message: add bounds check in transform code
diff: @@ -32,6 +32,10 @@ impl TransformType {
  let width = usize::from(width);
  let height = usize::from(height);
  + if image_data.len() < width * height {
  + return;
  + }
  +
  //handle top and left borders specially
  //this involves ignoring mode and just setting prediction values like this
  image_data[0] = add_pixels(image_data[0], 0xff000000);
  