Index: src/test/org/apache/lucene/StoreTest.java
===================================================================
--- src/test/org/apache/lucene/StoreTest.java	(revision 290385)
+++ src/test/org/apache/lucene/StoreTest.java	(working copy)
@@ -28,14 +28,13 @@
 class StoreTest {
   public static void main(String[] args) {
     try {
-      test(1000, true);
+      test(1000, true, true);
     } catch (Exception e) {
-      System.out.println(" caught a " + e.getClass() +
-			 "\n with message: " + e.getMessage());
+		e.printStackTrace();
     }
   }
 
-  public static void test(int count, boolean ram)
+  public static void test(int count, boolean ram, boolean buffered)
        throws Exception {
     Random gen = new Random(1251971);
     int i;
@@ -51,6 +50,8 @@
 
     final int LENGTH_MASK = 0xFFF;
 
+	final byte[] buffer = new byte[LENGTH_MASK];
+
     for (i = 0; i < count; i++) {
       String name = i + ".dat";
       int length = gen.nextInt() & LENGTH_MASK;
@@ -59,8 +60,14 @@
 
       IndexOutput file = store.createOutput(name);
 
-      for (int j = 0; j < length; j++)
-	file.writeByte(b);
+      if (buffered) {
+        for (int j = 0; j < length; j++)
+          buffer[j] = b;
+        file.writeBytes(buffer, length);
+      } else {
+        for (int j = 0; j < length; j++)
+          file.writeByte(b);
+      }
       
       file.close();
     }
@@ -89,9 +96,18 @@
       if (file.length() != length)
 	throw new Exception("length incorrect");
 
-      for (int j = 0; j < length; j++)
-	if (file.readByte() != b)
-	  throw new Exception("contents incorrect");
+      byte[] content = new byte[length];
+      if (buffered) {
+        file.readBytes(content, 0, length);
+        // check the buffer
+        for (int j = 0; j < length; j++)
+          if (content[j] != b)
+            throw new Exception("contents incorrect");
+      } else {
+        for (int j = 0; j < length; j++)
+          if (file.readByte() != b)
+            throw new Exception("contents incorrect");
+      }
 
       file.close();
     }
Index: src/java/org/apache/lucene/store/BufferedIndexOutput.java
===================================================================
--- src/java/org/apache/lucene/store/BufferedIndexOutput.java	(revision 290385)
+++ src/java/org/apache/lucene/store/BufferedIndexOutput.java	(working copy)
@@ -41,8 +41,32 @@
    * @see IndexInput#readBytes(byte[],int,int)
    */
   public void writeBytes(byte[] b, int length) throws IOException {
-    for (int i = 0; i < length; i++)
-      writeByte(b[i]);
+    int bytesLeft = BUFFER_SIZE - bufferPosition;
+    // is there enough space in the buffer?
+    if (bytesLeft >= length) {
+      // we add the data to the end of the buffer
+      System.arraycopy(b, 0, buffer, bufferPosition, length);
+      bufferPosition += length;
+      // if the buffer is full, flush it
+      if (BUFFER_SIZE - bufferPosition == 0)
+        flush();
+    } else {
+      // we fill/flush the buffer (until the input is written)
+      int pos = 0; // position in the input data
+      int pieceLength;
+      while (pos < length) {
+        pieceLength = (length - pos < bytesLeft) ? length - pos : bytesLeft;
+        System.arraycopy(b, pos, buffer, bufferPosition, pieceLength);
+        pos += pieceLength;
+        bufferPosition += pieceLength;
+        // if the buffer is full, flush it
+        bytesLeft = BUFFER_SIZE - bufferPosition;
+        if (bytesLeft == 0) {
+          flush();
+          bytesLeft = BUFFER_SIZE;
+        }
+      }
+    }
   }
 
   /** Forces any buffered output to be written. */