Fix query analyzer logic for mixed conjunctions of terms and ranges (#49803)

When the query analyzer examines a conjunction containing both terms and ranges,
it should only include ranges in the minimum_should_match calculation if there are no
other range queries on that same field within the conjunction. This is because we cannot
build a selection query over disjoint ranges on the same field, and it is not easy to check
if two range queries have an overlap.

The current logic to calculate this just sets minimum_should_match to 1 or 0, dependent
on whether or not the current range is over a field that has already been seen. However, this
can be incorrect in the case that there are terms in the same match group which adjust the
minimum_should_match downwards. Instead, the logic should be changed to match the
terms extraction, whereby we adjust minimum_should_match downwards if we have already
seen a range field.

Fixes #49684

modules/percolator/src/main/java/org/elasticsearch/percolator/QueryAnalyzer.java

@@ -232,7 +232,7 @@ final class QueryAnalyzer {
         List<Result> conjunctions = conjunctionsWithUnknowns.stream().filter(r -> r.isUnknown() == false).collect(Collectors.toList());
         if (conjunctions.isEmpty()) {
             if (conjunctionsWithUnknowns.isEmpty()) {
-                throw new IllegalArgumentException("Must have at least on conjunction sub result");
+                throw new IllegalArgumentException("Must have at least one conjunction sub result");
             }
             return conjunctionsWithUnknowns.get(0); // all conjunctions are unknown, so just return the first one
         }
@@ -247,47 +247,53 @@ final class QueryAnalyzer {
         int msm = 0;
         boolean verified = conjunctionsWithUnknowns.size() == conjunctions.size();
         boolean matchAllDocs = true;
-        boolean hasDuplicateTerms = false;
         Set<QueryExtraction> extractions = new HashSet<>();
         Set<String> seenRangeFields = new HashSet<>();
         for (Result result : conjunctions) {
-            // In case that there are duplicate query extractions we need to be careful with
-            // incrementing msm,
-            // because that could lead to valid matches not becoming candidate matches:
-            // query: (field:val1 AND field:val2) AND (field:val2 AND field:val3)
-            // doc: field: val1 val2 val3
-            // So lets be protective and decrease the msm:
+
             int resultMsm = result.minimumShouldMatch;
             for (QueryExtraction queryExtraction : result.extractions) {
                 if (queryExtraction.range != null) {
                     // In case of range queries each extraction does not simply increment the
-                    // minimum_should_match
-                    // for that percolator query like for a term based extraction, so that can lead
-                    // to more false
-                    // positives for percolator queries with range queries than term based queries.
-                    // The is because the way number fields are extracted from the document to be
-                    // percolated.
-                    // Per field a single range is extracted and if a percolator query has two or
-                    // more range queries
-                    // on the same field, then the minimum should match can be higher than clauses
-                    // in the CoveringQuery.
-                    // Therefore right now the minimum should match is incremented once per number
-                    // field when processing
-                    // the percolator query at index time.
-                    if (seenRangeFields.add(queryExtraction.range.fieldName)) {
-                        resultMsm = 1;
-                    } else {
-                        resultMsm = 0;
+                    // minimum_should_match for that percolator query like for a term based extraction,
+                    // so that can lead to more false positives for percolator queries with range queries
+                    // than term based queries.
+                    // This is because the way number fields are extracted from the document to be
+                    // percolated.  Per field a single range is extracted and if a percolator query has two or
+                    // more range queries on the same field, then the minimum should match can be higher than clauses
+                    // in the CoveringQuery. Therefore right now the minimum should match is only incremented once per
+                    // number field when processing the percolator query at index time.
+                    // For multiple ranges within a single extraction (ie from an existing conjunction or disjunction)
+                    // then this will already have been taken care of, so we only check against fieldnames from
+                    // previously processed extractions, and don't add to the seenRangeFields list until all
+                    // extractions from this result are processed
+                    if (seenRangeFields.contains(queryExtraction.range.fieldName)) {
+                        resultMsm = Math.max(0, resultMsm - 1);
+                        verified = false;
                     }
                 }
-
-                if (extractions.contains(queryExtraction)) {
-                    resultMsm = Math.max(0, resultMsm - 1);
-                    verified = false;
+                else {
+                    // In case that there are duplicate term query extractions we need to be careful with
+                    // incrementing msm, because that could lead to valid matches not becoming candidate matches:
+                    // query: (field:val1 AND field:val2) AND (field:val2 AND field:val3)
+                    // doc: field: val1 val2 val3
+                    // So lets be protective and decrease the msm:
+                    if (extractions.contains(queryExtraction)) {
+                        resultMsm = Math.max(0, resultMsm - 1);
+                        verified = false;
+                    }
                 }
             }
             msm += resultMsm;
 
+            // add range fields from this Result to the seenRangeFields set so that minimumShouldMatch is correctly
+            // calculated for subsequent Results
+            result.extractions.stream()
+                .map(e -> e.range)
+                .filter(Objects::nonNull)
+                .map(e -> e.fieldName)
+                .forEach(seenRangeFields::add);
+
             if (result.verified == false
                 // If some inner extractions are optional, the result can't be verified
                 || result.minimumShouldMatch < result.extractions.size()) {
@@ -299,7 +305,7 @@ final class QueryAnalyzer {
         if (matchAllDocs) {
             return new Result(matchAllDocs, verified);
         } else {
-            return new Result(verified, extractions, hasDuplicateTerms ? 1 : msm);
+            return new Result(verified, extractions, msm);
         }
     }
 

modules/percolator/src/test/java/org/elasticsearch/percolator/QueryAnalyzerTests.java

@@ -78,6 +78,7 @@ import java.util.stream.Collectors;
 import static org.elasticsearch.percolator.QueryAnalyzer.analyze;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
+import static org.hamcrest.collection.IsCollectionWithSize.hasSize;
 
 public class QueryAnalyzerTests extends ESTestCase {
 
@@ -1208,4 +1209,135 @@ public class QueryAnalyzerTests extends ESTestCase {
         assertTermsEqual(result.extractions, new Term("field", "a"));
     }
 
+    public void testCombinedRangeAndTermWithMinimumShouldMatch() {
+
+        Query disj = new BooleanQuery.Builder()
+            .add(IntPoint.newRangeQuery("i", 0, 10), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v1")), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v1")), Occur.SHOULD)
+            .setMinimumNumberShouldMatch(2)
+            .build();
+
+        Result r = analyze(disj, Version.CURRENT);
+        assertThat(r.minimumShouldMatch, equalTo(1));
+        assertThat(r.extractions, hasSize(2));
+        assertFalse(r.matchAllDocs);
+        assertFalse(r.verified);
+
+        Query q = new BooleanQuery.Builder()
+            .add(IntPoint.newRangeQuery("i", 0, 10), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v1")), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v1")), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v1")), Occur.FILTER)
+            .setMinimumNumberShouldMatch(2)
+            .build();
+
+        Result result = analyze(q, Version.CURRENT);
+        assertThat(result.minimumShouldMatch, equalTo(1));
+        assertThat(result.extractions.size(), equalTo(2));
+        assertFalse(result.verified);
+        assertFalse(result.matchAllDocs);
+
+        q = new BooleanQuery.Builder()
+            .add(q, Occur.MUST)
+            .add(q, Occur.MUST)
+            .build();
+
+        result = analyze(q, Version.CURRENT);
+        assertThat(result.minimumShouldMatch, equalTo(1));
+        assertThat(result.extractions.size(), equalTo(2));
+        assertFalse(result.verified);
+        assertFalse(result.matchAllDocs);
+
+        Query q2 = new BooleanQuery.Builder()
+            .add(new TermQuery(new Term("f", "v1")), Occur.FILTER)
+            .add(IntPoint.newRangeQuery("i", 15, 20), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v2")), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v2")), Occur.MUST)
+            .setMinimumNumberShouldMatch(1)
+            .build();
+
+        result = analyze(q2, Version.CURRENT);
+        assertThat(result.minimumShouldMatch, equalTo(2));
+        assertThat(result.extractions, hasSize(3));
+        assertFalse(result.verified);
+        assertFalse(result.matchAllDocs);
+
+        // multiple range queries on different fields
+        Query q3 = new BooleanQuery.Builder()
+            .add(IntPoint.newRangeQuery("i", 15, 20), Occur.SHOULD)
+            .add(IntPoint.newRangeQuery("i2", 15, 20), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v1")), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v2")), Occur.MUST)
+            .setMinimumNumberShouldMatch(1)
+            .build();
+        result = analyze(q3, Version.CURRENT);
+        assertThat(result.minimumShouldMatch, equalTo(2));
+        assertThat(result.extractions, hasSize(4));
+        assertFalse(result.verified);
+        assertFalse(result.matchAllDocs);
+
+        // multiple disjoint range queries on the same field
+        Query q4 = new BooleanQuery.Builder()
+            .add(IntPoint.newRangeQuery("i", 15, 20), Occur.SHOULD)
+            .add(IntPoint.newRangeQuery("i", 25, 30), Occur.SHOULD)
+            .add(IntPoint.newRangeQuery("i", 35, 40), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v1")), Occur.SHOULD)
+            .add(new TermQuery(new Term("f", "v2")), Occur.MUST)
+            .setMinimumNumberShouldMatch(1)
+            .build();
+        result = analyze(q4, Version.CURRENT);
+        assertThat(result.minimumShouldMatch, equalTo(2));
+        assertThat(result.extractions, hasSize(5));
+        assertFalse(result.verified);
+        assertFalse(result.matchAllDocs);
+
+        // multiple conjunction range queries on the same field
+        Query q5 = new BooleanQuery.Builder()
+            .add(new BooleanQuery.Builder()
+                .add(IntPoint.newRangeQuery("i", 15, 20), Occur.MUST)
+                .add(IntPoint.newRangeQuery("i", 25, 30), Occur.MUST)
+                .build(), Occur.MUST)
+            .add(IntPoint.newRangeQuery("i", 35, 40), Occur.MUST)
+            .add(new TermQuery(new Term("f", "v2")), Occur.MUST)
+            .build();
+        result = analyze(q5, Version.CURRENT);
+        assertThat(result.minimumShouldMatch, equalTo(2));
+        assertThat(result.extractions, hasSize(4));
+        assertFalse(result.verified);
+        assertFalse(result.matchAllDocs);
+
+        // multiple conjunction range queries on different fields
+        Query q6 = new BooleanQuery.Builder()
+            .add(new BooleanQuery.Builder()
+                .add(IntPoint.newRangeQuery("i", 15, 20), Occur.MUST)
+                .add(IntPoint.newRangeQuery("i2", 25, 30), Occur.MUST)
+                .build(), Occur.MUST)
+            .add(IntPoint.newRangeQuery("i", 35, 40), Occur.MUST)
+            .add(new TermQuery(new Term("f", "v2")), Occur.MUST)
+            .build();
+        result = analyze(q6, Version.CURRENT);
+        assertThat(result.minimumShouldMatch, equalTo(3));
+        assertThat(result.extractions, hasSize(4));
+        assertFalse(result.verified);
+        assertFalse(result.matchAllDocs);
+
+        // mixed term and range conjunctions
+        Query q7 = new BooleanQuery.Builder()
+            .add(new BooleanQuery.Builder()
+                .add(IntPoint.newRangeQuery("i", 1, 2), Occur.MUST)
+                .add(new TermQuery(new Term("f", "1")), Occur.MUST)
+                .build(), Occur.MUST)
+            .add(new BooleanQuery.Builder()
+                .add(IntPoint.newRangeQuery("i", 1, 2), Occur.MUST)
+                .add(new TermQuery(new Term("f", "2")), Occur.MUST)
+                .build(), Occur.MUST)
+            .build();
+        result = analyze(q7, Version.CURRENT);
+        assertThat(result.minimumShouldMatch, equalTo(3));
+        assertThat(result.extractions, hasSize(3));
+        assertFalse(result.verified);
+        assertFalse(result.matchAllDocs);
+    }
+
 }