[Bug classpath/22732] IntBuffer.compareTo is non-transitive

[gcc-bugzilla at gcc dot gnu dot org]

I think I noticed a bug in the Gnu Classpath implementation of
java.nio.IntBuffer while browsing CVS and I wouldn't be surprised if the same
bug is present in the other buffer classes as well. FYI, I have never seen the
Sun source code for the java.nio classes.

The compareTo method begins like this:

  public int compareTo (Object obj)
  {
    IntBuffer a = (IntBuffer) obj;

    if (a.remaining () != remaining ())
      return 1;

This fails transitivity. Consider two buffers a and b with different remaining
sizes:

a.compareTo(b) returns 1 and b.compareTo(a) returns 1. In other words a > b and
b > a. 

I have not actually written test code for this, so possibly I'm missing
something. If so, I apologize. Also my apologies if this is a duplicate report.
Savannah was acting up and I couldn't search the bug database. :-(

I suspect you need something like this instead:

    if (a.remaining () != remaining ()) {
        if (a.remaining() > b.remaining) return 1;
        else return -1;
  }

However, I don't yet know which case should return 1 and which one should
return -1. 


------- Comment #1 from from-classpath at savannah dot gnu dot org  2004-04-01 
17:03 -------
I congratulate you on not requiring me to log in to submit a bug report. Betas
the hell out of Apache. :-)

In case you need to contact me to ask about this. this bug was submitted by
Elliotte Harold. You can reach me at address@hidden,unc.edu. 


------- Comment #2 from from-classpath at savannah dot gnu dot org  2004-04-29 
18:05 -------
I commited a fix to cvs for all buffer classes. The new implementation is
backed by a new mauve test and should be okay now. Thx for your report.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22732