Fixed #23712 -- Fixed KeyError with BaseForm._html_output()

django/forms/forms.py

@@ -251,9 +251,14 @@ class BaseForm(object):
                     # that users write): if there are only top errors, we may
                     # not be able to conscript the last row for our purposes,
                     # so insert a new, empty row.
-                    last_row = (normal_row % {'errors': '', 'label': '',
+                    last_row = (normal_row % {
-                                              'field': '', 'help_text': '',
+                        'errors': '',
-                                              'html_class_attr': html_class_attr})
+                        'label': '',
+                        'field': '',
+                        'help_text': '',
+                        'html_class_attr': html_class_attr,
+                        'field_name': '',
+                    })
                     output.append(last_row)
                 output[-1] = last_row[:-len(row_ender)] + str_hidden + row_ender
             else:

tests/forms_tests/tests/test_forms.py

@@ -2191,6 +2191,60 @@ class FormsTestCase(TestCase):
         form = SomeForm()
         self.assertHTMLEqual(form.as_p(), '<p id="p_some_field"></p>')
 
+    def test_field_name_with_hidden_input(self):
+        """
+        BaseForm._html_output() should merge all the hidden input fields and
+        put them in the last row.
+        """
+        class SomeForm(Form):
+            hidden1 = CharField(widget=HiddenInput)
+            custom = CharField()
+            hidden2 = CharField(widget=HiddenInput)
+
+            def as_p(self):
+                return self._html_output(
+                    normal_row='<p%(html_class_attr)s>%(field)s %(field_name)s</p>',
+                    error_row='%s',
+                    row_ender='</p>',
+                    help_text_html=' %s',
+                    errors_on_separate_row=True,
+                )
+
+        form = SomeForm()
+        self.assertHTMLEqual(
+            form.as_p(),
+            '<p><input id="id_custom" name="custom" type="text" /> custom'
+            '<input id="id_hidden1" name="hidden1" type="hidden" />'
+            '<input id="id_hidden2" name="hidden2" type="hidden" /></p>'
+        )
+
+    def test_field_name_with_hidden_input_and_non_matching_row_ender(self):
+        """
+        BaseForm._html_output() should merge all the hidden input fields and
+        put them in the last row ended with the specific row ender.
+        """
+        class SomeForm(Form):
+            hidden1 = CharField(widget=HiddenInput)
+            custom = CharField()
+            hidden2 = CharField(widget=HiddenInput)
+
+            def as_p(self):
+                return self._html_output(
+                    normal_row='<p%(html_class_attr)s>%(field)s %(field_name)s</p>',
+                    error_row='%s',
+                    row_ender='<hr/><hr/>',
+                    help_text_html=' %s',
+                    errors_on_separate_row=True
+                )
+
+        form = SomeForm()
+        self.assertHTMLEqual(
+            form.as_p(),
+            '<p><input id="id_custom" name="custom" type="text" /> custom</p>\n'
+            '<input id="id_hidden1" name="hidden1" type="hidden" />'
+            '<input id="id_hidden2" name="hidden2" type="hidden" /><hr/><hr/>'
+        )
+
     def test_error_dict(self):
         class MyForm(Form):
             foo = CharField()