7076310: (file) AclEntry.Builder setFlags throws IllegalArgumentException if set argument is empty

[Alan Bateman]

On 21/12/2011 05:51, Stephen Flores wrote:
> Please review the following webrev (includes new test to demonstrate 
> the bug):
>
>   http://cr.openjdk.java.net/~sflores/7076310/
Thanks for taking one. It looks like the setPermissions method has the 
same issue so I think we should fix both together.

The simplest solution is probably to replace EnumSet.copyOf(flags) with 
new HashSet<>(flags). What you have is okay too although in theory 
someone could clear the set at just around the time that setFlags is 
called in which case the copyOf method would see an empty set (as 
AclEntry.Builder is clearly specified to not be safe for use by multiple 
concurrent threads then your approach is okay).

The test should be added to test/java/nio/file/attribute/AclEntry. 
Looking at it now, it seems I neglected to include a unit test for 
AclEntry which is probably how this bug sipped through (it is tested by 
AclFileAttributeView as it tests reading and writing ACLs, just didn't a 
complete test for AclEntry).

-Alan.