Issue #12839: Fix crash in zlib module due to version mismatch.
If the version of zlib used to compile the zlib module is incompatible
with the one that is actually linked in, then calls into zlib will fail.
This can leave attributes of the z_stream uninitialized, so we must take
care to avoid segfaulting by trying to use an invalid pointer.
Fix by Richard M. Tew.
diff --git a/Misc/NEWS b/Misc/NEWS
index e7faa4e..3709142 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -40,6 +40,9 @@
Library
-------
+- Issue #12839: Fix crash in zlib module due to version mismatch.
+ Fix by Richard M. Tew.
+
- Issue #12786: Set communication pipes used by subprocess.Popen CLOEXEC to
avoid them being inherited by other subprocesses.