Newline should be derived, not hard coded. It isn't 1 on windows.

I included the diff here, and attached it.

Index: GZipFilterTest.java
===================================================================
— GZipFilterTest.java (revision 17249)
+++ GZipFilterTest.java (working copy)
@@ -107,7 +107,7 @@
final byte[] compressedBytes = finalOutput.toByteArray();
assertTrue("output should be gzipped", GZipUtil.isGZipped(compressedBytes));
final byte[] uncompressed = GZipUtil.ungzip(compressedBytes);

• final int expectedLength = iterations * (SOME_10CHARSLONG_CHAIN.length() + 1); // n chars + newline
  + final int expectedLength = iterations * (SOME_10CHARSLONG_CHAIN.length() + System.getProperty("line.separator").length()); // n chars + newline
  assertEquals(expectedLength, uncompressed.length);
  }
  }