natsort.compat.(null_string -> null_string_locale).

This is in preparation for adding a few new versions of the null
string, one which will be sorted after other strings, and another
pair which will be used when locale is not enabled.

4 files changed, 15 insertions, 10 deletions

diff --git a/natsort/compat/locale.py b/natsort/compat/locale.py
index 4cbe5f5..cbed495 100644
--- a/natsort/compat/locale.py
+++ b/natsort/compat/locale.py
@@ -16,7 +16,7 @@ try:
     import icu
     from locale import getlocale
 
-    null_string = b''
+    null_string_locale = b''
 
     def dumb_sort():
         return False
@@ -44,11 +44,13 @@ except ImportError:
     if PY_VERSION < 3:
         from locale import strcoll
         strxfrm = cmp_to_key(strcoll)
-        null_string = strxfrm('')
     else:
         from locale import strxfrm
-        null_string = ''
 
+    null_string_locale = ''
+
+    if PY_VERSION < 3:
+        null_string_locale = cmp_to_key(cmp)(null_string_locale)
     # On some systems, locale is broken and does not sort in the expected
     # order. We will try to detect this and compensate.
     def dumb_sort():
diff --git a/natsort/natsort.py b/natsort/natsort.py
index be887c7..8703498 100644
--- a/natsort/natsort.py
+++ b/natsort/natsort.py
@@ -207,7 +207,10 @@ def natsort_keygen(key=None, alg=0, **_kwargs):
         alg |= ns._DUMB
 
     # Set some variables that will be passed to the factory functions
-    sep = natsort.compat.locale.null_string if alg & ns.LOCALEALPHA else ''
+    if alg & ns.LOCALEALPHA:
+        sep = natsort.compat.locale.null_string_locale
+    else:
+        sep = ''
     regex = _regex_chooser[alg & ns._NUMERIC_ONLY]
 
     # Create the functions that will be used to split strings.
diff --git a/test_natsort/test_natsort_keygen.py b/test_natsort/test_natsort_keygen.py
index e94d3d3..9ea408a 100644
--- a/test_natsort/test_natsort_keygen.py
+++ b/test_natsort/test_natsort_keygen.py
@@ -16,7 +16,7 @@ from natsort import (
 )
 from natsort.compat.py23 import PY_VERSION
 from natsort.compat.locale import (
-    null_string,
+    null_string_locale,
     get_strxfrm,
 )
 from compat.mock import patch
@@ -79,9 +79,9 @@ def test_natsort_keygen_splits_input_with_locale():
     load_locale('en_US')
     strxfrm = get_strxfrm()
     with patch('natsort.compat.locale.dumb_sort', return_value=False):
-        assert natsort_keygen(alg=ns.L)(INPUT) == ((null_string, 6, strxfrm('A-'), 5, strxfrm('.'), 34, strxfrm('e+'), 1), (strxfrm('/Folder ('), 1, strxfrm(')/Foo')), (null_string, 56.7))
+        assert natsort_keygen(alg=ns.L)(INPUT) == ((null_string_locale, 6, strxfrm('A-'), 5, strxfrm('.'), 34, strxfrm('e+'), 1), (strxfrm('/Folder ('), 1, strxfrm(')/Foo')), (null_string_locale, 56.7))
     with patch('natsort.compat.locale.dumb_sort', return_value=True):
-        assert natsort_keygen(alg=ns.L)(INPUT) == ((null_string, 6, strxfrm('aa--'), 5, strxfrm('..'), 34, strxfrm('eE++'), 1), (strxfrm('//ffoOlLdDeErR  (('), 1, strxfrm('))//ffoOoO')), (null_string, 56.7))
+        assert natsort_keygen(alg=ns.L)(INPUT) == ((null_string_locale, 6, strxfrm('aa--'), 5, strxfrm('..'), 34, strxfrm('eE++'), 1), (strxfrm('//ffoOlLdDeErR  (('), 1, strxfrm('))//ffoOoO')), (null_string_locale, 56.7))
     if PY_VERSION >= 3: assert natsort_keygen(alg=ns.LA)(b'6A-5.034e+1') == (b'6A-5.034e+1',)
     locale.setlocale(locale.LC_ALL, str(''))
 
@@ -90,7 +90,7 @@ def test_natsort_keygen_splits_input_with_locale_and_capitalfirst():
     load_locale('en_US')
     strxfrm = get_strxfrm()
     with patch('natsort.compat.locale.dumb_sort', return_value=False):
-        assert natsort_keygen(alg=ns.LA | ns.C)(INPUT) == ((('',), (null_string, 6, strxfrm('A-'), 5, strxfrm('.'), 34, strxfrm('e+'), 1)), (('/',), (strxfrm('/Folder ('), 1, strxfrm(')/Foo'))), (('',), (null_string, 56.7)))
+        assert natsort_keygen(alg=ns.LA | ns.C)(INPUT) == ((('',), (null_string_locale, 6, strxfrm('A-'), 5, strxfrm('.'), 34, strxfrm('e+'), 1)), (('/',), (strxfrm('/Folder ('), 1, strxfrm(')/Foo'))), (('',), (null_string_locale, 56.7)))
     if PY_VERSION >= 3: assert natsort_keygen(alg=ns.LA | ns.C)(b'6A-5.034e+1') == (b'6A-5.034e+1',)
     locale.setlocale(locale.LC_ALL, str(''))
 
diff --git a/test_natsort/test_utils.py b/test_natsort/test_utils.py
index cfa06b6..3a367cb 100644
--- a/test_natsort/test_utils.py
+++ b/test_natsort/test_utils.py
@@ -24,7 +24,7 @@ from natsort.utils import (
     chain_functions,
 )
 from natsort.compat.py23 import py23_str, py23_cmp
-from natsort.compat.locale import null_string
+from natsort.compat.locale import null_string_locale
 from slow_splitters import (
     sep_inserter,
     add_leading_space_if_first_is_num,
@@ -195,7 +195,7 @@ def test_sep_inserter_does_nothing_if_only_one_number_example():
 
 def test_sep_inserter_inserts_separator_string_between_two_numbers_example():
     assert list(_sep_inserter(iter([5, 9]), '')) == ['', 5, '', 9]
-    assert list(_sep_inserter(iter([5, 9]), null_string)) == [null_string, 5, null_string, 9]
+    assert list(_sep_inserter(iter([5, 9]), null_string_locale)) == [null_string_locale, 5, null_string_locale, 9]
 
 
 @given(lists(elements=text().filter(bool) | integers()))