bpo-30570: Use Py_EnterRecursiveCall() in issubclass()

[sweeneyde]

This is an alternative to GH-29017. This shouldn't affect performance too much because the recursion checks only occur once for each time a length>=2 __bases__ tuple is found (i.e. for multiple inheritance). Note that if we get stuck in the while (1) {...} loop, as long as the pathological __bases__ implementation is in Python, we can still interrupt with a KeyboardInterrupt.

https://bugs.python.org/issue30570

[gpshead]

I added another test case (the specific example from the bug). Yours likely already covers it, just wanted it for pedantic reasons. I like this. Much nicer than mine. I was unaware of our new EnterRecursiveCall API pair. perfect! :)

[miss-islington]

Thanks @sweeneyde for the PR, and @gpshead for merging it 🌮🎉.. I'm working now to backport this PR to: 3.10.
🐍🍒⛏🤖

[bedevere-bot]

GH-29175 is a backport of this pull request to the 3.10 branch.

[miss-islington]

Thanks @sweeneyde for the PR, and @gpshead for merging it 🌮🎉.. I'm working now to backport this PR to: 3.9.
🐍🍒⛏🤖

[bedevere-bot]

GH-29178 is a backport of this pull request to the 3.9 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Arch Linux Asan Debug 3.10 has failed when building commit f812fef.

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/621/builds/332) and take a look at the build logs.
4. Check if the failure is related to this commit (f812fef) 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/621/builds/332

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HEAD is now at f812fef2f8 [bpo-30570](https://bugs.python.org/issue30570): Use Py_EnterRecursiveCall() in issubclass() (GH-29048)
Switched to and reset branch '3.10'

renaming build/scripts-3.10/pydoc3 to build/scripts-3.10/pydoc3.10
renaming build/scripts-3.10/idle3 to build/scripts-3.10/idle3.10
renaming build/scripts-3.10/2to3 to build/scripts-3.10/2to3-3.10

renaming build/scripts-3.10/pydoc3 to build/scripts-3.10/pydoc3.10
renaming build/scripts-3.10/idle3 to build/scripts-3.10/idle3.10
renaming build/scripts-3.10/2to3 to build/scripts-3.10/2to3-3.10

renaming build/scripts-3.10/pydoc3 to build/scripts-3.10/pydoc3.10
renaming build/scripts-3.10/idle3 to build/scripts-3.10/idle3.10
renaming build/scripts-3.10/2to3 to build/scripts-3.10/2to3-3.10
test_flock (__main__.FNTLEINTRTest) ... ok
test_lockf (__main__.FNTLEINTRTest) ... ok
test_read (__main__.OSEINTRTest) ... ok
test_wait (__main__.OSEINTRTest) ... ok
test_wait3 (__main__.OSEINTRTest) ... ok
test_wait4 (__main__.OSEINTRTest) ... ok
test_waitpid (__main__.OSEINTRTest) ... ok
test_write (__main__.OSEINTRTest) ... ok
test_devpoll (__main__.SelectEINTRTest) ... skipped 'need select.devpoll'
test_epoll (__main__.SelectEINTRTest) ... ok
test_kqueue (__main__.SelectEINTRTest) ... skipped 'need select.kqueue'
test_poll (__main__.SelectEINTRTest) ... ok
test_select (__main__.SelectEINTRTest) ... ok
test_sigtimedwait (__main__.SignalEINTRTest) ... ok
test_sigwaitinfo (__main__.SignalEINTRTest) ... ok
test_accept (__main__.SocketEINTRTest) ... ok
test_open (__main__.SocketEINTRTest) ... ok
test_os_open (__main__.SocketEINTRTest) ... ok
test_recv (__main__.SocketEINTRTest) ... ok
test_recvmsg (__main__.SocketEINTRTest) ... ok
test_send (__main__.SocketEINTRTest) ... ok
test_sendall (__main__.SocketEINTRTest) ... ok
test_sendmsg (__main__.SocketEINTRTest) ... ok
test_sleep (__main__.TimeEINTRTest) ... ok

----------------------------------------------------------------------
Ran 24 tests in 7.352s

OK (skipped=2)
test_winsound skipped -- No module named 'winsound'
test_zipfile64 skipped -- test requires loads of disk-space bytes and a long time to run
test_msilib skipped -- No module named '_msi'
test_kqueue skipped -- test works only on BSD
test_winreg skipped -- No module named 'winreg'
test_winconsoleio skipped -- test only relevant on win32
test_startfile skipped -- object <module 'os' from '/buildbot/buildarea/3.10.pablogsal-arch-x86_64.asan_debug/build/Lib/os.py'> has no attribute 'startfile'
test_badargs (__main__.GeneralTest) ... ok
test_bound_methods (__main__.GeneralTest) ... ok
test_clear (__main__.GeneralTest) ... ok
test_exit (__main__.GeneralTest) ... ok
test_order (__main__.GeneralTest) ... ok
test_raise (__main__.GeneralTest) ... ok
test_raise_unnormalized (__main__.GeneralTest) ... ok
test_stress (__main__.GeneralTest) ... ok
test_unregister (__main__.GeneralTest) ... ok

----------------------------------------------------------------------
Ran 9 tests in 0.003s

OK
test_tk skipped -- Tk unavailable due to TclError: couldn't connect to display ":99"
test_ioctl skipped -- Unable to open /dev/tty
test_devpoll skipped -- test works only on Solaris OS family
test_ttk_guionly skipped -- Tk unavailable due to TclError: couldn't connect to display ":99"
test_tix skipped -- Tk unavailable due to TclError: couldn't connect to display ":99"
make: *** [Makefile:1256: buildbottest] Terminated

Cannot open file '/buildbot/buildarea/3.10.pablogsal-arch-x86_64.asan_debug/build/test-results.xml' for upload