old_contents: import unittest
  from os.path import join
  
  from scrapy.utils.gz import gunzip
  from tests import tests_datadir
  
  SAMPLEDIR = join(tests_datadir, 'compressed')
  
  
  class GunzipTest(unittest.TestCase):
  
      def test_gunzip_basic(self):
          with open(join(SAMPLEDIR, 'feed-sample1.xml.gz'), 'rb') as f:
              text = gunzip(f.read())
              self.assertEqual(len(text), 9950)
  
      def test_gunzip_truncated(self):
          with open(join(SAMPLEDIR, 'truncated-crc-error.gz'), 'rb') as f:
              text = gunzip(f.read())
              assert text.endswith(b'</html')
  
      def test_gunzip_no_gzip_file_raises(self):
          with open(join(SAMPLEDIR, 'feed-sample1.xml'), 'rb') as f:
              self.assertRaises(IOError, gunzip, f.read())
  
      def test_gunzip_truncated_short(self):
          with open(join(SAMPLEDIR, 'truncated-crc-error-short.gz'), 'rb') as f:
              text = gunzip(f.read())
              assert text.endswith(b'</html>')
  
new_contents: import unittest
  from os.path import join
  
  from scrapy.utils.gz import gunzip, is_gzipped
  from scrapy.http import Response, Headers
  from tests import tests_datadir
  
  SAMPLEDIR = join(tests_datadir, 'compressed')
  
  
  class GunzipTest(unittest.TestCase):
  
      def test_gunzip_basic(self):
          with open(join(SAMPLEDIR, 'feed-sample1.xml.gz'), 'rb') as f:
              text = gunzip(f.read())
              self.assertEqual(len(text), 9950)
  
      def test_gunzip_truncated(self):
          with open(join(SAMPLEDIR, 'truncated-crc-error.gz'), 'rb') as f:
              text = gunzip(f.read())
              assert text.endswith(b'</html')
  
      def test_gunzip_no_gzip_file_raises(self):
          with open(join(SAMPLEDIR, 'feed-sample1.xml'), 'rb') as f:
              self.assertRaises(IOError, gunzip, f.read())
  
      def test_gunzip_truncated_short(self):
          with open(join(SAMPLEDIR, 'truncated-crc-error-short.gz'), 'rb') as f:
              text = gunzip(f.read())
              assert text.endswith(b'</html>')
  
      def test_is_gzipped(self):
          hdrs = Headers({"Content-Type": "application/x-gzip"})
          r1 = Response("http://www.example.com", headers=hdrs)
          self.assertTrue(is_gzipped(r1))
          r2 = Response("http://www.example.com")
          self.assertTrue(not is_gzipped(r2))
          hdrs = Headers({"Content-Type": "application/javascript"})
          r3 = Response("http://www.example.com", headers=hdrs)
          self.assertTrue(not is_gzipped(r3))
          hdrs = Headers({"Content-Type": "application/x-gzip;charset=utf-8"})
          r1 = Response("http://www.example.com", headers=hdrs)
          self.assertTrue(is_gzipped(r1))
  
subject: Test to show bug with is_gzipped and Content-Type: application/gzip;charset.