[FIX] core: fix recursion check

Prevent an infinite loop when the cycle in the parents does not contain
the starting id: `3->2->1->2->1...`

Example:
```
>>> m=self.env['ir.module.category']
>>> c1,c2,c3 = map(m.browse,[1,2,3])
>>> c2.parent_id = False
>>> c3.parent_id = False
>>> c1.parent_id = c2
>>> (c3|c2).parent_id = c1  # this never ends
```

With current patch the call to `_check_recursion` successfully detects
the new cycle.

closes #151538

X-original-commit: d07ffce
Signed-off-by: Raphael Collet <rco@odoo.com>
Signed-off-by: Alvaro Fuentes Suarez (afu) <afu@odoo.com>

odoo/addons/base/tests/test_base.py

@@ -499,6 +499,14 @@ def test_110_res_partner_recursion_multi_update(self):
         ps = self.p1 + self.p2 + self.p3
         self.assertTrue(ps.write({'phone': '123456'}))
 
+    def test_111_res_partner_recursion_infinite_loop(self):
+        """ The recursion check must not loop forever """
+        self.p2.parent_id = False
+        self.p3.parent_id = False
+        self.p1.parent_id = self.p2
+        with self.assertRaises(ValidationError):
+            (self.p3|self.p2).write({'parent_id': self.p1.id})
+
 
 class TestParentStore(TransactionCase):
     """ Verify that parent_store computation is done right """

odoo/models.py

@@ -4389,12 +4389,14 @@ def _check_recursion(self, parent=None):
         query = 'SELECT "%s" FROM "%s" WHERE id = %%s' % (parent, self._table)
         for id in self.ids:
             current_id = id
+            seen_ids = {current_id}
             while current_id:
                 cr.execute(query, (current_id,))
                 result = cr.fetchone()
                 current_id = result[0] if result else None
-                if current_id == id:
+                if current_id in seen_ids:
                     return False
+                seen_ids.add(current_id)
         return True
 
     @api.multi