Issue #13989: Document that GzipFile does not support text mode.
Also, give a more helpful error message when opened with an invalid mode string.
diff --git a/Misc/NEWS b/Misc/NEWS
index da90e9e..f45da75 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -113,6 +113,9 @@
Library
-------
+- Issue #13989: Document that GzipFile does not support text mode, and give a
+ more helpful error message when opened with an invalid mode string.
+
- Issue #13590: On OS X 10.7 and 10.6 with Xcode 4.2, building
Distutils-based packages with C extension modules may fail because
Apple has removed gcc-4.2, the version used to build python.org