gh-158068: venv: do not clear env_dir if it's a symlink or a file

Lib/test/test_venv.py

@@ -663,6 +663,34 @@ def test_unoverwritable_fails(self):
             self.assertRaises((ValueError, OSError), venv.create, self.env_dir)
             self.clear_directory(self.env_dir)
 
+    @unittest.skipUnless(can_symlink(), 'Needs symlinks')
+    def test_clear_symlink_not_followed(self):
+        # gh-158068: venv --clear must not wipe the contents of a directory
+        # that env_dir merely points to via a symlink.
+        target = os.path.join(self.env_dir, 'target')
+        os.mkdir(target)
+        keep = os.path.join(target, 'keep')
+        with open(keep, 'wb') as f:
+            f.write(b'Still here?')
+        link = os.path.join(self.env_dir, 'link')
+        os.symlink(target, link)
+
+        with self.assertRaises(ValueError):
+            venv.create(link, clear=True)
+        # The symlink target and its content are left untouched.
+        self.assertTrue(os.path.islink(link))
+        self.assertTrue(os.path.exists(keep))
+
+    def test_clear_file_not_removed(self):
+        # gh-158068: venv --clear must not treat a regular file as env_dir.
+        target = os.path.join(self.env_dir, 'afile')
+        with open(target, 'wb') as f:
+            f.write(b'Still here?')
+
+        with self.assertRaises(ValueError):
+            venv.create(target, clear=True)
+        self.assertTrue(os.path.isfile(target))
+
     def test_upgrade(self):
         """
         Test upgrading an existing environment directory.

Lib/venv/__init__.py

@@ -149,8 +149,11 @@ def create_if_needed(d):
         if os.pathsep in os.fspath(env_dir):
             raise ValueError(f'Refusing to create a venv in {env_dir} because '
                              f'it contains the PATH separator {os.pathsep}.')
-        if os.path.exists(env_dir) and self.clear:
-            self.clear_directory(env_dir)
+        if self.clear:
+            if os.path.islink(env_dir) or os.path.isfile(env_dir):
+                raise ValueError('Unable to create directory %r' % env_dir)
+            if os.path.exists(env_dir):
+                self.clear_directory(env_dir)
         context = types.SimpleNamespace()
         context.env_dir = env_dir
         context.env_name = os.path.split(env_dir)[1]

Misc/NEWS.d/next/Library/2026-09-24-14-00-00.gh-issue-158068.Xf2ogr.rst

@@ -0,0 +1,4 @@
+:mod:`venv` no longer clears the target directory when it is a symlink or a
+regular file. Previously ``venv --clear`` followed a symlink and could delete
+the contents of the linked directory. It now raises :exc:`ValueError` before
+removing anything.