Issue #20053: new test to check an assumption

diff --git a/Lib/test/test_venv.py b/Lib/test/test_venv.py
index 6ddbacefadb3249ccdadd36515b8a7449594da99..58551bed9515877207af3bf46194782de14cd944 100644 (file)
--- a/Lib/test/test_venv.py
+++ b/Lib/test/test_venv.py
@@ -288,6 +288,13 @@ class EnsurePipTest(BaseTest):
         self.run_with_capture(venv.create, self.env_dir, with_pip=False)
         self.assert_pip_not_installed()
 
+    def test_devnull_exists_and_is_empty(self):
+        # Fix for issue #20053 uses os.devnull to force a config file to
+        # appear empty. Make sure that assumption is valid cross platform.
+        self.assertTrue(os.path.exists, os.devnull)
+        with open(os.devnull, "rb") as f:
+            self.assertEqual(f.read(), b"")
+
     # Requesting pip fails without SSL (http://bugs.python.org/issue19744)
     @unittest.skipIf(ssl is None, ensurepip._MISSING_SSL_MESSAGE)
     def test_with_pip(self):