Impacted versions:

8, 9, 10, master

Steps to reproduce:

Run `odoo shell --log-level=debug_sql` on a database where accounting is installed with demo data.

```
>>> AML = env['account.move.line']
>>> AML.search([('tax_ids.amount', '=', 15)])
```

You get the following trace of 4 sql statements:

The first one is ok:
```sql
SELECT "account_tax".id FROM "account_tax" WHERE (("account_tax"."active" = %s)  AND  ("account_tax"."amount" = %s)) ORDER BY "account_tax"."sequence"  
```

The second one can be improved and is discussed in https://github.com/odoo/odoo/pull/16066, it's not the point of this issue.
```sql
SELECT "account_move_line_id" FROM "account_move_line_account_tax_rel" WHERE "account_tax_id" IN %s
```

Then it does the same query twice with apparently no good reason (at least none I understand).
```sql
SELECT "account_move_line".id FROM "account_move_line" WHERE ("account_move_line"."id" in (%s)) ORDER BY "account_move_line"."date" DESC,"account_move_line"."id" DESC 
SELECT "account_move_line".id FROM "account_move_line" WHERE ("account_move_line"."id" in (%s)) ORDER BY "account_move_line"."date" DESC,"account_move_line"."id" DESC 
```

The problem has its source [here](https://github.com/odoo/odoo/blob/b8ce0db8e105ed3c9ab4aefe8bce5028764694f4/odoo/osv/expression.py#L879): at first glance I'd say lines 879 and 880 could be replaced with

```leaf.leaf = (path[0], 'in', right_ids)```
openerp/osv/expression.py
""" Test whether an object is a valid domain operator. """
    return isinstance(element, basestring) and element in DOMAIN_OPERATORS
def is_leaf(element, internal=False):
    """ Test whether an object is a valid :
        - is a list or tuple
        - with 3 elements
        - second element if a valid op
        :param tuple element: a leaf in form (left, operator, right)
        :param boolean internal: allow or not the 'inselect' internal operator
            in the term. This should be always left to False.
        Note: OLD TODO change the share wizard to use this function.
    """
    INTERNAL_OPS = TERM_OPERATORS + ('<>',)
    if internal:
        INTERNAL_OPS += ('inselect', 'not inselect')
    return (isinstance(element, tuple) or isinstance(element, list)) \
        and len(element) == 3 \
        and element[1] in INTERNAL_OPS \
        and ((isinstance(element[0], basestring) and element[0])
             or tuple(element) in (TRUE_LEAF, FALSE_LEAF))
# 
# SQL utils
# 
def select_from_where(cr, select_field, from_table, where_field, where_ids, where_operator):