[OLE #94] Correctly marshal NULL ppUnk refptrs in NdrPointerMarshall

Mike Hearn mh at codeweavers.com
Mon Jun 6 11:47:23 CDT 2005

On Mon, 2005-06-06 at 11:11 -0500, Robert Shearman wrote:
> Exactly. A refptr shouldn't have those extra 4 bytes because it should
> never be NULL. I would be very surprised if Microsoft have chosen to
> be inconsistent here.

Refptrs can't be NULL but their contents once de-referenced can be, the
problem here is that we have a function like this:

Foo([in] ?? a, [in] ?? b, [out] IBar **bar);

bar is a refptr, it's not NULL. But the contents once dereferenced are
(ie, it's returning a null ifptr). We aren't marshalling this correctly
at the moment, instead we don't allocate any space in the buffer for the
refptr itself and just dereference it. Then when we discover it's NULL,
we don't marshal anything (because there's nothing to demarshal) so we
lose sync on the receiving end.

thanks -mike

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