[PATCH 3/7] wsdapi: Build and write Types list for Hello message.

[Huw Davies]

On Fri, Apr 20, 2018 at 08:46:23AM +0100, Huw Davies wrote:
> On Fri, Apr 20, 2018 at 08:18:19AM +0100, Owen Rudge wrote:
> > Signed-off-by: Owen Rudge <orudge at codeweavers.com>
> > +static HRESULT build_types_list(LPWSTR buffer, size_t buffer_size, const WSD_NAME_LIST *list, struct list *namespaces)
> > +{
> > +    WCHAR format_string[] = { '%', 's', ':', '%', 's', ' ', 0 };
> > +    LPWSTR current_buf_pos = buffer;
> > +    size_t memory_needed = 0;
> > +    const WSD_NAME_LIST *cur = list;
> > +
> > +    ZeroMemory(buffer, buffer_size);
> > +
> > +    while (cur != NULL)
> > +    {
> > +        /* Calculate space needed, including NULL character, colon and potential trailing space */
> > +        memory_needed = sizeof(WCHAR) * (lstrlenW(cur->Element->LocalName) +
> > +            lstrlenW(cur->Element->Space->PreferredPrefix) + 3);
> > +
> > +        if (current_buf_pos + memory_needed > buffer + buffer_size)
> > +            return E_INVALIDARG;
> > +
> > +        current_buf_pos += wsprintfW(current_buf_pos, format_string, cur->Element->Space->PreferredPrefix,
> > +            cur->Element->LocalName);
> > +
> > +        /* Record the namespace in the discovered namespaces list */
> > +        if (!add_discovered_namespace(namespaces, cur->Element->Space))
> > +            return E_FAIL;
> > +
> > +        cur = cur->Next;
> > +    }
> > +
> > +    /* Remove the last trailing space */
> > +    current_buf_pos--;
> > +    *current_buf_pos = 0;
> 
> Is it possible that list could be NULL so that the while loop is never
> executed?  If so, then the above line would touch buffer[-1].  If
> list is never NULL consider rewriting the loop as a do-while.

And actually, thinking about it a bit more, it would most likely be
cleaner to add the space at the beginning of the loop if (cur != list).

Huw.