From f4923b98a613866901802795bcc731345b81b312 Mon Sep 17 00:00:00 2001
From: larsh <larsh@unknown>
Date: Sat, 27 Oct 2012 21:24:00 +0000
Subject: [PATCH] HBASE-6846 BitComparator bug - ArrayIndexOutOfBoundsException
 (Lucian George Iordache)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1402882 13f79535-47bb-0310-9956-ffa450edef68
---
 .../hadoop/hbase/filter/BitComparator.java    |  2 +-
 .../hbase/filter/TestBitComparator.java       | 27 +++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/filter/BitComparator.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/filter/BitComparator.java
index 77214845bf6..30bf1feae1c 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/filter/BitComparator.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/filter/BitComparator.java
@@ -114,7 +114,7 @@ public class BitComparator extends ByteArrayComparable {
     }
     int b = 0;
     //Iterating backwards is faster because we can quit after one non-zero byte.
-    for (int i = value.length - 1; i >= 0 && b == 0; i--) {
+    for (int i = length - 1; i >= 0 && b == 0; i--) {
       switch (bitOperator) {
         case AND:
           b = (this.value[i] & value[i+offset]) & 0xff;
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/filter/TestBitComparator.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/filter/TestBitComparator.java
index 302bd219f1a..423b7a57711 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/filter/TestBitComparator.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/filter/TestBitComparator.java
@@ -33,6 +33,11 @@ public class TestBitComparator {
   private static byte[] data1 = new byte[]{15, 0, 0, 0, 0, 0};
   private static byte[] data2 = new byte[]{0, 0, 0, 0, 0, 15};
   private static byte[] data3 = new byte[]{15, 15, 15, 15, 15};
+  
+  // data for testing compareTo method with offset and length parameters
+  private static byte[] data1_2 = new byte[]{15, 15, 0, 0, 0, 0, 0, 15};
+  private static byte[] data2_2 = new byte[]{15, 0, 0, 0, 0, 0, 15, 15};
+  
   private final int Equal = 0;
   private final int NotEqual = 1;
 
@@ -69,5 +74,27 @@ public class TestBitComparator {
     assertEquals(comparator.compareTo(data), expected);
   }
 
+  @Test
+  public void testANDOperationWithOffset() {
+    testOperationWithOffset(data1_2, ones, BitComparator.BitwiseOp.AND, Equal);
+    testOperationWithOffset(data1_2, data0, BitComparator.BitwiseOp.AND, NotEqual);
+    testOperationWithOffset(data2_2, data1, BitComparator.BitwiseOp.AND, NotEqual);
+  }
+
+  @Test
+  public void testOROperationWithOffset() {
+    testOperationWithOffset(data1_2, zeros, BitComparator.BitwiseOp.OR, Equal);
+    testOperationWithOffset(data2_2, data1, BitComparator.BitwiseOp.OR, Equal);
+  }
+
+  @Test
+  public void testXOROperationWithOffset() {
+    testOperationWithOffset(data2_2, data1, BitComparator.BitwiseOp.XOR, Equal);
+  }
+
+  private void testOperationWithOffset(byte[] data, byte[] comparatorBytes, BitComparator.BitwiseOp operator, int expected) {
+    BitComparator comparator = new BitComparator(comparatorBytes, operator);
+    assertEquals(comparator.compareTo(data, 1, comparatorBytes.length), expected);
+  }
 }