https://github.com/python/cpython/commit/8122ff4818f418e8ae984cf6964215689b00808d commit: 8122ff4818f418e8ae984cf6964215689b00808d branch: main author: GruffElixir <[email protected]> committer: StanFromIreland <[email protected]> date: 2026-09-26T11:48:13+01:00 summary:
gh-158169: Clear `zlib.Decompress.unconsumed_tail` at end of stream (#158177) Co-authored-by: Stan Ulbrych <[email protected]> files: A Misc/NEWS.d/next/Library/2026-09-25-22-15-54.gh-issue-158169.ZlibTail.rst M Lib/test/test_zlib.py M Modules/zlibmodule.c diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py index 205916579b5f49..dcb4eac1b77952 100644 --- a/Lib/test/test_zlib.py +++ b/Lib/test/test_zlib.py @@ -822,6 +822,18 @@ def test_decompress_unused_data(self): self.assertEqual(dco.unconsumed_tail, b'') self.assertEqual(dco.unused_data, remainder) + def test_decompress_unconsumed_tail_after_eof(self): + source = b'abcdefghijklmnopqrstuvwxyz' + remainder = b'0123456789' + dco = zlib.decompressobj() + data = dco.decompress(zlib.compress(source) + remainder, 1) + data += dco.decompress(dco.unconsumed_tail) + + self.assertTrue(dco.eof) + self.assertEqual(data, source) + self.assertEqual(dco.unconsumed_tail, b'') + self.assertEqual(dco.unused_data, remainder) + # issue27164 def test_decompress_raw_with_dictionary(self): zdict = b'abcdefghijklmnopqrstuvwxyz' diff --git a/Misc/NEWS.d/next/Library/2026-09-25-22-15-54.gh-issue-158169.ZlibTail.rst b/Misc/NEWS.d/next/Library/2026-09-25-22-15-54.gh-issue-158169.ZlibTail.rst new file mode 100644 index 00000000000000..7c965451c056a4 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-09-25-22-15-54.gh-issue-158169.ZlibTail.rst @@ -0,0 +1,2 @@ +Fix :attr:`zlib.Decompress.unconsumed_tail` duplicating +:attr:`~zlib.Decompress.unused_data` after end of stream when *max_length* was used. diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c index 56c119db7d10c0..31533fa047af0b 100644 --- a/Modules/zlibmodule.c +++ b/Modules/zlibmodule.c @@ -838,6 +838,7 @@ save_unconsumed_input(compobject *self, Py_buffer *data, int err) return -1; } Py_SETREF(self->unused_data, new_unused_data); + self->zst.next_in += left_size; self->zst.avail_in = 0; } } _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
