrectly.

I have attached a patch file that demonstrates this behaviour with 2 new testcases along with the logs of these testcases.