_io and _pyio inconsistenly raise ValueErrors on closed files #98999
Description
While working on typeshed stubs, I've noticed that _pyio.BufferedReader.read1 does not raise ValueError after .close. While _io.BufferedReader.read1 does that.
So, I went to see both implementation and tests.
C source clearly checks for this here:
cpython/Modules/_io/bufferedio.c
Line 910 in 0689b99
But, tests were not executed correctly. Tests were only covering C version: https://github.com/python/cpython/blame/0689b99bb8c4f6058af43a52effaa8a25609dbed/Lib/test/test_io.py#L1532-L1538
def test_read_on_closed(self): # Issue #23796 b = io.BufferedReader(io.BytesIO(b"12")) b.read(1) b.close() self.assertRaises(ValueError, b.peek) self.assertRaises(ValueError, b.read1, 1)While universal test would look like this:
def test_read_on_closed(self): # Issue #23796 b = self.BufferedReader(self.BytesIO(b"12")) b.read(1) b.close() self.assertRaises(ValueError, b.peek) self.assertRaises(ValueError, b.read1, 1)And now it is failing:
» ./python.exe -m test -v test_io -m test_read_on_closed == CPython 3.12.0a1+ (heads/main:7ea10567af, Oct 29 2022, 13:15:59) [Clang 11.0.0 (clang-1100.0.33.16)] == macOS-10.14.6-x86_64-i386-64bit little-endian == cwd: /Users/sobolev/Desktop/cpython/build/test_python_78918æ == CPU count: 4 == encodings: locale=UTF-8, FS=utf-8 0:00:00 load avg: 2.19 Run tests sequentially 0:00:00 load avg: 2.19 [1/1] test_io test_read_on_closed (test.test_io.CBufferedReaderTest.test_read_on_closed) ... ok test_read_on_closed (test.test_io.PyBufferedReaderTest.test_read_on_closed) ... FAIL test_read_on_closed (test.test_io.CBufferedRandomTest.test_read_on_closed) ... ok test_read_on_closed (test.test_io.PyBufferedRandomTest.test_read_on_closed) ... FAIL ====================================================================== FAIL: test_read_on_closed (test.test_io.PyBufferedReaderTest.test_read_on_closed) ---------------------------------------------------------------------- Traceback (most recent call last): File "/Users/sobolev/Desktop/cpython/Lib/test/test_io.py", line 1537, in test_read_on_closed self.assertRaises(ValueError, b.peek) AssertionError: ValueError not raised by peek ====================================================================== FAIL: test_read_on_closed (test.test_io.PyBufferedRandomTest.test_read_on_closed) ---------------------------------------------------------------------- Traceback (most recent call last): File "/Users/sobolev/Desktop/cpython/Lib/test/test_io.py", line 1537, in test_read_on_closed self.assertRaises(ValueError, b.peek) AssertionError: ValueError not raised by peek ---------------------------------------------------------------------- Ran 4 tests in 0.010s FAILED (failures=2) After that, I've tested other methods and here's a list of methods that work on closed in _pyio, but raises on _io:
- readinto1
- readinto
- read1
- peek
Related https://bugs.python.org/issue23796
Is it a bug or a feature? Is it worth fixing?
This clearly looks like a bug to me.
If others confirm, I have a patch ready :)