--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/lang/StringBuffer/Trim.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,118 @@
+/*
+ * Copyright 2003-2004 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/* @test
+ * @bug 4546734 5007612
+ * @summary Test StringBuffer.trimToSize
+ */
+
+import java.util.Random;
+
+public class Trim {
+    private static Random generator = new Random();
+
+    public static void main(String[] args) throws Exception {
+        bash();
+        //capacityCheck();
+    }
+
+    // Make sure trimToSize is safe to use; it should never cause an
+    // exception or mutation
+    private static void bash() throws Exception {
+        for (int i=0; i<1000; i++) {
+            StringBuffer sb1 = generateTestBuffer(0, 100);
+            StringBuffer sb2 = new StringBuffer(sb1);
+            sb1.trimToSize();
+            if (!sb1.toString().equals(sb2.toString()))
+                throw new RuntimeException(
+                    "trim mutated stringbuffer contents");
+            // Append a random sb
+            StringBuffer sb3 = generateTestBuffer(0, 100);
+            sb1.append(sb3);
+            sb2.append(sb3);
+            if (generator.nextInt(2) == 0)
+                sb1.trimToSize();
+            else
+                sb2.trimToSize();
+            if (!sb1.toString().equals(sb2.toString()))
+                throw new RuntimeException(
+                    "trim mutated stringbuffer contents");
+            // Append sb with lots of extra space
+            sb3 = new StringBuffer(100);
+            sb3.append("a");
+            sb1.append(sb3);
+            sb2.append(sb3);
+            if (generator.nextInt(2) == 0)
+                sb1.trimToSize();
+            else
+                sb2.trimToSize();
+            if (!sb1.toString().equals(sb2.toString()))
+                throw new RuntimeException(
+                    "trim mutated stringbuffer contents");
+        }
+    }
+
+    // This test gives some assurance that trimToSize is working but
+    // it should not be part of an automated run, and a failure here
+    // is not against spec; this method is provided simply to be run
+    // by hand and assure the engineer that it is working. The test
+    // may stop working at some time in the future depending on
+    // how String and StringBuffer are implemented because it depends
+    // upon the capacity method.
+    private static void capacityCheck() {
+        for (int i=0; i<100; i++) {
+            int sizeNeeded = generator.nextInt(1000)+1;
+            int sizeExtra = generator.nextInt(100) + 1;
+            StringBuffer sb = new StringBuffer(sizeNeeded + sizeExtra);
+            StringBuffer sb2 = generateTestBuffer(sizeNeeded, sizeNeeded);
+            if (sb2.length() != sizeNeeded)
+                throw new RuntimeException("sb generated incorrectly");
+            sb.append(sb2);
+            int oldCapacity = sb.capacity();
+            sb.trimToSize();
+            int newCapacity = sb.capacity();
+            if (oldCapacity == newCapacity)
+                throw new RuntimeException("trim failed");
+        }
+    }
+
+    private static int getRandomIndex(int constraint1, int constraint2) {
+        int range = constraint2 - constraint1;
+        if (range <= 0)
+            return constraint1;
+        int x = generator.nextInt(range);
+        return constraint1 + x;
+    }
+
+    private static StringBuffer generateTestBuffer(int min, int max) {
+        StringBuffer aNewStringBuffer = new StringBuffer();
+        int aNewLength = getRandomIndex(min, max);
+        for(int y=0; y<aNewLength; y++) {
+            int achar = generator.nextInt(30)+30;
+            char test = (char)(achar);
+            aNewStringBuffer.append(test);
+        }
+        return aNewStringBuffer;
+    }
+
+}