IndexSearcher's cumulative maxClauseCount check never counts a query held by a values source (FunctionScoreQuery.boostByQuery's boost query, DoubleValuesSource.fromQuery, QueryValueSource): the function queries' visit() stops at the source and each embedded query is checked alone with a fresh budget, so the total number of executed clauses is unbounded

Finding LFV-923Area: queries / function queries (FunctionScoreQuery, FunctionMatchQuery, FunctionRangeQuery and FunctionQuery QueryVisitor traversal of DoubleValuesSource/ValueSource; consumer: IndexSearcher's cumulative clause limit)Priority: lowImpact: minorNovelty: new

Finding page for LFV-923

AI-assisted finding, confirmed by automated checks, not yet triaged by a human Lucene committer. This site files nothing upstream.

What it shows

You search FunctionScoreQuery.boostByQuery(in, boostMatch, 2f), where in and boostMatch are each a 600-term disjunction (1,200 term clauses that all run), with the default maxClauseCount of 1024. You expect TooManyNestedClauses, which you do get for a BooleanQuery holding the same clauses (even when half of them are scoring-only SHOULD or MUST_NOT clauses), because the check counts 'total clauses cumulatively in all of its children' and LUCENE-8811 made it cumulative so that splitting clauses over sub-queries no longer bypasses it. Instead the search runs with correct hits: FunctionScoreQuery.visit visits only in, FunctionMatchQuery, FunctionRangeQuery and FunctionQuery.visit call visitLeaf(this), DoubleValuesSource and ValueSource have no visit hook, and the embedded query is rewritten later with searcher.rewrite, which checks it alone with a fresh count; FunctionScoreQuery(fromQuery), FunctionMatchQuery(fromQuery) and FunctionQuery/FunctionRangeQuery over QueryValueSource behave the same.

The test shows that FunctionScoreQuery.boostByQuery(in, boostMatch, 2f) with two 600-term disjunctions (1200 term clauses) is not rejected by IndexSearcher's cumulative clause limit, because the boost query is never visited.

Expected vs actual

Expected IndexSearcher.TooManyNestedClauses (default maxClauseCount 1024); actual: the search runs, Expected exception TooManyNestedClauses but no exception was thrown (-ea and -da).

Files

• src/org/apache/lucene/queries/function/TestBoostByQueryClauseLimit.java (JUnit test)

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=$CP:$LUCENE/lucene/queries/build/libs/lucene-queries-$V.jar
CP=$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.queries.function.TestBoostByQueryClauseLimit

Gradle 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.