In System Settings > Language Support > Regional Formats > Display numbers... if my setting is "Nederlands" then I can enter the DOT and the test fails. Changing that setting to US makes it impossible to enter a dot (but a comma is allowed), and the test does not fail. So it depends on your number format.
In System Settings > Language Support > Regional Formats > Display numbers... if my setting is "Nederlands" then I can enter the DOT and the test fails. Changing that setting to US makes it impossible to enter a dot (but a comma is allowed), and the test does not fail. So it depends on your number format.