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
""" Returns the list of tables for SQL queries, like select from ... """
        tables = []
        for leaf in self.:
            for table in leaf.get_tables():
                if table not in tables:
                    tables.append(table)
        table_name = _quote(self.root_model._table)
        if table_name not in tables:
            tables.append(table_name)
        return tables
    # 
    # 
    # 
    def parse(self, cr, uid, context):
        """ Transform the leaves of the expression
            The principle is to pop elements from a leaf stack one at a time.
            Each leaf is processed. The processing is a if/elif list of various
            cases that appear in the leafs (many2one, function fields, ...).
            Two things can happen as a processing :
            - the leaf has been modified and/or new leafs have to be introduced
              in the expression; they are pushed into the leaf stack, to be
              processed right after
            - the leaf is added to the 
            Some internal var explanation: