AttributeSource.removeAllAttributes() leaves the cached State chain in place, so until the next addAttribute() captureState/restoreState, copyTo, hashCode, the impls iterator, reflection and clearAttributes/endAttributes still act on the removed attributes

Finding LFV-500Area: core / util AttributeSource (removeAllAttributes and the cached State chain, getCurrentState / currentState[0])Priority: lowImpact: minorNovelty: new

Finding page for LFV-500

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 removeAllAttributes() on an AttributeSource (for example a token stream you reuse with a different set of attributes) after it has been used, for example by clearAttributes(), which every Tokenizer calls for each token. You expect it to behave like a new, empty source until you add attributes again, as hasAttributes() (false) and equals() (equal to a new AttributeSource) already say. Instead the method clears its two maps but not the cached chain of attribute instances that captureState(), copyTo(), hashCode(), the impls iterator, reflection and clearAttributes()/endAttributes() walk, so until the next addAttribute() they still see the removed attributes: restoreState(captureState()) on the same source throws IllegalArgumentException, hashCode() differs from that of an equal empty source, and reflectAsString() still prints 'term=foo,...'.

The test shows that AttributeSource.removeAllAttributes() leaves the cached State chain in place, so captureState() still returns the removed attributes and restoring that state into the same source fails.

Expected vs actual

Expected: restoreState(captureState()) after removeAllAttributes() succeeds (captureState javadoc: the state can be restored into this source); actual: IllegalArgumentException: State contains AttributeImpl of type ...CharTermAttributeImpl that is not in in this AttributeSource.

Files

• src/org/apache/lucene/util/TestRemoveAllAttributesCachedState.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.util.TestRemoveAllAttributesCachedState

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.