Pillow/Tests/test_imagefile.py
Jon Dufresne 4cd4adddc3 Improve handling of file resources
Follow Python's file object semantics. User code is responsible for
closing resources (usually through a context manager) in a deterministic
way.

To achieve this, remove __del__ functions. These functions used to
closed open file handlers in an attempt to silence Python
ResourceWarnings. However, using __del__ has the following drawbacks:

- __del__ isn't called until the object's reference count reaches 0.
  Therefore, resource handlers remain open or in use longer than
  necessary.

- The __del__ method isn't guaranteed to execute on system exit. See the
  Python documentation:

  https://docs.python.org/3/reference/datamodel.html#object.__del__

  > It is not guaranteed that __del__() methods are called for objects
  > that still exist when the interpreter exits.

- Exceptions that occur inside __del__ are ignored instead of raised.
  This has the potential of hiding bugs. This is also in the Python
  documentation:

  > Warning: Due to the precarious circumstances under which __del__()
  > methods are invoked, exceptions that occur during their execution
  > are ignored, and a warning is printed to sys.stderr instead.

Instead, always close resource handlers when they are no longer in use.
This will close the file handler at a specified point in the user's code
and not wait until the interpreter chooses to. It is always guaranteed
to run. And, if an exception occurs while closing the file handler, the
bug will not be ignored.

Now, when code receives a ResourceWarning, it will highlight an area
that is mishandling resources. It should not simply be silenced, but
fixed by closing resources with a context manager.

All warnings that were emitted during tests have been cleaned up. To
enable warnings, I passed the `-Wa` CLI option to Python. This exposed
some mishandling of resources in ImageFile.__init__() and
SpiderImagePlugin.loadImageSeries(), they too were fixed.
2019-10-12 08:27:17 -07:00

336 lines
10 KiB
Python

from io import BytesIO
from PIL import EpsImagePlugin, Image, ImageFile
from .helper import PillowTestCase, fromstring, hopper, tostring, unittest
try:
from PIL import _webp
HAVE_WEBP = True
except ImportError:
HAVE_WEBP = False
codecs = dir(Image.core)
# save original block sizes
MAXBLOCK = ImageFile.MAXBLOCK
SAFEBLOCK = ImageFile.SAFEBLOCK
class TestImageFile(PillowTestCase):
def test_parser(self):
def roundtrip(format):
im = hopper("L").resize((1000, 1000))
if format in ("MSP", "XBM"):
im = im.convert("1")
test_file = BytesIO()
im.copy().save(test_file, format)
data = test_file.getvalue()
parser = ImageFile.Parser()
parser.feed(data)
imOut = parser.close()
return im, imOut
self.assert_image_equal(*roundtrip("BMP"))
im1, im2 = roundtrip("GIF")
self.assert_image_similar(im1.convert("P"), im2, 1)
self.assert_image_equal(*roundtrip("IM"))
self.assert_image_equal(*roundtrip("MSP"))
if "zip_encoder" in codecs:
try:
# force multiple blocks in PNG driver
ImageFile.MAXBLOCK = 8192
self.assert_image_equal(*roundtrip("PNG"))
finally:
ImageFile.MAXBLOCK = MAXBLOCK
self.assert_image_equal(*roundtrip("PPM"))
self.assert_image_equal(*roundtrip("TIFF"))
self.assert_image_equal(*roundtrip("XBM"))
self.assert_image_equal(*roundtrip("TGA"))
self.assert_image_equal(*roundtrip("PCX"))
if EpsImagePlugin.has_ghostscript():
im1, im2 = roundtrip("EPS")
# This test fails on Ubuntu 12.04, PPC (Bigendian) It
# appears to be a ghostscript 9.05 bug, since the
# ghostscript rendering is wonky and the file is identical
# to that written on ubuntu 12.04 x64
# md5sum: ba974835ff2d6f3f2fd0053a23521d4a
# EPS comes back in RGB:
self.assert_image_similar(im1, im2.convert("L"), 20)
if "jpeg_encoder" in codecs:
im1, im2 = roundtrip("JPEG") # lossy compression
self.assert_image(im1, im2.mode, im2.size)
self.assertRaises(IOError, roundtrip, "PDF")
def test_ico(self):
with open("Tests/images/python.ico", "rb") as f:
data = f.read()
with ImageFile.Parser() as p:
p.feed(data)
self.assertEqual((48, 48), p.image.size)
def test_safeblock(self):
if "zip_encoder" not in codecs:
self.skipTest("PNG (zlib) encoder not available")
im1 = hopper()
try:
ImageFile.SAFEBLOCK = 1
im2 = fromstring(tostring(im1, "PNG"))
finally:
ImageFile.SAFEBLOCK = SAFEBLOCK
self.assert_image_equal(im1, im2)
def test_raise_ioerror(self):
self.assertRaises(IOError, ImageFile.raise_ioerror, 1)
def test_raise_typeerror(self):
with self.assertRaises(TypeError):
parser = ImageFile.Parser()
parser.feed(1)
def test_negative_stride(self):
with open("Tests/images/raw_negative_stride.bin", "rb") as f:
input = f.read()
p = ImageFile.Parser()
p.feed(input)
with self.assertRaises(IOError):
p.close()
def test_truncated_with_errors(self):
if "zip_encoder" not in codecs:
self.skipTest("PNG (zlib) encoder not available")
with Image.open("Tests/images/truncated_image.png") as im:
with self.assertRaises(IOError):
im.load()
# Test that the error is raised if loaded a second time
with self.assertRaises(IOError):
im.load()
def test_truncated_without_errors(self):
if "zip_encoder" not in codecs:
self.skipTest("PNG (zlib) encoder not available")
im = Image.open("Tests/images/truncated_image.png")
ImageFile.LOAD_TRUNCATED_IMAGES = True
try:
im.load()
finally:
ImageFile.LOAD_TRUNCATED_IMAGES = False
def test_broken_datastream_with_errors(self):
if "zip_encoder" not in codecs:
self.skipTest("PNG (zlib) encoder not available")
im = Image.open("Tests/images/broken_data_stream.png")
with self.assertRaises(IOError):
im.load()
def test_broken_datastream_without_errors(self):
if "zip_encoder" not in codecs:
self.skipTest("PNG (zlib) encoder not available")
im = Image.open("Tests/images/broken_data_stream.png")
ImageFile.LOAD_TRUNCATED_IMAGES = True
try:
im.load()
finally:
ImageFile.LOAD_TRUNCATED_IMAGES = False
class MockPyDecoder(ImageFile.PyDecoder):
def decode(self, buffer):
# eof
return -1, 0
xoff, yoff, xsize, ysize = 10, 20, 100, 100
class MockImageFile(ImageFile.ImageFile):
def _open(self):
self.rawmode = "RGBA"
self.mode = "RGBA"
self._size = (200, 200)
self.tile = [("MOCK", (xoff, yoff, xoff + xsize, yoff + ysize), 32, None)]
class TestPyDecoder(PillowTestCase):
def get_decoder(self):
decoder = MockPyDecoder(None)
def closure(mode, *args):
decoder.__init__(mode, *args)
return decoder
Image.register_decoder("MOCK", closure)
return decoder
def test_setimage(self):
buf = BytesIO(b"\x00" * 255)
im = MockImageFile(buf)
d = self.get_decoder()
im.load()
self.assertEqual(d.state.xoff, xoff)
self.assertEqual(d.state.yoff, yoff)
self.assertEqual(d.state.xsize, xsize)
self.assertEqual(d.state.ysize, ysize)
self.assertRaises(ValueError, d.set_as_raw, b"\x00")
def test_extents_none(self):
buf = BytesIO(b"\x00" * 255)
im = MockImageFile(buf)
im.tile = [("MOCK", None, 32, None)]
d = self.get_decoder()
im.load()
self.assertEqual(d.state.xoff, 0)
self.assertEqual(d.state.yoff, 0)
self.assertEqual(d.state.xsize, 200)
self.assertEqual(d.state.ysize, 200)
def test_negsize(self):
buf = BytesIO(b"\x00" * 255)
im = MockImageFile(buf)
im.tile = [("MOCK", (xoff, yoff, -10, yoff + ysize), 32, None)]
self.get_decoder()
self.assertRaises(ValueError, im.load)
im.tile = [("MOCK", (xoff, yoff, xoff + xsize, -10), 32, None)]
self.assertRaises(ValueError, im.load)
def test_oversize(self):
buf = BytesIO(b"\x00" * 255)
im = MockImageFile(buf)
im.tile = [("MOCK", (xoff, yoff, xoff + xsize + 100, yoff + ysize), 32, None)]
self.get_decoder()
self.assertRaises(ValueError, im.load)
im.tile = [("MOCK", (xoff, yoff, xoff + xsize, yoff + ysize + 100), 32, None)]
self.assertRaises(ValueError, im.load)
def test_no_format(self):
buf = BytesIO(b"\x00" * 255)
im = MockImageFile(buf)
self.assertIsNone(im.format)
self.assertIsNone(im.get_format_mimetype())
def test_exif_jpeg(self):
im = Image.open("Tests/images/exif-72dpi-int.jpg") # Little endian
exif = im.getexif()
self.assertNotIn(258, exif)
self.assertIn(40960, exif)
self.assertEqual(exif[40963], 450)
self.assertEqual(exif[11], "gThumb 3.0.1")
out = self.tempfile("temp.jpg")
exif[258] = 8
del exif[40960]
exif[40963] = 455
exif[11] = "Pillow test"
im.save(out, exif=exif)
with Image.open(out) as reloaded:
reloaded_exif = reloaded.getexif()
self.assertEqual(reloaded_exif[258], 8)
self.assertNotIn(40960, exif)
self.assertEqual(reloaded_exif[40963], 455)
self.assertEqual(exif[11], "Pillow test")
im = Image.open("Tests/images/no-dpi-in-exif.jpg") # Big endian
exif = im.getexif()
self.assertNotIn(258, exif)
self.assertIn(40962, exif)
self.assertEqual(exif[40963], 200)
self.assertEqual(exif[305], "Adobe Photoshop CC 2017 (Macintosh)")
out = self.tempfile("temp.jpg")
exif[258] = 8
del exif[34665]
exif[40963] = 455
exif[305] = "Pillow test"
im.save(out, exif=exif)
with Image.open(out) as reloaded:
reloaded_exif = reloaded.getexif()
self.assertEqual(reloaded_exif[258], 8)
self.assertNotIn(40960, exif)
self.assertEqual(reloaded_exif[40963], 455)
self.assertEqual(exif[305], "Pillow test")
@unittest.skipIf(
not HAVE_WEBP or not _webp.HAVE_WEBPANIM,
"WebP support not installed with animation",
)
def test_exif_webp(self):
im = Image.open("Tests/images/hopper.webp")
exif = im.getexif()
self.assertEqual(exif, {})
out = self.tempfile("temp.webp")
exif[258] = 8
exif[40963] = 455
exif[305] = "Pillow test"
def check_exif():
with Image.open(out) as reloaded:
reloaded_exif = reloaded.getexif()
self.assertEqual(reloaded_exif[258], 8)
self.assertEqual(reloaded_exif[40963], 455)
self.assertEqual(exif[305], "Pillow test")
im.save(out, exif=exif)
check_exif()
im.save(out, exif=exif, save_all=True)
check_exif()
def test_exif_png(self):
im = Image.open("Tests/images/exif.png")
exif = im.getexif()
self.assertEqual(exif, {274: 1})
out = self.tempfile("temp.png")
exif[258] = 8
del exif[274]
exif[40963] = 455
exif[305] = "Pillow test"
im.save(out, exif=exif)
with Image.open(out) as reloaded:
reloaded_exif = reloaded.getexif()
self.assertEqual(reloaded_exif, {258: 8, 40963: 455, 305: "Pillow test"})
def test_exif_interop(self):
with Image.open("Tests/images/flower.jpg") as im:
exif = im.getexif()
self.assertEqual(
exif.get_ifd(0xA005), {1: "R98", 2: b"0100", 4097: 2272, 4098: 1704}
)