Testing the imagesequence module with the multipage tiffs

Tests/test_imagesequence.py

@@ -1,6 +1,6 @@
 from helper import unittest, PillowTestCase, lena
 
-from PIL import ImageSequence
+from PIL import Image, ImageSequence, TiffImagePlugin
 
 
 class TestImageSequence(PillowTestCase):
@@ -22,6 +22,25 @@ class TestImageSequence(PillowTestCase):
 
         self.assertEqual(index, 1)
 
+    def _test_multipage_tiff(self):
+        im = Image.open('Tests/images/multipage.tiff')
+        for index, frame in enumerate(ImageSequence.Iterator(im)):
+            frame.load()
+            self.assertEqual(index, im.tell())
+            frame.convert('RGB')
+            
+    def test_tiff(self):
+        return self._test_multipage_tiff()
+
+    def test_libtiff(self):
+        codecs = dir(Image.core)
+        
+        if "libtiff_encoder" not in codecs or "libtiff_decoder" not in codecs:
+            self.skipTest("tiff support not available")
+
+        TiffImagePlugin.READ_LIBTIFF = True
+        self._test_multipage_tiff()
+        TiffImagePlugin.READ_LIBTIFF = False
         
 if __name__ == '__main__':
     unittest.main()