java.io.File#toPath() on Windows doesn't understand "NUL:" (null device)?

[Alan Bateman]

On 20/03/2021 07:16, Jaikiran Pai wrote:
> :
>
> I received some inputs on that Ant bugzilla issue. Based on that, I 
> was able to reproduce the exception and IMO it's a bug in 
> Files.newOutputStream() API. I have opened 
> https://bugs.openjdk.java.net/browse/JDK-8263898 with the relevant 
> details. I considered this a bug and took the liberty of opening that 
> JBS issue because as I note in that issue, this only happens 
> specifically when TRUNCATE_EXISTING (default) option gets used against 
> "nul" on Windows.

OutputStream.nullOutputStream() may be a better and more portable 
alternative. In general, the DOS era reserved names (including NUL) are 
very under specified and many file operations lead to surprising 
behavior (this isn't solely a JDK issue, I think other runtimes and 
languages also get tripped up). In this case, the attempt to truncate 
the file to zero length is failing. Sure, it can be be worked around but 
workarounds like this tend to cause issues in other unusual cases so 
care is required.

-Alan.