commit efdf316d23c2bc81f499c46faaba5e1b49509afa
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Mon Sep 17 06:08:45 2018 -0700
committer GitHub <noreply@github.com> Mon Sep 17 06:08:45 2018 -0700
tree 385f98d44ab18eab3e2401435cbf339feb0f1f3d
parent e2c0aea670d603b187733606a4601d77f355bc47

bpo-34341: Fix appending to ZIP archives with the ZIP64 extension. (GH-8683)

(cherry picked from commit 9bdb7be482aef8f60daa1d36606568a132dcb616)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Lib/test/test_zipfile.py

diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index ac9a4ff..b48366a 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -750,6 +750,20 @@
         with zipfile.ZipFile(TESTFN2, "r", zipfile.ZIP_STORED) as zipfp:
             self.assertEqual(zipfp.namelist(), ["absolute"])
 
+    def test_append(self):
+        # Test that appending to the Zip64 archive doesn't change
+        # extra fields of existing entries.
+        with zipfile.ZipFile(TESTFN2, "w", allowZip64=True) as zipfp:
+            zipfp.writestr("strfile", self.data)
+        with zipfile.ZipFile(TESTFN2, "r", allowZip64=True) as zipfp:
+            zinfo = zipfp.getinfo("strfile")
+            extra = zinfo.extra
+        with zipfile.ZipFile(TESTFN2, "a", allowZip64=True) as zipfp:
+            zipfp.writestr("strfile2", self.data)
+        with zipfile.ZipFile(TESTFN2, "r", allowZip64=True) as zipfp:
+            zinfo = zipfp.getinfo("strfile")
+            self.assertEqual(zinfo.extra, extra)
+
 @requires_zlib
 class DeflateTestZip64InSmallFiles(AbstractTestZip64InSmallFiles,
                                    unittest.TestCase):