[LUCENE-6680] BlendedInfixSuggester dedup bug

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.2.1
• Fix Version/s: 5.3, 6.0
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Arcadius Ahouansou
• Created: 15/Jul/15 15:06
• Updated: 28/Aug/22 14:39
• Resolved: 15/Jul/15 21:45

Description

I expect the following test to pass, but it's failing in the latest Lucene 5.2.1:

FailingTest.java

public void testBlendedInfixSuggesterDedupsOnWeightTitleAndPayload() throws Exception {

//Only the payload is different
    Input[] inputDocuments = new Input[]{
        new Input("lend me your ear", 7, new BytesRef("uid1")),
        new Input("lend me your ear", 7, new BytesRef("uid2")),
    };

    Analyzer a = new MockAnalyzer(random(), MockTokenizer.WHITESPACE, false);
    BlendedInfixSuggester suggester = new BlendedInfixSuggester(newDirectory(), a, a, AnalyzingInfixSuggester.DEFAULT_MIN_PREFIX_CHARS,
        BlendedInfixSuggester.BlenderType.POSITION_RECIPROCAL, 10, false);

    InputArrayIterator inputArrayIterator = new InputArrayIterator(inputDocuments);
    suggester.build(inputArrayIterator);

    List<Lookup.LookupResult> results = suggester.lookup(TestUtil.stringToCharSequence("ear", random()), 10, true, true);

    suggester.close();
    a.close();

    assertEquals(2, results.size());

  }

This test is failing because the BlendedInfixSuggester internally uses a TreeSet for storing the results and the corresponding Comparator only uses text+weight meaning that results with different payloads are collapsed into one.

mikemccand, The idea here is that if two ingested documents have the same title and weight, but different payloads, then they are two different things and folding them into a single document would mean loosing the payload information.