DoubleRangeFacetCounts orders -0.0 below +0.0 while DoubleRange.accept and getQuery treat the two zeros as equal: a document holding a zero of the opposite sign at an inclusive zero bound (for example -0.0 in [0, 1]) is matched by the range's own drill-down but not counted, and the accepted range [+0.0, -0.0] makes counting throw

Finding LFV-310Area: facet / range facet counts (DoubleRange bounds and values converted to sortable longs in DoubleRangeFacetCounts, against DoubleRange.accept and getQuery)Priority: lowImpact: silent wrong resultsNovelty: new

Finding page for LFV-310

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

What it shows

You count range facets over a double field with DoubleRangeFacetCounts and a range that starts at an inclusive 0.0, such as new DoubleRange("[0, 1]", 0.0, true, 1.0, true), and some documents hold -0.0 (Java's negative zero, which ordinary arithmetic such as Math.ceil(-0.25) or -1 * 0.0 produces). You expect the count to include every document the range accepts, because DoubleRange.accept and the range's own drill-down query getQuery() compare with primitive >= and <=, treat -0.0 as equal to 0.0, and match those documents. Instead the counter converts bounds and values with NumericUtils.doubleToSortableLong, where -0.0 sorts below +0.0, so those documents are silently left out of the count (likewise +0.0 at an inclusive -0.0 upper bound), and the range [+0.0, -0.0], which the DoubleRange constructor accepts, makes DoubleRangeFacetCounts throw IllegalArgumentException 'matches nothing'.

The test shows that DoubleRangeFacetCounts does not count a document with value -0.0 in the inclusive range [0, 1], although DoubleRange.accept(-0.0) (and so the range's drill-down) is true.

Expected vs actual

Expected a facet count of 1; actual: 0 (expected:<1> but was:<0>), with -ea and -da.

Files

Run it

# 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/facet/build/libs/lucene-facet-$V.jar
CP=$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.facet.range.TestDoubleRangeSignedZero

The module(s) facet also need their third-party runtime jars; ./gradlew -p lucene/<module> dependencies lists them.

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).

Formal models and scripts this finding's part of the hunt used: facet-taxonomy-ranges

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.