Fix clone() and add a unit test.

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@234360 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/lang/text/StrTokenizer.java

@@ -1056,7 +1056,7 @@ public Object clone() {
         try {
             StrTokenizer cloned = (StrTokenizer) super.clone();
             if (cloned.chars != null) {
-                cloned.chars = cloned.chars;
+                cloned.chars = (char[]) cloned.chars.clone();
             }
             cloned.reset();
             return cloned;

src/test/org/apache/commons/lang/text/StrTokenizerTest.java

@@ -542,6 +542,34 @@ public void testChaining() {
         assertEquals(tok, tok.setIgnoreEmptyTokens(false));
     }
 
+    public void testCloneNull() {
+        StrTokenizer tokenizer = new StrTokenizer((char[]) null);
+        // Start sanity check
+        assertEquals(null, tokenizer.nextToken());
+        tokenizer.reset();
+        assertEquals(null, tokenizer.nextToken());
+        // End sanity check
+        StrTokenizer clonedTokenizer = (StrTokenizer) tokenizer.clone();
+        tokenizer.reset();
+        assertEquals(null, tokenizer.nextToken());
+        assertEquals(null, clonedTokenizer.nextToken());
+    }
+
+    public void testCloneReset() {
+        char[] input = new char[]{'a'};
+        StrTokenizer tokenizer = new StrTokenizer(input);
+        // Start sanity check
+        assertEquals("a", tokenizer.nextToken());
+        tokenizer.reset();
+        assertEquals("a", tokenizer.nextToken());
+        // End sanity check
+        StrTokenizer clonedTokenizer = (StrTokenizer) tokenizer.clone();
+        input[0] = 'b';
+        tokenizer.reset();
+        assertEquals("b", tokenizer.nextToken());
+        assertEquals("a", clonedTokenizer.nextToken());
+    }
+  
     // -----------------------------------------------------------------------
     public void testConstructor_String() {
         StrTokenizer tok = new StrTokenizer("a b");