# This is a backport of following upstream patch:

# HG changeset patch

# User Benjamin Peterson <benjamin@python.org>

# Date 1396394277 14400

# Node ID 6370d44013f7e7e0892dd7f78b91d3a929e2d343

# Parent  cb3a8abc0870d8d81a3521b3c8f397c5ccc73d7d# Parent  9186f4a18584f5038a9f875f2a7a3194ee46a571

merge 3.2 (#21082)

diff --git a/Doc/library/os.rst b/Doc/library/os.rst

--- a/Doc/library/os.rst

+++ b/Doc/library/os.rst

@@ -1563,11 +1563,8 @@ features:

    The default *mode* is ``0o777`` (octal).  On some systems, *mode* is

    ignored.  Where it is used, the current umask value is first masked out.

-   If *exists_ok* is ``False`` (the default), an :exc:`OSError` is raised if

-   the target directory already exists.  If *exists_ok* is ``True`` an

-   :exc:`OSError` is still raised if the umask-masked *mode* is different from

-   the existing mode, on systems where the mode is used.  :exc:`OSError` will

-   also be raised if the directory creation fails.

+   If *exist_ok* is ``False`` (the default), an :exc:`OSError` is raised if the

+   target directory already exists.

    .. note::

diff --git a/Lib/os.py b/Lib/os.py

--- a/Lib/os.py

+++ b/Lib/os.py

@@ -230,23 +230,16 @@ SEEK_SET = 0

 SEEK_CUR = 1

 SEEK_END = 2

-

-def _get_masked_mode(mode):

-    mask = umask(0)

-    umask(mask)

-    return mode & ~mask

-

 # Super directory utilities.

 # (Inspired by Eric Raymond; the doc strings are mostly his)

 def makedirs(name, mode=0o777, exist_ok=False):

     """makedirs(path [, mode=0o777][, exist_ok=False])

-    Super-mkdir; create a leaf directory and all intermediate ones.

-    Works like mkdir, except that any intermediate path segment (not

-    just the rightmost) will be created if it does not exist. If the

-    target directory with the same mode as we specified already exists,

-    raises an OSError if exist_ok is False, otherwise no exception is

+    Super-mkdir; create a leaf directory and all intermediate ones.  Works like

+    mkdir, except that any intermediate path segment (not just the rightmost)

+    will be created if it does not exist. If the target directory already

+    exists, raise an OSError if exist_ok is False. Otherwise no exception is

     raised.  This is recursive.

     """

@@ -268,20 +261,7 @@ def makedirs(name, mode=0o777, exist_ok=

     try:

         mkdir(name, mode)

     except OSError as e:

-        dir_exists = path.isdir(name)

-        expected_mode = _get_masked_mode(mode)

-        if dir_exists:

-            # S_ISGID is automatically copied by the OS from parent to child

-            # directories on mkdir.  Don't consider it being set to be a mode

-            # mismatch as mkdir does not unset it when not specified in mode.

-            actual_mode = st.S_IMODE(lstat(name).st_mode) & ~st.S_ISGID

-        else:

-            actual_mode = -1

-        if not (e.errno == errno.EEXIST and exist_ok and dir_exists and

-                actual_mode == expected_mode):

-            if dir_exists and actual_mode != expected_mode:

-                e.strerror += ' (mode %o != expected mode %o)' % (

-                        actual_mode, expected_mode)

+        if not exist_ok or e.errno != errno.EEXIST or not path.isdir(name):

             raise

 def removedirs(name):

diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py

--- a/Lib/test/test_os.py

+++ b/Lib/test/test_os.py

@@ -872,7 +872,7 @@ class MakedirTests(unittest.TestCase):

         os.makedirs(path, mode)

         self.assertRaises(OSError, os.makedirs, path, mode)

         self.assertRaises(OSError, os.makedirs, path, mode, exist_ok=False)

-        self.assertRaises(OSError, os.makedirs, path, 0o776, exist_ok=True)

+        os.makedirs(path, 0o776, exist_ok=True)

         os.makedirs(path, mode=mode, exist_ok=True)

         os.umask(old_mask)

@@ -898,9 +898,8 @@ class MakedirTests(unittest.TestCase):

             os.makedirs(path, mode, exist_ok=True)

             # remove the bit.

             os.chmod(path, stat.S_IMODE(os.lstat(path).st_mode) & ~S_ISGID)

-            with self.assertRaises(OSError):

-                # Should fail when the bit is not already set when demanded.

-                os.makedirs(path, mode | S_ISGID, exist_ok=True)

+            # May work even when the bit is not already set when demanded.

+            os.makedirs(path, mode | S_ISGID, exist_ok=True)

         finally:

             os.umask(old_mask)