bpo-10496: posixpath.expanduser() catchs pwd.getpwuid() error (GH-10919) (GH-10930)

* posixpath.expanduser() now returns the input path unchanged if
  the HOME environment variable is not set and pwd.getpwuid() raises
  KeyError (the current user identifier doesn't exist in the password
  database).
* Add test_no_home_directory() to test_site.

(cherry picked from commit f2f4555d8287ad217a1dba7bbd93103ad4daf3a8)

1 files changed, 45 insertions, 23 deletions

diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py
index deaa577..0663a21 100644
--- a/Lib/test/test_posixpath.py
+++ b/Lib/test/test_posixpath.py
@@ -262,34 +262,56 @@ class PosixPathTest(unittest.TestCase):
 
     def test_expanduser(self):
         self.assertEqual(posixpath.expanduser("foo"), "foo")
-        with test_support.EnvironmentVarGuard() as env:
+
+    def test_expanduser_home_envvar(self):
+        with support.EnvironmentVarGuard() as env:
+            env['HOME'] = '/home/victor'
+            self.assertEqual(posixpath.expanduser("~"), "/home/victor")
+
+            # expanduser() strips trailing slash
+            env['HOME'] = '/home/victor/'
+            self.assertEqual(posixpath.expanduser("~"), "/home/victor")
+
             for home in '/', '', '//', '///':
                 env['HOME'] = home
                 self.assertEqual(posixpath.expanduser("~"), "/")
                 self.assertEqual(posixpath.expanduser("~/"), "/")
                 self.assertEqual(posixpath.expanduser("~/foo"), "/foo")
-        try:
-            import pwd
-        except ImportError:
-            pass
-        else:
-            self.assertIsInstance(posixpath.expanduser("~/"), basestring)
-            # if home directory == root directory, this test makes no sense
-            if posixpath.expanduser("~") != '/':
-                self.assertEqual(
-                    posixpath.expanduser("~") + "/",
-                    posixpath.expanduser("~/")
-                )
-            self.assertIsInstance(posixpath.expanduser("~root/"), basestring)
-            self.assertIsInstance(posixpath.expanduser("~foo/"), basestring)
-
-            with test_support.EnvironmentVarGuard() as env:
-                # expanduser should fall back to using the password database
-                del env['HOME']
-                home = pwd.getpwuid(os.getuid()).pw_dir
-                # $HOME can end with a trailing /, so strip it (see #17809)
-                home = home.rstrip("/") or '/'
-                self.assertEqual(posixpath.expanduser("~"), home)
+
+    def test_expanduser_pwd(self):
+        pwd = support.import_module('pwd')
+
+        self.assertIsInstance(posixpath.expanduser("~/"), str)
+
+        # if home directory == root directory, this test makes no sense
+        if posixpath.expanduser("~") != '/':
+            self.assertEqual(
+                posixpath.expanduser("~") + "/",
+                posixpath.expanduser("~/")
+            )
+        self.assertIsInstance(posixpath.expanduser("~root/"), str)
+        self.assertIsInstance(posixpath.expanduser("~foo/"), str)
+
+        with support.EnvironmentVarGuard() as env:
+            # expanduser should fall back to using the password database
+            del env['HOME']
+
+            home = pwd.getpwuid(os.getuid()).pw_dir
+            # $HOME can end with a trailing /, so strip it (see #17809)
+            home = home.rstrip("/") or '/'
+            self.assertEqual(posixpath.expanduser("~"), home)
+
+            # bpo-10496: If the HOME environment variable is not set and the
+            # user (current identifier or name in the path) doesn't exist in
+            # the password database (pwd.getuid() or pwd.getpwnam() fail),
+            # expanduser() must return the path unchanged.
+            def raise_keyerror(*args):
+                raise KeyError
+
+            with support.swap_attr(pwd, 'getpwuid', raise_keyerror), \
+                 support.swap_attr(pwd, 'getpwnam', raise_keyerror):
+                for path in ('~', '~/.local', '~vstinner/'):
+                    self.assertEqual(posixpath.expanduser(path), path)
 
     def test_normpath(self):
         self.assertEqual(posixpath.normpath(""), ".")