add cover letter

import 95a19b7

xdiff/xhistogram: drop need for additional variable

Having an additional variable (ptr) instead of changing line(1|2) and
count(1|2) was for debugging purposes.

Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>

xdiff/xprepare: use a smaller sample size for histogram diff

For histogram diff, we can afford a smaller sample size and thus a
poorer estimate of the number of lines, as the hash table (rhash) won't
be filled up/grown. This is safe as the final count of lines (xdf.nrecs)
will be updated correctly anyway by xdl_prepare_ctx().

This gives us a small boost in performance.

Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>

further simplify next and cnt access

try_lcs: fix chain enumeration

check ha before doing comparison

further simplify next and cnt access

scanA: fix orphaning of chains

gen_cnt: fix last un-init