gh-90104: avoid RecursionError on recursive dataclass field repr

[carljm]

Closes #90104.

• Issue: RecursionError when annotating a field with the same name as a field #90104

[hauntsaninja]

Thank you!

[ericvsmith]

I think I'd just test that "type=..." is in the repr, not for the rest of the values. If new ones are added, this test would need to be modified.

Also, I think an additional test for the original problem:

@dataclass
class D:
    C: C = field()

would be good.

Otherwise looks good!

[ericvsmith]

And to be clear: I'd just add the second test to make sure it doesn't raise RecursionError, I wouldn't go nuts on testing the exact output.

[carljm]

Let me know if the assertion in the new test qualifies as "going nuts" -- just seemed easy to check, and more confusing to have a test with no assertions at all.

[ericvsmith]

Maybe "go nuts" wasn't the best wording to use 😃. Your change is exactly what I would have done, down to the commas, so I think it's perfect. Thanks!

[miss-islington]

Thanks @carljm for the PR, and @ericvsmith for merging it 🌮🎉.. I'm working now to backport this PR to: 3.10, 3.11.
🐍🍒⛏🤖

[miss-islington]

Sorry, @carljm and @ericvsmith, I could not cleanly backport this to 3.11 due to a conflict.
Please backport using cherry_picker on command line.
cherry_picker 0a7936a38f0bab1619ee9fe257880a51c9d839d5 3.11

[miss-islington]

Sorry @carljm and @ericvsmith, I had trouble checking out the 3.10 backport branch.
Please retry by removing and re-adding the "needs backport to 3.10" label.
Alternatively, you can backport using cherry_picker on the command line.
cherry_picker 0a7936a38f0bab1619ee9fe257880a51c9d839d5 3.10

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot ARM Raspbian 3.x has failed when building commit 0a7936a.

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/424/builds/3235) and take a look at the build logs.
4. Check if the failure is related to this commit (0a7936a) 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/424/builds/3235

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

== Tests result: ENV CHANGED ==

411 tests OK.

10 slowest tests:

• test_venv: 6 min 48 sec
• test_largefile: 6 min 47 sec
• test_multiprocessing_spawn: 4 min 44 sec
• test_concurrent_futures: 3 min 16 sec
• test_ctypes: 3 min 13 sec
• test_zipfile: 3 min 3 sec
• test_asyncio: 2 min 53 sec
• test_pyclbr: 2 min 40 sec
• test_multiprocessing_forkserver: 1 min 57 sec
• test_tokenize: 1 min 54 sec

1 test altered the execution environment:
test_multiprocessing_fork

21 tests skipped:
test_check_c_globals test_devpoll test_idle test_ioctl test_kqueue
test_launcher test_msilib test_peg_generator test_perf_profiler
test_startfile test_tcl test_tix test_tkinter test_ttk
test_ttk_textonly test_turtle test_winconsoleio test_winreg
test_winsound test_wmi test_zipfile64

Total duration: 30 min 7 sec

Click to see traceback logs

remote: Enumerating objects: 11, done.        
remote: Counting objects:  10% (1/10)        
remote: Counting objects:  20% (2/10)        
remote: Counting objects:  30% (3/10)        
remote: Counting objects:  40% (4/10)        
remote: Counting objects:  50% (5/10)        
remote: Counting objects:  60% (6/10)        
remote: Counting objects:  70% (7/10)        
remote: Counting objects:  80% (8/10)        
remote: Counting objects:  90% (9/10)        
remote: Counting objects: 100% (10/10)        
remote: Counting objects: 100% (10/10), done.        
remote: Compressing objects:  11% (1/9)        
remote: Compressing objects:  22% (2/9)        
remote: Compressing objects:  33% (3/9)        
remote: Compressing objects:  44% (4/9)        
remote: Compressing objects:  55% (5/9)        
remote: Compressing objects:  66% (6/9)        
remote: Compressing objects:  77% (7/9)        
remote: Compressing objects:  88% (8/9)        
remote: Compressing objects: 100% (9/9)        
remote: Compressing objects: 100% (9/9), done.        
remote: Total 11 (delta 1), reused 2 (delta 1), pack-reused 1        
From https://github.com/python/cpython
 * branch                  main       -> FETCH_HEAD
Note: switching to '0a7936a38f0bab1619ee9fe257880a51c9d839d5'.

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Turn off this advice by setting config variable advice.detachedHead to false

HEAD is now at 0a7936a38f gh-90104: avoid RecursionError on recursive dataclass field repr (gh-100756)
Switched to and reset branch 'main'

Objects/obmalloc.c:776:1: warning: ‘always_inline’ function might not be inlinable [-Wattributes]
  776 | arena_map_get(pymem_block *p, int create)
      | ^~~~~~~~~~~~~

make: *** [Makefile:1906: buildbottest] Error 3

[carljm]

On the failing buildbot, test_multiprocessing_fork left behind a temporary file. That seems pretty likely a false positive, doesn't seem like it could be caused by this PR.

[carljm]

I'll put up manual backport PRs since the auto-backporting failed.

[ericvsmith]

I'll put up manual backport PRs since the auto-backporting failed.

Thanks. I had started looking at doing this, but I'm having some issue with cherry_picker. I'm sure I'm doing something stupid.

On the failing buildbot, test_multiprocessing_fork left behind a temporary file. That seems pretty likely a false positive, doesn't seem like it could be caused by this PR.

Agreed.

[bedevere-bot]

GH-100784 is a backport of this pull request to the 3.11 branch.

[bedevere-bot]

GH-100785 is a backport of this pull request to the 3.10 branch.