Fixed #26281 -- Added a helpful error message for an invalid format specifier to dateformat.format().

django/template/defaultfilters.py

@@ -767,10 +767,10 @@ def time(value, arg=None):
         return ''
     try:
         return formats.time_format(value, arg)
-    except AttributeError:
+    except (AttributeError, TypeError):
         try:
             return time_format(value, arg)
-        except AttributeError:
+        except (AttributeError, TypeError):
             return ''
 
 

django/utils/dateformat.py

@@ -34,6 +34,11 @@ class Formatter(object):
         pieces = []
         for i, piece in enumerate(re_formatchars.split(force_text(formatstr))):
             if i % 2:
+                if type(self.data) is datetime.date and hasattr(TimeFormat, piece):
+                    raise TypeError(
+                        "The format for date objects may not contain "
+                        "time-related format specifiers (found '%s')." % piece
+                    )
                 pieces.append(force_text(getattr(self, piece)()))
             elif piece:
                 pieces.append(re_escaped.sub(r'\1', piece))

tests/utils_tests/test_dateformat.py

@@ -153,3 +153,14 @@ class DateFormatTests(SimpleTestCase):
 
         # Ticket #16924 -- We don't need timezone support to test this
         self.assertEqual(dateformat.format(aware_dt, 'O'), '-0330')
+
+    def test_invalid_time_format_specifiers(self):
+        my_birthday = date(1984, 8, 7)
+
+        for specifier in ['a', 'A', 'f', 'g', 'G', 'h', 'H', 'i', 'P', 's', 'u']:
+            msg = (
+                "The format for date objects may not contain time-related "
+                "format specifiers (found '%s')." % specifier
+            )
+            with self.assertRaisesMessage(TypeError, msg):
+                dateformat.format(my_birthday, specifier)