jython-users

[Jython-users] Method overriding problem

[Peter B. <bri...@ma...>]

Hi!
I've noticed a problem related to jython classes derived from java
classes. The problem occurs under the following circumstances:

1. A package derives a class A from a java class and overrides a
method M of the java class but calls the original method at some point.
2. The same package derives a class B from class A, overrides the same
method M but calls the corresponding method of A at some point.

Then, when B.M is called, jython seems to go into an infinite loop.
Here's a little program that reproduces the problem:
 
----------------------------------------------------
import java

class spam(java.lang.Object):
    def hashCode(self):
        print 'spam'
        return java.lang.Object.hashCode(self)

class eggs(spam):
    def hashCode(self):
        print 'eggs'
        return spam.hashCode(self)

s=spam()
e=eggs()

print s.hashCode()	# this one works
print e.hashCode()      # here we get stuck
----------------------------------------------------

This shouldn't be happening, right?
Best,
	Peter

Re: [Jython-users] Method overriding problem

[Samuele P. <pe...@in...>]

[Peter Brinkmann]
> ----------------------------------------------------
> import java
> 
> class spam(java.lang.Object):
>     def hashCode(self):
>         print 'spam'
>         return java.lang.Object.hashCode(self)
> 
> class eggs(spam):
>     def hashCode(self):
>         print 'eggs'
>         return spam.hashCode(self)
> 
> s=spam()
> e=eggs()
> 
> print s.hashCode() # this one works
> print e.hashCode()      # here we get stuck
> ----------------------------------------------------
> 
> This shouldn't be happening, right?
Right, this was long standing bug, but has already been fixed in 2.1 codebase.

regards, Samuele Pedroni.  

Re: [Jython-users] Method overriding problem

[Peter B. <bri...@ma...>]

Samuele:
> Right, this was long standing bug, but has already been fixed in 2.1 codebase.

Hmm, is it possible that this bug fix has created a new bug in 2.1 that
I ran into a few days ago? I reported it and it's now listed as bug #449956.
Best,
	Peter



On Mon, Aug 13, 2001 at 12:39:53AM +0200, Samuele Pedroni wrote:
> [Peter Brinkmann]
> > ----------------------------------------------------
> > import java
> > 
> > class spam(java.lang.Object):
> >     def hashCode(self):
> >         print 'spam'
> >         return java.lang.Object.hashCode(self)
> > 
> > class eggs(spam):
> >     def hashCode(self):
> >         print 'eggs'
> >         return spam.hashCode(self)
> > 
> > s=spam()
> > e=eggs()
> > 
> > print s.hashCode() # this one works
> > print e.hashCode()      # here we get stuck
> > ----------------------------------------------------
> > 
> > This shouldn't be happening, right?
> Right, this was long standing bug, but has already been fixed in 2.1 codebase.
> 
> regards, Samuele Pedroni.  
>