"Error by one" in the definition of the radius of revert detection?

[he7d3r]

The API provides the following excerpt of the history of a page:

                    {
                        "revid": 40689105,
                        "parentid": 40686393,
                        "sha1": "2143678744b3ff595b998daa11f97e366212e18e"
                    },
                    {
                        "revid": 40686393,
                        "parentid": 40679748,
                        "sha1": "84c489b7d568795b3da6696968f1483893b6519b"
                    },
                    {
                        "revid": 40679748,
                        "parentid": 40632743,
                        "sha1": "2143678744b3ff595b998daa11f97e366212e18e"
                    }

However,

from mw.api import Session
from mw.lib import reverts
session = Session("https://pt.wikipedia.org/w/api.php")
reverts.api.check_rev(session, {'revid':40679748,'pageid':40677}, radius=1)

returns nothing and

reverts.api.check_rev(session, {'revid':40679748,'pageid':40677}, radius=2)

returns

Revert(reverting={'revid': 40686393, 'page': {'title': 'João Figueiredo', 'pageid': 40677, 'ns': 0}, 'sha1': '84c489b7d568795b3da6696968f1483893b6519b', 'parentid': 40679748, 'timestamp': '2014-11-23T17:40:23Z'}, reverteds=[{'revid': 40679748, 'page': {'title': 'João Figueiredo', 'pageid': 40677, 'ns': 0}, 'sha1': '2143678744b3ff595b998daa11f97e366212e18e', 'parentid': 40632743, 'timestamp': '2014-11-22T22:24:20Z'}, {'revid': 40679748, 'page': {'title': 'João Figueiredo', 'pageid': 40677, 'ns': 0}, 'sha1': '2143678744b3ff595b998daa11f97e366212e18e', 'parentid': 40632743, 'timestamp': '2014-11-22T22:24:20Z'}], reverted_to={'revid': 40632743, 'page': {'title': 'João Figueiredo', 'pageid': 40677, 'ns': 0}, 'sha1': '84c489b7d568795b3da6696968f1483893b6519b', 'parentid': 40396585, 'timestamp': '2014-11-17T03:24:51Z'})

Therefore, I believe there is an "error by one" somewhere in the definition of the radius ("the maximum number of revisions that can be reverted"), because this is the simplest revert case where a single revision is reverted right after it is saved (A --> B --> A).

[he7d3r]

Compare with

>>> from mw.lib import reverts
>>> detector = reverts.Detector(radius=1)
>>> detector.process("aaa", {'rev_id': 1})
>>> detector.process("bbb", {'rev_id': 2})
>>> detector.process("aaa", {'rev_id': 3})
Revert(reverting={'rev_id': 3}, reverteds=[{'rev_id': 2}], reverted_to={'rev_id': 1})

which works fine (the radius here is defined as "the maximum revision distance that a revert can span")

[halfak]

Fixed in. a293667

And released as v0.4.11