handle unimplemented function stubs

Hello all,

I'm a Windows software developer and I'm trying to execute an application under the wine environment.
Now I have a problem introduced with wine 0.9.49.

I use the function RegOverridePredefKey from the advapi32.dll.
To be compatible with older windows versions, I use the following code:

LONG WINAPI (*RegOverridePredefKey)(HKEY hKey, HKEY hNewHKey);
  HMODULE hMod=GetModuleHandle("Advapi32");
  if (hMod)
    (FARPROC)RegOverridePredefKey=GetProcAddress(hMod,"RegOverridePredefKey");
  if (RegOverridePredefKey)
    RegOverridePredefKey(HKEY_CLASSES_ROOT, hKey);

In wine 0.9.49 a stub entry for this function was created, but the implementation is missing.
The result is, that the GetProcAddress function is successful, but the RegOverridePredefKey call fails.
I can catch the EXCEPTION_WINE_STUB exception (see code below), but the application will nevertheless closed.

if (RegOverridePredefKey)
    {
    long err  = ERROR_CALL_NOT_IMPLEMENTED;
    try
      {         // test for C-based structured exceptions
      err=RegOverridePredefKey(HKEY_CLASSES_ROOT, hKey);
      }

#define EXCEPTION_WINE_STUB       0x80000100
    __except(GetExceptionCode()==EXCEPTION_WINE_STUB  ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH)
      {
      RegOverridePredefKey=NULL;
      }
    }

What can I do ?
I know, that I can find a workaround for this case, but this in not my problem. How can I handle, in principle, such exceptions?
What is the reason for creating a function stub without an implementation ???

Thanks 
Nessi

[Stefan Dösinger]

Am Montag, 3. Dezember 2007 13:55:59 schrieb [e-mail]:
> I know, that I can find a workaround for this case, but this in not my
> problem. How can I handle, in principle, such exceptions? What is the
> reason for creating a function stub without an implementation ???

The reason is often that there is an application that tries to load the 
function, but never calls it. It refuses to start without getting a pointer 
to this unused function. Or an application that refuses to run if it doesn't 
like the exports from a DLL. For example, copy protection systems might check 
the exports, and refuse if your DLL has different exports than Windows.

The @stub stubs are pretty rare nowadays, for exactly the reason you give. 
Usual stubs have a real implementation function which just returns an error 
or OK and writes a note to the FIXME channel.

The stub in question was added by patch 
27e8b829a4cc56969836c0dbbb4db4b775d52a9f, which was intended to fix bug 
#9116.

To answer your question what to do, the usual way to fix this is to implement 
the function in Wine. I understand that this is most likely not a suitable 
solution for you, after all you're working on your application, not Wine. I 
do not know advapi32, so I cannot implement this function myself, but if no 
one steps up in the next days I can send a small patch that just adds a nicer 
stub that doesn't crash.