Attempt to guard against ExoCache corruption.

library/src/main/java/com/google/android/exoplayer/upstream/TeeDataSource.java

@@ -61,8 +61,11 @@ public final class TeeDataSource implements DataSource {
 
   @Override
   public void close() throws IOException {
-    upstream.close();
-    dataSink.close();
+    try {
+      upstream.close();
+    } finally {
+      dataSink.close();
+    }
   }
 
 }

library/src/main/java/com/google/android/exoplayer/upstream/cache/CacheDataSink.java

@@ -19,6 +19,7 @@ import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.upstream.DataSink;
 import com.google.android.exoplayer.upstream.DataSpec;
 import com.google.android.exoplayer.util.Assertions;
+import com.google.android.exoplayer.util.Util;
 
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -115,11 +116,23 @@ public class CacheDataSink implements DataSink {
   }
 
   private void closeCurrentOutputStream() throws IOException {
-    if (outputStream != null) {
+    if (outputStream == null) {
+      return;
+    }
+
+    boolean success = false;
+    try {
       outputStream.flush();
-      outputStream.close();
+      outputStream.getFD().sync();
+      success = true;
+    } finally {
+      Util.closeQuietly(outputStream);
+      if (success) {
+        cache.commitFile(file);
+      } else {
+        file.delete();
+      }
       outputStream = null;
-      cache.commitFile(file);
       file = null;
     }
   }

library/src/main/java/com/google/android/exoplayer/util/Util.java

@@ -22,6 +22,7 @@ import android.text.TextUtils;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.lang.reflect.Method;
 import java.math.BigDecimal;
 import java.net.HttpURLConnection;
@@ -129,6 +130,19 @@ public final class Util {
     }
   }
 
+  /**
+   * Closes an {@link OutputStream}, suppressing any {@link IOException} that may occur.
+   *
+   * @param outputStream The {@link OutputStream} to close.
+   */
+  public static void closeQuietly(OutputStream outputStream) {
+    try {
+      outputStream.close();
+    } catch (IOException e) {
+      // Ignore.
+    }
+  }
+
   /**
    * Converts text to lower case using {@link Locale#US}.
    *