Re: [Pkg-octave-devel] Bug#394982: octave2.9: Crashes on "x(:, :)=speye(1)"

[Rafael Laboissiere]

* David Bateman <address@hidden> [2006-10-24 14:18]:

> Thomas Weber wrote:
> >Hi, 
> >
> >Am Dienstag, den 24.10.2006, 12:55 +0200 schrieb Rafael Laboissiere:
> >  
> >>>address@hidden:~/orion/trunk/solver$ octave -q
> >>>octave:1> x(:,:)=speye(1);
> >>>panic: Segmentation fault -- stopping myself...
> >>>Segmentation fault
> >>>address@hidden:~/orion/trunk/solver$
> >>>      
> >
> >I tried this with CVS and it crashes as well:
> >
> >==================================================================
> >octave-2.9.9+:1> x(:,:)=speye(1);
> >*** glibc detected *** free(): invalid next size (fast): 
> >0x0000000001611150 ***
> >panic: Aborted -- stopping myself...
> >attempting to save variables to `octave-core'...
> >save to `octave-core' complete
> >Aborted
> >==================================================================
> >
> >     Thomas
> >
> >  
> 
> I just tried this with a CVS from Sunday on an Mandriva 2006 system and 
> could not generate that same error..

This works in my Debian etch system with octave2.9-2.9.9-3::

    octave2.9:1> speye (1);
    octave2.9:2> x = speye (1);

But this don't:

    octave2.9:1> x (:, :) = speye (1);
    panic: Segmentation fault -- stopping myself...
    *** glibc detected *** malloc(): memory corruption (fast): 0x0904d970 ***
    panic: attempted clean up apparently failed -- aborting...
    Aborted

There is something weird with the indexing operation on the lefthand side
when the variable being assigned is undefined.  For instance, this works:

    octave2.9:1> x = speye (1);
    octave2.9:2> x (:, :) = speye (1);

At any rate, the malloc problem reported in the error message may indicate
some Debian-specific bug.

-- 
Rafael