try-with-resources and null resource

[Jesper Öqvist]

Rémi Forax wrote:
> On 01/21/2011 07:24 PM, Paul Benedict wrote:
>   
>> The NPE is more useful than the language silently doing nothing with a 
>> null pointer. While your idea is convenient, I believe it assumes too 
>> much. If anything, perhaps the language shouldn't allow an explicit 
>> null assignment in a try-with-resources block.
>>     
>
> Hi Paul,
> the null assignement is just an example. Perhaps, you prefer this one:
>
> 4. try(AutoCloseable c = getAnAutoCloseableThatMayBeNull()) {
> 5.     // nothing
> 6. }
>
> Rémi
>   

I am concerned about the consistency between what the programmer expects 
and what the compiler produces.

It seems to me that the following code should be legal, and execute 
without throwing an NPE:

try (Resource r = null) {
    r = new SomeResource();
}

However with a null check in the try part of the try-with-resource 
statement, or an NPE, execution might not pass through the statement as 
the programmer expects it to.

Jesper