ZipFile.Source.Key constructor takes file argument passed from ZipFile constructor. Since ZipFile.Source.Key is used as key in HashMap lookups, the file should be stored with an absolute path value.

see ZipFile:
            synchronized (files) {
                src = files.get(key);
                if (src != null) {
                    src.refs++;
                    return src;
                }
            }
            src = new Source(key, toDelete, zc);