bug#51362: python font-lock-mode in emacs 28 seems broken

[Kévin Le Gouguec]

Stefan Kangas <stefan@marxist.se> writes:

> Do you have an example file or snippet where font-lock fails?

I've tried to come up with a minimal reproducer; see attached file, and
screenshots.  In Emacs 28, the second assignment is not fontified until
the user starts editing the buffer.

I glanced at python.el's font-lock rules and tried to revert recent
changes, but tripped over conflicts.  I'm speculatively CC'ing Dario, in
case the issue looks obvious to him?

a = foo(x='a')
b = a.bar()

Screenshot_20211031_103332.png
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