Data corruption due to source-of-truth mismatch

[jcranendonk]

When the client and the server disagree about the value of a ref, and the node has a $timestamp value newer than what the server provides, it is possible to cause cached data to be overwritten with atoms of undefined.

Although setting refs with a $timestamp value on the client is not explicitly supported, we want to avoid corrupting cached data.

More investigation is needed to define reproducible steps to trigger.

[ghost]

We don't understand that