[bug] Django 2.2.6 breaks postgres orm querying for list inside a jsonfield

[Mehran Kader]

Assuming I have a model Like this:

    class Sequence(models.Model):

        triggers = JSONField()

Now, all my instances will be of the format:
triggers = {'list1': [], 'list2': []) 

So a query which worked in 2.2.5 Sequence.objects.filter(triggers__list1__contains=['str']) does not work in django 2.2.6.
It raises a TypeError

 {"message": "Traceback (most recent call last):   File '/code/webhooks/facebook/views.py', line 318, in post     handle_messenger_webhook(parsed_obj=parsed_obj, test=if_test)   File '/code/webhooks/facebook/views.py', line 277, in handle_messenger_webhook     sequence, serial = get_triggered_sequence_and_serial(customer=customer, payload=payload)   File '/code/webhooks/facebook/views.py', line 226, in get_triggered_sequence_and_serial     sequence = Sequence.objects.filter(platform=customer.platform, triggers__postbacks__contains=[payload]).first()   File '/usr/local/lib/python3.6/site-packages/django/db/models/query.py', line 653, in first     for obj in (self if self.ordered else self.order_by('pk'))[:1]:   File '/usr/local/lib/python3.6/site-packages/django/db/models/query.py', line 274, in __iter__     self._fetch_all()   File '/usr/local/lib/python3.6/site-packages/django/db/models/query.py', line 1242, in _fetch_all     self._result_cache = list(self._iterable_class(self))   File '/usr/local/lib/python3.6/site-packages/django/db/models/query.py', line 55, in __iter__     results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)   File '/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py', line 1087, in execute_sql     sql, params = self.as_sql()   File '/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py', line 489, in as_sql     where, w_params = self.compile(self.where) if self.where is not None else ('', [])   File '/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py', line 405, in compile     sql, params = node.as_sql(self, self.connection)   File '/usr/local/lib/python3.6/site-packages/django/db/models/sql/where.py', line 81, in as_sql     sql, params = compiler.compile(child)   File '/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py', line 405, in compile     sql, params = node.as_sql(self, self.connection)   File '/usr/local/lib/python3.6/site-packages/django/contrib/postgres/lookups.py', line 11, in as_sql     params = lhs_params + rhs_params TypeError: can only concatenate tuple (not 'list') to tuple "}

Would you bee kind enough to check it? Thanks!