Duplicate entries on server when deleting single instances of recurring events

[SheridanVespo]

When deleting a single instance from a recurring event on an android device, the adapter creates a duplicate entry with the same time frame as the deleted event.

This duplicate event shows up on the server and in other applications, but will not sync back to the adapter.

Steps to reproduce:

• Create a recurring event with multiple instances anywhere
• delete one instance on an android calendar app
• synchronize to the server
• view the calendar on the server side
• You should now see a duplicate entry for the instance "deleted", meaning the original instance is also still there.