Merge pull request #365 from Nadahar/BitShiftingBug

Fix bit shifting bug

Source/com/drew/lang/ByteUtil.java

@@ -36,11 +36,11 @@ public static long getLong64(byte[] buffer, int offset, boolean bigEndian)
     {
         if (bigEndian) {
             return
-                ((buffer[offset    ] & 0xFF) << 56) |
-                ((buffer[offset + 1] & 0xFF) << 48) |
-                ((buffer[offset + 2] & 0xFF) << 40) |
-                ((buffer[offset + 3] & 0xFF) << 32) |
-                ((buffer[offset + 4] & 0xFF) << 24) |
+                ((long) (buffer[offset    ] & 0xFF) << 56) |
+                ((long) (buffer[offset + 1] & 0xFF) << 48) |
+                ((long) (buffer[offset + 2] & 0xFF) << 40) |
+                ((long) (buffer[offset + 3] & 0xFF) << 32) |
+                ((long) (buffer[offset + 4] & 0xFF) << 24) |
                 ((buffer[offset + 5] & 0xFF) << 16) |
                 ((buffer[offset + 6] & 0xFF) <<  8) |
                 ((buffer[offset + 7] & 0xFF));
@@ -50,11 +50,11 @@ public static long getLong64(byte[] buffer, int offset, boolean bigEndian)
                 ((buffer[offset    ] & 0xFF)      ) |
                 ((buffer[offset + 1] & 0xFF) <<  8) |
                 ((buffer[offset + 2] & 0xFF) << 16) |
-                ((buffer[offset + 3] & 0xFF) << 24) |
-                ((buffer[offset + 4] & 0xFF) << 32) |
-                ((buffer[offset + 5] & 0xFF) << 40) |
-                ((buffer[offset + 6] & 0xFF) << 48) |
-                ((buffer[offset + 7] & 0xFF) << 56);
+                ((long) (buffer[offset + 3] & 0xFF) << 24) |
+                ((long) (buffer[offset + 4] & 0xFF) << 32) |
+                ((long) (buffer[offset + 5] & 0xFF) << 40) |
+                ((long) (buffer[offset + 6] & 0xFF) << 48) |
+                ((long) (buffer[offset + 7] & 0xFF) << 56);
         }
     }
 }

Tests/com/drew/lang/ByteUtilTest.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2002-2018 Drew Noakes
+ *
+ *    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.
+ *
+ * More information about this project is available at:
+ *
+ *    https://drewnoakes.com/code/exif/
+ *    https://github.com/drewnoakes/metadata-extractor
+ */
+
+package com.drew.lang;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Nadahar
+ */
+public class ByteUtilTest
+{
+    @Test
+    public void testGetInt16() {
+        byte[] buffer = new byte[] {0x7F, (byte) 0xFF};
+        assertEquals(0x7FFF, ByteUtil.getInt16(buffer, 0, true));
+        assertEquals(0xFF7F, ByteUtil.getInt16(buffer, 0, false));
+
+        buffer = new byte[] {(byte) 0xFF, (byte) 0xFF};
+        assertEquals(0xFFFF, ByteUtil.getInt16(buffer, 0, true));
+        assertEquals(0xFFFF, ByteUtil.getInt16(buffer, 0, false));
+
+        buffer = new byte[] {0x1, 0x0};
+        assertEquals(0x100, ByteUtil.getInt16(buffer, 0, true));
+        assertEquals(0x1, ByteUtil.getInt16(buffer, 0, false));
+
+        buffer = new byte[] {0x7F, (byte) 0xFF, 0x7F, (byte) 0xFF, 0x7F, (byte) 0xFF};
+        assertEquals(0xFF7F, ByteUtil.getInt16(buffer, 1, true));
+        assertEquals(0x7FFF, ByteUtil.getInt16(buffer, 1, false));
+        assertEquals(0x7FFF, ByteUtil.getInt16(buffer, 2, true));
+        assertEquals(0xFF7F, ByteUtil.getInt16(buffer, 2, false));
+    }
+
+    @Test
+    public void testGetInt32() {
+        byte[] buffer = new byte[] {0x7F, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF};
+        assertEquals(0x7FFFFFFF, ByteUtil.getInt32(buffer, 0, true));
+        assertEquals(0xFFFFFF7F, ByteUtil.getInt32(buffer, 0, false));
+
+        buffer = new byte[] {(byte) 0xFF, (byte) 0xFF, 0x0, 0x0};
+        assertEquals(0xFFFF0000, ByteUtil.getInt32(buffer, 0, true));
+        assertEquals(0xFFFF, ByteUtil.getInt32(buffer, 0, false));
+
+        buffer = new byte[] {0x1, 0x0, 0x1, 0x0};
+        assertEquals(0x1000100, ByteUtil.getInt32(buffer, 0, true));
+        assertEquals(0x10001, ByteUtil.getInt32(buffer, 0, false));
+
+        buffer = new byte[] {0x7F, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, 0x7F, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF};
+        assertEquals(0xFFFFFF7F, ByteUtil.getInt32(buffer, 1, true));
+        assertEquals(0x7FFFFFFF, ByteUtil.getInt32(buffer, 1, false));
+        assertEquals(0x7FFFFFFF, ByteUtil.getInt32(buffer, 4, true));
+        assertEquals(0xFFFFFF7F, ByteUtil.getInt32(buffer, 4, false));
+    }
+
+    @Test
+    public void testGetInt64() {
+        byte[] buffer = new byte[] {
+            0x7F, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF,
+            (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF
+        };
+        assertEquals(0x7FFFFFFFFFFFFFFFL, ByteUtil.getLong64(buffer, 0, true));
+        assertEquals(0xFFFFFFFFFFFFFF7FL, ByteUtil.getLong64(buffer, 0, false));
+
+        buffer = new byte[] {(byte) 0xFF, (byte) 0xFF, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0};
+        assertEquals(0xFFFF000000000000L, ByteUtil.getLong64(buffer, 0, true));
+        assertEquals(0xFFFFL, ByteUtil.getLong64(buffer, 0, false));
+
+        buffer = new byte[] {0x1, 0x0, 0x1, 0x0, 0x1, 0x0, 0x1, 0x0};
+        assertEquals(0x100010001000100L, ByteUtil.getLong64(buffer, 0, true));
+        assertEquals(0x1000100010001L, ByteUtil.getLong64(buffer, 0, false));
+
+        buffer = new byte[] {
+            0x7F, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF,
+            0x7F, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF,
+            0x7F, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF,
+            0x7F, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF
+        };
+        assertEquals(0xFFFFFF7FFFFFFF7FL, ByteUtil.getLong64(buffer, 1, true));
+        assertEquals(0x7FFFFFFF7FFFFFFFL, ByteUtil.getLong64(buffer, 1, false));
+        assertEquals(0x7FFFFFFF7FFFFFFFL, ByteUtil.getLong64(buffer, 8, true));
+        assertEquals(0xFFFFFF7FFFFFFF7FL, ByteUtil.getLong64(buffer, 8, false));
+    }
+}