[Bug 37185] DirectPlayCreate fails to create instance in the game "Swing"

https://bugs.winehq.org/show_bug.cgi?id=37185

Anastasius Focht  changed:

What    |Removed                     |Added
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--- Comment #10 from Anastasius Focht  ---
Hello folks,

thanks for the email Bruno to interrupt my coffee break ... j/k :)

--- quote ---
The bug is: Why when running in Wine a crazy GUID is passed to
DirectPlayCreate?
--- quote ---

The game provided SP enum callback does something stupid: instead of copying
the service provider GUID it stores the address in an internal structure for
later use.
Actually it's an array of structures, with 'IPX' structure entry being indexed.

The GUID variable lives on stack within DirectPlayEnumerateAW() context so the
data only remains valid during the enumerate API call.

Source:
http://source.winehq.org/git/wine.git/blob/7e17eec75005e0e1c16b9b56422544246...

--- snip ---
5768 static HRESULT DirectPlayEnumerateAW(LPDPENUMDPCALLBACKA lpEnumCallbackA,
5769                                      LPDPENUMDPCALLBACKW lpEnumCallbackW,
5770                                      LPVOID lpContext)
5771 {
...
5803     /* Traverse all the service providers we have available */
5804     dwIndex = 0;
5805     while (1)
5806     {
5807         WCHAR subKeyName[255]; /* 255 is the maximum key size according to
MSDN */
5808         DWORD sizeOfSubKeyName = sizeof(subKeyName) / sizeof(WCHAR);
5809         HKEY hkServiceProvider;
5810         GUID serviceProviderGUID;
5811         WCHAR guidKeyContent[(2 * 16) + 1 + 6 /* This corresponds to
'{....-..-..-..-......}' */ ];
5812         DWORD sizeOfGuidKeyContent = sizeof(guidKeyContent);
5813         LONG ret_value;
...
5845         CLSIDFromString(guidKeyContent, &serviceProviderGUID );
...
5853         if (lpEnumCallbackA)
5854         {
5855             DWORD sizeOfDescription = 0;
5856

5873             if (!lpEnumCallbackA(&serviceProviderGUID, descriptionA, 6, 0,
lpContext))
5874                 goto end;
...
--- snip ---

This obviously can't work with code that makes the assumption that the address
and the referenced content is still accessible outside of
DirectPlayEnumerateAW() context.

Since the data is read from registry and not very "dynamic" during runtime,
it's probably fine to retrieve and store it upon dplay creation (heap, list) to
be returned in DirectPlayEnumerateAW().
This also avoids the registry queries each time DirectPlayEnumerateAW() is
getting called.

Regards