winmm: Initialize Memory in mciSendStringA

[Alexandre Julliard]

Rico Schüller <kgbricola at web.de> writes:

> @@ -1498,7 +1498,10 @@ DWORD WINAPI mciSendStringA(LPCSTR lpstrCommand, LPSTR lpstrRet,
>      MultiByteToWideChar( CP_ACP, 0, lpstrCommand, -1, lpwstrCommand, len );
>      if (lpstrRet)
>      {
> -        lpwstrRet = HeapAlloc(GetProcessHeap(), 0, uRetLen * sizeof(WCHAR));
> +        /* Use HEAP_ZERO_MEMORY, otherwise WideCharToMultiByte could crash if mciSendStringW fails,
> +         * because the length is taken from the uninizialized data!
> +         */
> +        lpwstrRet = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, uRetLen * sizeof(WCHAR));

That's just hiding the bug. The string shouldn't be converted at all if
we failed to retrieve it.

-- 
Alexandre Julliard
julliard at winehq.org