try to fix Windows tests

Author: picnixz

Lib/test/test_os/test_os.py

@@ -2624,18 +2624,12 @@ def test_execve_invalid_env(self):
         with self.assertRaises(ValueError):
             os.execve(args[0], args, newenv)
 
-    def test_execve_env_concurrent_mutation_with_fspath(self):
+    @unittest.skipIf(os.name == "nt", "POSIX-specific test")
+    def test_execve_env_concurrent_mutation_with_fspath_posix(self):
         # Prevent crash when mutating environment during parsing.
         # Regression test for https://github.com/python/cpython/issues/143309.
 
-        if os.name == "nt":
-            # See https://github.com/python/cpython/pull/143314
-            # to understand why we cannot use spaces in strings
-            # when using subprocess and os.execve() on Windows.
-            message = "123456"
-        else:
-            message = "hello from execve"
-
+        message = "hello from execve"
         code = """
         import os, sys
 
@@ -2647,14 +2641,54 @@ def __fspath__(self):
         mutated = KEYS = VALUES = [MyPath()]
 
         class MyEnv:
+            def __getitem__(self): raise RuntimeError("must not be called")
             def __len__(self): return 1
-            def __getitem__(self): return 1
             def keys(self): return KEYS
             def values(self): return VALUES
 
         args = [sys.executable, '-c', "print({message!r})"]
         os.execve(args[0], args, MyEnv())
-        """.format(message=message)
+        """.format(message="hello from execve")
+
+        # Use '__cleanenv' to signal to assert_python_ok() not
+        # to do a copy of os.environ on its own.
+        rc, out, _ = assert_python_ok('-c', code, __cleanenv=True)
+        self.assertEqual(rc, 0)
+        self.assertIn(bytes(message, "ascii"), out)
+
+    @unittest.skipUnless(os.name == "nt", "Windows-specific test")
+    def test_execve_env_concurrent_mutation_with_fspath_posix(self):
+        # See https://github.com/python/cpython/pull/143314
+        # to understand why we cannot use spaces in strings
+        # when using subprocess and os.execve() on Windows.
+        message = "123456"
+
+        code = """
+        import os, sys
+
+        assert list(os.environ.keys()) == ["SYSTEMROOT"]
+        assert list(os.environ.values()) == [{SYSTEMROOT}]
+
+        class MyPath:
+            def __fspath__(self):
+                mutated1.clear()
+                mutated2.clear()
+                return b"pwn"
+
+        # Python requires "SYSTEMROOT" to be set so we make sure
+        # that the side effect happens afterwards.
+        mutated1 = KEYS = ["SYSTEMROOT", MyPath()]
+        mutated2 = VALUES = [{SYSTEMROOT}, b"ed"]
+
+        class MyEnv:
+            def __getitem__(self): raise RuntimeError("must not be called")
+            def __len__(self): return 2
+            def keys(self): return KEYS
+            def values(self): return VALUES
+
+        args = [sys.executable, '-c', "print({message!r})"]
+        os.execve(args[0], args, MyEnv())
+        """.format(message=message, SYSTEMROOT=os.environ["SYSTEMROOT"])
 
         # Use '__cleanenv' to signal to assert_python_ok() not
         # to do a copy of os.environ on its own.