bpo-28494: Test existing zipfile working behavior. (GH-15853)

Add unittests for executables with a zipfile appended to test_zipfile, as zipfile.is_zipfile and zipfile.ZipFile work properly on these today.

Lib/test/test_zipfile.py

@@ -5,6 +5,8 @@ import os
 import pathlib
 import posixpath
 import struct
+import subprocess
+import sys
 import time
 import unittest
 import zipfile
@@ -2470,6 +2472,44 @@ def build_alpharep_fixture():
     return zf
 
 
+class TestExecutablePrependedZip(unittest.TestCase):
+    """Test our ability to open zip files with an executable prepended."""
+
+    def setUp(self):
+        self.exe_zip = findfile('exe_with_zip', subdir='ziptestdata')
+        self.exe_zip64 = findfile('exe_with_z64', subdir='ziptestdata')
+
+    def _test_zip_works(self, name):
+        # bpo-28494 sanity check: ensure is_zipfile works on these.
+        self.assertTrue(zipfile.is_zipfile(name),
+                        f'is_zipfile failed on {name}')
+        # Ensure we can operate on these via ZipFile.
+        with zipfile.ZipFile(name) as zipfp:
+            for n in zipfp.namelist():
+                data = zipfp.read(n)
+                self.assertIn(b'FAVORITE_NUMBER', data)
+
+    def test_read_zip_with_exe_prepended(self):
+        self._test_zip_works(self.exe_zip)
+
+    def test_read_zip64_with_exe_prepended(self):
+        self._test_zip_works(self.exe_zip64)
+
+    @unittest.skipUnless(sys.executable, 'sys.executable required.')
+    @unittest.skipUnless(os.access('/bin/bash', os.X_OK),
+                         'Test relies on #!/bin/bash working.')
+    def test_execute_zip2(self):
+        output = subprocess.check_output([self.exe_zip, sys.executable])
+        self.assertIn(b'number in executable: 5', output)
+
+    @unittest.skipUnless(sys.executable, 'sys.executable required.')
+    @unittest.skipUnless(os.access('/bin/bash', os.X_OK),
+                         'Test relies on #!/bin/bash working.')
+    def test_execute_zip64(self):
+        output = subprocess.check_output([self.exe_zip64, sys.executable])
+        self.assertIn(b'number in executable: 5', output)
+
+
 class TestPath(unittest.TestCase):
     def setUp(self):
         self.fixtures = contextlib.ExitStack()