Index: lucene/analysis/common/src/java/org/apache/lucene/analysis/util/StemmerUtil.java
===================================================================
--- lucene/analysis/common/src/java/org/apache/lucene/analysis/util/StemmerUtil.java	(revision 1525521)
+++ lucene/analysis/common/src/java/org/apache/lucene/analysis/util/StemmerUtil.java	(working copy)
@@ -85,11 +85,14 @@
    * @param pos Position of character to delete
    * @param len length of input buffer
    * @return length of input buffer after deletion
+   * 
+   * @lucene.internal
    */
   public static int delete(char s[], int pos, int len) {
-    if (pos < len) 
+    assert pos < len;
+    if (pos < len - 1) { // don't arraycopy if asked to delete last character
       System.arraycopy(s, pos + 1, s, pos, len - pos - 1);
-    
+    }
     return len - 1;
   }
   
@@ -101,11 +104,14 @@
    * @param len Length of input buffer
    * @param nChars number of characters to delete
    * @return length of input buffer after deletion
+   * 
+   * @lucene.internal
    */
   public static int deleteN(char s[], int pos, int len, int nChars) {
-    // TODO: speed up, this is silly
-    for (int i = 0; i < nChars; i++)
-      len = delete(s, pos, len);
-    return len;
+    assert pos + nChars <= len;
+    if (pos + nChars < len) { // don't arraycopy if asked to delete the last characters
+      System.arraycopy(s, pos + nChars, s, pos, len - pos - nChars);
+    }
+    return len - nChars;
   }
 }