com.sleepycat.je.tree.IN.logDirtyChildren()
When splits and checkpoints intermingle in a deferred write databases, a checkpoint target may appear which has a valid target but a null LSN. Deferred write dbs are written out in checkpoint style by either Database.sync() or a checkpoint which has cleaned a file containing deferred write entries. For example, INa | BINb A checkpoint or Database.sync starts The INList is traversed, dirty nodes are selected BINb is bypassed on the INList, since it's not dirty BINb is split, creating a new sibling, BINc, and dirtying INa INa is selected as a dirty node for the ckpt If this happens, INa is in the selected dirty set, but not its dirty child BINb and new child BINc. In a durable db, the existence of BINb and BINc are logged anyway. But in a deferred write db, there is an entry that points to BINc, but no logged version. This will not cause problems with eviction, because INa can't be evicted until BINb and BINc are logged, are non-dirty, and are detached. But it can cause problems at recovery, because INa will have a null LSN for a valid entry, and the LN children of BINc will not find a home. To prevent this, search for all dirty children that might have been missed during the selection phase, and write them out. It's not sufficient to write only null-LSN children, because the existing sibling must be logged lest LN children recover twice (once in the new sibling, once in the old existing sibling.