XYShape.newLineQuery / newGeometryQuery accept QueryRelation.WITHIN with an XYLine, which LatLonShape (and XYShape itself up to 8.4.1) rejects with IllegalArgumentException; the accepted query silently returns only indexed points lying on the line and never an indexed line, not even one identical to the query line (the check was lost in LUCENE-9194, 8.5.0)

Finding LFV-434Area: core / document: XYShape queries (XYShape.newLineQuery and newGeometryQuery, XYShapeQuery, Line2D)Priority: lowImpact: wrong errorNovelty: new

Finding page for LFV-434

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

What it shows

You build XYShape.newLineQuery(field, QueryRelation.WITHIN, line) with a valid XYLine and expect the IllegalArgumentException that LatLonShape.newLineQuery throws for the same relation ('does not support WITHIN queries with line geometries'), and that XYShape itself threw up to 8.4.1 ('XYShapeLineQuery does not support WITHIN queries'). Instead the query is accepted, because the XYShapeQuery constructor has validated nothing since LUCENE-9194 (8.5.0) folded the old XY line query into it. The search then returns indexed points that lie on the line but no indexed line, not even one identical to the query line, because Line2D.containsLine and containsTriangle always return false.

The test shows that XYShape.newLineQuery(field, QueryRelation.WITHIN, line) accepts a WITHIN query with a line geometry (lost check since LUCENE-9194, 8.5.0).

Expected vs actual

Expected IllegalArgumentException, as LatLonShape.newLineQuery throws and XYShape threw up to 8.4.1; actual: no exception (-ea and -da).

Files

• src/org/apache/lucene/document/TestXYShapeWithinLineRejected.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=$CP:randomizedtesting-runner-2.9.2.jar:junit-4.13.2.jar:hamcrest-3.0.jar   # test-framework dependencies (Maven Central)
CP=$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.document.TestXYShapeWithinLineRejected

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 2026-11-03. AI-assisted; not yet triaged by a human Lucene committer. Feedback: open an issue in lucene-ai-bug-hunt.