[PATCH v2] msvcrt: Don't crash if _vsnwprintf gets NULL as format string and add test

[Piotr Caban]

On 11/18/17 20:04, Fabian Maurer wrote:
> +    if(!fmt)
> +        return -1;
Newer versions of the dll are also setting errno and calling invalid 
parameter handler.

> +static BOOL is_vista_or_newer(void)
> +{
> +    OSVERSIONINFOA version;
> +    version.dwOSVersionInfoSize = sizeof(version);
> +    GetVersionExA(&version);
> +    return version.dwMajorVersion > 5;
> +}
Please test dll functionality instead of checking system version. You 
can e.g. check for function existence that was added in newer version.

Thanks,
Piotr