Index: contrib/queryparser/src/test/org/apache/lucene/queryParser/core/builders/TestQueryTreeBuilder.java
===================================================================
--- contrib/queryparser/src/test/org/apache/lucene/queryParser/core/builders/TestQueryTreeBuilder.java	(revision 0)
+++ contrib/queryparser/src/test/org/apache/lucene/queryParser/core/builders/TestQueryTreeBuilder.java	(revision 0)
@@ -0,0 +1,31 @@
+package org.apache.lucene.queryParser.core.builders;
+
+import junit.framework.Assert;
+
+import org.apache.lucene.queryParser.core.QueryNodeException;
+import org.apache.lucene.queryParser.core.nodes.FieldQueryNode;
+import org.apache.lucene.queryParser.core.nodes.QueryNode;
+import org.apache.lucene.queryParser.core.util.UnescapedCharSequence;
+import org.apache.lucene.util.LuceneTestCase;
+import org.junit.Test;
+
+public class TestQueryTreeBuilder extends LuceneTestCase {
+  
+  @Test
+  public void testSetFieldBuilder() throws QueryNodeException {
+    QueryTreeBuilder qtb = new QueryTreeBuilder();
+    qtb.setBuilder("field", new DummyBuilder());
+    Object result = qtb.build(new FieldQueryNode(new UnescapedCharSequence("field"), "foo", 0, 0));
+    Assert.assertEquals("OK", result);
+    
+  }
+  
+  private static class DummyBuilder implements QueryBuilder {
+
+    public Object build(QueryNode queryNode) throws QueryNodeException {
+      return "OK";
+    }
+    
+  }
+
+}

Property changes on: contrib/queryparser/src/test/org/apache/lucene/queryParser/core/builders/TestQueryTreeBuilder.java
___________________________________________________________________
Added: svn:keywords
   + Rev Date
Added: svn:eol-style
   + native

Index: contrib/queryparser/src/java/org/apache/lucene/queryParser/core/builders/QueryTreeBuilder.java
===================================================================
--- contrib/queryparser/src/java/org/apache/lucene/queryParser/core/builders/QueryTreeBuilder.java	(revision 1056994)
+++ contrib/queryparser/src/java/org/apache/lucene/queryParser/core/builders/QueryTreeBuilder.java	(working copy)
@@ -61,7 +61,7 @@
 
   private HashMap<Class<? extends QueryNode>, QueryBuilder> queryNodeBuilders;
 
-  private HashMap<CharSequence, QueryBuilder> fieldNameBuilders;
+  private HashMap<String, QueryBuilder> fieldNameBuilders;
 
   /**
    * {@link QueryTreeBuilder} constructor.
@@ -73,28 +73,25 @@
   /**
    * Associates a field name with a builder.
    * 
-   * @param fieldName
-   *          the field name
-   * @param builder
-   *          the builder to be associated
+   * @param fieldName the field name
+   * @param builder the builder to be associated
    */
   public void setBuilder(CharSequence fieldName, QueryBuilder builder) {
 
     if (this.fieldNameBuilders == null) {
-      this.fieldNameBuilders = new HashMap<CharSequence, QueryBuilder>();
+      this.fieldNameBuilders = new HashMap<String, QueryBuilder>();
     }
 
-    this.fieldNameBuilders.put(fieldName, builder);
+    this.fieldNameBuilders.put(fieldName.toString(), builder);
 
+
   }
 
   /**
    * Associates a class with a builder
    * 
-   * @param queryNodeClass
-   *          the class
-   * @param builder
-   *          the builder to be associated
+   * @param queryNodeClass the class
+   * @param builder the builder to be associated
    */
   public void setBuilder(Class<? extends QueryNode> queryNodeClass,
       QueryBuilder builder) {
@@ -135,9 +132,14 @@
     QueryBuilder builder = null;
 
     if (this.fieldNameBuilders != null && node instanceof FieldableNode) {
+      CharSequence field = ((FieldableNode) node).getField();
 
-      builder = this.fieldNameBuilders.get(((FieldableNode) node).getField());
+      if (field != null) {
+        field = field.toString();
+      }
 
+      builder = this.fieldNameBuilders.get(field);
+
     }
 
     if (builder == null && this.queryNodeBuilders != null) {
@@ -203,14 +205,13 @@
    * Builds some kind of object from a query tree. Each node in the query tree
    * is built using an specific builder associated to it.
    * 
-   * @param queryNode
-   *          the query tree root node
+   * @param queryNode the query tree root node
    * 
    * @return the built object
    * 
-   * @throws QueryNodeException
-   *           if some node builder throws a {@link QueryNodeException} or if
-   *           there is a node which had no builder associated to it
+   * @throws QueryNodeException if some node builder throws a
+   *         {@link QueryNodeException} or if there is a node which had no
+   *         builder associated to it
    */
   public Object build(QueryNode queryNode) throws QueryNodeException {
     process(queryNode);
Index: contrib/CHANGES.txt
===================================================================
--- contrib/CHANGES.txt	(revision 1056994)
+++ contrib/CHANGES.txt	(working copy)
@@ -48,6 +48,11 @@
 
 Bug fixes
 
+ * LUCENE-2855: contrib queryparser was using CharSequence as key in some internal 
+   Map instances, which was leading to incorrect behaviour, since some CharSequence
+   implementors do not override hashcode and equals methods. Now the internal Maps 
+   are using String instead.
+
  * LUCENE-2068: Fixed ReverseStringFilter which was not aware of supplementary
    characters. During reverse the filter created unpaired surrogates, which
    will be replaced by U+FFFD by the indexer, but not at query time. The filter