Unstable formatting with long conditional expression

[wyattanderson]

To Reproduce

Run Black on this code:

if shopify_order_action in [SHOPIFY_HEADER_ORDER_FULFILLED, SHOPIFY_HEADER_ORDER_PARTIALLY_FULFILLED] and (not fulfillments or len(fulfillments) == 0):
    pass

The code itself isn't fantastic, for sure, but it still breaks Black, and that ain't great.

Reformatting fails with error: cannot format testcase.py: INTERNAL ERROR: Black produced different code on the second pass of the formatter..

Environment (please complete the following information):

• Version: latest release on PyPI and on master
• OS and Python version: Mac OS X, Python 3.8.5

Does this bug also happen on master?

Yes, running this on black.now.sh also fails.

[mik-laj]

I have more examples.
apache/airflow#12091

[ichard26]

Hello!

All reproduction cases in this issue format without error on master. The fixing commit was 8672af3 from PR GH-2126. I'll be marking this issue as a duplicate of GH-1629 since that's what GH-2126 aimed to fix and it's highly likely this issue falls under GH-1629.

Since we use the issue tracker as a reflection of what's on master, I'll be closing this issue. If you have any issues, especially with the new (but stable) output, please open a new issue. Oh and the fix should be available in a published release soon, see GH-2125 for more info.

Thank you for reporting!