Re: oleaut32: Fix SAFEARRAY marshalling on 64-bit platforms.

[Alexandre Julliard]

Rob Shearman  writes:
> @@ -874,8 +874,8 @@ unsigned char * WINAPI LPSAFEARRAY_UserMarshal(ULONG *pFlags, unsigned char *Buf
>      *(ULONG *)Buffer = ulCellCount;
>      Buffer += sizeof(ULONG);
> -
>    *(ULONG_PTR *)Buffer = (ULONG_PTR)psa->pvData;
> -
>    Buffer += sizeof(ULONG_PTR);
> -
>    *(ULONG *)Buffer = (ULONG)(ULONG_PTR)psa->pvData;
> -
>    Buffer += sizeof(ULONG);

Wouldn't this break if the pointer happens to be 4Gb-aligned?

oleaut32: Fix SAFEARRAY marshalling on 64-bit platforms.

[Rob Shearman]

2009/2/9 Alexandre Julliard :
> Rob Shearman  writes:
> > @@ -874,8 +874,8 @@ unsigned char * WINAPI LPSAFEARRAY_UserMarshal(ULONG *pFlags, unsigned char *Buf
> >      *(ULONG *)Buffer = ulCellCount;
> >      Buffer += sizeof(ULONG);
> > -
> >    *(ULONG_PTR *)Buffer = (ULONG_PTR)psa->pvData;
> > -
> >    Buffer += sizeof(ULONG_PTR);
> > -
> >    *(ULONG *)Buffer = (ULONG)(ULONG_PTR)psa->pvData;
> > -
> >    Buffer += sizeof(ULONG);
>
> Wouldn't this break if the pointer happens to be 4Gb-aligned?

It would write 0 into memory, yes, but the value written here isn't
used during unmarshalling so it is fine and I believe this matches
what native does.

If we wanted to relax the tests, we could change this to "*(ULONG
*)Buffer = psa->pvData ? 0x2 : 0x0" and check the value during
unmarshalling to be totally correct with the NDR-formatted data that
we are writing.

oleaut32: Fix SAFEARRAY marshalling on 64-bit platforms.

[Alexandre Julliard]

Rob Shearman  writes:
> 2009/2/9 Alexandre Julliard :
> > Rob Shearman  writes:
> > > @@ -874,8 +874,8 @@ unsigned char * WINAPI LPSAFEARRAY_UserMarshal(ULONG *pFlags, unsigned char *Buf
> > >      *(ULONG *)Buffer = ulCellCount;
> > >      Buffer += sizeof(ULONG);
> > > -
> > >    *(ULONG_PTR *)Buffer = (ULONG_PTR)psa->pvData;
> > > -
> > >    Buffer += sizeof(ULONG_PTR);
> > > -
> > >    *(ULONG *)Buffer = (ULONG)(ULONG_PTR)psa->pvData;
> > > -
> > >    Buffer += sizeof(ULONG);
> >
> > Wouldn't this break if the pointer happens to be 4Gb-aligned?
>
> It would write 0 into memory, yes, but the value written here isn't
> used during unmarshalling so it is fine and I believe this matches
> what native does.

The exact value doesn't matter, but it seems to me that it won't get
unmarshaled correctly if the value happens to be 0. Am I missing
something?
> If we wanted to relax the tests, we could change this to "*(ULONG
> *)Buffer = psa->pvData ? 0x2 : 0x0" and check the value during
> unmarshalling to be totally correct with the NDR-formatted data that
> we are writing.

Without relaxing the tests you could still write the pointer and only
store 0x2 when you would have stored 0 for a non-null pointer.