Fixed #18751 -- Cleaned up BaseFormSet._should_delete_form

We can do that now that cleaned_data is guaranteed to be
present. Related to [121fd109].
Thanks Simon Charette for his work on the ticket.

django/forms/formsets.py

@@ -254,13 +254,10 @@ class BaseFormSet(object):
     errors = property(_get_errors)
 
     def _should_delete_form(self, form):
-        # The way we lookup the value of the deletion field here takes
-        # more code than we'd like, but the form's cleaned_data will
-        # not exist if the form is invalid.
-        field = form.fields[DELETION_FIELD_NAME]
-        raw_value = form._raw_value(DELETION_FIELD_NAME)
-        should_delete = field.clean(raw_value)
-        return should_delete
+        """
+        Returns whether or not the form was marked for deletion.
+        """
+        return form.cleaned_data.get(DELETION_FIELD_NAME, False)
 
     def is_valid(self):
         """

django/forms/models.py

@@ -591,6 +591,10 @@ class BaseModelFormSet(BaseFormSet):
             return []
 
         saved_instances = []
+        try:
+            forms_to_delete = self.deleted_forms
+        except AttributeError:
+            forms_to_delete = []
         for form in self.initial_forms:
             pk_name = self._pk_field.name
             raw_pk_value = form._raw_value(pk_name)
@@ -601,7 +605,7 @@ class BaseModelFormSet(BaseFormSet):
             pk_value = getattr(pk_value, 'pk', pk_value)
 
             obj = self._existing_object(pk_value)
-            if self.can_delete and self._should_delete_form(form):
+            if form in forms_to_delete:
                 self.deleted_objects.append(obj)
                 obj.delete()
                 continue