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Fix bit shifting bug #365

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merged 1 commit into from
Oct 2, 2018
Merged

Fix bit shifting bug #365

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20 changes: 10 additions & 10 deletions Source/com/drew/lang/ByteUtil.java
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Original file line number Diff line number Diff line change
Expand Up @@ -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));
Expand All @@ -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);
}
}
}
103 changes: 103 additions & 0 deletions Tests/com/drew/lang/ByteUtilTest.java
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Original file line number Diff line number Diff line change
@@ -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));
}
}