Before this patch, when a domain leaf was a string (such as `&`, `|` or `!`), it was being treated as an array. This was leading to errors such as this one:
```
2017-10-19 11:22:01,578 1 ERROR devel odoo.http: Exception during JSON request handling.
Traceback (most recent call last):
File "/opt/odoo/custom/src/odoo/odoo/http.py", line 640, in _handle_exception
return super(JsonRequest, self)._handle_exception(exception)
File "/opt/odoo/custom/src/odoo/odoo/http.py", line 677, in dispatch
result = self._call_function(**self.params)
File "/opt/odoo/custom/src/odoo/odoo/http.py", line 333, in _call_function
return checked_call(self.db, *args, **kwargs)
File "/opt/odoo/custom/src/odoo/odoo/service/model.py", line 101, in wrapper
return f(dbname, *args, **kwargs)
File "/opt/odoo/custom/src/odoo/odoo/http.py", line 326, in checked_call
result = self.endpoint(*a, **kw)
File "/opt/odoo/custom/src/odoo/odoo/http.py", line 935, in __call__
return self.method(*args, **kw)
File "/opt/odoo/custom/src/odoo/odoo/http.py", line 506, in response_wrap
response = f(*args, **kw)
File "/opt/odoo/auto/addons/web/controllers/main.py", line 827, in search_read
return self.do_search_read(model, fields, offset, limit, domain, sort)
File "/opt/odoo/auto/addons/web/controllers/main.py", line 849, in do_search_read
offset=offset or 0, limit=limit or False, order=sort or False)
File "/opt/odoo/custom/src/odoo/odoo/models.py", line 4733, in search_read
records = self.search(domain or [], offset=offset, limit=limit, order=order)
File "/opt/odoo/custom/src/odoo/odoo/models.py", line 1559, in search
res = self._search(args, offset=offset, limit=limit, order=order, count=count)
File "/opt/odoo/custom/src/odoo/odoo/models.py", line 4275, in _search
query = self._where_calc(args)
File "/opt/odoo/custom/src/odoo/odoo/models.py", line 4074, in _where_calc
e = expression.expression(domain, self)
File "/opt/odoo/custom/src/odoo/odoo/osv/expression.py", line 640, in __init__
self.expression = distribute_not(normalize_domain(domain))
File "/opt/odoo/custom/src/odoo/odoo/osv/expression.py", line 289, in distribute_not
elif token in DOMAIN_OPERATORS_NEGATION:
TypeError: unhashable type: 'list'
```
Now they are treated specifically and the problem is fixed.
Jairo Llopis
fb2c263145