From 26209efac2a40f60626cf8bddff7ebf87d780350 Mon Sep 17 00:00:00 2001
From: Dain <dain.darnell@readytalk.com>
Date: Fri, 6 Jul 2012 13:53:18 -0600
Subject: [PATCH] Fix an off-by-1 error in the remove method.

The change to only grow the array when the capacity has been reached
exposed a bug in the remove method when shifting the array elements.
---
 classpath/java/util/ArrayList.java |  7 ++++---
 test/List.java                     | 19 +++++++++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/classpath/java/util/ArrayList.java b/classpath/java/util/ArrayList.java
index 3935aa44ec..498d442ecb 100644
--- a/classpath/java/util/ArrayList.java
+++ b/classpath/java/util/ArrayList.java
@@ -131,13 +131,14 @@ public class ArrayList<T> extends AbstractList<T> implements java.io.Serializabl
   public T remove(int index) {
     T v = get(index);
 
-    if (index == size - 1) {
+    int newSize = size - 1;
+
+    if (index == newSize) {
       array[index] = null;
     } else {
-      System.arraycopy(array, index + 1, array, index, size - index);
+      System.arraycopy(array, index + 1, array, index, newSize - index);
     }
 
-    int newSize = size - 1;
     shrink(newSize);
     size = newSize;
 
diff --git a/test/List.java b/test/List.java
index c7d73d93fc..c25950c525 100644
--- a/test/List.java
+++ b/test/List.java
@@ -145,6 +145,24 @@ public class List {
     }
   }
 
+  private static void testRemove() {
+    ArrayList<String> foo = new ArrayList<String>(2);
+    foo.add("Uno");
+    foo.add("Dos");
+    foo.add("Tres");
+    foo.add("Cuatro");
+
+    ArrayList<String> fooToRemove = new ArrayList<String>(2);
+    fooToRemove.add(foo.get(0));
+    fooToRemove.add(foo.get(1));
+
+    for (String s : fooToRemove) {
+      foo.remove(s);
+    }
+
+    expect(foo.size() == 2);
+  }
+
   public static void main(String args[]) {
     ArrayList<Integer> l = new ArrayList<Integer>();
     l.add(1); l.add(2); l.add(3); l.add(4); l.add(5);
@@ -170,5 +188,6 @@ public class List {
     testIterators2(new ArrayList());
     testIterators2(new LinkedList());
     testGrow();
+    testRemove();
   }
 }