Datastore index corruption

[bernie]

Today we figured out one of the possibly many ways in which the index of the datastore can get corrupted in Sugar.

Here's an almost infallible recipe to reproduce it:

1. open Write
2. type something
3. close Write
4. wait a few seconds
5. kill -9 the datastore process
6. restart sugar (ctrl-alt-del)

Your saved entry is gone. It still takes up space on disk, but it's no longer visible until you rebuild the index.

Step 5 is just an artificial way to reproduce the problem. Other equally effective ways to trigger this data loss issue in the real-world include running out of battery, holding the power button for 4 seconds, and triggering the kernel out-of-memory killer.