Fix #2687: Uninstall sphinx directives and roles after build

CHANGES

@@ -141,6 +141,7 @@ Bugs fixed
 * #1734: Could not translate the caption of toctree directive
 * Could not translate the content of meta directive (ref: #1734)
 * #2550: external links are opened in help viewer
+* #2687: Running Sphinx multiple times produces 'already registered' warnings
 
 Documentation
 -------------

sphinx/cmdline.py

@@ -23,6 +23,7 @@ from sphinx.errors import SphinxError
 from sphinx.application import Sphinx
 from sphinx.util import Tee, format_exception_cut_frames, save_traceback
 from sphinx.util.console import red, nocolor, color_terminal
+from sphinx.util.docutils import docutils_namespace
 from sphinx.util.osutil import abspath, fs_encoding
 from sphinx.util.pycompat import terminal_safe
 
@@ -288,11 +289,12 @@ def main(argv):
 
     app = None
     try:
-        app = Sphinx(srcdir, confdir, outdir, doctreedir, opts.builder,
-                     confoverrides, status, warning, opts.freshenv,
-                     opts.warningiserror, opts.tags, opts.verbosity, opts.jobs)
-        app.build(opts.force_all, filenames)
-        return app.statuscode
+        with docutils_namespace():
+            app = Sphinx(srcdir, confdir, outdir, doctreedir, opts.builder,
+                         confoverrides, status, warning, opts.freshenv,
+                         opts.warningiserror, opts.tags, opts.verbosity, opts.jobs)
+            app.build(opts.force_all, filenames)
+            return app.statuscode
     except (Exception, KeyboardInterrupt) as exc:
         handle_exception(app, opts, exc, error)
         return 1

sphinx/setup_command.py

@@ -23,6 +23,7 @@ from distutils.errors import DistutilsOptionError, DistutilsExecError
 from sphinx.application import Sphinx
 from sphinx.cmdline import handle_exception
 from sphinx.util.console import nocolor, color_terminal
+from sphinx.util.docutils import docutils_namespace
 from sphinx.util.osutil import abspath
 
 
@@ -165,15 +166,16 @@ class BuildDoc(Command):
             confoverrides['copyright'] = self.copyright
 
         try:
-            app = Sphinx(self.source_dir, self.config_dir,
-                         self.builder_target_dir, self.doctree_dir,
-                         self.builder, confoverrides, status_stream,
-                         freshenv=self.fresh_env,
-                         warningiserror=self.warning_is_error)
-            app.build(force_all=self.all_files)
-            if app.statuscode:
-                raise DistutilsExecError(
-                    'caused by %s builder.' % app.builder.name)
+            with docutils_namespace():
+                app = Sphinx(self.source_dir, self.config_dir,
+                             self.builder_target_dir, self.doctree_dir,
+                             self.builder, confoverrides, status_stream,
+                             freshenv=self.fresh_env,
+                             warningiserror=self.warning_is_error)
+                app.build(force_all=self.all_files)
+                if app.statuscode:
+                    raise DistutilsExecError(
+                        'caused by %s builder.' % app.builder.name)
         except Exception as exc:
             handle_exception(app, self, exc, sys.stderr)
             if not self.pdb:

sphinx/util/__init__.py

@@ -8,6 +8,7 @@
     :copyright: Copyright 2007-2016 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 """
+from __future__ import absolute_import
 
 import os
 import re

sphinx/util/compat.py

@@ -8,6 +8,8 @@
     :copyright: Copyright 2007-2016 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 """
+from __future__ import absolute_import
+
 import warnings
 
 from docutils import nodes

sphinx/util/docfields.py

@@ -9,6 +9,7 @@
     :copyright: Copyright 2007-2016 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 """
+from __future__ import absolute_import
 
 from docutils import nodes
 

sphinx/util/docutils.py

@@ -0,0 +1,28 @@
+# -*- coding: utf-8 -*-
+"""
+    sphinx.util.docutils
+    ~~~~~~~~~~~~~~~~~~~~
+
+    Utility functions for docutils.
+
+    :copyright: Copyright 2007-2016 by the Sphinx team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+from __future__ import absolute_import
+
+from copy import copy
+from contextlib import contextmanager
+from docutils.parsers.rst import directives, roles
+
+
+@contextmanager
+def docutils_namespace():
+    """Create namespace for reST parsers."""
+    try:
+        _directives = copy(directives._directives)
+        _roles = copy(roles._roles)
+
+        yield
+    finally:
+        directives._directives = _directives
+        roles._roles = _roles

sphinx/util/fileutil.py

@@ -8,6 +8,8 @@
     :copyright: Copyright 2007-2016 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 """
+from __future__ import absolute_import
+
 import os
 import codecs
 import posixpath

sphinx/util/nodes.py

@@ -8,6 +8,7 @@
     :copyright: Copyright 2007-2016 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 """
+from __future__ import absolute_import
 
 import re