[fix #537] fix convert byte[] to long error (#538)

Co-authored-by: Liangliang Gu <marsishandsome@gmail.com>
Co-authored-by: Jian Zhang <zjsariel@gmail.com>

Author: 3 people

src/main/java/org/tikv/common/columnar/TiChunkColumnVector.java

@@ -178,7 +178,7 @@ private long getLongFromBinary(int rowId) {
     if (bytes.length == 0) return 0;
     long result = 0;
     for (byte b : bytes) {
-      result = (result << 8) | b;
+      result = (result << 8) | (b & 0xff);
     }
     return result;
   }

src/test/java/org/tikv/common/columnar/TiChunkColumnVectorTest.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2022 TiKV Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.tikv.common.columnar;
+
+import java.nio.ByteBuffer;
+import junit.framework.TestCase;
+import org.junit.Assert;
+import org.junit.Test;
+import org.tikv.common.types.BitType;
+
+public class TiChunkColumnVectorTest extends TestCase {
+
+  @Test
+  public void testGetLong() {
+    long expect = 32767;
+    ByteBuffer buffer = ByteBuffer.allocate(8);
+    buffer.putLong(expect);
+    TiChunkColumnVector tiChunkColumnVector =
+        new TiChunkColumnVector(BitType.BIT, -1, 1, 0, new byte[] {-1}, new long[] {0, 8}, buffer);
+    Assert.assertEquals(expect, tiChunkColumnVector.getLong(0));
+  }
+}