doReconstructionLog doesn't handle empty files correctly:
Notice it actually compares the length of the array instead of the file length.
It should call getLen() and delete the file afterwards
Also. This is a situation that shouldn't happen as an empty oldlogfile.log should be deleted when HMaster does the split in HLog.splitLog().
I couldn't figure what would make it leave it there as I also see in the logs that other empty logs are deleted. This might expose a thornier situation.