KB156798 - BUG: IsEqualGUIDBase(...) Always Returns TRUE Under C++

Article ID: 156798

Article Last Modified on 11/7/2002

APPLIES TO

Microsoft OLE 1.0

This article was previously published under Q156798

1.00 WINDOWS kbusage kbbug1.00

BUG #: 2725 (OLEDBSDK)

SYMPTOMS

In the Oledb.h header file, the IsEqualGUIBase(...) function is defined by the following lines:

   #ifdef __cplusplus
   inline BOOL IsEqualGUIDBase(const GUID &rguid1, const GUID  &rguid2)
   { return !memcmp(&(rguid1.Data2), &(rguid1.Data2),    sizeof(GUID) -
   sizeof(rguid1.Data1)); }

This function will always return TRUE, because it is comparing rguid1.Data2 to itself (rguid1.Data2).

WORKAROUND

To work around this problem, change the second parameter in the memcmp function from rguid1.Data2 to rguid2.Data2. The following is the correct function definition:

   #ifdef __cplusplus
   inline BOOL IsEqualGUIDBase(const GUID &rguid1, const GUID  &rguid2)
   { return !memcmp(&(rguid1.Data2), &(rguid2.Data2),    sizeof(GUID) -
   sizeof(rguid1.Data1)); }

STATUS

Microsoft has confirmed this to be a problem in the OLE Database SDK version 1.0. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional query words: OLE DB 1.00

Keywords: KB156798