#14399: zipfile now correctly handles comments added to empty zipfiles.

Patch by Serhiy Storchaka.
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index 7ebb663..76fcc70 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -908,6 +908,22 @@
         with zipfile.ZipFile(TESTFN, mode="r") as zipf:
             self.assertEqual(zipf.comment, comment2)
 
+    def test_change_comment_in_empty_archive(self):
+        with zipfile.ZipFile(TESTFN, "a", zipfile.ZIP_STORED) as zipf:
+            self.assertFalse(zipf.filelist)
+            zipf.comment = b"this is a comment"
+        with zipfile.ZipFile(TESTFN, "r") as zipf:
+            self.assertEqual(zipf.comment, b"this is a comment")
+
+    def test_change_comment_in_nonempty_archive(self):
+        with zipfile.ZipFile(TESTFN, "w", zipfile.ZIP_STORED) as zipf:
+            zipf.writestr("foo.txt", "O, for a Muse of Fire!")
+        with zipfile.ZipFile(TESTFN, "a", zipfile.ZIP_STORED) as zipf:
+            self.assertTrue(zipf.filelist)
+            zipf.comment = b"this is a comment"
+        with zipfile.ZipFile(TESTFN, "r") as zipf:
+            self.assertEqual(zipf.comment, b"this is a comment")
+
     def check_testzip_with_bad_crc(self, compression):
         """Tests that files with bad CRCs return their name from testzip."""
         zipdata = self.zips_with_bad_crc[compression]