Merge pull request #8 from wiredfool/hugo-png-trns

Fix for handling P + transparency -> RGBA conversions

PIL/Image.py

@@ -867,8 +867,18 @@ class Image:
                     trns = trns_im.getpixel((0,0))
 
             elif self.mode == 'P' and mode == 'RGBA':
+                t = self.info['transparency']
                 delete_trns = True
                 
+                if isinstance(t, bytes):
+                    self.im.putpalettealphas(t)
+                elif isinstance(t, int):
+                    self.im.putpalettealpha(t,0)
+                else:
+                    raise ValueError("Transparency for P mode should" +
+                                     " be bytes or int")
+
+
         if mode == "P" and palette == ADAPTIVE:
             im = self.im.quantize(colors)
             new = self._new(im)

Tests/test_file_png.py

@@ -347,8 +347,8 @@ class TestFilePng(PillowTestCase):
         im2 = Image.open(f)
         self.assertIn('transparency', im2.info)
 
-        self.assert_image_similar(im2.convert('RGBA'), im.convert('RGBA'),
-                                  16)
+        self.assert_image_equal(im2.convert('RGBA'),
+                                im.convert('RGBA'))
 
     def test_save_icc_profile_none(self):
         # check saving files with an ICC profile set to None (omit profile)