From 694d1de4a912dcb1baade3edfecbe6e152c12e24 Mon Sep 17 00:00:00 2001
From: Stephen Colebourne <scolebourne@apache.org>
Date: Wed, 10 Mar 2004 23:54:48 +0000
Subject: [PATCH] Fix replaceChars() to complete bug 25454

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@137826 13f79535-47bb-0310-9956-ffa450edef68
---
 .../org/apache/commons/lang/StringUtils.java     | 16 +++++++++++-----
 .../org/apache/commons/lang/StringUtilsTest.java | 10 +++++-----
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/java/org/apache/commons/lang/StringUtils.java b/src/java/org/apache/commons/lang/StringUtils.java
index 7e2e5d15d..22a8188e1 100644
--- a/src/java/org/apache/commons/lang/StringUtils.java
+++ b/src/java/org/apache/commons/lang/StringUtils.java
@@ -111,7 +111,7 @@ import java.util.List;
  * @author Al Chou
  * @author Michael Davey
  * @since 1.0
- * @version $Id: StringUtils.java,v 1.128 2004/02/24 22:31:42 fredrik Exp $
+ * @version $Id: StringUtils.java,v 1.129 2004/03/10 23:54:48 scolebourne Exp $
  */
 public class StringUtils {
     // Performance testing notes (JDK 1.4, Jul03, scolebourne)
@@ -2675,19 +2675,25 @@ public class StringUtils {
         if (replaceChars == null) {
             replaceChars = "";
         }
-        StringBuffer buffer = new StringBuffer(str.length());
+        boolean modified = false;
+        StringBuffer buf = new StringBuffer(str.length());
         for (int i = 0; i < str.length(); i++) {
             char ch = str.charAt(i);
             int index = searchChars.indexOf(ch);
             if (index >= 0) {
+                modified = true;
                 if (index < replaceChars.length()) {
-                    buffer.append(replaceChars.charAt(index));
+                    buf.append(replaceChars.charAt(index));
                 }
             } else {
-                buffer.append(ch);
+                buf.append(ch);
             }
         }
-        return buffer.toString();
+        if (modified) {
+            return buf.toString();
+        } else {
+            return str;
+        }
     }
 
     // Overlay
diff --git a/src/test/org/apache/commons/lang/StringUtilsTest.java b/src/test/org/apache/commons/lang/StringUtilsTest.java
index 6da51d24e..d1ab8d986 100644
--- a/src/test/org/apache/commons/lang/StringUtilsTest.java
+++ b/src/test/org/apache/commons/lang/StringUtilsTest.java
@@ -38,7 +38,7 @@ import junit.textui.TestRunner;
  * @author Phil Steitz
  * @author Gary D. Gregory
  * @author Al Chou
- * @version $Id: StringUtilsTest.java,v 1.58 2004/02/18 23:06:19 ggregory Exp $
+ * @version $Id: StringUtilsTest.java,v 1.59 2004/03/10 23:54:48 scolebourne Exp $
  */
 public class StringUtilsTest extends TestCase {
     
@@ -471,8 +471,7 @@ public class StringUtilsTest extends TestCase {
         assertEquals("ayzya", StringUtils.replaceChars("abcba", "bc", "yzx"));
         
         assertEquals("abcba", StringUtils.replaceChars("abcba", "z", "w"));
-        // Comment out for now, delete later when discussion completes [Gary Gregory, Dec 14 2003]
-        //assertSame("abcba", StringUtils.replaceChars("abcba", "z", "w"));
+        assertSame("abcba", StringUtils.replaceChars("abcba", "z", "w"));
         
         // Javadoc examples:
         assertEquals("jelly", StringUtils.replaceChars("hello", "ho", "jy"));
@@ -482,8 +481,9 @@ public class StringUtilsTest extends TestCase {
         
         // From http://nagoya.apache.org/bugzilla/show_bug.cgi?id=25454
         assertEquals("bcc", StringUtils.replaceChars("abc", "ab", "bc"));
-        assertEquals("q651.506bera", StringUtils.replaceChars("d216.102oren", "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789",
-                "nopqrstuvwxyzabcdefghijklmNOPQRSTUVWXYZABCDEFGHIJKLM567891234"));
+        assertEquals("q651.506bera", StringUtils.replaceChars("d216.102oren",
+            "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789",
+            "nopqrstuvwxyzabcdefghijklmNOPQRSTUVWXYZABCDEFGHIJKLM567891234"));
     }
     
     public void testOverlayString_StringStringIntInt() {