Index: src/java/org/apache/lucene/analysis/CharArraySet.java
===================================================================
--- src/java/org/apache/lucene/analysis/CharArraySet.java	(revision 893325)
+++ src/java/org/apache/lucene/analysis/CharArraySet.java	(working copy)
@@ -1,5 +1,6 @@
 package org.apache.lucene.analysis;
 
+import java.util.Arrays;
 import java.util.AbstractSet;
 import java.util.Collection;
 import java.util.Collections;
@@ -143,6 +144,13 @@
     this.charUtils = CharacterUtils.getInstance(matchVersion);
     this.matchVersion = matchVersion;
   }
+  
+  /** Clears all entries in this set. This method is supported for reusing, but not {@link Set#remove}. */
+  @Override
+  public void clear() {
+    count = 0;
+    Arrays.fill(entries, null);
+  }
 
   /** true if the <code>len</code> chars of <code>text</code> starting at <code>off</code>
    * are in the set */
@@ -465,6 +473,11 @@
     }
 
     @Override
+    public void clear() {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
     public boolean add(Object o){
       throw new UnsupportedOperationException();
     }
Index: src/test/org/apache/lucene/analysis/TestCharArraySet.java
===================================================================
--- src/test/org/apache/lucene/analysis/TestCharArraySet.java	(revision 893325)
+++ src/test/org/apache/lucene/analysis/TestCharArraySet.java	(working copy)
@@ -72,13 +72,14 @@
     CharArraySet set=new CharArraySet(Version.LUCENE_CURRENT, 10,true);
     set.addAll(Arrays.asList(TEST_STOP_WORDS));
     assertEquals("Not all words added", TEST_STOP_WORDS.length, set.size());
-    try{
-      set.clear();
-      fail("remove is not supported");
-    }catch (UnsupportedOperationException e) {
-      // expected
-      assertEquals("Not all words added", TEST_STOP_WORDS.length, set.size());
-    }
+    set.clear();
+    assertEquals("not empty", 0, set.size());
+    for(int i=0;i<TEST_STOP_WORDS.length;i++)
+      assertFalse(set.contains(TEST_STOP_WORDS[i]));
+    set.addAll(Arrays.asList(TEST_STOP_WORDS));
+    assertEquals("Not all words added", TEST_STOP_WORDS.length, set.size());
+    for(int i=0;i<TEST_STOP_WORDS.length;i++)
+      assertTrue(set.contains(TEST_STOP_WORDS[i]));
   }
   
   public void testModifyOnUnmodifiable(){