Name: saC57035 Date: 12/03/96


The java.io.PushbackInputStream.available() method returns incorrect
number of bytes available.


Here is the test demonstrating the bug:

-----------------Test.java------------------------
import java.io.*;

public class Test {

public static void main( String argv[] ) {
 PushbackInputStream in = new PushbackInputStream(
          new ByteArrayInputStream(new byte[10]),5);
 try {
   System.out.println("Here must be 10: "+in.available());
   in.read();
   System.out.println("Here must be 9: "+in.available());
   in.unread(20);
   System.out.println("Here must be 10: "+in.available());
   in.unread(20);
   System.out.println("Here must be 11: "+in.available());
 } catch (Throwable e) {
   System.out.println("Test failed: unexpected "+e+" is thrown");
 }
}

}
---------Output from the test---------------------
Here must be 10: 15
Here must be 9: 14
Here must be 10: 13
Here must be 11: 12
-------------------------------------------------

The bug is easy to fix replacing the statement in

    public int available() throws IOException {
return pos + super.available();
    }

with

return buf.length - pos + super.available();

That's all. Thanks.


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