Fixed #22171 -- Improved sanitize_separators cleverness

Thanks Klaas van Schelven for the report and Tim Graham for the
review.

2 files changed, 13 insertions, 3 deletions

diff --git a/django/utils/formats.py b/django/utils/formats.py
index 521ab5c763..3441f0f420 100644
--- a/django/utils/formats.py
+++ b/django/utils/formats.py
@@ -221,9 +221,13 @@ def sanitize_separators(value):
             parts.append(decimals)
         if settings.USE_THOUSAND_SEPARATOR:
             thousand_sep = get_format('THOUSAND_SEPARATOR')
-            for replacement in set([
-                    thousand_sep, unicodedata.normalize('NFKD', thousand_sep)]):
-                value = value.replace(replacement, '')
+            if thousand_sep == '.' and value.count('.') == 1 and len(value.split('.')[-1]) != 3:
+                # Special case where we suspect a dot meant decimal separator (see #22171)
+                pass
+            else:
+                for replacement in set([
+                        thousand_sep, unicodedata.normalize('NFKD', thousand_sep)]):
+                    value = value.replace(replacement, '')
         parts.append(value)
         value = '.'.join(reversed(parts))
     return value
diff --git a/tests/i18n/tests.py b/tests/i18n/tests.py
index 986b4bfa1e..0599b0b006 100644
--- a/tests/i18n/tests.py
+++ b/tests/i18n/tests.py
@@ -734,6 +734,12 @@ class FormattingTests(TestCase):
             with self.settings(USE_THOUSAND_SEPARATOR=True, USE_L10N=False):
                 self.assertEqual(sanitize_separators('12\xa0345'), '12\xa0345')
 
+        with patch_formats(get_language(), THOUSAND_SEPARATOR='.', DECIMAL_SEPARATOR=','):
+            with self.settings(USE_THOUSAND_SEPARATOR=True):
+                self.assertEqual(sanitize_separators('10.234'), '10234')
+                # Suspicion that user entered dot as decimal separator (#22171)
+                self.assertEqual(sanitize_separators('10.10'), '10.10')
+
     def test_iter_format_modules(self):
         """
         Tests the iter_format_modules function.