Merge pull request #2442 from hugovk/test-xvthumb

Test XVThumbImagePlugin for correctness

PIL/XVThumbImagePlugin.py

@@ -18,7 +18,7 @@
 #
 
 from . import Image, ImageFile, ImagePalette
-from ._binary import o8
+from ._binary import i8, o8
 
 __version__ = "0.1"
 
@@ -47,7 +47,7 @@ class XVThumbImageFile(ImageFile.ImageFile):
     def _open(self):
 
         # check magic
-        if self.fp.read(6) != _MAGIC:
+        if not _accept(self.fp.read(6)):
             raise SyntaxError("not an XV thumbnail file")
 
         # Skip to beginning of next line
@@ -58,14 +58,14 @@ class XVThumbImageFile(ImageFile.ImageFile):
             s = self.fp.readline()
             if not s:
                 raise SyntaxError("Unexpected EOF reading XV thumbnail file")
-            if s[0] != b'#':
+            if i8(s[0]) != 35:  # ie. when not a comment: '#'
                 break
 
         # parse header line (already read)
         s = s.strip().split()
 
         self.mode = "P"
-        self.size = int(s[0:1]), int(s[1:2])
+        self.size = int(s[0]), int(s[1])
 
         self.palette = ImagePalette.raw("RGB", PALETTE)
 
@@ -74,6 +74,7 @@ class XVThumbImageFile(ImageFile.ImageFile):
              self.fp.tell(), (self.mode, 0, 1)
              )]
 
+
 # --------------------------------------------------------------------
 
 Image.register_open(XVThumbImageFile.format, XVThumbImageFile, _accept)

Tests/images/hopper_bad.p7

@@ -0,0 +1,2 @@
+P7 332
+# Artificially edited file to cause unexpected EOF

Tests/test_file_xvthumb.py

@@ -1,13 +1,38 @@
-from helper import unittest, PillowTestCase
+from helper import hopper, unittest, PillowTestCase
 
-from PIL import XVThumbImagePlugin
+from PIL import Image, XVThumbImagePlugin
+
+TEST_FILE = "Tests/images/hopper.p7"
 
 
 class TestFileXVThumb(PillowTestCase):
 
+    def test_open(self):
+        # Act
+        im = Image.open(TEST_FILE)
+
+        # Assert
+        self.assertEqual(im.format, "XVThumb")
+
+        # Create a Hopper image with a similar XV palette
+        im_hopper = hopper().quantize(palette=im)
+        self.assert_image_similar(im, im_hopper, 9)
+
+    def test_unexpected_eof(self):
+        # Test unexpected EOF reading XV thumbnail file
+        # Arrange
+        bad_file = "Tests/images/hopper_bad.p7"
+
+        # Act / Assert
+        self.assertRaises(SyntaxError,
+                          lambda:
+                          XVThumbImagePlugin.XVThumbImageFile(bad_file))
+
     def test_invalid_file(self):
+        # Arrange
         invalid_file = "Tests/images/flower.jpg"
 
+        # Act / Assert
         self.assertRaises(SyntaxError,
                           lambda:
                           XVThumbImagePlugin.XVThumbImageFile(invalid_file))