On main, a field-sorted TopFieldCollectorManager with numHits >= ArrayUtil.MAX_ARRAY_LENGTH (e.g. Integer.MAX_VALUE) throws OutOfMemoryError instead of the IllegalArgumentException that 10.x throws, because since #14873 FieldValueHitQueue.create allocates the numHits-sized sort comparators before the PriorityQueue size check runs (unreleased regression of the SOLR-5661 guard)
Finding LFV-993Area: core / search: field-sorted top-N collection (FieldValueHitQueue, TopFieldCollectorManager)Priority: lowImpact: wrong errorNovelty: new
AI-assisted finding, confirmed by automated checks, not yet triaged by a human Lucene committer. This site files nothing upstream.
What it shows
You call new TopFieldCollectorManager(sort, Integer.MAX_VALUE, null, 1).newCollector() with any built-in sort (a long field, a string field, Sort.RELEVANCE), directly or through SortRescorer.rescore(searcher, topDocs, Integer.MAX_VALUE), and expect the IllegalArgumentException 'maxSize must be >= 0 and < 2147483631' that Lucene 7.5.0 to 10.6.0 throw (main's score-ordered TopScoreDocCollectorManager still throws an IllegalArgumentException, with its own message). On main you get OutOfMemoryError 'Requested array size exceeds VM limit' instead ('Java heap space' at 2147483631 with a 1 GB heap). Since #14873, FieldValueHitQueue.create builds the sort comparators, each of which pre-allocates a numHits-sized array, before it calls the PriorityQueue constructor, whose size check exists to prevent exactly this confusing OutOfMemoryError (SOLR-5661).
The test shows that on main new TopFieldCollectorManager(sort, Integer.MAX_VALUE, null, 1).newCollector() with a LONG sort allocates the numHits-sized comparator in FieldValueHitQueue.create before PriorityQueue's size check runs (regression from #14873).
Expected vs actual
Expected: PriorityQueue's IllegalArgumentException ('maxSize must be >= 0 and < 2147483631'), as in 4.7.0-10.5.2. Actual: OutOfMemoryError: Requested array size exceeds VM limit.
Files
Run it
- Tested on Lucene main e1faeba08bde (2026-11-02): still reproduces.
- Tested on Lucene main 645d4fe14a20 (2026-10-28): reproduced.
- Recorded outcome of run 1 on Lucene main 645d4fe14a20: 1 test(s) run, 1 failed.
- How to read the outcome: a failing test is the finding reproducing (the failure message states expected against actual).
- Seeds: a rerun with the same seed replays the same random choices. Assertions off (-da -dsa -Dtests.asserts=false) is the production-like setting.
# Lucene checkout at the tested commit, built with: ./gradlew --no-daemon assemble (JDK 25)
LUCENE=/path/to/lucene; V=12.0.0-SNAPSHOT
CP=$LUCENE/lucene/core/build/libs/lucene-core-$V.jar
CP=$CP:$LUCENE/lucene/codecs/build/libs/lucene-codecs-$V.jar
CP=$CP:$LUCENE/lucene/test-framework/build/libs/lucene-test-framework-$V.jar
CP=$CP:randomizedtesting-runner-2.9.2.jar:junit-4.13.2.jar:hamcrest-3.0.jar # test-framework dependencies (Maven Central)
CP=$CP:junit-platform-console-standalone-6.1.3.jar # JUnit Platform console launcher (Maven Central)
javac -d classes -cp "$CP" $(find src -name '*.java')
# run 1: assertions on, seed DEADBEEF
java -ea -esa --add-modules jdk.incubator.vector --enable-native-access=ALL-UNNAMED -Dtests.seed=DEADBEEF \
-cp "classes:$CP" org.junit.platform.console.ConsoleLauncher \
execute --select-class org.apache.lucene.search.TestTopFieldCollectorManagerMaxNumHitsGradle alternative: copy the test into the matching module's src/test/ tree of the checkout and run ./gradlew -p lucene/<module> test --tests <class> -Ptests.seed=<seed> (add -Ptests.asserts=false for a run without assertions).
Feedback
Open an issue in lucene-ai-bug-hunt. Please do not open issues or pull requests in apache/lucene about this finding unless a Lucene committer agrees it should be filed.
Snapshot of 2026-11-04. AI-assisted; not yet triaged by a human Lucene committer. Feedback: open an issue in lucene-ai-bug-hunt.