Include JpegImageFile layers in state

Tests/test_pickle.py

@@ -74,6 +74,17 @@ def test_pickle_image(
     helper_pickle_file(tmp_path, protocol, test_file, test_mode)
 
 
+def test_pickle_jpeg() -> None:
+    # Arrange
+    with Image.open("Tests/images/hopper.jpg") as image:
+        # Act: roundtrip
+        unpickled_image = pickle.loads(pickle.dumps(image))
+
+    # Assert
+    assert len(unpickled_image.layer) == 3
+    assert unpickled_image.layers == 3
+
+
 def test_pickle_la_mode_with_palette(tmp_path: Path) -> None:
     # Arrange
     filename = str(tmp_path / "temp.pkl")

src/PIL/Image.py

@@ -763,7 +763,7 @@ class Image:
 
     def __setstate__(self, state: list[Any]) -> None:
         Image.__init__(self)
-        info, mode, size, palette, data = state
+        info, mode, size, palette, data = state[:5]
         self.info = info
         self._mode = mode
         self._size = size

src/PIL/JpegImagePlugin.py

@@ -395,6 +395,13 @@ class JpegImageFile(ImageFile.ImageFile):
             return getattr(self, "_" + name)
         raise AttributeError(name)
 
+    def __getstate__(self) -> list[Any]:
+        return super().__getstate__() + [self.layers, self.layer]
+
+    def __setstate__(self, state: list[Any]) -> None:
+        super().__setstate__(state)
+        self.layers, self.layer = state[5:]
+
     def load_read(self, read_bytes: int) -> bytes:
         """
         internal: read more image data