Bug in iterators for PersistentVector

[zmanchun]

Hi, I've come across a bug involving iterators for PersistentVectors. The test follows. It happens when you iterate over a vector of length >= 33, but without calling the iterator's "hasNext()" method. (There is no requirement that the hasNext be called if you are sure there is a next element, as far as I know.) If you call the hasNext() method in each iteration the problem goes away.

package edu.udel.cis.vsl.sarl.collections;

import java.util.Iterator;
import org.junit.Test;
import com.github.krukow.clj_ds.PersistentVector;
import com.github.krukow.clj_ds.Persistents;

public class PersistentVectorTest {

private PersistentVector<Integer> makeVec(int n) {
    PersistentVector<Integer> pv = Persistents.vector();

    for (int i = 0; i < n; i++)
        pv = pv.plus(i);
    return pv;
}

private void check(int n) {
    PersistentVector<Integer> pv = makeVec(n);
    Iterator<Integer> iter = pv.iterator();

    for (int i = 0; i < n; i++)
        System.out.println(iter.next());
}

@Test
public void test() {
    check(33);
}

}

java.lang.ArrayIndexOutOfBoundsException: 32
at com.github.krukow.clj_lang.PersistentVector$PersistentVectorIterator.next(PersistentVector.java:370)
at edu.udel.cis.vsl.sarl.collections.PersistentVectorTest.check(PersistentVectorTest.java:25)
at edu.udel.cis.vsl.sarl.collections.PersistentVectorTest.test(PersistentVectorTest.java:30)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)