diff --git a/CHANGES b/CHANGES
index a344a5752..57257bff2 100644
--- a/CHANGES
+++ b/CHANGES
@@ -171,6 +171,9 @@ Bugs fixed
 * #2665, #2607: Link names in C++ docfields, and make it possible for other domains.
 * #3542: C++, fix parsing error of non-type template argument with template.
 * #3065, #3520: python domain fails to recognize nested class
+* #3575: Problems with pdflatex in a Turkish document built with sphinx has
+  reappeared (refs #2997, #2397)
+* #3577: Fix intersphinx debug tool
 
 Testing
 --------
diff --git a/doc/conf.py b/doc/conf.py
index 1a5be5736..d52b996dd 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -4,7 +4,7 @@
 
 import re
 import sphinx
-
+language = 'ja'
 
 extensions = ['sphinx.ext.autodoc', 'sphinx.ext.doctest', 'sphinx.ext.todo',
               'sphinx.ext.autosummary', 'sphinx.ext.extlinks',
diff --git a/doc/domains.rst b/doc/domains.rst
index 5236b3205..1b0dfac8c 100644
--- a/doc/domains.rst
+++ b/doc/domains.rst
@@ -76,9 +76,10 @@ directive name.
 
 .. rubric:: Default Domain
 
-To avoid having to writing the domain name all the time when you e.g. only
-describe Python objects, a default domain can be selected with either the config
-value :confval:`primary_domain` or this directive:
+For documentation describing objects from solely one domain, authors will not
+have to state again its name at each directive, role, etc... after
+having specified a default. This can be done either via the config
+value :confval:`primary_domain` or via this directive:
 
 .. rst:directive:: .. default-domain:: name
 
diff --git a/sphinx/config.py b/sphinx/config.py
index 03d38fd77..0dbe8a58e 100644
--- a/sphinx/config.py
+++ b/sphinx/config.py
@@ -56,7 +56,7 @@ class ENUM(object):
     """represents the config value should be a one of candidates.
 
     Example:
-        app.add_config_value('latex_show_urls', 'no', ENUM('no', 'footnote', 'inline'))
+        app.add_config_value('latex_show_urls', 'no', None, ENUM('no', 'footnote', 'inline'))
     """
     def __init__(self, *candidates):
         # type: (unicode) -> None
diff --git a/sphinx/ext/intersphinx.py b/sphinx/ext/intersphinx.py
index d952812bc..90cb94de6 100644
--- a/sphinx/ext/intersphinx.py
+++ b/sphinx/ext/intersphinx.py
@@ -26,6 +26,7 @@
 
 from __future__ import print_function
 
+import sys
 import time
 import functools
 import posixpath
@@ -340,17 +341,27 @@ def setup(app):
     return {'version': sphinx.__display_version__, 'parallel_read_safe': True}
 
 
-if __name__ == '__main__':
-    # debug functionality to print out an inventory
-    import sys
+def debug(argv):
+    # type: (List[unicode]) -> None
+    """Debug functionality to print out an inventory"""
+    if len(argv) < 2:
+        print("Print out an inventory file.\n"
+              "Error: must specify local path or URL to an inventory file.",
+              file=sys.stderr)
+        sys.exit(1)
+
+    class MockConfig(object):
+        intersphinx_timeout = None  # type: int
+        tls_verify = False
 
     class MockApp(object):
         srcdir = ''
+        config = MockConfig()
 
         def warn(self, msg):
             print(msg, file=sys.stderr)
 
-    filename = sys.argv[1]
+    filename = argv[1]
     invdata = fetch_inventory(MockApp(), '', filename)  # type: ignore
     for key in sorted(invdata or {}):
         print(key)
@@ -358,3 +369,7 @@ if __name__ == '__main__':
             print('\t%-40s %s%s' % (entry,
                                     einfo[3] != '-' and '%-40s: ' % einfo[3] or '',
                                     einfo[2]))
+
+
+if __name__ == '__main__':
+    debug(argv=sys.argv)  # type: ignore
diff --git a/sphinx/writers/latex.py b/sphinx/writers/latex.py
index 36f2062d4..ddc6e239c 100644
--- a/sphinx/writers/latex.py
+++ b/sphinx/writers/latex.py
@@ -185,9 +185,10 @@ class ExtBabel(Babel):
         if shortlang in ('de', 'ngerman', 'sl', 'slovene', 'pt', 'portuges',
                          'es', 'spanish', 'nl', 'dutch', 'pl', 'polish', 'it',
                          'italian'):
-            return '\\if\\catcode`\\"\\active\\shorthandoff{"}\\fi'
+            return '\\ifnum\\catcode`\\"=\\active\\shorthandoff{"}\\fi'
         elif shortlang in ('tr', 'turkish'):
-            return '\\if\\catcode`\\=\\active\\shorthandoff{=}\\fi'
+            # memo: if ever Sphinx starts supporting 'Latin', do as for Turkish
+            return '\\ifnum\\catcode`\\=\\string=\\active\\shorthandoff{=}\\fi'
         return ''
 
     def uses_cyrillic(self):
diff --git a/tests/test_ext_intersphinx.py b/tests/test_ext_intersphinx.py
index 6e722b90b..79e41bb13 100644
--- a/tests/test_ext_intersphinx.py
+++ b/tests/test_ext_intersphinx.py
@@ -13,12 +13,15 @@ import unittest
 
 from docutils import nodes
 import mock
+import pytest
+import requests
+from io import BytesIO
 
 from sphinx import addnodes
 from sphinx.ext.intersphinx import setup as intersphinx_setup
 from sphinx.ext.intersphinx import (
     load_mappings, missing_reference, _strip_basic_auth,
-    _get_safe_url, fetch_inventory, INVENTORY_FILENAME
+    _get_safe_url, fetch_inventory, INVENTORY_FILENAME, debug
 )
 from test_util_inventory import inventory_v2
 
@@ -229,3 +232,53 @@ def test_getsafeurl_unauthed():
     expected = 'https://domain.com/project/objects.inv'
     actual = _get_safe_url(url)
     assert expected == actual
+
+
+def test_debug_noargs(capsys):
+    """debug interface, without arguments"""
+    with pytest.raises(SystemExit):
+        debug(['sphinx/ext/intersphinx.py'])
+
+    expected = (
+        "Print out an inventory file.\n"
+        "Error: must specify local path or URL to an inventory file."
+    )
+    stdout, stderr = capsys.readouterr()
+    assert stdout == ""
+    assert stderr == expected + "\n"
+
+
+def test_debug_file(capsys, tempdir):
+    """debug interface, with file argument"""
+    inv_file = tempdir / 'inventory'
+    inv_file.write_bytes(inventory_v2)
+
+    debug(['sphinx/ext/intersphinx.py', str(inv_file)])
+
+    stdout, stderr = capsys.readouterr()
+    assert stdout.startswith("c:function\n")
+    assert stderr == ""
+
+
+@mock.patch('requests.get')
+def test_debug_url(fake_get, capsys):
+    """debug interface, with url argument"""
+    raw = BytesIO(inventory_v2)
+    real_read = raw.read
+
+    def fake_read(*args, **kwargs):
+        return real_read()
+
+    raw.read = fake_read
+    url = 'http://hostname/' + INVENTORY_FILENAME
+    resp = requests.Response()
+    resp.status_code = 200
+    resp.url = url
+    resp.raw = raw
+    fake_get.return_value = resp
+
+    debug(['sphinx/ext/intersphinx.py', url])
+
+    stdout, stderr = capsys.readouterr()
+    assert stdout.startswith("c:function\n")
+    assert stderr == ""