Bug 25850: Regression Test

Bug 25850: Regression Test

This patch adds a unit test to test for an infinite loop as highlighted
by the bug.

Test plan
1/ Run the test before applying the fix
2/ The test should fail for 'Sundays'
3/ Apply the subsquent patch
4/ Re-run the test
5/ It should now pass

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit 95c8d19530e8bef20e02be0b74d7927764bf7ed1)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>