diff --git a/lucene/core/src/java/org/apache/lucene/search/ConjunctionDISI.java b/lucene/core/src/java/org/apache/lucene/search/ConjunctionDISI.java
index 780e854033a..30bdabbfd44 100644
--- a/lucene/core/src/java/org/apache/lucene/search/ConjunctionDISI.java
+++ b/lucene/core/src/java/org/apache/lucene/search/ConjunctionDISI.java
@@ -31,6 +31,7 @@ import org.apache.lucene.util.BitSetIterator;
import org.apache.lucene.util.CollectionUtil;
/** A conjunction of DocIdSetIterators.
+ * Requires that all of its sub-iterators must be on the same document all the time.
* This iterates over the doc ids that are present in each given DocIdSetIterator.
*
Public only for use in {@link org.apache.lucene.search.spans}.
* @lucene.internal
@@ -140,6 +141,15 @@ public final class ConjunctionDISI extends DocIdSetIterator {
private static DocIdSetIterator createConjunction(
List allIterators,
List twoPhaseIterators) {
+
+ // check that all sub-iterators are on the same doc ID
+ int curDoc = allIterators.size() > 0 ? allIterators.get(0).docID() : twoPhaseIterators.get(0).approximation.docID();
+ boolean iteratorsOnTheSameDoc = allIterators.stream().allMatch(it -> it.docID() == curDoc);
+ iteratorsOnTheSameDoc = iteratorsOnTheSameDoc && twoPhaseIterators.stream().allMatch(it -> it.approximation().docID() == curDoc);
+ if (iteratorsOnTheSameDoc == false) {
+ throw new IllegalArgumentException("Sub-iterators of ConjunctionDISI are not on the same document!");
+ }
+
long minCost = allIterators.stream().mapToLong(DocIdSetIterator::cost).min().getAsLong();
List bitSetIterators = new ArrayList<>();
List iterators = new ArrayList<>();
@@ -177,6 +187,7 @@ public final class ConjunctionDISI extends DocIdSetIterator {
private ConjunctionDISI(List extends DocIdSetIterator> iterators) {
assert iterators.size() >= 2;
+
// Sort the array the first time to allow the least frequent DocsEnum to
// lead the matching.
CollectionUtil.timSort(iterators, new Comparator() {
@@ -227,6 +238,7 @@ public final class ConjunctionDISI extends DocIdSetIterator {
@Override
public int advance(int target) throws IOException {
+ assert assertItersOnSameDoc() : "Sub-iterators of ConjunctionDISI are not one the same document!";
return doNext(lead1.advance(target));
}
@@ -237,6 +249,7 @@ public final class ConjunctionDISI extends DocIdSetIterator {
@Override
public int nextDoc() throws IOException {
+ assert assertItersOnSameDoc() : "Sub-iterators of ConjunctionDISI are not on the same document!";
return doNext(lead1.nextDoc());
}
@@ -245,6 +258,16 @@ public final class ConjunctionDISI extends DocIdSetIterator {
return lead1.cost(); // overestimate
}
+ // Returns {@code true} if all sub-iterators are on the same doc ID, {@code false} otherwise
+ private boolean assertItersOnSameDoc() {
+ int curDoc = lead1.docID();
+ boolean iteratorsOnTheSameDoc = (lead2.docID() == curDoc);
+ for (int i = 0; (i < others.length && iteratorsOnTheSameDoc); i++) {
+ iteratorsOnTheSameDoc = iteratorsOnTheSameDoc && (others[i].docID() == curDoc);
+ }
+ return iteratorsOnTheSameDoc;
+ }
+
/** Conjunction between a {@link DocIdSetIterator} and one or more {@link BitSetIterator}s. */
private static class BitSetConjunctionDISI extends DocIdSetIterator {
@@ -256,6 +279,7 @@ public final class ConjunctionDISI extends DocIdSetIterator {
BitSetConjunctionDISI(DocIdSetIterator lead, Collection bitSetIterators) {
this.lead = lead;
assert bitSetIterators.size() > 0;
+
this.bitSetIterators = bitSetIterators.toArray(new BitSetIterator[0]);
// Put the least costly iterators first so that we exit as soon as possible
ArrayUtil.timSort(this.bitSetIterators, (a, b) -> Long.compare(a.cost(), b.cost()));
@@ -276,11 +300,13 @@ public final class ConjunctionDISI extends DocIdSetIterator {
@Override
public int nextDoc() throws IOException {
+ assert assertItersOnSameDoc() : "Sub-iterators of ConjunctionDISI are not on the same document!";
return doNext(lead.nextDoc());
}
@Override
public int advance(int target) throws IOException {
+ assert assertItersOnSameDoc() : "Sub-iterators of ConjunctionDISI are not on the same document!";
return doNext(lead.advance(target));
}
@@ -306,6 +332,16 @@ public final class ConjunctionDISI extends DocIdSetIterator {
return lead.cost();
}
+ // Returns {@code true} if all sub-iterators are on the same doc ID, {@code false} otherwise
+ private boolean assertItersOnSameDoc() {
+ int curDoc = lead.docID();
+ boolean iteratorsOnTheSameDoc = true;
+ for (int i = 0; (i < bitSetIterators.length && iteratorsOnTheSameDoc); i++) {
+ iteratorsOnTheSameDoc = iteratorsOnTheSameDoc && (bitSetIterators[i].docID() == curDoc);
+ }
+ return iteratorsOnTheSameDoc;
+ }
+
}
/**
diff --git a/lucene/core/src/test/org/apache/lucene/search/TestConjunctionDISI.java b/lucene/core/src/test/org/apache/lucene/search/TestConjunctionDISI.java
index e729ed61872..43cfbe68fe8 100644
--- a/lucene/core/src/test/org/apache/lucene/search/TestConjunctionDISI.java
+++ b/lucene/core/src/test/org/apache/lucene/search/TestConjunctionDISI.java
@@ -41,7 +41,7 @@ public class TestConjunctionDISI extends LuceneTestCase {
return new TwoPhaseIterator(approximation) {
@Override
- public boolean matches() throws IOException {
+ public boolean matches() {
return confirmed.get(approximation.docID());
}
@@ -391,4 +391,21 @@ public class TestConjunctionDISI extends LuceneTestCase {
public void testCollapseSubConjunctionScorers() throws IOException {
testCollapseSubConjunctions(true);
}
+
+ public void testIllegalAdvancementOfSubIteratorsTripsAssertion() throws IOException {
+ assumeTrue("Assertions must be enabled for this test!", LuceneTestCase.assertsAreEnabled);
+ int maxDoc = 100;
+ final int numIterators = TestUtil.nextInt(random(), 2, 5);
+ FixedBitSet set = randomSet(maxDoc);
+
+ DocIdSetIterator[] iterators = new DocIdSetIterator[numIterators];
+ for (int i = 0; i < iterators.length; ++i) {
+ iterators[i] = new BitDocIdSet(set).iterator();
+ }
+ final DocIdSetIterator conjunction = ConjunctionDISI.intersectIterators(Arrays.asList(iterators));
+ int idx = TestUtil.nextInt(random() , 0, iterators.length-1);
+ iterators[idx].nextDoc(); // illegally advancing one of the sub-iterators outside of the conjunction iterator
+ AssertionError ex = expectThrows(AssertionError.class, () -> conjunction.nextDoc());
+ assertEquals("Sub-iterators of ConjunctionDISI are not on the same document!", ex.getMessage());
+ }
}