gh-110365: Fix error overwrite in termios.tcsetattr

[sobolevn]

@erlend-aasland we fixed several similar errors before, would you mind to take a look?

• Issue: termios.tpsetattr does rewrite errors #110365

[serhiy-storchaka]

See also the loop below. The result of PyLong_AsLong() is not checked.

[serhiy-storchaka]

See also PyLong_AsLong() in the loop below.

[sobolevn]

@serhiy-storchaka yes, you found one more problem, this code crashes!

Before:

>>> termios.tcsetattr(0, 0, [0, 1, 2, 3, 4, 5, [*range(0, 19), sys.maxsize * 10]])
Fatal Python error: _Py_CheckFunctionResult: a function returned a result with an exception set
    Python runtime state: initialized
                                     OverflowError: Python int too large to convert to C long

  The above exception was the direct cause of the following exception:

                                                                      SystemError: <built-in function tcsetattr> returned a result with an exception set

                                                             Current thread 0x00000001de555300 (most recent call first):
                               File "<stdin>", line 1 in <module>
                                                                 [1]    20789 abort      ./python.exe

After:

>>> import termios, sys
>>> termios.tcsetattr(0, 0, [0, 1, 2, 3, 4, 5, [*range(0, 19), sys.maxsize * 10]])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OverflowError: Python int too large to convert to C long
>>> 
KeyboardInterrupt
>>> ^D

[erlend-aasland]

[...] found one more problem, this code crashes! [...]

Could you add this test case to the test suite?

My suggestion was buggy, and there is no tests

[sobolevn]

Could you add this test case to the test suite?

Please, see my comment here: #110365

We don't have test_termios.py at all.
I can start small with tests that are described in this issue/PR. But, I won't be able to create the whole suite right now.

[sobolevn]

Thanks, @erlend-aasland!

[sobolevn]

New issue about missing tests: #110380

[miss-islington]

Thanks @sobolevn for the PR, and @erlend-aasland for merging it 🌮🎉.. I'm working now to backport this PR to: 3.11, 3.12.
🐍🍒⛏🤖

[bedevere-app]

GH-110389 is a backport of this pull request to the 3.12 branch.

[bedevere-app]

GH-110390 is a backport of this pull request to the 3.11 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot s390x Fedora LTO 3.x has failed when building commit 2bbbab2.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/55/builds/3943) and take a look at the build logs.
4. Check if the failure is related to this commit (2bbbab2) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/55/builds/3943

Failed tests:

• test_subprocess

Failed subtests:

• test_pipesize_default - test.test_subprocess.ProcessTestCase.test_pipesize_default

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/dje/cpython-buildarea/3.x.edelsohn-fedora-z.lto/build/Lib/test/test_subprocess.py", line 763, in test_pipesize_default
    self.assertEqual(
AssertionError: 65536 != 8192

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Debian root 3.x has failed when building commit 2bbbab2.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/345/builds/6019) and take a look at the build logs.
4. Check if the failure is related to this commit (2bbbab2) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/345/builds/6019

Failed tests:

• test.test_concurrent_futures.test_shutdown

Failed subtests:

• test_interpreter_shutdown - test.test_concurrent_futures.test_shutdown.ProcessPoolSpawnProcessPoolShutdownTest.test_interpreter_shutdown

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/test_concurrent_futures/test_shutdown.py", line 50, in test_interpreter_shutdown
    self.assertEqual(out.strip(), b"apple")
AssertionError: b'' != b'apple'