Python tarfile 模块，ReadError() 实例源码

def read_tar(f):
    result = {}

    try:
        with tarfile.open(f) as t:
            for m in t:
                if m.isfile():
                    f = t.extractfile(m)
                    sha512 = sha512_file(f)
                else:
                    sha512 = None
                result[m.name] = TarMemberInfo(m, sha512)
    except tarfile.ReadError:
        # if we can't read the tar archive, we should never consider it to have
        # the same contents as another tar archive...
        result[f] = None

    return result

#
#
#

def unzip(self, path=None):

        if not path:
            path = os.path.join(os.path.split(self.zip_file)[0], self.name)

        if not self.zipped:
            raise Exception('Scene does not have a zip file associated with it')
        else:
            try:
                tar = tarfile.open(self.zip_file, 'r')
                tar.extractall(path=path)
                tar.close()
            except tarfile.ReadError:
                subprocess.check_call(['tar', '-xf', self.zip_file, '-C', path])

            formats = ['*.tif', '*.TIF', '*.jp2']

            for f in formats:
                for image in glob.glob(os.path.join(path, f)):
                    self.add(image)

            self.zipped = False

def test_empty_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test checks if tarfile.open() is able to open an empty tar
        # archive successfully. Note that an empty tar archive is not the
        # same as an empty file!
        with tarfile.open(tmpname, self.mode.replace("r", "w")):
            pass
        try:
            tar = tarfile.open(tmpname, self.mode)
            tar.getnames()
        except tarfile.ReadError:
            self.fail("tarfile.open() failed on empty archive")
        else:
            self.assertListEqual(tar.getmembers(), [])
        finally:
            tar.close()

def test_init_close_fobj(self):
        # Issue #7341: Close the internal file object in the TarFile
        # constructor in case of an error. For the test we rely on
        # the fact that opening an empty file raises a ReadError.
        empty = os.path.join(TEMPDIR, "empty")
        with open(empty, "wb") as fobj:
            fobj.write(b"")

        try:
            tar = object.__new__(tarfile.TarFile)
            try:
                tar.__init__(empty)
            except tarfile.ReadError:
                self.assertTrue(tar.fileobj.closed)
            else:
                self.fail("ReadError not raised")
        finally:
            support.unlink(empty)

def test_empty_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test checks if tarfile.open() is able to open an empty tar
        # archive successfully. Note that an empty tar archive is not the
        # same as an empty file!
        with tarfile.open(tmpname, self.mode.replace("r", "w")):
            pass
        try:
            tar = tarfile.open(tmpname, self.mode)
            tar.getnames()
        except tarfile.ReadError:
            self.fail("tarfile.open() failed on empty archive")
        else:
            self.assertListEqual(tar.getmembers(), [])
        finally:
            tar.close()

def test_premature_end_of_archive(self):
        for size in (512, 600, 1024, 1200):
            with tarfile.open(tmpname, "w:") as tar:
                t = tarfile.TarInfo("foo")
                t.size = 1024
                tar.addfile(t, StringIO.StringIO("a" * 1024))

            with open(tmpname, "r+b") as fobj:
                fobj.truncate(size)

            with tarfile.open(tmpname) as tar:
                with self.assertRaisesRegexp(tarfile.ReadError, "unexpected end of data"):
                    for t in tar:
                        pass

            with tarfile.open(tmpname) as tar:
                t = tar.next()

                with self.assertRaisesRegexp(tarfile.ReadError, "unexpected end of data"):
                    tar.extract(t, TEMPDIR)

                with self.assertRaisesRegexp(tarfile.ReadError, "unexpected end of data"):
                    tar.extractfile(t).read()

def test_init_close_fobj(self):
        # Issue #7341: Close the internal file object in the TarFile
        # constructor in case of an error. For the test we rely on
        # the fact that opening an empty file raises a ReadError.
        empty = os.path.join(TEMPDIR, "empty")
        with open(empty, "wb") as fobj:
            fobj.write("")

        try:
            tar = object.__new__(tarfile.TarFile)
            try:
                tar.__init__(empty)
            except tarfile.ReadError:
                self.assertTrue(tar.fileobj.closed)
            else:
                self.fail("ReadError not raised")
        finally:
            support.unlink(empty)

def _test_partial_input(self, mode):
        class MyStringIO(StringIO.StringIO):
            hit_eof = False
            def read(self, n):
                if self.hit_eof:
                    raise AssertionError("infinite loop detected in tarfile.open()")
                self.hit_eof = self.pos == self.len
                return StringIO.StringIO.read(self, n)
            def seek(self, *args):
                self.hit_eof = False
                return StringIO.StringIO.seek(self, *args)

        data = bz2.compress(tarfile.TarInfo("foo").tobuf())
        for x in range(len(data) + 1):
            try:
                tarfile.open(fileobj=MyStringIO(data[:x]), mode=mode)
            except tarfile.ReadError:
                pass # we have no interest in ReadErrors

def test_empty_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test checks if tarfile.open() is able to open an empty tar
        # archive successfully. Note that an empty tar archive is not the
        # same as an empty file!
        with tarfile.open(tmpname, self.mode.replace("r", "w")):
            pass
        try:
            tar = tarfile.open(tmpname, self.mode)
            tar.getnames()
        except tarfile.ReadError:
            self.fail("tarfile.open() failed on empty archive")
        else:
            self.assertListEqual(tar.getmembers(), [])
        finally:
            tar.close()

def test_premature_end_of_archive(self):
        for size in (512, 600, 1024, 1200):
            with tarfile.open(tmpname, "w:") as tar:
                t = tarfile.TarInfo("foo")
                t.size = 1024
                tar.addfile(t, StringIO.StringIO("a" * 1024))

            with open(tmpname, "r+b") as fobj:
                fobj.truncate(size)

            with tarfile.open(tmpname) as tar:
                with self.assertRaisesRegexp(tarfile.ReadError, "unexpected end of data"):
                    for t in tar:
                        pass

            with tarfile.open(tmpname) as tar:
                t = tar.next()

                with self.assertRaisesRegexp(tarfile.ReadError, "unexpected end of data"):
                    tar.extract(t, TEMPDIR)

                with self.assertRaisesRegexp(tarfile.ReadError, "unexpected end of data"):
                    tar.extractfile(t).read()

def test_init_close_fobj(self):
        # Issue #7341: Close the internal file object in the TarFile
        # constructor in case of an error. For the test we rely on
        # the fact that opening an empty file raises a ReadError.
        empty = os.path.join(TEMPDIR, "empty")
        with open(empty, "wb") as fobj:
            fobj.write("")

        try:
            tar = object.__new__(tarfile.TarFile)
            try:
                tar.__init__(empty)
            except tarfile.ReadError:
                self.assertTrue(tar.fileobj.closed)
            else:
                self.fail("ReadError not raised")
        finally:
            support.unlink(empty)

def _test_partial_input(self, mode):
        class MyStringIO(StringIO.StringIO):
            hit_eof = False
            def read(self, n):
                if self.hit_eof:
                    raise AssertionError("infinite loop detected in tarfile.open()")
                self.hit_eof = self.pos == self.len
                return StringIO.StringIO.read(self, n)
            def seek(self, *args):
                self.hit_eof = False
                return StringIO.StringIO.seek(self, *args)

        data = bz2.compress(tarfile.TarInfo("foo").tobuf())
        for x in range(len(data) + 1):
            try:
                tarfile.open(fileobj=MyStringIO(data[:x]), mode=mode)
            except tarfile.ReadError:
                pass # we have no interest in ReadErrors

def test_empty_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test checks if tarfile.open() is able to open an empty tar
        # archive successfully. Note that an empty tar archive is not the
        # same as an empty file!
        with tarfile.open(tmpname, self.mode.replace("r", "w")):
            pass
        try:
            tar = tarfile.open(tmpname, self.mode)
            tar.getnames()
        except tarfile.ReadError:
            self.fail("tarfile.open() failed on empty archive")
        else:
            self.assertListEqual(tar.getmembers(), [])
        finally:
            tar.close()

def test_init_close_fobj(self):
        # Issue #7341: Close the internal file object in the TarFile
        # constructor in case of an error. For the test we rely on
        # the fact that opening an empty file raises a ReadError.
        empty = os.path.join(TEMPDIR, "empty")
        with open(empty, "wb") as fobj:
            fobj.write(b"")

        try:
            tar = object.__new__(tarfile.TarFile)
            try:
                tar.__init__(empty)
            except tarfile.ReadError:
                self.assertTrue(tar.fileobj.closed)
            else:
                self.fail("ReadError not raised")
        finally:
            support.unlink(empty)

def _test_partial_input(self, mode):
        class MyBytesIO(io.BytesIO):
            hit_eof = False
            def read(self, n):
                if self.hit_eof:
                    raise AssertionError("infinite loop detected in "
                                         "tarfile.open()")
                self.hit_eof = self.tell() == len(self.getvalue())
                return super(MyBytesIO, self).read(n)
            def seek(self, *args):
                self.hit_eof = False
                return super(MyBytesIO, self).seek(*args)

        data = bz2.compress(tarfile.TarInfo("foo").tobuf())
        for x in range(len(data) + 1):
            try:
                tarfile.open(fileobj=MyBytesIO(data[:x]), mode=mode)
            except tarfile.ReadError:
                pass # we have no interest in ReadErrors

def extract_files(self):
        self.extract_error = None
        location = self.get_setting('download_dir').value
        version = self.selected_version()
        for setting_name, setting in self.settings['export_settings'].items():
            save_file_path = setting.save_file_path(version,
                                                    location)
            try:
                if setting.value:
                    extract_path = get_data_path('files/'+setting.name)
                    setting.extract(extract_path, version)

                    self.progress_text += '.'

            except (tarfile.ReadError, zipfile.BadZipfile) as e:
                if os.path.exists(save_file_path):
                    os.remove(save_file_path)
                self.extract_error = e
                self.logger.error(self.extract_error)
                # cannot use GUI in thread to notify user. Save it for later
        self.progress_text = '\nDone.\n'
        return True

def test_empty_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test checks if tarfile.open() is able to open an empty tar
        # archive successfully. Note that an empty tar archive is not the
        # same as an empty file!
        with tarfile.open(tmpname, self.mode.replace("r", "w")):
            pass
        try:
            tar = tarfile.open(tmpname, self.mode)
            tar.getnames()
        except tarfile.ReadError:
            self.fail("tarfile.open() failed on empty archive")
        else:
            self.assertListEqual(tar.getmembers(), [])
        finally:
            tar.close()

def test_init_close_fobj(self):
        # Issue #7341: Close the internal file object in the TarFile
        # constructor in case of an error. For the test we rely on
        # the fact that opening an empty file raises a ReadError.
        empty = os.path.join(TEMPDIR, "empty")
        with open(empty, "wb") as fobj:
            fobj.write(b"")

        try:
            tar = object.__new__(tarfile.TarFile)
            try:
                tar.__init__(empty)
            except tarfile.ReadError:
                self.assertTrue(tar.fileobj.closed)
            else:
                self.fail("ReadError not raised")
        finally:
            test_support.unlink(empty)

def test_empty_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test checks if tarfile.open() is able to open an empty tar
        # archive successfully. Note that an empty tar archive is not the
        # same as an empty file!
        with tarfile.open(tmpname, self.mode.replace("r", "w")):
            pass
        try:
            tar = tarfile.open(tmpname, self.mode)
            tar.getnames()
        except tarfile.ReadError:
            self.fail("tarfile.open() failed on empty archive")
        else:
            self.assertListEqual(tar.getmembers(), [])
        finally:
            tar.close()

def test_premature_end_of_archive(self):
        for size in (512, 600, 1024, 1200):
            with tarfile.open(tmpname, "w:") as tar:
                t = tarfile.TarInfo("foo")
                t.size = 1024
                tar.addfile(t, io.BytesIO(b"a" * 1024))

            with open(tmpname, "r+b") as fobj:
                fobj.truncate(size)

            with tarfile.open(tmpname) as tar:
                with self.assertRaisesRegex(tarfile.ReadError, "unexpected end of data"):
                    for t in tar:
                        pass

            with tarfile.open(tmpname) as tar:
                t = tar.next()

                with self.assertRaisesRegex(tarfile.ReadError, "unexpected end of data"):
                    tar.extract(t, TEMPDIR)

                with self.assertRaisesRegex(tarfile.ReadError, "unexpected end of data"):
                    tar.extractfile(t).read()

def test_init_close_fobj(self):
        # Issue #7341: Close the internal file object in the TarFile
        # constructor in case of an error. For the test we rely on
        # the fact that opening an empty file raises a ReadError.
        empty = os.path.join(TEMPDIR, "empty")
        with open(empty, "wb") as fobj:
            fobj.write(b"")

        try:
            tar = object.__new__(tarfile.TarFile)
            try:
                tar.__init__(empty)
            except tarfile.ReadError:
                self.assertTrue(tar.fileobj.closed)
            else:
                self.fail("ReadError not raised")
        finally:
            support.unlink(empty)

def test_init_close_fobj(self):
        # Issue #7341: Close the internal file object in the TarFile
        # constructor in case of an error. For the test we rely on
        # the fact that opening an empty file raises a ReadError.
        empty = os.path.join(TEMPDIR, "empty")
        open(empty, "wb").write("")

        try:
            tar = object.__new__(tarfile.TarFile)
            try:
                tar.__init__(empty)
            except tarfile.ReadError:
                self.assertTrue(tar.fileobj.closed)
            else:
                self.fail("ReadError not raised")
        finally:
            os.remove(empty)

def test_empty_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test checks if tarfile.open() is able to open an empty tar
        # archive successfully. Note that an empty tar archive is not the
        # same as an empty file!
        with tarfile.open(tmpname, self.mode.replace("r", "w")):
            pass
        try:
            tar = tarfile.open(tmpname, self.mode)
            tar.getnames()
        except tarfile.ReadError:
            self.fail("tarfile.open() failed on empty archive")
        else:
            self.assertListEqual(tar.getmembers(), [])
        finally:
            tar.close()

def test_init_close_fobj(self):
        # Issue #7341: Close the internal file object in the TarFile
        # constructor in case of an error. For the test we rely on
        # the fact that opening an empty file raises a ReadError.
        empty = os.path.join(TEMPDIR, "empty")
        with open(empty, "wb") as fobj:
            fobj.write(b"")

        try:
            tar = object.__new__(tarfile.TarFile)
            try:
                tar.__init__(empty)
            except tarfile.ReadError:
                self.assertTrue(tar.fileobj.closed)
            else:
                self.fail("ReadError not raised")
        finally:
            support.unlink(empty)

def _test_partial_input(self, mode):
        class MyBytesIO(io.BytesIO):
            hit_eof = False
            def read(self, n):
                if self.hit_eof:
                    raise AssertionError("infinite loop detected in "
                                         "tarfile.open()")
                self.hit_eof = self.tell() == len(self.getvalue())
                return super(MyBytesIO, self).read(n)
            def seek(self, *args):
                self.hit_eof = False
                return super(MyBytesIO, self).seek(*args)

        data = bz2.compress(tarfile.TarInfo("foo").tobuf())
        for x in range(len(data) + 1):
            try:
                tarfile.open(fileobj=MyBytesIO(data[:x]), mode=mode)
            except tarfile.ReadError:
                pass # we have no interest in ReadErrors

def _untar_layers(dir, layers):
    output = {}
    # Untar layer filesystem bundle
    for layer in layers:
        tarfile = TarFile(dir + "/" + layer)
        for member in tarfile.getmembers():
            output[member.name] = member
    for member_name in output:
        try:
            tarfile.extract(output[member_name], path=dir, set_attrs=False)
        except (ValueError, ReadError):
            pass

    # Clean up
    for layer in layers:
        clean_up(dir + "/" + layer[:-10])

def untar(destination, source):
    """
        Untar source file into destination folder. tar.tarfile.extractall
    will create all necessary (sub)directories.
    Note: When untaring into the existing folder to overwrite files,
    tarfile.extractall function will throw a FileExistsError
    if it can not overwrite broken symlinks of the tar'ed file.
    Nuke it from orbit, it's the only way to be sure.

    :param 'destination': [str] path to where to extract target into.
    :param 'source': [str] path to a .tar file to untar.
    :return: [str] path to untared content.  Raise RuntimeError on problems.
    """

    try:
        destination = destination + '/untar'
        remove_target(destination)  # succeeds even if missing
        with tarfile.open(source) as tar_obj:
            tar_obj.extractall(path=destination)
        return destination
    except (AssertionError, tarfile.ReadError, tarfile.ExtractError) as err:
        raise RuntimeError('Error occured while untaring "%s": %s' % (source, str(err)))

def train_or_val_pairs(self, setn):
        """
        untar imagenet tar files into directories that indicate their label.

        returns [(filename, label), ...] for train or val set partitions
        """
        img_dir = os.path.join(self.out_dir, setn)

        neon_logger.display("Extracting %s files" % (setn))
        root_tf_path = self.tars[setn]
        if not os.path.exists(root_tf_path):
            raise IOError(("tar file {} not found. Ensure you have ImageNet downloaded"
                           ).format(root_tf_path))

        try:
            root_tf = tarfile.open(root_tf_path)
        except tarfile.ReadError as e:
            raise ValueError('ReadError opening {}: {}'.format(root_tf_path, e))

        label_dict = self.extract_labels(setn)
        subpaths = root_tf.getmembers()
        arg_iterator = zip(repeat(self.target_size), repeat(root_tf_path), repeat(img_dir),
                           repeat(setn), repeat(label_dict), subpaths)
        pool = multiprocessing.Pool()

        pairs = []
        for pair_list in tqdm.tqdm(pool.imap_unordered(process_i1k_tar_subpath, arg_iterator),
                                   total=len(subpaths)):
            pairs.extend(pair_list)
        pool.close()
        pool.join()
        root_tf.close()

        return pairs

def test_null_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test guarantees that tarfile.open() does not treat an empty
        # file as an empty tar archive.
        with open(tmpname, "wb"):
            pass
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, self.mode)
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname)

def test_fail_comp(self):
        # For Gzip and Bz2 Tests: fail with a ReadError on an uncompressed file.
        if self.mode == "r:":
            return
        self.assertRaises(tarfile.ReadError, tarfile.open, tarname, self.mode)
        with open(tarname, "rb") as fobj:
            self.assertRaises(tarfile.ReadError, tarfile.open,
                              fileobj=fobj, mode=self.mode)

def _testfunc_file(self, name, mode):
        try:
            tar = tarfile.open(name, mode)
        except tarfile.ReadError as e:
            self.fail()
        else:
            tar.close()

def _test_modes(self, testfunc):
        testfunc(tarname, "r")
        testfunc(tarname, "r:")
        testfunc(tarname, "r:*")
        testfunc(tarname, "r|")
        testfunc(tarname, "r|*")

        if gzip:
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r:gz")
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r|gz")
            self.assertRaises(tarfile.ReadError, tarfile.open, gzipname, mode="r:")
            self.assertRaises(tarfile.ReadError, tarfile.open, gzipname, mode="r|")

            testfunc(gzipname, "r")
            testfunc(gzipname, "r:*")
            testfunc(gzipname, "r:gz")
            testfunc(gzipname, "r|*")
            testfunc(gzipname, "r|gz")

        if bz2:
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r:bz2")
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r|bz2")
            self.assertRaises(tarfile.ReadError, tarfile.open, bz2name, mode="r:")
            self.assertRaises(tarfile.ReadError, tarfile.open, bz2name, mode="r|")

            testfunc(bz2name, "r")
            testfunc(bz2name, "r:*")
            testfunc(bz2name, "r:bz2")
            testfunc(bz2name, "r|*")
            testfunc(bz2name, "r|bz2")

def test_truncated_longname(self):
        longname = self.subdir + "/" + "123/" * 125 + "longname"
        tarinfo = self.tar.getmember(longname)
        offset = tarinfo.offset
        self.tar.fileobj.seek(offset)
        fobj = io.BytesIO(self.tar.fileobj.read(3 * 512))
        self.assertRaises(tarfile.ReadError, tarfile.open, name="foo.tar", fileobj=fobj)

def test_append_gz(self):
        if gzip is None:
            return
        self._create_testtar("w:gz")
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, "a")

def test_append_bz2(self):
        if bz2 is None:
            return
        self._create_testtar("w:bz2")
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, "a")

    # Append mode is supposed to fail if the tarfile to append to
    # does not end with a zero block.

def _test_error(self, data):
        with open(self.tarname, "wb") as fobj:
            fobj.write(data)
        self.assertRaises(tarfile.ReadError, self._add_testfile)

def test_null_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test guarantees that tarfile.open() does not treat an empty
        # file as an empty tar archive.
        with open(tmpname, "wb"):
            pass
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, self.mode)
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname)

def test_fail_comp(self):
        # For Gzip and Bz2 Tests: fail with a ReadError on an uncompressed file.
        if self.mode == "r:":
            self.skipTest('needs a gz or bz2 mode')
        self.assertRaises(tarfile.ReadError, tarfile.open, tarname, self.mode)
        with open(tarname, "rb") as fobj:
            self.assertRaises(tarfile.ReadError, tarfile.open,
                              fileobj=fobj, mode=self.mode)

def _testfunc_fileobj(self, name, mode):
        try:
            tar = tarfile.open(name, mode, fileobj=open(name, "rb"))
        except tarfile.ReadError:
            self.fail()
        else:
            tar.close()

def _test_modes(self, testfunc):
        testfunc(tarname, "r")
        testfunc(tarname, "r:")
        testfunc(tarname, "r:*")
        testfunc(tarname, "r|")
        testfunc(tarname, "r|*")

        if gzip:
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r:gz")
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r|gz")
            self.assertRaises(tarfile.ReadError, tarfile.open, gzipname, mode="r:")
            self.assertRaises(tarfile.ReadError, tarfile.open, gzipname, mode="r|")

            testfunc(gzipname, "r")
            testfunc(gzipname, "r:*")
            testfunc(gzipname, "r:gz")
            testfunc(gzipname, "r|*")
            testfunc(gzipname, "r|gz")

        if bz2:
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r:bz2")
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r|bz2")
            self.assertRaises(tarfile.ReadError, tarfile.open, bz2name, mode="r:")
            self.assertRaises(tarfile.ReadError, tarfile.open, bz2name, mode="r|")

            testfunc(bz2name, "r")
            testfunc(bz2name, "r:*")
            testfunc(bz2name, "r:bz2")
            testfunc(bz2name, "r|*")
            testfunc(bz2name, "r|bz2")

def test_truncated_longname(self):
        longname = self.subdir + "/" + "123/" * 125 + "longname"
        tarinfo = self.tar.getmember(longname)
        offset = tarinfo.offset
        self.tar.fileobj.seek(offset)
        fobj = StringIO.StringIO(self.tar.fileobj.read(3 * 512))
        self.assertRaises(tarfile.ReadError, tarfile.open, name="foo.tar", fileobj=fobj)

def test_append_gz(self):
        self._create_testtar("w:gz")
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, "a")

def test_append_bz2(self):
        self._create_testtar("w:bz2")
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, "a")

    # Append mode is supposed to fail if the tarfile to append to
    # does not end with a zero block.

def test_null_tarfile(self):
        # Test for issue6123: Allow opening empty archives.
        # This test guarantees that tarfile.open() does not treat an empty
        # file as an empty tar archive.
        with open(tmpname, "wb"):
            pass
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, self.mode)
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname)

def test_fail_comp(self):
        # For Gzip and Bz2 Tests: fail with a ReadError on an uncompressed file.
        if self.mode == "r:":
            self.skipTest('needs a gz or bz2 mode')
        self.assertRaises(tarfile.ReadError, tarfile.open, tarname, self.mode)
        with open(tarname, "rb") as fobj:
            self.assertRaises(tarfile.ReadError, tarfile.open,
                              fileobj=fobj, mode=self.mode)

def _testfunc_fileobj(self, name, mode):
        try:
            tar = tarfile.open(name, mode, fileobj=open(name, "rb"))
        except tarfile.ReadError:
            self.fail()
        else:
            tar.close()

def _test_modes(self, testfunc):
        testfunc(tarname, "r")
        testfunc(tarname, "r:")
        testfunc(tarname, "r:*")
        testfunc(tarname, "r|")
        testfunc(tarname, "r|*")

        if gzip:
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r:gz")
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r|gz")
            self.assertRaises(tarfile.ReadError, tarfile.open, gzipname, mode="r:")
            self.assertRaises(tarfile.ReadError, tarfile.open, gzipname, mode="r|")

            testfunc(gzipname, "r")
            testfunc(gzipname, "r:*")
            testfunc(gzipname, "r:gz")
            testfunc(gzipname, "r|*")
            testfunc(gzipname, "r|gz")

        if bz2:
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r:bz2")
            self.assertRaises(tarfile.ReadError, tarfile.open, tarname, mode="r|bz2")
            self.assertRaises(tarfile.ReadError, tarfile.open, bz2name, mode="r:")
            self.assertRaises(tarfile.ReadError, tarfile.open, bz2name, mode="r|")

            testfunc(bz2name, "r")
            testfunc(bz2name, "r:*")
            testfunc(bz2name, "r:bz2")
            testfunc(bz2name, "r|*")
            testfunc(bz2name, "r|bz2")

def test_truncated_longname(self):
        longname = self.subdir + "/" + "123/" * 125 + "longname"
        tarinfo = self.tar.getmember(longname)
        offset = tarinfo.offset
        self.tar.fileobj.seek(offset)
        fobj = StringIO.StringIO(self.tar.fileobj.read(3 * 512))
        self.assertRaises(tarfile.ReadError, tarfile.open, name="foo.tar", fileobj=fobj)

def test_append_gz(self):
        self._create_testtar("w:gz")
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, "a")

def test_append_bz2(self):
        self._create_testtar("w:bz2")
        self.assertRaises(tarfile.ReadError, tarfile.open, tmpname, "a")

    # Append mode is supposed to fail if the tarfile to append to
    # does not end with a zero block.