Tang-- I think the scenario you listed can't happen, because the first bucket we try in the hash-search is 0. If the circular buffer has wrapped, that will be detected immediately and we'll leave the loop with l=0. We should add a comment that we need to try the first index first for correctness so that we don't inadvertently change this behavior. One thing took me a long time to convince myself was safe with the original code: If we have 'YYNYYYYYYY', we'll start at l=0, and then we'll search across the N; I think this is OK because sequence numbers will cause us to do the right thing. Mike On Wed, Nov 1, 2017 at 12:10 AM, <tang.junhui@xxxxxxxxxx> wrote: > From: Tang Junhui <tang.junhui@xxxxxxxxxx> > > Hello Mike, Coly > > I found this issue by code reading. > It looks serious. > May I am wrong. > Please have a review. > > Thanks, > Tang > >