Calculating minimum score instead of maximum score in ToParentBlockJoinQuery.BlockJoinScorer.setScoreAndFreq [LUCENE-7833]

[asfimport]

We recently upgraded our Elasticsearch cluster from 5.3 to 5.4 and found a bug when we score nested documents.

I spent some time to check the code from Elasticsearch and Lucene and I found a problem in ToParentBlockJoinQuery.BlockJoinScorer.setScoreAndFreq.

In the switch statement for the scoreMode in the case "Max" the function Math.min is used and I guess it should be Math.max.

This would explain our problem in Elasticsearch because we see exactly the problem that instead of the maximum the minimum is returned.

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Migrated from LUCENE-7833 by Bernhard Altendorfer (@baltendo), resolved May 19 2017
Attachments: LUCENE-7833.patch
Linked issues:

• To-parent block joins should implement two-phase iteration [LUCENE-7654] #8705

[asfimport]

selckin (migrated from JIRA)

@jpountz https://github.com/apache/lucene-solr/blob/master/lucene/join/src/java/org/apache/lucene/search/join/ToParentBlockJoinQuery.java#L315

[asfimport]

Adrien Grand (@jpountz) (migrated from JIRA)

Good catch selckin! Would you like to work on a patch + test?

[asfimport]

selckin (migrated from JIRA)

Original poster found it and talked about it on irc with a few of us, i just wanted to highlight it would be an easy fix so it doesn't get lost

I believe he said he was interested in creating a test for it

[asfimport]

Bernhard Altendorfer (@baltendo) (migrated from JIRA)

I would love to try it, but unfortunately I don't have time ..

[asfimport]

Adrien Grand (@jpountz) (migrated from JIRA)

No worries, I'll take it.

[asfimport]

Adrien Grand (@jpountz) (migrated from JIRA)

Here is a patch.

[asfimport]

Jim Ferenczi (@jimczi) (migrated from JIRA)

patch looks good, +1

[asfimport]

ASF subversion and git services (migrated from JIRA)

Commit 8a88eaf in lucene-solr's branch refs/heads/branch_6_6 from @jpountz
https://git-wip-us.apache.org/repos/asf?p=lucene-solr.git;h=8a88eaf

LUCENE-7833: Fix score computation with ToParentBlockJoinQuery and ScoreMode.MAX.

[asfimport]

ASF subversion and git services (migrated from JIRA)

Commit 43220c3 in lucene-solr's branch refs/heads/branch_6x from @jpountz
https://git-wip-us.apache.org/repos/asf?p=lucene-solr.git;h=43220c3

LUCENE-7833: Fix score computation with ToParentBlockJoinQuery and ScoreMode.MAX.

[asfimport]

ASF subversion and git services (migrated from JIRA)

Commit 3bb4662 in lucene-solr's branch refs/heads/master from @jpountz
https://git-wip-us.apache.org/repos/asf?p=lucene-solr.git;h=3bb4662

LUCENE-7833: Fix score computation with ToParentBlockJoinQuery and ScoreMode.MAX.