[omniORB] crash in _NP_alignedSize

[Duncan Grisby]

On Thursday 29 November, garfield-omniorb@irving.iisd.sra.com wrote:

[...]
> My C++ servant implementation returns 0.  Something like:
> 
>         class B_impl : ..... {
>             A *op(void) { return 0; }
>         };
> 
> This causes a segmentation violation in the function _NP_alignedSize
> of the structure's implementation.  I have tried this with both the
> 3.0.4 release and with the omni3_develop cvs branch.
> 
> My question is: is this a bug in omniORB or am I performing an illegal
> operation.  If the later, can you give me a reference as to where it
> is declared illegal?

It is illegal. You must never return null pointers from CORBA
operations. See section 1.22 of the C++ mapping, where it says:

  "...A callee may not return a null pointer under any of the
   following circumstances:

     * out and return variable-length struct
     ...
  "

This is on page 105 of http://www.omg.org/cgi-bin/doc?ptc/2001-06-07

Cheers,

Duncan.

-- 
 -- Duncan Grisby  \  Research Engineer  --
  -- AT&T Laboratories Cambridge          --
   -- http://www.uk.research.att.com/~dpg1 --