From 0a475f29cae15e44f4eba3cfd89770ddbca7e8ef Mon Sep 17 00:00:00 2001
From: linnil1 <linnil1.886@gmail.com>
Date: Tue, 31 Jan 2017 03:34:48 +0800
Subject: [PATCH 1/4] Add disposal option

---
 PIL/GifImagePlugin.py | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/PIL/GifImagePlugin.py b/PIL/GifImagePlugin.py
index 2e519c7ac..aa3db4703 100644
--- a/PIL/GifImagePlugin.py
+++ b/PIL/GifImagePlugin.py
@@ -453,15 +453,24 @@ def _get_local_header(fp, im, offset, flags):
         duration = int(im.encoderinfo["duration"] / 10)
     else:
         duration = 0
+
+    if "disposal" in im.encoderinfo:
+        disposal = int(im.encoderinfo['disposal'])
+        if not 0<= disposal <=3:
+            disposal = 2
+    else:
+        disposal = 2
+
     if transparent_color_exists or duration != 0:
-        transparency_flag = 1 if transparent_color_exists else 0
+        packed_flag = 1 if transparent_color_exists else 0
+        packed_flag |= disposal << 2
         if not transparent_color_exists:
             transparency = 0
 
         fp.write(b"!" +
                  o8(249) +                # extension intro
                  o8(4) +                  # length
-                 o8(transparency_flag) +  # packed fields
+                 o8(packed_flag) +        # packed fields
                  o16(duration) +          # duration
                  o8(transparency) +       # transparency index
                  o8(0))

From b4a63c1c2003bd27ed87753ee3aba67e5104573c Mon Sep 17 00:00:00 2001
From: linnil1 <linnil1.886@gmail.com>
Date: Tue, 31 Jan 2017 03:55:49 +0800
Subject: [PATCH 2/4] Add dispoal description in documents

---
 docs/handbook/image-file-formats.rst | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/docs/handbook/image-file-formats.rst b/docs/handbook/image-file-formats.rst
index 21339e75f..9e8974df0 100644
--- a/docs/handbook/image-file-formats.rst
+++ b/docs/handbook/image-file-formats.rst
@@ -127,6 +127,14 @@ are available::
 **palette**
     Use the specified palette for the saved image.
 
+**disposal**
+    Indicates the way in which the graphic is to be treated after being displayed.
+
+    * 0 - No disposal specified.
+    * 1 - Do not dispose.
+    * 2 - Restore to background color.
+    * 3 - Restore to previous content.
+
 Reading local images
 ~~~~~~~~~~~~~~~~~~~~
 

From 4c9143ef2d39a22eedac505f288f05b274322916 Mon Sep 17 00:00:00 2001
From: linnil1 <linnil1.886@gmail.com>
Date: Tue, 31 Jan 2017 15:22:54 +0800
Subject: [PATCH 3/4] Add dispose test

---
 Tests/test_file_gif.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/Tests/test_file_gif.py b/Tests/test_file_gif.py
index d987f6851..96c07106b 100644
--- a/Tests/test_file_gif.py
+++ b/Tests/test_file_gif.py
@@ -259,6 +259,28 @@ class TestFileGif(PillowTestCase):
         except EOFError:
             pass
 
+    def test_save_dispose(self):
+        out = self.tempfile('temp.gif')
+        im_list = [
+            Image.new('L', (100, 100), '#000'),
+            Image.new('L', (100, 100), '#111'),
+            Image.new('L', (100, 100), '#222'),
+        ]
+        for method in range(0,4):
+            im_list[0].save(
+                out,
+                save_all=True,
+                append_images=im_list[1:],
+                disposal=method
+            )
+            img = Image.open(out)
+            try:
+                while True:
+                    img.seek(img.tell() + 1)
+                    self.assertEqual(img.disposal_method, method)
+            except EOFError:
+                pass
+
     def test_iss634(self):
         img = Image.open("Tests/images/iss634.gif")
         # seek to the second frame

From fa8c4b3551d99072516ad59b69e7cf07e4e9c90c Mon Sep 17 00:00:00 2001
From: linnil1 <linnil1.886@gmail.com>
Date: Tue, 31 Jan 2017 15:32:01 +0800
Subject: [PATCH 4/4] Thanks @wiredfool sugguest for disposal

---
 PIL/GifImagePlugin.py | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/PIL/GifImagePlugin.py b/PIL/GifImagePlugin.py
index aa3db4703..a2db9fcf2 100644
--- a/PIL/GifImagePlugin.py
+++ b/PIL/GifImagePlugin.py
@@ -454,14 +454,9 @@ def _get_local_header(fp, im, offset, flags):
     else:
         duration = 0
 
-    if "disposal" in im.encoderinfo:
-        disposal = int(im.encoderinfo['disposal'])
-        if not 0<= disposal <=3:
-            disposal = 2
-    else:
-        disposal = 2
+    disposal = int(im.encoderinfo.get('disposal', 0))
 
-    if transparent_color_exists or duration != 0:
+    if transparent_color_exists or duration != 0 or disposal:
         packed_flag = 1 if transparent_color_exists else 0
         packed_flag |= disposal << 2
         if not transparent_color_exists: