Re: Segmentation Fault with Octave MXE under Windows

[Daniel J Sebald]

On 07/09/2014 12:17 PM, ijourneaux wrote:
> Daniel Sebald wrote
> > If this destructor is called such that "delete rep" occurs, and then it
> > is called again, rep is out of scope and trying to access rep->count
> > fails.  Try changing this hunk of code to something like the following:
> >
> >     virtual ~Array (void)
> >     {
> >       if (!rep)
> >         return;
> >
> >       if (--rep->count == 0)
> >       {
> >         delete rep;
> >         rep = NULL;
> >       }
> >     }
> >
> > If that fixes the problem, then we need a changeset for that (one that
> > makes sure "rep" is initialized properly at the constructor.
> >
> > Dan
>
> I was finally able to try this modification out. That produced a different
> error.
>
>
> 0x00DCAD12 (0x0022F960 0x1A181D98 0x0022FFC4 0x778B8CD5), _ZN5ArrayIdED2Ev()
> + 0
> x12 bytes(s)
> panic: Segmentation violation -- stopping myself...
> attempting to save variables to 'octave-workspace'...
> save to 'octave-workspace' complete
> [Inferior 1 (process 8860) exited with code 03]
>
> trying to back trace produced the message
> No stack
>
> Any thoungts on what I could try next.
> Ian

Did you mean "same error".  Looks very similar, except for the "x12 
bytes(s)" [should be "byte(s)", apparently a typo in the kernel], where 
before it was "x10 bytes(s)".  Or is it the

"[Inferior 1 (process 8860) exited with code 03]"

that is new?

What to try next?  Not sure.  One simple thing you could do so long as 
you are compiling is add the line "fprintf" below to rule out use of the 
null pointer as being an (i.e., one of multiple) issue:

   virtual ~Array (void)
   {
     if (!rep)
     {
       fprintf(stderr, "NULL POINTER!  RETURNING.\n");
       return;
     }

     if (--rep->count == 0)
     {
       delete rep;
       rep = NULL;
     }
   }

Dan