gh-149495: Fix input assuming the last character being a '\n'

[Virv12]

Fix input assuming the last character being a '\n'

When reading from the tty python's builtin input function assumes that the last character read is a newline and proceed to strip it out leading to missing input.

Current behaviour:

$ ./python -c 'print(repr(input()))'     # press ^D three times to send EOF without a newline
abc'ab'

Expected behaviour:

$ ./python -c 'print(repr(input()))'
abc'abc'

• Issue: input assumes the last character is a '\n' and always strips it #149495

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Documentation build overview

📚 cpython-previews | 🛠️ Build #32586566 | 📁 Comparing 8418eac against main (bb5e41e)

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15 files changed · ± 15 modified

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• faq/programming.html
• howto/descriptor.html
• howto/perf_profiling.html
• library/compression.zstd.html
• library/concurrency.html
• library/email.policy.html
• library/statistics.html
• library/tarfile.html
• library/threading.html
• library/zlib.html
• and 5 more...

[StanFromIreland]

Please open an issue, and add a test.

[picnixz]

1. Please create an issue.
2. This is a non-trivial change. Are we totally sure that this won't be an issue?
3. Is it standard to press ^D 3x to get an EOF without a \n? does it work for any terminal as well?
4. Please add tests and update the documentation if necessary.
5. What happens on WIndows where new lines are of the form \r\n can we get a trailing \r instead?

[Virv12]

1. Please create an issue.

Done.

2. This is a non-trivial change. Are we totally sure that this won't be an issue?

I don't see how this could be an issue, the comment already said that we wanted to remove a \n, now we are just explicitly checking that it's true.

3. Is it standard to press ^D 3x to get an EOF without a \n? does it work for any terminal as well?

I don't know but it doesn't seem relevant to the PR.

4. Please add tests and update the documentation if necessary.

Added test. The documentation does not need to be updated.

5. What happens on WIndows where new lines are of the form \r\n can we get a trailing \r instead?

Both \r\n and \r were already supported and are still supoprted.