Hi, please review this fix of a regression in zipfs after JDK-8222532 [0].
Bug: https://bugs.openjdk.java.net/browse/JDK-8223597 Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8223597.0/ The issue occurs when an empty file/channel is persisted into a zip file. The entry had already been compressed with CRC of 0 at the time the output stream to the zipfs was closed. But when the Entry is eventually synced to the zip file, this is not detected and the bytes get compressed again. The test was adapted to reliably provoke this intermittent error. In the test I also suppressed printout of an expected Exception to avoid some distraction when reading its JTR files. Thanks Christoph [0] https://bugs.openjdk.java.net/browse/JDK-8222532
