From b3e24660c9583afec0a83e631b89635877ca3bf1 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Mon, 21 Sep 2026 18:41:37 +1000
Subject: [PATCH] Ignore putpalette rawmode if data is an ImagePalette

---
 Tests/test_image_putpalette.py |  5 +++++
 src/PIL/GifImagePlugin.py      |  2 +-
 src/PIL/Image.py               | 16 +++++++++-------
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/Tests/test_image_putpalette.py b/Tests/test_image_putpalette.py
index 237de63305a..7e9b4928b54 100644
--- a/Tests/test_image_putpalette.py
+++ b/Tests/test_image_putpalette.py
@@ -56,6 +56,11 @@ def test_imagepalette() -> None:
     im.putpalette(ImagePalette.wedge())
     assert_image_equal_tofile(im.convert("RGB"), "Tests/images/palette_wedge.png")
 
+    # Check that rawmode is ignored
+    im.putpalette(ImagePalette.wedge(), "RGBA")
+    assert im.palette is not None
+    assert im.palette.mode == "RGB"
+
 
 def test_putpalette_with_alpha_values() -> None:
     with Image.open("Tests/images/transparent.gif") as im:
diff --git a/src/PIL/GifImagePlugin.py b/src/PIL/GifImagePlugin.py
index 0e05d8761be..61a0c82c475 100644
--- a/src/PIL/GifImagePlugin.py
+++ b/src/PIL/GifImagePlugin.py
@@ -720,7 +720,7 @@ def _write_multiple_frames(
                             background_im = Image.new("P", im_frame.size, background)
                             first_palette = im_frames[0].im.palette
                             assert first_palette is not None
-                            background_im.putpalette(first_palette, first_palette.mode)
+                            background_im.putpalette(first_palette)
                         bbox = _getbbox(background_im, im_frame)[1]
                     else:
                         bbox = (0, 0, *im_frame.size)
diff --git a/src/PIL/Image.py b/src/PIL/Image.py
index 873de8607bf..c614c8ab58e 100644
--- a/src/PIL/Image.py
+++ b/src/PIL/Image.py
@@ -1145,7 +1145,7 @@ def convert_transparency(
                     trns_im = new(self.mode, (1, 1))
                     if self.mode == "P":
                         assert self.palette is not None
-                        trns_im.putpalette(self.palette, self.palette.mode)
+                        trns_im.putpalette(self.palette)
                         if isinstance(t, tuple):
                             err = "Couldn't allocate a palette color for transparency"
                             assert trns_im.palette is not None
@@ -2151,9 +2151,10 @@ def putpalette(
 
         Alternatively, an 8-bit string may be used instead of an integer sequence.
 
-        :param data: A palette sequence (either a list or a string).
+        :param data: A palette sequence (either a list or a string) or an ImagePalette.
         :param rawmode: The raw mode of the palette. Either "RGB", "RGBA", "CMYK", or a
            mode that can be transformed to one of those modes (e.g. "R", "RGBA;L").
+           Ignored if ``data`` is an ImagePalette.
         """
         from . import ImagePalette
 
@@ -2161,15 +2162,16 @@ def putpalette(
             msg = "illegal image mode"
             raise ValueError(msg)
         if isinstance(data, ImagePalette.ImagePalette):
-            palette = ImagePalette.raw(data.rawmode or "RGB", data.palette)
+            palette = data.copy()
+            palette.dirty = 1
         else:
             palette = ImagePalette.raw(rawmode, data)
+            if rawmode.startswith("CMYK"):
+                palette.mode = "CMYK"
+            elif "A" in rawmode:
+                palette.mode = "RGBA"
         self._mode = "PA" if "A" in self.mode else "P"
         self.palette = palette
-        if rawmode.startswith("CMYK"):
-            self.palette.mode = "CMYK"
-        elif "A" in rawmode:
-            self.palette.mode = "RGBA"
         self.load()  # install new palette
 
     def putpixel(