Assert palette is not None (#8877)

Tests/test_file_gif.py

@@ -224,6 +224,7 @@ def test_optimize_if_palette_can_be_reduced_by_half() -> None:
         out = BytesIO()
         im.save(out, "GIF", optimize=optimize)
         with Image.open(out) as reloaded:
+            assert reloaded.palette is not None
             assert len(reloaded.palette.palette) // 3 == colors
 
 
@@ -1361,6 +1362,7 @@ def test_palette_save_all_P(tmp_path: Path) -> None:
         # Assert that the frames are correct, and each frame has the same palette
         assert_image_equal(im.convert("RGB"), frames[0].convert("RGB"))
         assert im.palette is not None
+        assert im.global_palette is not None
         assert im.palette.palette == im.global_palette.palette
 
         im.seek(1)

Tests/test_image_quantize.py

@@ -70,6 +70,7 @@ def test_quantize_no_dither() -> None:
     converted = image.quantize(dither=Image.Dither.NONE, palette=palette)
     assert converted.mode == "P"
     assert converted.palette is not None
+    assert palette.palette is not None
     assert converted.palette.palette == palette.palette.palette
 
 

Tests/test_image_transform.py

@@ -48,6 +48,7 @@ class TestImageTransform:
                 im.size, Image.Transform.AFFINE, [1, 0, 0, 0, 1, 0]
             )
             assert im.palette is not None
+            assert transformed.palette is not None
             assert im.palette.palette == transformed.palette.palette
 
     def test_extent(self) -> None: