Merge "Use the correct buffer size for the Pushback stream."

2 files changed, 56 insertions, 3 deletions

diff --git a/luni/src/main/java/java/util/zip/GZIPInputStream.java b/luni/src/main/java/java/util/zip/GZIPInputStream.java
index 790adb2..1bfc496 100644
--- a/luni/src/main/java/java/util/zip/GZIPInputStream.java
+++ b/luni/src/main/java/java/util/zip/GZIPInputStream.java
@@ -166,10 +166,14 @@ public class GZIPInputStream extends InflaterInputStream {
         // successfully consumed the GZIP trailer.
         final int remaining = inf.getRemaining() - GZIP_TRAILER_SIZE;
         if (remaining > 0) {
-            // NOTE: This prevents us from creating multiple layers of nested
-            // PushbackInputStreams if we have multiple members in this stream.
+            // NOTE: We make sure we create a pushback stream exactly once,
+            // even if the input stream contains multiple members.
+            //
+            // The push back stream we create must therefore be able to contain
+            // (worst case) the entire buffer even though there may be fewer bytes
+            // remaining when it is first created.
             if (!(in instanceof PushbackInputStream)) {
-                in = new PushbackInputStream(in, BUF_SIZE);
+                in = new PushbackInputStream(in, buf.length);
             }
             ((PushbackInputStream) in).unread(buf,
                     inf.getCurrentOffset() + GZIP_TRAILER_SIZE, remaining);
diff --git a/luni/src/test/java/libcore/java/util/zip/GZIPInputStreamTest.java b/luni/src/test/java/libcore/java/util/zip/GZIPInputStreamTest.java
index b2e012e..494520a 100644
--- a/luni/src/test/java/libcore/java/util/zip/GZIPInputStreamTest.java
+++ b/luni/src/test/java/libcore/java/util/zip/GZIPInputStreamTest.java
@@ -19,12 +19,18 @@ package libcore.java.util.zip;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.EOFException;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Arrays;
 import java.util.Random;
 import java.util.zip.GZIPInputStream;
+import java.util.zip.GZIPOutputStream;
 import junit.framework.TestCase;
+import libcore.io.IoUtils;
+import libcore.io.Streams;
 
 public final class GZIPInputStreamTest extends TestCase {
 
@@ -112,6 +118,49 @@ public final class GZIPInputStreamTest extends TestCase {
         }
     }
 
+    // https://code.google.com/p/android/issues/detail?id=66409
+    public void testMultipleMembersWithCustomBufferSize() throws Exception {
+        final int[] memberSizes = new int[] { 1000, 2000 };
+
+        // We don't care what the exact contents of this file is, as long
+        // as the file has multiple members, and that the (compressed) size of
+        // the second member is larger than the size of the input buffer.
+        //
+        // There's no way to achieve this for a GZIPOutputStream so we generate
+        // pseudo-random sequence of bytes and assert that they don't compress
+        // well.
+        final Random r = new Random(10);
+        byte[] bytes = new byte[3000];
+        r.nextBytes(bytes);
+
+        File f = File.createTempFile("GZIPInputStreamTest", ".gzip");
+        int offset = 0;
+        for (int size : memberSizes) {
+            GZIPOutputStream gzos = null;
+            try {
+                FileOutputStream fos = new FileOutputStream(f, true /* append */);
+                gzos = new GZIPOutputStream(fos, size + 1);
+                gzos.write(bytes, offset, size);
+                offset += size;
+                gzos.finish();
+            } finally {
+                IoUtils.closeQuietly(gzos);
+            }
+        }
+
+        assertTrue(f.length() > 2048);
+
+        FileInputStream fis = new FileInputStream(f);
+        GZIPInputStream gzip = null;
+        try {
+            gzip = new GZIPInputStream(fis, memberSizes[0]);
+            byte[] unzipped = Streams.readFully(gzip);
+            assertTrue(Arrays.equals(bytes, unzipped));
+        } finally {
+            IoUtils.closeQuietly(gzip);
+        }
+    }
+
     public static byte[] gunzip(byte[] bytes) throws IOException {
         ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
         InputStream in = new GZIPInputStream(bis);