Related to SF patch 618135: gzip.py and files > 2G.
Fixed the signed/unsigned confusions when dealing with files >= 2GB.
4GB is still a hard limitation of the gzip file format, though.

Testing this was a bitch on Win98SE due to frequent system freezes.  It
didn't freeze while running gzip, it kept freezing while trying to *create*
a > 2GB test file!  This wasn't Python's doing.  I don't know of a
reasonable way to test this functionality in regrtest.py, so I'm not
checking in a test case (a test case would necessarily require creating
a 2GB+ file first, using gzip to zip it, using gzip to unzip it again,
and then compare before-and-after; so >4GB free space would be required,
and a loooong time; I did all this "by hand" once).

Bugfix candidate, I guess.
diff --git a/Misc/NEWS b/Misc/NEWS
index c8334d7..980e4d2 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -355,6 +355,10 @@
 Library
 -------
 
+- gzip.py now handles files exceeding 2GB.  Note that 4GB is still a
+  fundamental limitation of the underlying gzip file format (it only
+  has 32 bits to record the file size).
+
 - xml.sax.saxutils.unescape has been added, to replace entity references
   with their entity value.
 
@@ -365,7 +369,7 @@
 
 - Various configure methods of Tkinter have been stream-lined, so that
   tag_configure, image_configure, window_configure now return a
-  dictionary when invoked with no argument. 
+  dictionary when invoked with no argument.
 
 - Importing the readline module now no longer has the side effect of
   calling setlocale(LC_CTYPE, "").  The initial "C" locale, or