test/java/lang/StringBuffer/SetLength.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
 * 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).
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 * 2 along with this work; if not, write to the Free Software Foundation,
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/* @test
   @bug 4089062
   @summary A String created from a StringBuffer can be overwritten
   if setLength() to a value less than the buffer length is called
   on the StringBuffer and then the StringBuffer is appended to.
   @author Robert Field
*/

public class SetLength {
    public static void main(String[] argv) throws Exception {
        StringBuffer active = new StringBuffer();
        active.append("first one");
        String a = active.toString();
        active.setLength(0);
        active.append("second");
        String b = active.toString();
        active.setLength(0);
        System.out.println("first: " + a);
        System.out.println("second: " + b);
        if (!a.equals("first one")) {
            throw new Exception("StringBuffer.setLength() overwrote string");
        }
    }
}