Merge pull request #5667 from radarhere/ico

Read ICO AND mask from end
python-pillow · Sep 5, 2021 · a918186 · a918186
2 parents 65b5f91 + cbdc751
commit a918186
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Showing 4 changed files with 6 additions and 1 deletion.
diff --git a/Tests/images/hopper_mask.ico b/Tests/images/hopper_mask.ico
diff --git a/Tests/images/hopper_mask.png b/Tests/images/hopper_mask.png
diff --git a/Tests/test_file_ico.py b/Tests/test_file_ico.py
@@ -18,6 +18,11 @@ def test_sanity():
     assert im.get_format_mimetype() == "image/x-icon"
 
 
+def test_mask():
+    with Image.open("Tests/images/hopper_mask.ico") as im:
+        assert_image_equal_tofile(im, "Tests/images/hopper_mask.png")
+
+
 def test_black_and_white():
     with Image.open("Tests/images/black_and_white.ico") as im:
         assert im.mode == "RGBA"

diff --git a/src/PIL/IcoImagePlugin.py b/src/PIL/IcoImagePlugin.py
@@ -235,8 +235,8 @@ def frame(self, idx):
                 # the total mask data is
                 # padded row size * height / bits per char
 
-                and_mask_offset = o + int(im.size[0] * im.size[1] * (bpp / 8.0))
                 total_bytes = int((w * im.size[1]) / 8)
+                and_mask_offset = header["offset"] + header["size"] - total_bytes
 
                 self.buf.seek(and_mask_offset)
                 mask_data = self.buf.read(total_bytes)