Index: lucene/src/java/org/apache/lucene/index/ParallelReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/ParallelReader.java	(revision 1239141)
+++ lucene/src/java/org/apache/lucene/index/ParallelReader.java	(working copy)
@@ -21,10 +21,9 @@
 import java.util.*;
 
 import org.apache.lucene.util.Bits;
-import org.apache.lucene.util.BytesRef;
 
 
-/** An AtomicIndexReader which reads multiple, parallel indexes.  Each index added
+/** An {@link AtomicReader} which reads multiple, parallel indexes.  Each index added
  * must have the same number of documents, but typically each contains
  * different fields.  Each document contains the union of the fields of all
  * documents with the same document number.  When searching, matches for a
@@ -42,48 +41,42 @@
  * undefined behavior</em>.
  */
 public class ParallelReader extends AtomicReader {
-  private List<AtomicReader> readers = new ArrayList<AtomicReader>();
-  private List<Boolean> decrefOnClose = new ArrayList<Boolean>(); // remember which subreaders to decRef on close
-  boolean incRefReaders = false;
-  private SortedMap<String,AtomicReader> fieldToReader = new TreeMap<String,AtomicReader>();
-  private Map<AtomicReader,Collection<String>> readerToFields = new HashMap<AtomicReader,Collection<String>>();
-  private List<AtomicReader> storedFieldReaders = new ArrayList<AtomicReader>();
-  private Map<String, DocValues> normsCache = new HashMap<String,DocValues>();
-  private int maxDoc;
-  private int numDocs;
-  private boolean hasDeletions;
-  private final FieldInfos fieldInfos;
-
+  private final FieldInfos fieldInfos = new FieldInfos();
   private final ParallelFields fields = new ParallelFields();
+  private final List<AtomicReader> readers = new ArrayList<AtomicReader>();
+  private final List<Boolean> decrefOnClose = new ArrayList<Boolean>(); // remember which subreaders to decRef on close
+  private final boolean incRefReaders;
+  final SortedMap<String,AtomicReader> fieldToReader = new TreeMap<String,AtomicReader>();
+  private final List<AtomicReader> storedFieldReaders = new ArrayList<AtomicReader>();
+  private final Map<String, DocValues> normsCache = new HashMap<String,DocValues>();
+  private int maxDoc = 0;
+  private int numDocs = 0;
+  private boolean hasDeletions = false;
 
  /** Construct a ParallelReader. 
   * <p>Note that all subreaders are closed if this ParallelReader is closed.</p>
   */
-  public ParallelReader() throws IOException { this(true); }
+  public ParallelReader() throws IOException {
+    this(true);
+  }
    
  /** Construct a ParallelReader. 
   * @param closeSubReaders indicates whether the subreaders should be closed
   * when this ParallelReader is closed
   */
   public ParallelReader(boolean closeSubReaders) throws IOException {
-    super();
     this.incRefReaders = !closeSubReaders;
-    fieldInfos = new FieldInfos();
   }
 
   /** {@inheritDoc} */
   @Override
   public String toString() {
     final StringBuilder buffer = new StringBuilder("ParallelReader(");
-    final Iterator<AtomicReader> iter = readers.iterator();
-    if (iter.hasNext()) {
+    for (final Iterator<AtomicReader> iter = readers.iterator(); iter.hasNext();) {
       buffer.append(iter.next());
+      if (iter.hasNext()) buffer.append(", ");
     }
-    while (iter.hasNext()) {
-      buffer.append(", ").append(iter.next());
-    }
-    buffer.append(')');
-    return buffer.toString();
+    return buffer.append(')').toString();
   }
   
  /** Add an AtomicIndexReader.
@@ -104,11 +97,9 @@
   *     of {@link AtomicReader#maxDoc()}
   * @throws IOException if there is a low-level IO error
   */
-  public void add(AtomicReader reader, boolean ignoreStoredFields)
-    throws IOException {
-
+  public void add(AtomicReader reader, boolean ignoreStoredFields) throws IOException {
     ensureOpen();
-    if (readers.size() == 0) {
+    if (readers.isEmpty()) {
       this.maxDoc = reader.maxDoc();
       this.numDocs = reader.numDocs();
       this.hasDeletions = reader.hasDeletions();
@@ -121,7 +112,7 @@
       throw new IllegalArgumentException
         ("All readers must have same numDocs: "+numDocs+"!="+reader.numDocs());
 
-    final FieldInfos readerFieldInfos = MultiFields.getMergedFieldInfos(reader);
+    final FieldInfos readerFieldInfos = reader.getFieldInfos();
     for(FieldInfo fieldInfo : readerFieldInfos) {   // update fieldToReader map
       // NOTE: first reader having a given field "wins":
       if (fieldToReader.get(fieldInfo.name) == null) {
@@ -144,9 +135,9 @@
     }
   }
 
-  private class ParallelFieldsEnum extends FieldsEnum {
-    String currentField;
-    Iterator<String> keys;
+  private final class ParallelFieldsEnum extends FieldsEnum {
+    private String currentField;
+    private final Iterator<String> keys;
     private final Fields fields;
 
     ParallelFieldsEnum(Fields fields) {
@@ -172,10 +163,13 @@
   }
 
   // Single instance of this, per ParallelReader instance
-  private class ParallelFields extends Fields {
+  private final class ParallelFields extends Fields {
     final HashMap<String,Terms> fields = new HashMap<String,Terms>();
 
-    public void addField(String fieldName, Terms terms) throws IOException {
+    ParallelFields() {
+    }
+
+    void addField(String fieldName, Terms terms) throws IOException {
       fields.put(fieldName, terms);
     }
 
@@ -203,7 +197,7 @@
   @Override
   public Bits getLiveDocs() {
     ensureOpen();
-    return readers.get(0).getLiveDocs();
+    return readers.isEmpty() ? null : readers.get(0).getLiveDocs();
   }
 
   @Override
@@ -261,11 +255,6 @@
     return reader==null ? false : reader.hasNorms(field);
   }
 
-  // for testing
-  AtomicReader[] getSubReaders() {
-    return readers.toArray(new AtomicReader[readers.size()]);
-  }
-
   @Override
   protected synchronized void doClose() throws IOException {
     for (int i = 0; i < readers.size(); i++) {
@@ -280,6 +269,7 @@
   // TODO: I suspect this is completely untested!!!!!
   @Override
   public DocValues docValues(String field) throws IOException {
+    ensureOpen();
     AtomicReader reader = fieldToReader.get(field);
     return reader == null ? null : reader.docValues(field);
   }
@@ -287,6 +277,7 @@
   // TODO: I suspect this is completely untested!!!!!
   @Override
   public synchronized DocValues normValues(String field) throws IOException {
+    ensureOpen();
     DocValues values = normsCache.get(field);
     if (values == null) {
       AtomicReader reader = fieldToReader.get(field);