From ed4c0a58e8c84ee842e88d2c3fc81ca54e1596bb Mon Sep 17 00:00:00 2001
From: hugovk <hugovk@users.noreply.github.com>
Date: Wed, 30 Nov 2016 16:36:04 +0200
Subject: [PATCH 1/3] Test case for #2266

---
 Tests/test_file_ico.py | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Tests/test_file_ico.py b/Tests/test_file_ico.py
index dc5c041b2..3904340f3 100644
--- a/Tests/test_file_ico.py
+++ b/Tests/test_file_ico.py
@@ -61,6 +61,24 @@ class TestFileIco(PillowTestCase):
         # Assert
         self.assertEqual(im_saved.size, (256, 256))
 
+    def test_only_save_relevant_sizes(self):
+        """Issue #2266 https://github.com/python-pillow/Pillow/issues/2266
+        Should save in 16x16, 24x24, 32x32, 48x48 sizes
+        and not in 16x16, 24x24, 32x32, 48x48, 48x48, 48x48, 48x48 sizes
+        """
+        # Arrange
+        im = Image.open("Tests/images/python.ico")  # 16x16, 32x32, 48x48
+        outfile = self.tempfile("temp_saved_python.ico")
+
+        # Act
+        im.save(outfile)
+        im_saved = Image.open(outfile)
+
+        # Assert
+        self.assertEqual(
+            im_saved.info['sizes'],
+            set([(16, 16), (24, 24), (32, 32), (48, 48)]))
+
 
 if __name__ == '__main__':
     unittest.main()

From 880464f46c231e4e1c74abf61613af1306be1128 Mon Sep 17 00:00:00 2001
From: hugovk <hugovk@users.noreply.github.com>
Date: Wed, 30 Nov 2016 16:41:43 +0200
Subject: [PATCH 2/3] Only save relevant sizes

---
 PIL/IcoImagePlugin.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/PIL/IcoImagePlugin.py b/PIL/IcoImagePlugin.py
index 5dbf31f9f..195bbe42e 100644
--- a/PIL/IcoImagePlugin.py
+++ b/PIL/IcoImagePlugin.py
@@ -46,8 +46,9 @@ def _save(im, fp, filename):
                                [(16, 16), (24, 24), (32, 32), (48, 48),
                                 (64, 64), (128, 128), (256, 256)])
     width, height = im.size
-    filter(lambda x: False if (x[0] > width or x[1] > height or
-                               x[0] > 256 or x[1] > 256) else True, sizes)
+    sizes = filter(lambda x: False if (x[0] > width or x[1] > height or
+                                       x[0] > 256 or x[1] > 256) else True,
+                   sizes)
     fp.write(struct.pack("<H", len(sizes)))  # idCount(2)
     offset = fp.tell() + len(sizes)*16
     for size in sizes:

From adfda1a5a41f888226957906f4de51839c7ef407 Mon Sep 17 00:00:00 2001
From: hugovk <hugovk@users.noreply.github.com>
Date: Wed, 30 Nov 2016 16:50:44 +0200
Subject: [PATCH 3/3] Python 3 compatibility

---
 PIL/IcoImagePlugin.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/PIL/IcoImagePlugin.py b/PIL/IcoImagePlugin.py
index 195bbe42e..3436ae84f 100644
--- a/PIL/IcoImagePlugin.py
+++ b/PIL/IcoImagePlugin.py
@@ -49,6 +49,7 @@ def _save(im, fp, filename):
     sizes = filter(lambda x: False if (x[0] > width or x[1] > height or
                                        x[0] > 256 or x[1] > 256) else True,
                    sizes)
+    sizes = list(sizes)
     fp.write(struct.pack("<H", len(sizes)))  # idCount(2)
     offset = fp.tell() + len(sizes)*16
     for size in sizes: