Name: avC70361 Date: 10/01/98



  The java.awt.TextArea instance serialized in jdk 1.1.6 is incorectly deserialized in jdk1.2.
In jdk 1.1.6 the constructor accepts all possible values for the scrollbarVisibility parameter,
but in jdk1.2 the constructor tests if the parameter is legal and corrects it if needed. But
this check is not performed during deserialization and if the scrollbarVisibility field has
been set to an illegal value in jdk1.1.6, serialized and deserialized in jdk1.2, the field will
have an illegal value.

Here is a test demonstrating the bug
--------------TextAreaTest.java-------------
import java.awt.TextArea;
import java.io.*;

public class TextAreaTest {

  public static void main(String args[]) {
    TextArea area = new TextArea("area", 40, 60, 5/* an illegal value*/);

    if (args[0].equals("write")) {

      try {

        FileOutputStream fos = new FileOutputStream(args[1]);
        ObjectOutputStream ostream = new ObjectOutputStream(fos);

        ostream.writeObject(area);
        ostream.flush();
        fos.close();

        System.out.println(args[1] + " is successfuly created");

      } catch(IOException e) {
        System.out.println("Unexpected exception : " + e);
      }

    } else if (args[0].equals("read")) {

      try {

        FileInputStream fis = new FileInputStream(args[1]);
        ObjectInputStream istream = new ObjectInputStream(fis);

        TextArea ta = (TextArea)istream.readObject();

        System.out.println(
          "expected scrollbar visibility = " + area.getScrollbarVisibility()
          + ", received scrollbar visibility = " + ta.getScrollbarVisibility()
        );

      } catch(Exception e) {
        System.out.println("Unexpected exception : " + e);
      }
    }

    System.exit(0);
  }
}
-------------The test output---------
JKD1.1.6:
> java -version
java version "1.1.6"
> java TextAreaTest write file
file is successfuly created

JDK1.2:
> java -version
java version "1.2fcs"
Classic VM (build JDK-1.2fcs-L, green threads, sunwjit)
> java TextAreaTest read file
expected scrollbar visibility = 0, received scrollbar visibility = 5

======================================================================