Another round on SF patch 618135: gzip.py and files > 2G
The last round boosted "the limit" from 2GB to 4GB.  This round gets
rid of the 4GB limit.  For files > 4GB, gzip stores just the last 32
bits of the file size, and now we play along with that too.  Tested
by hand (on a 6+GB file) on Win2K.

Boosting from 2GB to 4GB was arguably enough "a bugfix".  Going beyond
that smells more like "new feature" to me.
diff --git a/Misc/NEWS b/Misc/NEWS
index c43474e..96263e7 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -355,9 +355,12 @@
 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).
+- gzip.py now handles files exceeding 2GB.  Files over 4GB also work
+  now (provided the OS supports it, and Python is configured with large
+  file support), but in that case the underlying gzip file format can
+  record only the least-significant 32 bits of the file size, so that
+  some tools working with gzipped files may report an incorrect file
+  size.
 
 - xml.sax.saxutils.unescape has been added, to replace entity references
   with their entity value.