Flexible query parser: SlopQueryNode and PhraseSlopQueryNode print their int slop through a float, so toQueryString changes every slop above 2^24 (~16777217 prints ~16777216, ~2147483647 prints ~2147483648, which the parser rejects)

Finding LFV-892Area: queryparser / flexible parser node serialization (SlopQueryNode and PhraseSlopQueryNode toQueryString/toString)Priority: lowImpact: minorNovelty: new

Finding page for LFV-892

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

What it shows

You parse "a b"~16777217, or the 'any distance' phrase "a b"~2147483647, with the flexible StandardSyntaxParser, print the node tree with toQueryString, and expect the same slop back, since QueryNode#toQueryString is documented as 'convert to a query string understood by the query parser' and the package documentation says the string 'can be parsed back by the original text parser'. Instead SlopQueryNode prints ~16777216, and ~2147483648 for the second query, which the same parser rejects with NumberFormatException, because getValueString boxes the int slop into a Float and prints its long value, so every slop above 2^24 is rounded to the nearest float. PhraseSlopQueryNode has the same helper (123456789 prints ~123456792), and toString() of both nodes uses it too.

The test shows that the flexible StandardSyntaxParser parses f:"a b"~2147483647 into a SlopQueryNode that keeps the int slop, but SlopQueryNode.toQueryString prints the slop through a Float, so the text does not round-trip.

Expected vs actual

Expected f:"a b"~2147483647; actual f:"a b"~2147483648 (a slop the parser rejects), 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:$LUCENE/lucene/queries/build/libs/lucene-queries-$V.jar
CP=$CP:$LUCENE/lucene/queryparser/build/libs/lucene-queryparser-$V.jar
CP=$CP:$LUCENE/lucene/sandbox/build/libs/lucene-sandbox-$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.queryparser.flexible.core.nodes.TestSlopQueryNodeToQueryString

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).

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.