Fixed #27138 -- Restored pre-Python 3.6 behavior of localtime() and make_naive() on Python 3.6.

Reverted test changes in a7a7ecd2b026c61a39a46d2d7eced0e06a92c970 and
e43ea36b7681e43ea99505a2cf7550d4d36016b3 (refs #27025).

1 files changed, 6 insertions, 4 deletions

diff --git a/django/utils/timezone.py b/django/utils/timezone.py
index 82c14f4f96..29885caac8 100644
--- a/django/utils/timezone.py
+++ b/django/utils/timezone.py
@@ -209,8 +209,9 @@ def localtime(value=None, timezone=None):
         value = now()
     if timezone is None:
         timezone = get_current_timezone()
-    # If `value` is naive, astimezone() will raise a ValueError,
-    # so we don't need to perform a redundant check.
+    # Emulate the behavior of astimezone() on Python < 3.6.
+    if is_naive(value):
+        raise ValueError("localtime() cannot be applied to a naive datetime")
     value = value.astimezone(timezone)
     if hasattr(timezone, 'normalize'):
         # This method is available for pytz time zones.
@@ -295,8 +296,9 @@ def make_naive(value, timezone=None):
     """
     if timezone is None:
         timezone = get_current_timezone()
-    # If `value` is naive, astimezone() will raise a ValueError,
-    # so we don't need to perform a redundant check.
+    # Emulate the behavior of astimezone() on Python < 3.6.
+    if is_naive(value):
+        raise ValueError("make_naive() cannot be applied to a naive datetime")
     value = value.astimezone(timezone)
     if hasattr(timezone, 'normalize'):
         # This method is available for pytz time zones.