From 4fbea3e553d304544228dd7e7a215f772640b021 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@gmail.com>
Date: Wed, 1 Jul 2015 09:18:05 +1000
Subject: [PATCH] Added multiframe GIF test

---
 PIL/GifImagePlugin.py  | 27 +++++++++++++++++----------
 Tests/test_file_gif.py | 10 ++++++++++
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/PIL/GifImagePlugin.py b/PIL/GifImagePlugin.py
index 51fd11999..08567fcd0 100644
--- a/PIL/GifImagePlugin.py
+++ b/PIL/GifImagePlugin.py
@@ -299,9 +299,22 @@ RAWMODE = {
     "P": "P",
 }
 
+
+def _convert_mode(im):
+    # convert on the fly (EXPERIMENTAL -- I'm not sure PIL
+    # should automatically convert images on save...)
+    if Image.getmodebase(im.mode) == "RGB":
+        palette_size = 256
+        if im.palette:
+            palette_size = len(im.palette.getdata()[1]) // 3
+        return im.convert("P", palette=1, colors=palette_size)
+    return im.convert("L")
+
+
 def _save_all(im, fp, filename):
     _save(im, fp, filename, save_all=True)
 
+
 def _save(im, fp, filename, save_all=False):
 
     if _imaging_gif:
@@ -315,15 +328,7 @@ def _save(im, fp, filename, save_all=False):
     if im.mode in RAWMODE:
         im_out = im.copy()
     else:
-        # convert on the fly (EXPERIMENTAL -- I'm not sure PIL
-        # should automatically convert images on save...)
-        if Image.getmodebase(im.mode) == "RGB":
-            palette_size = 256
-            if im.palette:
-                palette_size = len(im.palette.getdata()[1]) // 3
-            im_out = im.convert("P", palette=1, colors=palette_size)
-        else:
-            im_out = im.convert("L")
+        im_out = _convert_mode(im)
 
     # header
     try:
@@ -335,7 +340,9 @@ def _save(im, fp, filename, save_all=False):
     if save_all:
         previous = None
 
-        for im_frame in ImageSequence.Iterator(im_out):
+        for im_frame in ImageSequence.Iterator(im):
+            im_frame = _convert_mode(im_frame)
+
             # To specify duration, add the time in milliseconds to getdata(),
             # e.g. getdata(im_frame, duration=1000)
             if not previous:
diff --git a/Tests/test_file_gif.py b/Tests/test_file_gif.py
index 1141e0372..666e1f16d 100644
--- a/Tests/test_file_gif.py
+++ b/Tests/test_file_gif.py
@@ -72,6 +72,7 @@ class TestFileGif(PillowTestCase):
         self.assert_image_similar(reread.convert('RGB'), hopper(), 50)
 
     def test_roundtrip_save_all(self):
+        # Single frame image
         out = self.tempfile('temp.gif')
         im = hopper()
         im.save(out, save_all=True)
@@ -79,6 +80,15 @@ class TestFileGif(PillowTestCase):
 
         self.assert_image_similar(reread.convert('RGB'), im, 50)
 
+        # Multiframe image
+        im = Image.open("Tests/images/dispose_bgnd.gif")
+
+        out = self.tempfile('temp.gif')
+        im.save(out, save_all=True)
+        reread = Image.open(out)
+
+        self.assertEqual(im.n_frames, 5)
+
     def test_palette_handling(self):
         # see https://github.com/python-pillow/Pillow/issues/513