From 8ce9ae9e2669b459903440060cb64a42889d921d Mon Sep 17 00:00:00 2001
From: emopers <emopers@gmail.com>
Date: Tue, 15 Jan 2019 08:20:32 -0600
Subject: [PATCH] Fixing hasNext violation in a public class.

Fixing hasNext violation in a public class.
---
 src/main/java/net/imglib2/util/Partition.java  |  4 ++++
 .../java/net/imglib2/util/PartitionTest.java   | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/src/main/java/net/imglib2/util/Partition.java b/src/main/java/net/imglib2/util/Partition.java
index 847c5191b3..2c0639b8c1 100644
--- a/src/main/java/net/imglib2/util/Partition.java
+++ b/src/main/java/net/imglib2/util/Partition.java
@@ -37,6 +37,7 @@
 import java.util.Comparator;
 import java.util.List;
 import java.util.ListIterator;
+import java.util.NoSuchElementException;
 
 /**
  * TODO
@@ -1115,6 +1116,9 @@ else if ( j.previousIndex() == i.nextIndex() - 1 )
 	 */
 	public static < T extends Comparable< T > > void partitionSubList( final ListIterator< T > i, final ListIterator< T > j, final int[] permutation )
 	{
+                if (!i.hasNext() || !j.hasPrevious()) {
+                    throw new NoSuchElementException("Invalid iterators for partitioning a sublist.");
+                }
 		final int pivotIndex = j.previousIndex();
 		final int permutationPivot = permutation[ pivotIndex ];
 		final T pivot = j.previous();
diff --git a/src/test/java/net/imglib2/util/PartitionTest.java b/src/test/java/net/imglib2/util/PartitionTest.java
index bce83b4c46..ad1983d536 100644
--- a/src/test/java/net/imglib2/util/PartitionTest.java
+++ b/src/test/java/net/imglib2/util/PartitionTest.java
@@ -36,12 +36,15 @@
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.ListIterator;
+import java.util.NoSuchElementException;
 
 import org.junit.Test;
 
@@ -405,6 +408,21 @@ public void testPartitionFloatObjectComparatorPermutation()
 			assertTrue( values.get( k ).equals( origvalues.get( permutation[ k ] ) ) );
 	}
 
+	@Test
+	public void testPartitionEmptyFloatObjectIteratorPermutation()
+        {
+            final ArrayList< Float > values = new ArrayList< Float >();
+            final ListIterator< Float > iIterator = values.listIterator();
+            final ListIterator< Float > jIterator = values.listIterator( values.size() );
+            final int[] permutation = new int[ values.size() ];
+            try {
+                Partition.partitionSubList( iIterator, jIterator, permutation );
+                fail( "Expected a NoSuchElementException to be thrown" );
+            } catch ( NoSuchElementException noSuchElementException )  {
+                assertEquals( noSuchElementException.getMessage(), "Invalid iterators for partitioning a sublist." );
+            }
+        }
+
 	@Test
 	public void testPartitionFloatObjectIteratorPermutation()
 	{