diff options
author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2019-05-31 13:03:22 -0700 |
---|---|---|
committer | Berker Peksag <berker.peksag@gmail.com> | 2019-05-31 23:03:22 +0300 |
commit | a6dc5d4e1c9ef465dc1f1ad95c382aa8e32b178f (patch) | |
tree | b6e5ef3c4eb1473779c586128ebba303848de137 /Lib | |
parent | 49fc57abf5fcf60129e460046d78c9bf20a19931 (diff) | |
download | cpython-git-a6dc5d4e1c9ef465dc1f1ad95c382aa8e32b178f.tar.gz |
bpo-33361: Fix bug with seeking in StreamRecoders (GH-8278)
(cherry picked from commit a6ec1ce1ac05b1258931422e96eac215b6a05459)
Co-authored-by: Ammar Askar <ammar_askar@hotmail.com>
Diffstat (limited to 'Lib')
-rw-r--r-- | Lib/codecs.py | 6 | ||||
-rw-r--r-- | Lib/test/test_codecs.py | 25 |
2 files changed, 31 insertions, 0 deletions
diff --git a/Lib/codecs.py b/Lib/codecs.py index 3cd78fc9f1..cfca5d38b0 100644 --- a/Lib/codecs.py +++ b/Lib/codecs.py @@ -847,6 +847,12 @@ class StreamRecoder: self.reader.reset() self.writer.reset() + def seek(self, offset, whence=0): + # Seeks must be propagated to both the readers and writers + # as they might need to reset their internal buffers. + self.reader.seek(offset, whence) + self.writer.seek(offset, whence) + def __getattr__(self, name, getattr=getattr): diff --git a/Lib/test/test_codecs.py b/Lib/test/test_codecs.py index a3a2f6563a..248ef6fe07 100644 --- a/Lib/test/test_codecs.py +++ b/Lib/test/test_codecs.py @@ -3318,6 +3318,31 @@ class StreamRecoderTest(unittest.TestCase): sr.write(text.encode('latin1')) self.assertEqual(bio.getvalue(), text.encode('utf-8')) + def test_seeking_read(self): + bio = io.BytesIO('line1\nline2\nline3\n'.encode('utf-16-le')) + sr = codecs.EncodedFile(bio, 'utf-8', 'utf-16-le') + + self.assertEqual(sr.readline(), b'line1\n') + sr.seek(0) + self.assertEqual(sr.readline(), b'line1\n') + self.assertEqual(sr.readline(), b'line2\n') + self.assertEqual(sr.readline(), b'line3\n') + self.assertEqual(sr.readline(), b'') + + def test_seeking_write(self): + bio = io.BytesIO('123456789\n'.encode('utf-16-le')) + sr = codecs.EncodedFile(bio, 'utf-8', 'utf-16-le') + + # Test that seek() only resets its internal buffer when offset + # and whence are zero. + sr.seek(2) + sr.write(b'\nabc\n') + self.assertEqual(sr.readline(), b'789\n') + sr.seek(0) + self.assertEqual(sr.readline(), b'1\n') + self.assertEqual(sr.readline(), b'abc\n') + self.assertEqual(sr.readline(), b'789\n') + if __name__ == "__main__": unittest.main() |