Merge "Improve error message when attempting to open an empty zip"

5 files changed, 68 insertions, 7 deletions

diff --git a/luni/src/main/java/java/util/zip/ZipFile.java b/luni/src/main/java/java/util/zip/ZipFile.java
index 40036cf..4380281 100644
--- a/luni/src/main/java/java/util/zip/ZipFile.java
+++ b/luni/src/main/java/java/util/zip/ZipFile.java
@@ -357,6 +357,9 @@ public class ZipFile implements Closeable, ZipConstants {
 
         raf.seek(0);
         final int headerMagic = Integer.reverseBytes(raf.readInt());
+        if (headerMagic == ENDSIG) {
+            throw new ZipException("Empty zip archive not supported");
+        }
         if (headerMagic != LOCSIG) {
             throw new ZipException("Not a zip archive");
         }
diff --git a/luni/src/test/java/libcore/java/util/zip/ZipFileTest.java b/luni/src/test/java/libcore/java/util/zip/ZipFileTest.java
index 60af4d0..8afc223 100644
--- a/luni/src/test/java/libcore/java/util/zip/ZipFileTest.java
+++ b/luni/src/test/java/libcore/java/util/zip/ZipFileTest.java
@@ -21,7 +21,6 @@ import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
-import java.io.FileWriter;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Enumeration;
@@ -34,6 +33,8 @@ import java.util.zip.ZipInputStream;
 import java.util.zip.ZipOutputStream;
 import junit.framework.TestCase;
 
+import tests.support.resource.Support_Resources;
+
 public final class ZipFileTest extends TestCase {
     /**
      * Exercise Inflater's ability to refill the zlib's input buffer. As of this
@@ -468,4 +469,30 @@ public final class ZipFileTest extends TestCase {
         out.closeEntry();
         out.close();
     }
+
+    /**
+     * RI does not allow reading of an empty zip using a {@link ZipFile}.
+     */
+    public void testConstructorFailsWhenReadingEmptyZipArchive() throws IOException {
+
+        File resources = Support_Resources.createTempFolder();
+        File emptyZip = Support_Resources.copyFile(
+                resources, "java/util/zip", "EmptyArchive.zip");
+
+        try {
+            // The following should fail with an exception but if it doesn't then we need to clean
+            // up the resource so we need a reference to it.
+            ZipFile zipFile = new ZipFile(emptyZip);
+
+            // Clean up the resource.
+            try {
+                zipFile.close();
+            } catch (Exception e) {
+                // Ignore
+            }
+            fail();
+        } catch (ZipException expected) {
+            // expected
+        }
+    }
 }
diff --git a/luni/src/test/java/libcore/java/util/zip/ZipInputStreamTest.java b/luni/src/test/java/libcore/java/util/zip/ZipInputStreamTest.java
index cb98322..3d6e600 100644
--- a/luni/src/test/java/libcore/java/util/zip/ZipInputStreamTest.java
+++ b/luni/src/test/java/libcore/java/util/zip/ZipInputStreamTest.java
@@ -20,15 +20,16 @@ import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.OutputStream;
 import java.util.Arrays;
 import java.util.Random;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
-import java.util.zip.ZipOutputStream;
 import junit.framework.TestCase;
 
+import tests.support.resource.Support_Resources;
+
 public final class ZipInputStreamTest extends TestCase {
+
     public void testShortMessage() throws IOException {
         byte[] data = "Hello World".getBytes("UTF-8");
         byte[] zipped = ZipOutputStreamTest.zip("short", data);
@@ -59,4 +60,18 @@ public final class ZipInputStreamTest extends TestCase {
         in.close();
         return out.toByteArray();
     }
+
+    /**
+     * Reference implementation allows reading of empty zip using a {@link ZipInputStream}.
+     */
+    public void testReadEmpty() throws IOException {
+        InputStream emptyZipIn = Support_Resources.getStream("java/util/zip/EmptyArchive.zip");
+        ZipInputStream in = new ZipInputStream(emptyZipIn);
+        try {
+            ZipEntry entry = in.getNextEntry();
+            assertNull("An empty zip has no entries", entry);
+        } finally {
+            in.close();
+        }
+    }
 }
diff --git a/luni/src/test/java/libcore/java/util/zip/ZipOutputStreamTest.java b/luni/src/test/java/libcore/java/util/zip/ZipOutputStreamTest.java
index e7c518f..dc80512 100644
--- a/luni/src/test/java/libcore/java/util/zip/ZipOutputStreamTest.java
+++ b/luni/src/test/java/libcore/java/util/zip/ZipOutputStreamTest.java
@@ -16,15 +16,15 @@
 
 package libcore.java.util.zip;
 
-import java.io.ByteArrayInputStream;
+import java.io.BufferedOutputStream;
 import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
 import java.util.Arrays;
 import java.util.Random;
 import java.util.zip.ZipEntry;
-import java.util.zip.ZipInputStream;
+import java.util.zip.ZipException;
 import java.util.zip.ZipOutputStream;
 import junit.framework.TestCase;
 
@@ -60,4 +60,20 @@ public final class ZipOutputStreamTest extends TestCase {
         zippedOut.close();
         return bytesOut.toByteArray();
     }
+
+    /**
+     * Reference implementation does NOT allow writing of an empty zip using a
+     * {@link ZipOutputStream}.
+     */
+    public void testCreateEmpty() throws IOException {
+        File result = File.createTempFile("ZipFileTest", "zip");
+        ZipOutputStream out =
+                new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(result)));
+        try {
+            out.close();
+            fail("Close on empty stream failed to throw exception");
+        } catch (ZipException e) {
+            // expected
+        }
+    }
 }
diff --git a/luni/src/test/resources/tests/resources/java/util/zip/EmptyArchive.zip b/luni/src/test/resources/tests/resources/java/util/zip/EmptyArchive.zip
new file mode 100644
index 0000000..15cb0ec
--- /dev/null
+++ b/luni/src/test/resources/tests/resources/java/util/zip/EmptyArchive.zip