Added GifImagePlugin tests

PIL/GifImagePlugin.py

@@ -341,7 +341,7 @@ def get_local_header(fp, im, offset=(0, 0)):
                     transparent_color_exists = False
 
     if "duration" in im.encoderinfo:
-        duration = im.encoderinfo["duration"] / 10
+        duration = int(im.encoderinfo["duration"] / 10)
     else:
         duration = 0
     if transparent_color_exists or duration != 0:
@@ -360,7 +360,8 @@ def get_local_header(fp, im, offset=(0, 0)):
     if "loop" in im.encoderinfo:
         number_of_loops = im.encoderinfo["loop"]
         fp.write(b"!" +
-                 o8(255) + o8(11) +      # extension intro
+                 o8(255) +               # extension intro
+                 o8(11) +
                  b"NETSCAPE2.0" +
                  o8(3) +
                  o8(1) +

Tests/test_file_gif.py

@@ -169,6 +169,33 @@ class TestFileGif(PillowTestCase):
         # first frame
         self.assertEqual(img.histogram()[img.info['transparency']], 0)
 
+    def test_duration(self):
+        duration = 1000
+
+        out = self.tempfile('temp.gif')
+        fp = open(out, "wb")
+        im = Image.new('L',(100,100),'#000')
+        for s in GifImagePlugin.getheader(im)[0] + GifImagePlugin.getdata(im, duration=duration):
+            fp.write(s)
+        fp.write(b";")
+        fp.close()
+        reread = Image.open(out)
+
+        self.assertEqual(reread.info['duration'], duration)
+
+    def test_number_of_loops(self):
+        number_of_loops = 2
+
+        out = self.tempfile('temp.gif')
+        fp = open(out, "wb")
+        im = Image.new('L',(100,100),'#000')
+        for s in GifImagePlugin.getheader(im)[0] + GifImagePlugin.getdata(im, loop=number_of_loops):
+            fp.write(s)
+        fp.write(b";")
+        fp.close()
+        reread = Image.open(out)
+
+        self.assertEqual(reread.info['loop'], number_of_loops)
 
 if __name__ == '__main__':
     unittest.main()