message: fix: Resolves a regression from
diff: @@ -917,9 +917,6 @@ class Superset(BaseSupersetView):
  )
  if action in ("saveas", "overwrite"):
  - if not slc:
  - return json_error_response("The slice does not exist")
  -
  return self.save_or_overwrite_slice(
  slc,
  slice_add_perm,
  @@ -1003,7 +1000,7 @@ class Superset(BaseSupersetView):
  def save_or_overwrite_slice(
  self,
  - slc: Slice,
  + slc: Optional[Slice],
  slice_add_perm: bool,
  slice_overwrite_perm: bool,
  slice_download_perm: bool,
  @@ -1025,6 +1022,7 @@ class Superset(BaseSupersetView):
  form_data.get("adhoc_filters", [])
  )
  + assert slc
  slc.params = json.dumps(form_data, indent=2, sort_keys=True)
  slc.datasource_name = datasource_name
  slc.viz_type = form_data["viz_type"]
  