Avoid some false positives for addremove -s The original code uses the similary score 1 - len(diff(after, before)) / len(after) The diff can at most be the size of the 'before' file, so any small 'before' file would be considered very similar. Removing an empty file would cause all files added in the same revision to be considered copies of the removed file. This changes the metric to bytes_overlap(before, after) / len(before + after) i.e. the actual percentage of bytes shared between the two files.

changeset:   0:0acdaf898367
tag:         tip
user:        test
date:        Mon Jan 12 13:46:40 1970 +0000
summary:     test

b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 644 a
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checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions