From 05bbcf3ea630596e7b8cd4fcea3625761af5c2ca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miro=20Hron=C4=8Dok?= <miro@hroncok.cz>
Date: Tue, 5 Dec 2023 20:39:28 +0100
Subject: [PATCH] gh-112769: test_zlib: Fix comparison of ZLIB_RUNTIME_VERSION
 with non-int suffix (GH-112771)
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zlib-ng defines the version as "1.3.0.zlib-ng".
(cherry picked from commit d384813ff18b33280a90b6d2011654528a2b6ad1)

Co-authored-by: Miro Hrončok <miro@hroncok.cz>
---
 Lib/test/test_zlib.py                         | 29 +++++++++++--------
 ...-12-05-19-50-03.gh-issue-112769.kdLJmS.rst |  3 ++
 2 files changed, 20 insertions(+), 12 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Tests/2023-12-05-19-50-03.gh-issue-112769.kdLJmS.rst

diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index ff5ce11b965b7c..2be3eb2afe3ae0 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -19,6 +19,21 @@
         hasattr(zlib.decompressobj(), "copy"),
         'requires Decompress.copy()')
 
+
+def _zlib_runtime_version_tuple(zlib_version=zlib.ZLIB_RUNTIME_VERSION):
+    # Register "1.2.3" as "1.2.3.0"
+    # or "1.2.0-linux","1.2.0.f","1.2.0.f-linux"
+    v = zlib_version.split('-', 1)[0].split('.')
+    if len(v) < 4:
+        v.append('0')
+    elif not v[-1].isnumeric():
+        v[-1] = '0'
+    return tuple(map(int, v))
+
+
+ZLIB_RUNTIME_VERSION_TUPLE = _zlib_runtime_version_tuple()
+
+
 # bpo-46623: On s390x, when a hardware accelerator is used, using different
 # ways to compress data with zlib can produce different compressed data.
 # Simplified test_pair() code:
@@ -477,9 +492,8 @@ def test_flushes(self):
         sync_opt = ['Z_NO_FLUSH', 'Z_SYNC_FLUSH', 'Z_FULL_FLUSH',
                     'Z_PARTIAL_FLUSH']
 
-        ver = tuple(int(v) for v in zlib.ZLIB_RUNTIME_VERSION.split('.'))
         # Z_BLOCK has a known failure prior to 1.2.5.3
-        if ver >= (1, 2, 5, 3):
+        if ZLIB_RUNTIME_VERSION_TUPLE >= (1, 2, 5, 3):
             sync_opt.append('Z_BLOCK')
 
         sync_opt = [getattr(zlib, opt) for opt in sync_opt
@@ -797,16 +811,7 @@ def test_large_unconsumed_tail(self, size):
 
     def test_wbits(self):
         # wbits=0 only supported since zlib v1.2.3.5
-        # Register "1.2.3" as "1.2.3.0"
-        # or "1.2.0-linux","1.2.0.f","1.2.0.f-linux"
-        v = zlib.ZLIB_RUNTIME_VERSION.split('-', 1)[0].split('.')
-        if len(v) < 4:
-            v.append('0')
-        elif not v[-1].isnumeric():
-            v[-1] = '0'
-
-        v = tuple(map(int, v))
-        supports_wbits_0 = v >= (1, 2, 3, 5)
+        supports_wbits_0 = ZLIB_RUNTIME_VERSION_TUPLE >= (1, 2, 3, 5)
 
         co = zlib.compressobj(level=1, wbits=15)
         zlib15 = co.compress(HAMLET_SCENE) + co.flush()
diff --git a/Misc/NEWS.d/next/Tests/2023-12-05-19-50-03.gh-issue-112769.kdLJmS.rst b/Misc/NEWS.d/next/Tests/2023-12-05-19-50-03.gh-issue-112769.kdLJmS.rst
new file mode 100644
index 00000000000000..1bbbb26fc322fa
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2023-12-05-19-50-03.gh-issue-112769.kdLJmS.rst
@@ -0,0 +1,3 @@
+The tests now correctly compare zlib version when
+:const:`zlib.ZLIB_RUNTIME_VERSION` contains non-integer suffixes. For
+example zlib-ng defines the version as ``1.3.0.zlib-ng``.