I need help debugging COM

[Ove Kaaven]

On Fri, 20 Dec 2002, Mehmet YASAR wrote:

> Hi,
> 
> I'm working on enhancing Wine's Ddraw surface code. I have not enough
> experience of COM (and very small knowledge asm) to understand why I
> have a crash on the following line in my test app test.exe :
> 
> lpov->Lock(NULL, &SurfaceDesc, DDLOCK_WAIT, NULL);
> 
> Here is more info on the crash :
> 
> Wine-dbg>c
> First chance exception: page fault on read access to 0x00000064 in
> 32-bit code (0x00401a7b).

I'd say this probably points to that the vtbl of the interface pointed to
by lpov has not been initialized (the vtbl seems to be a null pointer).
Perhaps you should look into the surface constructor code.