The ActiveSync backend now detects the daemon's "Sync error: Invalid
synchronization key" and falls back to a slow sync. This is only done
if the sync key was already invalid when beginSync()
started. Otherwise something fishy must be going on and it seems
prudent to rather abort the sync with an error.
It would be nice if this special error could be detected without
having to resort to a string comparison, but this is not currently
supported by libeasclient because error codes are not yet part of the
API (BMC #23618).
b1b18eadb5