oxenstored does not implement an error indicator on the ring

[last-genius]

cxenstored commit from upstream: https://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=aeaed47023377a20d0f77c82e54f504e99468fb6

From docs/misc/xenstore-ring.txt:

The "Connection error indicator" is used to let the server indicate it has
detected some error that led to deactivation of the connection by the server.
If the feature has been advertised then the "Connection error indicator" may
take the following values (new values might be added in future without them
being advertised as a new feature):

Value   Description
-----------------------------------------------------------------
0       No error, connection is valid
1       Communication problems (event channel not functional)
2       Inconsistent producer or consumer offset
3       Protocol violation (client data package too long)

The connection error feature
============================

The connection error feature allows the server to signal error conditions
leading to a stop of the communication with the client. In case such an error
condition has occurred, the server will set the appropriate error condition in
the Connection error indicator and will stop communication with the client.

Any value different from 0 is indicating an error. The value used is meant
just for diagnostic purposes. A client reading the error value should be
prepared to see values not described here, as new error cases might be added
in future.

The server will discard any already read or written packets, in-flight
requests, watches and transactions associated with the connection.

Depending on the error cause it might be possible that a reconnect via the
ring reconnection feature (if present) can be performed. There is no guarantee
this will succeed.