bpo-43651: Fix EncodingWarning in os.fdopen() and test_os (GH-25654)

Author: methane

Lib/os.py

@@ -983,16 +983,16 @@ def popen(cmd, mode="r", buffering=-1):
  import subprocess, io
  if mode == "r":
  proc = subprocess.Popen(cmd,
- shell=True,
+ shell=True, text=True,
  stdout=subprocess.PIPE,
  bufsize=buffering)
- return _wrap_close(io.TextIOWrapper(proc.stdout), proc)
+ return _wrap_close(proc.stdout, proc)
  else:
  proc = subprocess.Popen(cmd,
- shell=True,
+ shell=True, text=True,
  stdin=subprocess.PIPE,
  bufsize=buffering)
- return _wrap_close(io.TextIOWrapper(proc.stdin), proc)
+ return _wrap_close(proc.stdin, proc)
 
  # Helper for popen() -- a proxy for a file whose close waits for the process
  class _wrap_close:

Lib/test/test_os.py

@@ -269,7 +269,7 @@ def test_write_windows_console(self):
 
  def fdopen_helper(self, *args):
  fd = os.open(os_helper.TESTFN, os.O_RDONLY)
- f = os.fdopen(fd, *args)
+ f = os.fdopen(fd, *args, encoding="utf-8")
  f.close()
 
  def test_fdopen(self):
@@ -290,7 +290,7 @@ def test_replace(self):
 
  os.replace(os_helper.TESTFN, TESTFN2)
  self.assertRaises(FileNotFoundError, os.stat, os_helper.TESTFN)
- with open(TESTFN2, 'r') as f:
+ with open(TESTFN2, 'r', encoding='utf-8') as f:
  self.assertEqual(f.read(), "1")
 
  def test_open_keywords(self):
@@ -1627,7 +1627,7 @@ def test_exist_ok_s_isgid_directory(self):
  def test_exist_ok_existing_regular_file(self):
  base = os_helper.TESTFN
  path = os.path.join(os_helper.TESTFN, 'dir1')
- with open(path, 'w') as f:
+ with open(path, 'w', encoding='utf-8') as f:
  f.write('abc')
  self.assertRaises(OSError, os.makedirs, path)
  self.assertRaises(OSError, os.makedirs, path, exist_ok=False)
@@ -2094,7 +2094,7 @@ def test_chmod(self):
 
 
 class TestInvalidFD(unittest.TestCase):
- singles = ["fchdir", "dup", "fdopen", "fdatasync", "fstat",
+ singles = ["fchdir", "dup", "fdatasync", "fstat",
  "fstatvfs", "fsync", "tcgetpgrp", "ttyname"]
  #singles.append("close")
  #We omit close because it doesn't raise an exception on some platforms
@@ -2106,15 +2106,18 @@ def helper(self):
  for f in singles:
  locals()["test_"+f] = get_single(f)
 
- def check(self, f, *args):
+ def check(self, f, *args, **kwargs):
  try:
- f(os_helper.make_bad_fd(), *args)
+ f(os_helper.make_bad_fd(), *args, **kwargs)
  except OSError as e:
  self.assertEqual(e.errno, errno.EBADF)
  else:
  self.fail("%r didn't raise an OSError with a bad file descriptor"
  % f)
 
+ def test_fdopen(self):
+ self.check(os.fdopen, encoding="utf-8")
+
  @unittest.skipUnless(hasattr(os, 'isatty'), 'test needs os.isatty()')
  def test_isatty(self):
  self.assertEqual(os.isatty(os_helper.make_bad_fd()), False)
@@ -2210,7 +2213,7 @@ def _test_link(self, file1, file2):
  os.link(file1, file2)
  except PermissionError as e:
  self.skipTest('os.link(): %s' % e)
- with open(file1, "r") as f1, open(file2, "r") as f2:
+ with open(file1, "rb") as f1, open(file2, "rb") as f2:
  self.assertTrue(os.path.sameopenfile(f1.fileno(), f2.fileno()))
 
  def test_link(self):
@@ -3009,7 +3012,7 @@ def create_args(self, *, with_env=False, use_bytes=False):
  code = ('import sys, os; magic = os.environ[%r]; sys.exit(%s)'
  % (self.key, self.exitcode))
 
- with open(filename, "w") as fp:
+ with open(filename, "w", encoding="utf-8") as fp:
  fp.write(code)
 
  args = [sys.executable, filename]
@@ -3149,7 +3152,7 @@ def _test_invalid_env(self, spawn):
  # equal character in the environment variable value
  filename = os_helper.TESTFN
  self.addCleanup(os_helper.unlink, filename)
- with open(filename, "w") as fp:
+ with open(filename, "w", encoding="utf-8") as fp:
  fp.write('import sys, os\n'
  'if os.getenv("FRUIT") != "orange=lemon":\n'
  ' raise AssertionError')