ole32: Allow the marshaling/unmarshaling of NULL interfaces for IClassFactory.

dlls/ole32/oleproxy.c

@@ -181,12 +181,19 @@ CFStub_Invoke(
 	    FIXME("Failed to create stream on hglobal\n");
 	    goto getbuffer;
 	}
+	hres = IStream_Write(pStm, &ppv, sizeof(ppv), NULL);
+	if (hres) {
+	   ERR("IStream_Write failed, 0x%08x\n", hres);
+	   goto getbuffer;
+	}
+	if (ppv) {
         hres = CoMarshalInterface(pStm,&iid,ppv,0,NULL,0);
-	IUnknown_Release((IUnknown*)ppv);
+        IUnknown_Release(ppv);
         if (hres) {
             FIXME("CoMarshalInterface failed, %x!\n",hres);
             goto getbuffer;
         }
+    }
 	hres = IStream_Stat(pStm,&ststg,0);
 	if (hres) {
 	    FIXME("Stat failed.\n");
@@ -401,11 +408,16 @@ static HRESULT WINAPI CFProxy_CreateInstance(
 	IRpcChannelBuffer_FreeBuffer(This->chanbuf,&msg);
 	return hres;
     }
+    hres = IStream_Read(pStream, ppv, sizeof(*ppv), NULL);
+    if (hres != S_OK)
+        hres = E_FAIL;
+    else if (*ppv) {
         hres = CoUnmarshalInterface(
 	       pStream,
 	       riid,
 	       ppv
         );
+    }
     IStream_Release(pStream); /* Does GlobalFree hGlobal too. */
 
     IRpcChannelBuffer_FreeBuffer(This->chanbuf,&msg);