The attached test demonstrates that two (I think) different URIs are 'equal'.
The RFC 3986 states (5.2.1.):
"... A component is undefined if its associated delimiter does not appear in the URI reference; ..."
In our case 'authority' delimiter is present, consequently authority isn't defined, it is empty.
It seems that query & fragment have the same problem.
I think 'backward compatibility' isn't actual for URI class now.
If you not fix this problem, I will have to exclude valid tests from JCK or adopt them to RI (I think this is very bad)