# HG changeset patch
# User martin
# Date 1410831496 25200
# Node ID 3caa40031b3f881d83ddfcbf26776452d69bfff5
# Parent  1b1ec4291abc0ba6da7bf79b754f08dd759a4a0c
8058520: jar xf does not work on zip files with leading garbage
Summary: Fall back to ZipFile if ZipInputStream finds no entries
Reviewed-by: sherman

diff -r 1b1ec4291abc -r 3caa40031b3f jdk/src/jdk.dev/share/classes/sun/tools/jar/Main.java
--- a/jdk/src/jdk.dev/share/classes/sun/tools/jar/Main.java	Wed Jul 05 20:01:50 2017 +0200
+++ b/jdk/src/jdk.dev/share/classes/sun/tools/jar/Main.java	Mon Sep 15 18:38:16 2014 -0700
@@ -214,7 +214,7 @@
                     in.close();
                 }
                 out.close();
-                if(nflag) {
+                if (nflag) {
                     JarFile jarFile = null;
                     File packFile = null;
                     JarOutputStream jos = null;
@@ -287,11 +287,14 @@
                 }
             } else if (tflag) {
                 replaceFSC(files);
+                // For the "list table contents" action, access using the
+                // ZipFile class is always most efficient since only a
+                // "one-finger" scan through the central directory is required.
                 if (fname != null) {
                     list(fname, files);
                 } else {
                     InputStream in = new FileInputStream(FileDescriptor.in);
-                    try{
+                    try {
                         list(new BufferedInputStream(in), files);
                     } finally {
                         in.close();
@@ -299,6 +302,15 @@
                 }
             } else if (xflag) {
                 replaceFSC(files);
+                // For the extract action, when extracting all the entries,
+                // access using the ZipInputStream class is most efficient,
+                // since only a single sequential scan through the zip file is
+                // required.  When using the ZipFile class, a "two-finger" scan
+                // is required, but this is likely to be more efficient when a
+                // partial extract is requested.  In case the zip file has
+                // "leading garbage", we fall back from the ZipInputStream
+                // implementation to the ZipFile implementation, since only the
+                // latter can handle it.
                 if (fname != null && files != null) {
                     extract(fname, files);
                 } else {
@@ -306,7 +318,9 @@
                         ? new FileInputStream(FileDescriptor.in)
                         : new FileInputStream(fname);
                     try {
-                        extract(new BufferedInputStream(in), files);
+                        if (!extract(new BufferedInputStream(in), files) && fname != null) {
+                            extract(fname, files);
+                        }
                     } finally {
                         in.close();
                     }
@@ -921,14 +935,19 @@
 
     /**
      * Extracts specified entries from JAR file.
+     *
+     * @return whether entries were found and successfully extracted
+     * (indicating this was a zip file without "leading garbage")
      */
-    void extract(InputStream in, String files[]) throws IOException {
+    boolean extract(InputStream in, String files[]) throws IOException {
         ZipInputStream zis = new ZipInputStream(in);
         ZipEntry e;
         // Set of all directory entries specified in archive.  Disallows
         // null entries.  Disallows all entries if using pre-6.0 behavior.
+        boolean entriesFound = false;
         Set<ZipEntry> dirs = newDirSet();
         while ((e = zis.getNextEntry()) != null) {
+            entriesFound = true;
             if (files == null) {
                 dirs.add(extractFile(zis, e));
             } else {
@@ -947,6 +966,8 @@
         // instead of during, because creating a file in a directory changes
         // that directory's timestamp.
         updateLastModifiedTime(dirs);
+
+        return entriesFound;
     }
 
     /**
@@ -958,7 +979,6 @@
         Enumeration<? extends ZipEntry> zes = zf.entries();
         while (zes.hasMoreElements()) {
             ZipEntry e = zes.nextElement();
-            InputStream is;
             if (files == null) {
                 dirs.add(extractFile(zf.getInputStream(e), e));
             } else {
diff -r 1b1ec4291abc -r 3caa40031b3f jdk/test/tools/jar/LeadingGarbage.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/tools/jar/LeadingGarbage.java	Mon Sep 15 18:38:16 2014 -0700
@@ -0,0 +1,139 @@
+/*
+ * Copyright 2014 Google Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * 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.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import sun.tools.jar.Main;
+
+import jdk.testlibrary.OutputAnalyzer;
+import jdk.testlibrary.ProcessTools;
+
+import org.testng.annotations.Test;
+
+/**
+ * @test
+ * @bug 8058520
+ * @summary jar tf and jar xf should work on zip files with leading garbage
+ * @library /lib/testlibrary
+ * @run testng LeadingGarbage
+ */
+@Test
+public class LeadingGarbage {
+    final String jar =
+        Paths.get(new File(System.getProperty("java.home")).getParent(),
+                  "bin", "jar").toString();
+    final File[] files = { new File("a"), new File("b") };
+    final File normalZip = new File("normal.zip");
+    final File leadingGarbageZip = new File("leadingGarbage.zip");
+
+    void createFile(File f) throws IOException {
+        OutputStream fos = new FileOutputStream(f);
+        fos.write(f.getName().getBytes("UTF-8"));
+        fos.close();
+    }
+
+    void createFiles() throws IOException {
+        for (File file : files)
+            createFile(file);
+    }
+
+    void deleteFiles() throws IOException {
+        for (File file : files)
+            assertTrue(file.delete());
+    }
+
+    void assertFilesExist() throws IOException {
+        for (File file : files)
+            assertTrue(file.exists());
+    }
+
+    void createNormalZip() throws Throwable {
+        createFiles();
+        String[] cmd = { jar, "c0Mf", "normal.zip", "a", "b" };
+        ProcessBuilder pb = new ProcessBuilder(cmd);
+        OutputAnalyzer a = ProcessTools.executeProcess(pb);
+        a.shouldHaveExitValue(0);
+        a.stdoutShouldMatch("\\A\\Z");
+        a.stderrShouldMatch("\\A\\Z");
+        deleteFiles();
+    }
+
+    void createZipWithLeadingGarbage() throws Throwable {
+        createNormalZip();
+        createFile(leadingGarbageZip);
+        OutputStream fos = new FileOutputStream(leadingGarbageZip, true);
+        Files.copy(normalZip.toPath(), fos);
+        assertTrue(normalZip.length() < leadingGarbageZip.length());
+        assertTrue(normalZip.delete());
+    }
+
+    public void test_canList() throws Throwable {
+        createNormalZip();
+        assertCanList("normal.zip");
+    }
+
+    public void test_canListWithLeadingGarbage() throws Throwable {
+        createZipWithLeadingGarbage();
+        assertCanList("leadingGarbage.zip");
+    }
+
+    void assertCanList(String zipFileName) throws Throwable {
+        String[] cmd = { jar, "tf", zipFileName };
+        ProcessBuilder pb = new ProcessBuilder(cmd);
+        OutputAnalyzer a = ProcessTools.executeProcess(pb);
+        a.shouldHaveExitValue(0);
+        StringBuilder expected = new StringBuilder();
+        for (File file : files)
+            expected.append(file.getName()).append('\n');
+        a.stdoutShouldMatch(expected.toString());
+        a.stderrShouldMatch("\\A\\Z");
+    }
+
+    public void test_canExtract() throws Throwable {
+        createNormalZip();
+        assertCanExtract("normal.zip");
+    }
+
+    public void test_canExtractWithLeadingGarbage() throws Throwable {
+        createZipWithLeadingGarbage();
+        assertCanExtract("leadingGarbage.zip");
+    }
+
+    void assertCanExtract(String zipFileName) throws Throwable {
+        String[] cmd = { jar, "xf", zipFileName };
+        ProcessBuilder pb = new ProcessBuilder(cmd);
+        OutputAnalyzer a = ProcessTools.executeProcess(pb);
+        a.shouldHaveExitValue(0);
+        a.stdoutShouldMatch("\\A\\Z");
+        a.stderrShouldMatch("\\A\\Z");
+        assertFilesExist();
+    }
+
+}