Fix older versions of Pillow

daniilS · timhoffm · web-flow · commit 6b5372436fe0 · 2022-01-09T22:05:20.000Z
Co-authored-by: Tim Hoffmann &lt;2836374+timhoffm@users.noreply.github.com&gt;
diff --git a/lib/matplotlib/backends/_backend_tk.py b/lib/matplotlib/backends/_backend_tk.py
@@ -665,7 +665,7 @@ def _set_image_for_button(self, button):
                     # the dark background.
                     foreground = (255 / 65535) * np.array(
                         button.winfo_rgb(button.cget("foreground")))
-                    image_data = np.asarray(im)
+                    image_data = np.asarray(im).copy()
                     black_mask = (image_data[..., :3] == 0).all(axis=-1)
                     image_data[black_mask, :3] = foreground
                     im = Image.fromarray(image_data, mode="RGBA")
