[1/4] msxml3: Added common ISupportErrorInfo implementation

[Jacek Caban]

On 11/21/11 15:16, Nikolay Sivov wrote:
> On 11/21/2011 16:09, Jacek Caban wrote:
>> Hi Nikolay,
>>
>> On 11/21/11 08:24, Nikolay Sivov wrote:
>>>   Added common ISupportErrorInfo implementation
>>
>> +/* common ISupportErrorInfo implementation */
>> +typedef struct {
>> +   ISupportErrorInfo ISupportErrorInfo_iface;
>> +   LONG ref;
>> +
>> +   const tid_t* iids;
>> +} SupportErrorInfo;
>> +
>> +static inline SupportErrorInfo 
>> *impl_from_ISupportErrorInfo(ISupportErrorInfo *iface)
>> +{
>> +    return CONTAINING_RECORD(iface, SupportErrorInfo, 
>> ISupportErrorInfo_iface);
>> +}
>> +
>> +static HRESULT WINAPI 
>> SupportErrorInfo_QueryInterface(ISupportErrorInfo *iface, REFIID 
>> riid, void **obj)
>> +{
>> +    SupportErrorInfo *This = impl_from_ISupportErrorInfo(iface);
>> +    TRACE("(%p)->(%s %p)\n", This, debugstr_guid(riid), obj);
>> +
>> +    *obj = NULL;
>> +
>> +    if (IsEqualGUID(riid,&IID_IUnknown) || 
>> IsEqualGUID(riid,&IID_ISupportErrorInfo)) {
>> +        *obj = iface;
>> +        ISupportErrorInfo_AddRef(iface);
>> +        return S_OK;
>> +    }
>> +
>> +    return E_NOINTERFACE;
>> +}
>>
>>
>>
>> This doesn't seem to be the right approach. You need to return here 
>> interfaces of an object that inherits your ISupportErrorInfo 
>> implementation - that's the COM rule.
> I know but that's not how native works. ISupportErrorInfo reference 
> counting is completely separated from object your queried it from.

Still, QI doesn't look right (unless you also have tests for this). See 
something like this:

IDOMXMLNode_QueryInterface(node, &IID_ISupportErrorInfo, (void**)&sei);
ISupportErrorInfo_QueryInterface(sei, &IID_IDOMXMLNode, (void**)&node2);

The second QueryInterface call should succeeded, but it won't with your 
implementation.

>> Also you probably don't want to create new SupportErrorInfo instance 
>> on each QI call.
> I do. Tests shows that two consecutive QI calls return different 
> pointers.

That's fine then.

Jacek