ntdll/file.c: Fix a possible NULL dereferencing.

[Henri Verbeet]

2008/8/27 Nikolay Sivov <bunglehead at gmail.com>:
> Markus Hitter wrote:
>> if (!attr || !attr->ObjectName) return STATUS_INVALID_PARAMETER;
> Shouldn't this be splitted? It isn't safe to rely on evaluation order.
> Or is it a default compiler setting for us?
>
This is well defined in C. !attr will be evaluated first, and if it
evaluates to true, the rest of the condition won't be evaluated. This
is also known as short-circuit evaluation.