png.py 文件源码

def testBadFilter(self):
        def eachchunk(chunk):
            if chunk[0] != 'IDAT':
                return chunk
            data = zlib.decompress(chunk[1])
            # Corrupt the first filter byte
            data = strtobytes('\x99') + data[1:]
            data = zlib.compress(data)
            return (chunk[0], data)
        self.assertRaises(FormatError, self.helperFormat, eachchunk)