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https://issues.apache.org/jira/browse/LUCENE-4978?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13938837#comment-13938837
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ASF subversion and git services commented on LUCENE-4978:
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Commit 1578741 from [~dsmiley] in branch 'dev/trunk'
[ https://svn.apache.org/r1578741 ]

LUCENE-4978: spatial grid false-negatives at edge

> Spatial search with point query won't find identical indexed point
> ------------------------------------------------------------------
>
>                 Key: LUCENE-4978
>                 URL: https://issues.apache.org/jira/browse/LUCENE-4978
>             Project: Lucene - Core
>          Issue Type: Bug
>          Components: modules/spatial
>    Affects Versions: 4.1
>            Reporter: David Smiley
>            Assignee: David Smiley
>            Priority: Minor
>             Fix For: 4.8
>
>         Attachments: LUCENE-4978_fix_small_grid_false_negatives.patch
>
>
> Given a document with indexed POINT (10 20), when a search for INTERSECTS( 
> POINT (10 20)) is issued, no results are returned.
> The work-around is to not search with a point shape, use a very small-radius 
> circle or rectangle.  (I'm marking this issue as "minor" because it's easy to 
> do this).
> An unstated objective of the PrefixTree/grid approximation is that no matter 
> what precision you use, an intersects query will find all true-positives.  
> Due to approximations, it may also find some close false-positives.  But in 
> the case above, that unstated promise is violated.  But it can also happen 
> for query shapes other than points which do in fact barely enclose the point 
> given at index time yet the indexed point is in-effect shifted to the center 
> point of a cell which could be outside the query shape, and ultimately 
> leading to a false-negative.



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