The stated purpose of the test 'test/jdk/java/util/zip/NoExtensionSignature.java' is to verify that ZipInputStream can read a data descriptor record without the recommended, but optional signature.

The test uses a test vector which is a binary zip file checked into source control. The test does not describe how the test vector can be reproduced.

The concern of the missing signature is also covered by the test 'DataDescriptorSignatureMissing'. This test has better documentation and contains code to reproduce the missing signature.

To reduce duplicated tests, I suggest that we retire the NoExtensionSignature test. Before doing so, the binary test vector should be analyzed to see if there are unrelated aspects being 'accidentally' covered by the test.