From 0a25e61effbc3cbd7ce8f9648a70ca9e53f8aa8c Mon Sep 17 00:00:00 2001
From: Takayuki Shimizukawa <shimizukawa@gmail.com>
Date: Fri, 26 Sep 2014 01:46:29 +0900
Subject: [PATCH] refactoring by using `with cd`

---
 sphinx/config.py      | 10 +++-------
 sphinx/ext/pngmath.py | 12 ++++--------
 sphinx/make_mode.py   | 21 +++++----------------
 sphinx/util/osutil.py | 12 ++++++++++++
 4 files changed, 24 insertions(+), 31 deletions(-)

diff --git a/sphinx/config.py b/sphinx/config.py
index a4fc234ac..69ba7cfe1 100644
--- a/sphinx/config.py
+++ b/sphinx/config.py
@@ -8,15 +8,15 @@
     :copyright: Copyright 2007-2014 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 """
+from __future__ import with_statement
 
-import os
 import re
 import sys
 from os import path
 
 from sphinx.errors import ConfigError
 from sphinx.locale import l_
-from sphinx.util.osutil import make_filename
+from sphinx.util.osutil import make_filename, cd
 from sphinx.util.pycompat import bytes, b, execfile_
 
 nonascii_re = re.compile(b(r'[\x80-\xff]'))
@@ -220,17 +220,13 @@ class Config(object):
             config_file = path.join(dirname, filename)
             config['__file__'] = config_file
             config['tags'] = tags
-            olddir = os.getcwd()
-            try:
+            with cd(dirname):
                 # we promise to have the config dir as current dir while the
                 # config file is executed
-                os.chdir(dirname)
                 try:
                     execfile_(filename, config)
                 except SyntaxError, err:
                     raise ConfigError(CONFIG_SYNTAX_ERROR % err)
-            finally:
-                os.chdir(olddir)
 
         self._raw_config = config
         # these two must be preinitialized because extensions can add their
diff --git a/sphinx/ext/pngmath.py b/sphinx/ext/pngmath.py
index b6546301c..abac15cd3 100644
--- a/sphinx/ext/pngmath.py
+++ b/sphinx/ext/pngmath.py
@@ -8,13 +8,14 @@
     :copyright: Copyright 2007-2014 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 """
+from __future__ import with_statement
 
 import re
 import codecs
 import shutil
 import tempfile
 import posixpath
-from os import path, getcwd, chdir
+from os import path
 from subprocess import Popen, PIPE
 try:
     from hashlib import sha1 as sha
@@ -25,7 +26,7 @@ from docutils import nodes
 
 from sphinx.errors import SphinxError
 from sphinx.util.png import read_png_depth, write_png_depth
-from sphinx.util.osutil import ensuredir, ENOENT
+from sphinx.util.osutil import ensuredir, ENOENT, cd
 from sphinx.util.pycompat import b, sys_encoding
 from sphinx.ext.mathbase import setup_math as mathbase_setup, wrap_displaymath
 
@@ -117,10 +118,7 @@ def render_math(self, math):
     ltx_args.extend(self.builder.config.pngmath_latex_args)
     ltx_args.append('math.tex')
 
-    curdir = getcwd()
-    chdir(tempdir)
-
-    try:
+    with cd(tempdir):
         try:
             p = Popen(ltx_args, stdout=PIPE, stderr=PIPE)
         except OSError, err:
@@ -131,8 +129,6 @@ def render_math(self, math):
                               self.builder.config.pngmath_latex)
             self.builder._mathpng_warned_latex = True
             return None, None
-    finally:
-        chdir(curdir)
 
     stdout, stderr = p.communicate()
     if p.returncode != 0:
diff --git a/sphinx/make_mode.py b/sphinx/make_mode.py
index bf6764aa3..45f62b9b1 100644
--- a/sphinx/make_mode.py
+++ b/sphinx/make_mode.py
@@ -14,6 +14,7 @@
     :copyright: Copyright 2007-2014 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 """
+from __future__ import with_statement
 
 import os
 import sys
@@ -23,7 +24,7 @@ from subprocess import call
 
 import sphinx
 from sphinx.util.console import bold, blue
-from sphinx.util.pycompat import getcwd
+from sphinx.util.osutil import cd
 
 proj_name = os.getenv('SPHINXPROJ', '<project>')
 
@@ -160,22 +161,14 @@ class Make(object):
     def build_latexpdf(self):
         if self.run_generic_build('latex') > 0:
             return 1
-        cwd = getcwd()
-        try:
-            os.chdir(self.builddir_join('latex'))
+        with cd(self.builddir_join('latex')):
             os.system('make all-pdf')
-        finally:
-            os.chdir(cwd)
 
     def build_latexpdfja(self):
         if self.run_generic_build('latex') > 0:
             return 1
-        cwd = getcwd()
-        try:
-            os.chdir(self.builddir_join('latex'))
+        with cd(self.builddir_join('latex')):
             os.system('make all-pdf-ja')
-        finally:
-            os.chdir(cwd)
 
     def build_text(self):
         if self.run_generic_build('text') > 0:
@@ -195,12 +188,8 @@ class Make(object):
     def build_info(self):
         if self.run_generic_build('texinfo') > 0:
             return 1
-        cwd = getcwd()
-        try:
-            os.chdir(self.builddir_join('texinfo'))
+        with cd(self.builddir_join('texinfo')):
             os.system('make info')
-        finally:
-            os.chdir(cwd)
 
     def build_gettext(self):
         dtdir = self.builddir_join('gettext', '.doctrees')
diff --git a/sphinx/util/osutil.py b/sphinx/util/osutil.py
index d7b292b3e..e98c49b20 100644
--- a/sphinx/util/osutil.py
+++ b/sphinx/util/osutil.py
@@ -18,6 +18,7 @@ import locale
 import shutil
 import gettext
 from os import path
+import contextlib
 
 # Errnos that we need.
 EEXIST = getattr(errno, 'EEXIST', 0)
@@ -196,3 +197,14 @@ def abspath(pathdir):
     if isinstance(pathdir, bytes):
         pathdir = pathdir.decode(fs_encoding)
     return pathdir
+
+
+@contextlib.contextmanager
+def cd(target_dir):
+    from sphinx.util.pycompat import getcwd
+    cwd = getcwd()
+    try:
+        os.chdir(target_dir)
+        yield
+    finally:
+        os.chdir(cwd)