/*
* Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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*/
/* @test
* @bug 6334171
* @summary Test that zip file's data descriptor is written correctly.
*/
import java.io.*;
import java.util.*;
import java.util.zip.*;
/**
* Bug 6252735 ZipEntry contains wasteful "temporary storage" fields introduced
* a regression. The value of the general purpose flag bit in a LOC header is
* written incorrectly, because it is computed on stale data.
* <p>
* With the bug present, zipbytes2 is written incorrectly: when the LOC
* header is written, (flag(e) & 8) == 8. This is correct: the data will be
* compressed, so we don't have data length, etc. yet; that should be written
* in the DataDescriptor after the data itself is written. However, when the
* ZipOutputStream that wraps zipbytes2 is closed, the data length _is_
* available, therefore (flag(e) & 8) = 0), therefore the DataDescriptor is
* not written. This is why, with the bug, zipbytes1.length == sizeof(ext
* header) + zipbytes2.length.
* <p>
* The result is an invalid LOC header in zipbytes2. So when we again use
* copyZip, we attempt to read a data length not from the LOC header but from
* the non-existent EXT header, and at that position in the file is some
* arbitrary and incorrect value.
*/
public class DataDescriptor {
static void copyZip(ZipInputStream in, ZipOutputStream out) throws IOException {
byte[] buffer = new byte[1 << 14];
for (ZipEntry ze; (ze = in.getNextEntry()) != null; ) {
out.putNextEntry(ze);
// When the bug is present, it shows up here. The second call to
// copyZip will throw an exception while reading data.
for (int nr; 0 < (nr = in.read(buffer)); ) {
out.write(buffer, 0, nr);
}
}
in.close();
}
private static void realMain(String[] args) throws Throwable {
// Create zip output in byte array zipbytes
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ZipOutputStream zos = new ZipOutputStream(baos);
ZipEntry e = new ZipEntry("testdir/foo");
byte[] data = "entry data".getBytes("ASCII");
zos.putNextEntry(e);
zos.write(data);
zos.close();
byte[] zipbytes1 = baos.toByteArray();
int length1 = zipbytes1.length;
System.out.println("zip bytes pre-copy length=" + length1);
// Make a ZipInputStream around zipbytes, and use
// copyZip to get a new byte array.
ZipInputStream zis =
new ZipInputStream(
new ByteArrayInputStream(zipbytes1));
baos.reset();
zos = new ZipOutputStream(baos);
copyZip(zis, zos);
zos.close();
byte[] zipbytes2 = baos.toByteArray();
int length2 = zipbytes2.length;
// When the bug is present, pre- and post-copy lengths are different!
System.out.println("zip bytes post-copy length=" + length2);
equal(length1, length2);
check(Arrays.equals(zipbytes1, zipbytes2));
// Now use copyZip again on the bytes resulting from the previous
// copy. When the bug is present, copyZip will get an exception this
// time.
baos.reset();
zos = new ZipOutputStream(baos);
copyZip(new ZipInputStream(new ByteArrayInputStream(zipbytes2)), zos);
zos.close();
byte[] zipbytes3 = baos.toByteArray();
int length3 = zipbytes3.length;
System.out.println("zip bytes post-copy length=" + length3);
equal(length1, length3);
check(Arrays.equals(zipbytes1, zipbytes3));
}
//--------------------- Infrastructure ---------------------------
static volatile int passed = 0, failed = 0;
static void pass() {passed++;}
static void fail() {failed++; Thread.dumpStack();}
static void fail(String msg) {System.out.println(msg); fail();}
static void unexpected(Throwable t) {failed++; t.printStackTrace();}
static void check(boolean cond) {if (cond) pass(); else fail();}
static void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else fail(x + " not equal to " + y);}
public static void main(String[] args) throws Throwable {
try {realMain(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new AssertionError("Some tests failed");}
}