dxdiag: Do not omit mandatory argument to WriteFile.

[Thomas Faber]

On 2014-07-12 17:07, Lauri Kenttä wrote:
> I'm sorry if I missed something, but at least MSDN clearly states that 
> this is usually an optional argument.
> 
> http://msdn.microsoft.com/en-us/library/windows/desktop/aa365747%28v=vs.85%29.aspx
> 
> For example,
> "lpNumberOfBytesWritten [out, optional]"
> "Use NULL for this parameter if this is an asynchronous operation to 
> avoid potentially erroneous results."
> "This parameter can be NULL only when the lpOverlapped parameter is not 
> NULL."

It can only be NULL for asynchronous writes. Notice the last sentence.
Invocations with both lpNumberOfBytesWritten = NULL and
lpOverlapped = NULL always crash on Windows.