[PATCH] Discard unusable hash table entries

During an in-place update, a block can not be matched if its offset is prior to the sender offset, if SUMFLG_SAME_OFFSET is not set. As the sender offset is only ever incremented, and SUMFLG_SAME_OFFSET is never cleared on a block, a block that fails this test will never pass it in the future. It c

Improve --inplace updates on pathological inputs

.33 bytes/sec total size is 20,971,520 speedup is 417.10 real0m0.598s user0m0.314s sys 0m0.043s $ md5sum a b 07c84be14041575befb779ca6dee16ab a 07c84be14041575befb779ca6dee16ab b Michael Chapman (