[1.10.x] Fixed #26729 -- Allowed overriding a form field's label/help_text in Form.__init__() for TabularInline.

Backport of 9c2d5a8d33 from master

django/contrib/admin/helpers.py

@@ -279,7 +279,7 @@ class InlineAdminFormSet(object):
                     'help_text': help_text_for_field(field_name, self.opts.model),
                 }
             else:
-                form_field = self.formset.form.base_fields[field_name]
+                form_field = self.formset.empty_form.fields[field_name]
                 label = form_field.label
                 if label is None:
                     label = label_for_field(field_name, self.opts.model, self.opts)

tests/admin_inlines/admin.py

@@ -192,6 +192,10 @@ class SomeChildModelForm(forms.ModelForm):
             'position': forms.HiddenInput,
         }
 
+    def __init__(self, *args, **kwargs):
+        super(SomeChildModelForm, self).__init__(*args, **kwargs)
+        self.fields['name'].label = 'new label'
+
 
 class SomeChildModelInline(admin.TabularInline):
     model = SomeChildModel

tests/admin_inlines/tests.py

@@ -95,6 +95,16 @@ class TestInline(TestDataMixin, TestCase):
         response = self.client.get(reverse('admin:admin_inlines_titlecollection_add'))
         self.assertContains(response, '<th class="required">Title1</th>', html=True)
 
+    def test_custom_form_tabular_inline_overridden_label(self):
+        """
+        SomeChildModelForm.__init__() overrides the label of a form field.
+        That label is displayed in the TabularInline.
+        """
+        response = self.client.get(reverse('admin:admin_inlines_someparentmodel_add'))
+        field = list(response.context['inline_admin_formset'].fields())[0]
+        self.assertEqual(field['label'], 'new label')
+        self.assertContains(response, '<th class="required">New label</th>', html=True)
+
     def test_tabular_non_field_errors(self):
         """
         Ensure that non_field_errors are displayed correctly, including the