Index: CHANGES.txt
===================================================================
--- CHANGES.txt	(revision 928716)
+++ CHANGES.txt	(working copy)
@@ -48,6 +48,10 @@
    (for example, text:foo^0) sorted incorrectly and produced
    invalid docids. (yonik)
 
+ * LUCENE-2422: Don't reuse byte[] in IndexInput/Output -- it gains
+   little performance, and ties up possibly large amounts of memory
+   for apps that index large docs.  (Ross Woolf via Mike McCandless)
+
 API Changes
 
  * LUCENE-2190: Added a new class CustomScoreProvider to function package
Index: src/java/org/apache/lucene/store/IndexInput.java
===================================================================
--- src/java/org/apache/lucene/store/IndexInput.java	(revision 918466)
+++ src/java/org/apache/lucene/store/IndexInput.java	(working copy)
@@ -26,7 +26,6 @@
  * @see Directory
  */
 public abstract class IndexInput implements Cloneable {
-  private byte[] bytes;                           // used by readString()
   private char[] chars;                           // used by readModifiedUTF8String()
   private boolean preUTF8Strings;                 // true if we are reading old (modified UTF8) string format
 
@@ -121,8 +120,7 @@
     if (preUTF8Strings)
       return readModifiedUTF8String();
     int length = readVInt();
-    if (bytes == null || length > bytes.length)
-      bytes = new byte[(int) (length*1.25)];
+    final byte[] bytes = new byte[length];
     readBytes(bytes, 0, length);
     return new String(bytes, 0, length, "UTF-8");
   }
@@ -222,7 +220,6 @@
       clone = (IndexInput)super.clone();
     } catch (CloneNotSupportedException e) {}
 
-    clone.bytes = null;
     clone.chars = null;
 
     return clone;
Index: src/java/org/apache/lucene/store/IndexOutput.java
===================================================================
--- src/java/org/apache/lucene/store/IndexOutput.java	(revision 918466)
+++ src/java/org/apache/lucene/store/IndexOutput.java	(working copy)
@@ -29,8 +29,6 @@
  */
 public abstract class IndexOutput {
 
-  private UnicodeUtil.UTF8Result utf8Result = new UnicodeUtil.UTF8Result();
-
   /** Writes a single byte.
    * @see IndexInput#readByte()
    */
@@ -101,6 +99,7 @@
    * @see IndexInput#readString()
    */
   public void writeString(String s) throws IOException {
+    final UnicodeUtil.UTF8Result utf8Result = new UnicodeUtil.UTF8Result();
     UnicodeUtil.UTF16toUTF8(s, 0, s.length(), utf8Result);
     writeVInt(utf8Result.length);
     writeBytes(utf8Result.result, 0, utf8Result.length);