Adjust buffer size when icc_profile > MAXBLOCK (issue #148)

We were encountering some errors when saving specific JPEG images.
The error was shown in stderr as:
  IOError: encoder error -2 when writing image file

And on stdout it printed:
    Suspension not allowed here

The problem was the bufsize not contemplating the icc_profile block.

PIL/JpegImagePlugin.py

@@ -732,8 +732,9 @@ def _save(im, fp, filename):
             bufsize = im.size[0] * im.size[1]
 
     # The exif info needs to be written as one block, + APP1, + one spare byte.
-    # Ensure that our buffer is big enough
+    # Ensure that our buffer is big enough. Same with the icc_profile block.
-    bufsize = max(ImageFile.MAXBLOCK, bufsize, len(info.get("exif", b"")) + 5)
+    bufsize = max(ImageFile.MAXBLOCK, bufsize, len(info.get("exif", b"")) + 5,
+                  len(extra) + 1)
 
     ImageFile._save(im, fp, [("jpeg", (0, 0)+im.size, 0, rawmode)], bufsize)
 

Tests/test_file_jpeg.py

@@ -133,6 +133,21 @@ class TestFileJpeg(PillowTestCase):
         test(ImageFile.MAXBLOCK+1)  # full buffer block plus one byte
         test(ImageFile.MAXBLOCK*4+3)  # large block
 
+    def test_large_icc_meta(self):
+        # https://github.com/python-pillow/Pillow/issues/148
+        # Sometimes the meta data on the icc_profile block is biger than
+        # Image.MAXBLOCK or the image size.
+        im = Image.open('Tests/images/icc_profile_big.jpg')
+        f = self.tempfile("temp.jpg")
+        icc_profile = im.info["icc_profile"]
+        try:
+            im.save(f, format='JPEG', progressive=True,quality=95,
+                    icc_profile=icc_profile, optimize=True)
+            assert True
+        except IOError:
+            assert False, "Failed saving image with icc larger than image size"
+
+
     def test_optimize(self):
         im1 = self.roundtrip(hopper())
         im2 = self.roundtrip(hopper(), optimize=0)