message: Split up the (frame.left, frame.width) condition
diff: @@ -106,7 +106,7 @@ impl<'a, R: 'a + Read> ImageDecoder<'a> for GifDecoder<R> {
  let (width, height) = self.dimensions();
  - if (frame.left, frame.width) == (0, width) && (frame.top as u64 + frame.height as u64 <= height as u64) {
  + if frame.left == 0 && frame.width == width && (frame.top as u64 + frame.height as u64 <= height as u64) {
  // If the frame matches the logical screen, or, as a more general case,
  // fits into it and touches its left and right borders, then
  // we can directly write it into the buffer without causing line wraparound.
  