NullPointerException in HIDManager.openByPath() and openById()

[GoogleCodeExporter]

What steps will reproduce the problem?
1. In 32-bit Linux, attempt to open a device when there are none plugged into 
the system. I tried both OpenJDK and Oracle JREs. The issue is not present on 
my 64-bit Windows machine.

The line:

for(HIDDeviceInfo d : devs)

throws a NullPointerException because listDevices() returns null.

I fixed the problem by changing to the source code:

public HIDDevice openById(int vendor_id, int product_id, String serial_number) 
throws IOException, HIDDeviceNotFoundException
{
    HIDDeviceInfo[] devs = listDevices();

    if(devs == null)
    {
        throw new HIDDeviceNotFoundException();
    }
    else
    {
        for(HIDDeviceInfo d : devs)
        {
            if(d.getVendor_id() == vendor_id && d.getProduct_id() == product_id && (serial_number == null || d.getSerial_number().equals(serial_number)))
                return d.open();
        }
        throw new HIDDeviceNotFoundException();
    }
}

Original issue reported on code.google.com by dmorr...@gmail.com on 23 Nov 2013 at 5:01