**Build scan:**
https://gradle-enterprise.elastic.co/s/jdlwrszl7eytk/tests/:server:test/org.elasticsearch.search.aggregations.bucket.composite.InternalCompositeTests/testReduceRandom

**Reproduction line:**
`./gradlew ':server:test' --tests "org.elasticsearch.search.aggregations.bucket.composite.InternalCompositeTests.testReduceRandom" -Dtests.seed=AF4A53AFCDB3506E -Dtests.locale=sr-RS -Dtests.timezone=Asia/Pontianak -Druntime.java=17`

**Applicable branches:**
master

**Reproduces locally?:**
Yes

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.search.aggregations.bucket.composite.InternalCompositeTests&tests.test=testReduceRandom

**Failure excerpt:**
```
java.lang.IndexOutOfBoundsException: Index -1 out of bounds for length 0

  at __randomizedtesting.SeedInfo.seed([AF4A53AFCDB3506E:6F77FFBEEBEEC938]:0)
  at jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:64)
  at jdk.internal.util.Preconditions.outOfBoundsCheckIndex(Preconditions.java:70)
  at jdk.internal.util.Preconditions.checkIndex(Preconditions.java:266)
  at java.util.Objects.checkIndex(Objects.java:359)
  at java.util.ArrayList.get(ArrayList.java:427)
  at org.elasticsearch.search.aggregations.bucket.composite.InternalComposite.finalizeSampling(InternalComposite.java:264)
  at org.elasticsearch.test.InternalAggregationTestCase.testReduceRandom(InternalAggregationTestCase.java:479)
  at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java:-2)
  at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
  at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:568)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.invoke(RandomizedRunner.java:1758)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$8.evaluate(RandomizedRunner.java:946)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$9.evaluate(RandomizedRunner.java:982)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$10.evaluate(RandomizedRunner.java:996)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleSetupTeardownChained$1.evaluate(TestRuleSetupTeardownChained.java:44)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleThreadAndTestName$1.evaluate(TestRuleThreadAndTestName.java:45)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:375)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.forkTimeoutingTask(ThreadLeakControl.java:824)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$3.evaluate(ThreadLeakControl.java:475)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.runSingleTest(RandomizedRunner.java:955)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$5.evaluate(RandomizedRunner.java:840)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$6.evaluate(RandomizedRunner.java:891)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$7.evaluate(RandomizedRunner.java:902)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleStoreClassName$1.evaluate(TestRuleStoreClassName.java:38)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleAssertionsRequired$1.evaluate(TestRuleAssertionsRequired.java:53)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleIgnoreTestSuites$1.evaluate(TestRuleIgnoreTestSuites.java:47)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:375)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.lambda$forkTimeoutingTask$0(ThreadLeakControl.java:831)
  at java.lang.Thread.run(Thread.java:833)

```
server/src/main/java/org/elasticsearch/search/aggregations/bucket/composite/InternalComposite.java
return pos < values.length;
                        }
                        @Override
                        public Entry<String, Object> next() {
                            SimpleEntry<String, Object> entry = new SimpleEntry<>(
                                keys.get(pos),
                                formatObject(values[pos], formats.get(pos))
                            );
                            ++pos;
                            return entry;
                        }
                    };
                }
                @Override
                public int size() {
                    return keys.size();
                }
            };
        }
        @Override
        @SuppressWarnings({ "rawtypes", "unchecked" })
        public int compareTo(ArrayMap that) {
            if (that == this) {
                return 0;
            }
            int idx = 0;
            int max = Math.min(this.keys.size(), that.keys.size());
            while (idx < max) {
                int compare = compareNullables(keys.get(idx), that.keys.get(idx));
                if (compare == 0) {