From fef3ceb2c02ef241a508ee020fe2617e10e33e42 Mon Sep 17 00:00:00 2001
From: hugovk <hugovk@users.noreply.github.com>
Date: Sun, 20 Jul 2014 01:50:05 +0300
Subject: [PATCH] If we can't read a file due to unsupported compression, raise
 an error

---
 PIL/SgiImagePlugin.py  | 10 +++++-----
 Tests/test_file_sgi.py | 18 +++---------------
 2 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/PIL/SgiImagePlugin.py b/PIL/SgiImagePlugin.py
index bf3c18a43..2b8fcd8e4 100644
--- a/PIL/SgiImagePlugin.py
+++ b/PIL/SgiImagePlugin.py
@@ -45,7 +45,7 @@ class SgiImageFile(ImageFile.ImageFile):
         # HEAD
         s = self.fp.read(512)
         if i16(s) != 474:
-            raise SyntaxError("not an SGI image file")
+            raise ValueError("Not an SGI image file")
 
         # relevant header entries
         compression = i8(s[2])
@@ -61,7 +61,7 @@ class SgiImageFile(ImageFile.ImageFile):
         elif layout == (1, 3, 4):
             self.mode = "RGBA"
         else:
-            raise SyntaxError("unsupported SGI image mode")
+            raise ValueError("Unsupported SGI image mode")
 
         # size
         self.size = i16(s[6:]), i16(s[8:])
@@ -76,8 +76,7 @@ class SgiImageFile(ImageFile.ImageFile):
                     ("raw", (0, 0)+self.size, offset, (layer, 0, -1)))
                 offset = offset + pagesize
         elif compression == 1:
-            self.tile = [
-                ("sgi_rle", (0, 0)+self.size, 512, (self.mode, 0, -1))]
+            raise ValueError("SGI RLE encoding not supported")
 
 #
 # registry
@@ -87,5 +86,6 @@ Image.register_open("SGI", SgiImageFile, _accept)
 Image.register_extension("SGI", ".bw")
 Image.register_extension("SGI", ".rgb")
 Image.register_extension("SGI", ".rgba")
-
 Image.register_extension("SGI", ".sgi")
+
+# End of file
diff --git a/Tests/test_file_sgi.py b/Tests/test_file_sgi.py
index e94f0d989..84b184b63 100644
--- a/Tests/test_file_sgi.py
+++ b/Tests/test_file_sgi.py
@@ -5,44 +5,32 @@ from PIL import Image
 
 class TestFileSgi(PillowTestCase):
 
-    def sanity(self, filename, expected_mode, expected_size=(128, 128)):
-        # Act
-        im = Image.open(filename)
-
-        # Assert
-        self.assertEqual(im.mode, expected_mode)
-        self.assertEqual(im.size, expected_size)
-
     def test_rgb(self):
         # Arrange
         # Created with ImageMagick then renamed:
         # convert lena.ppm lena.sgi
         test_file = "Tests/images/lena.rgb"
-        expected_mode = "RGB"
 
         # Act / Assert
-        self.sanity(test_file, expected_mode)
+        self.assertRaises(ValueError, lambda: Image.open(test_file))
 
     def test_l(self):
         # Arrange
         # Created with ImageMagick then renamed:
         # convert lena.ppm -monochrome lena.sgi
         test_file = "Tests/images/lena.bw"
-        expected_mode = "L"
 
         # Act / Assert
-        self.sanity(test_file, expected_mode)
+        self.assertRaises(ValueError, lambda: Image.open(test_file))
 
     def test_rgba(self):
         # Arrange
         # Created with ImageMagick:
         # convert transparent.png transparent.sgi
         test_file = "Tests/images/transparent.sgi"
-        expected_mode = "RGBA"
-        expected_size = (200, 150)
 
         # Act / Assert
-        self.sanity(test_file, expected_mode, expected_size)
+        self.assertRaises(ValueError, lambda: Image.open(test_file))
 
 
 if __name__ == '__main__':